f / DYEING AND CLEANING, WORKS ON THE TEXTILE INDUSTRIES Second Edition. Revised throughout. In Two Vols. Cloth. A MANUAL OF DYEING: FOR THE USE OF PRACTICAL DYERS, MANUFACTURERS, STUDENTS, ETC. By E. KNECHT, Ph.D., CHR. RAWSON, F.I.C., AND R. LOEWENTHAL, Ph.D. "This authoritative and exhaustive work . . . the most complete we have yet seen on the subject." — Textile Manufacturer. In Large 8vo. Handsome Cloth. Pp. i-xv+405. 16s.net. THE SYNTHETIC DYESTUFFS AND THE INTERMEDIATE PRODUCTS FROM WHICH THEY ARE DERIVED. BY JOHN CAN NELL CAIN, D.Sc, AND JOCELYN FIELD THURPE, Ph.D. "One of the most valuable books that has appeared."— CAermca^ Trade Journal. In Large 8vo. Handsome Cloth. 16s. net. A DICTIONARY OF DYES, MORDANTS, AND OTHER COMPOUNDS USED IN DYEING AND CALICO-PRINTING. By CHR. RAWSON, F.I.C., W. M. GARDNER, F.C.S., AND W. F. LAYCOCK, Ph.D. "On any subject, or any substance connected with the trade, a reference is sure to be found." — Textile Mercury. In Crown 8vo. Cloth. With numerous Illustrations. 6s. net. THE COTTON WEAVERS' HANDBOOK: A PRACTICAL GUIDE TO THE CONSTRUCTION AND COSTING OF COTTON FABRICS, WITH STUDIES IN DESIGN. By H. B. HEYLIN, of the Royal Technical Institute, Salford. In Large 8vo. Profusely Illustrated. 16s. net. THE SPINNING AND TWISTING OF LONG VEGETABLE FIBRES (FLAX, HEMP, JUTE, TOW, AND RAMIE). By H. C. CARTER, of Belfast and Lille. " We must highly commend the work as representing up-to-date practice." — Nature. In Large 8vo. Handsome Cloth. Illustrated. Os. net. TEXTILE FIBRES OF COMMERCE (OCCURRENCE, DISTRIBUTION, PREPARATION, AND INDUSTRIAL USES). BY WILLIAM F. HANNAN. " Useful information . . . admirable illustrations . . . valuable." — Textile Recorder. In Large 8vo. With Illustrations and Printed Patterns. 21s. TEXTILE PRINTING. By C. F. SEYMOUR ROTHWELL, F.C.S. By far the best and most practical book on Textile Printing which has yet been brought out." — Textile Mercury. In Large 8vo. Handsome Cloth. 12s. 6d. BLEACHING AND CALICO-PRINTING: A SHORT MANUAL FOR STUDENTS AND PRACTICAL MEN. By GEORGE DUERR AND WILLIAM TURNBULL. "Most useful . . . thoroughly practical ... of great \Si\\ie."— Textile Manufacturer. LONDON: CHARLES GRIFFIN & CO., Ltd., Kxetep. St., Strand. DYEING AND GLEANING A PRACTICAL HANDBOOK. FKANK J. FAREELL, M.Sc. (Vict.), SOMETIME ASST. LECTURER IN DYEING, ROYAL TECHNICAL INSTITUTE, SALFORD ; JIEMBER OF THE SOCIETY OF CHEMICAL INDUSTRY ; MEMBER OF THE COUNCIL OF THE INCORPORATED ASSOCIATION OF LONDON DYERS AND CLEANERS; MEMBER OF THE SOCIETY OF DYERS AND COLOURISTS. mitb 78 5llu6tration6, LONDON: CHARLES GRIFFIN & COMPANY, LTD. EXETER STREET, STRAND. 1 908. [All rights reserved.] PREFACE. In this book I have endeavoured to justify the sub-title "A Practical Handbook " ; I have, however, paid more attention to the general principles which govern the metliods employed than to minute working details. The latter are superfluous to the practical man, and of little value to the beginner. In the chapter devoted to Dyeing it has been found impractic- able to mention more than a tithe of the colouring matters which are now available ; therefore only one or two series of dyestufls have been given as prototypes. I have avoided as far as possible detailed descriptions of substances or methods which are fully described in more general text-books on dyeing ; to those requiring further particulars the following brief bibliography may be useful : — Plant, etc. Davis, A Handbook of Chemical Engineering. Technology of the Fibres. Hannan, A Dictionary of the Textile Fibres. Matthews, The Textile Fibres. Petroleum. Thomson and Redwood, Handbook on Petroleum. Dyestuffs and Dyeing. Cain and Thorpe, The Synthetic Dyestuffs. Dreaper, Chemittry and Physics of Dyeing. Knecht, Rawson, and Loewenthal, A Manual of Dyeing. Rawson, Gardner, and Laycock, A Dictionary of Dyestuffs. Dyeing and Cleaning. Gouillon, Manuel du Teinturier-Degraisseur, Periodicals. Journal of the Society of Dyers and Colourists. Journal of the Society of Chemical Industry. The Dytr. I wish to express my indebtedness to the following gentlemen for information or suggestions : — Sir Robert Pullar, M. Jolly (President of the Paris Syndicate of Dyers), J. Ollis, Esq. (Public V 19004 vi PREFACE. Control Dept., L.C.C.), and F. E. Robertson, Esq. ; and to the following firms for the use of blocks illustrating their machinery : Messrs Braithwaite & Son, Downham & Co., Gorrie & Son, Grether & Co., Hill & Herbert, Ltd., J. Hill, Nonex, Ltd., Robatel, Buffaud & Co., Scott & Son, Ltd., and Watson, Laidlaw & Co., Ltd. I beg to thank Messrs C. W. May and F. E. Robertson for their help in the revision of the proofs. F J. F. . London, 1908. CONTENTS. CHAPTER 1. TECHNOLOGY OF THE TEXTILE FIBRES. PAGES Textile fibres — Cotton — Chemical composition and propeities of cotton — Mercerised cotton — Artificial silk — Linen — Hemp — Jute — China grass — Wool — Physical and chemical properties of wool — Silk — Physical and chemical properties of silk — Wild silks — Tussore silk . . . . . . . . . 1-20 CHAPTER 11. DRY CLEANING. Reception of goods — Marking— History of dry cleaning — Benzine — Benzol — Carbon tetrachloride — Machinery and methods for dry cleaning — Dry-cleaning soaps — Glove cleaning— -Barbe system — Scott system — Purification and recovery of benzine— Stain removal or " Spotting" — Regulations and fire precautions . 21-105 CHAPTER III. WET CLEANING. Soap — Tetrapol — Machinery — Fancy cleaning — Bleaching — Blankets— Curtains— Cretonne —Chintz — Window blinds . 106-122 CHAPTER IV. DYEING. Appliances — Colouring matters — Assistants — Preparation of goods for dyeing — Stripping processes — Selection of process — Selection of dyes — Wool and cotton — Wool, silk and cotton — Wool — Cotton or linen — Silk — Wool and silk — Silk and cotton — Other fibres — General notes ....... 123-165 vii viii CONTENTS. CHAPTER Y. DRY DYEINa PAGES Definition — Dyeing with basic colours — Disadvantages — Miscibility of solvents — Dyeing with acid colours — Methods of application 166-171 CHAPTER VI. SPECIAL METHODS— CLEANING AND DYEING SKIN RUGS, FEATHERS, AND HATS. Skin rugs — Method of cleaning — Bleaching skins — Dyeing skins — Feather cleaning and dyeing — Methods of cleaning and bleaching - Dyeing feathers — Finishing feathers' — Hat cleaning and dyeing — Straw — Chip — Artificial silk — Felts and beavers . 172-181 CHAPTER YII. FINISHING. Examination — Finishing wearing apparel — Appliances and methods — Finishing furnishings — Curtains and window blinds — Chintz glazing— Cretonne — Pile fabrics — Cylinder — Blankets. . . 182-212 Appendix A. — Reprint from Lancet on Adulteration of Fabrics . 213-220 Appendix B.— Useful Tables 221-228 Appendix C— Nomenclature of Stable Hydrosulphites . . . 229 Index ^ 230-232 ABBREVIATIONS. J. S.C.I. Journal of the Society of Chemical Industry. J.S.D.C. Journal of the Society of Dyers and Colourists. B.A.S.F. Badische Anil in- und Soda-Fabrik, Ludwigshafen. Ber. Actien Gesellschaft fiir Anilinfabrikation, Berlin. By. Farbenfabriken vorm. Fr. Bayer & Co., Elberfeld. 0. Leopold Cassella & Co., Frankfort. M.L.B. Farbwerke vorm. Meister Lucius & Brtining, Hochst. DYEING AND CLEANING. CHAPTER I. TECHNOLOGY OF THE TEXTILE FIBRES. The fabrics submitted to the dyer and cleaner are manufactured from a considerable number of fibres, and some knowledge of their chemical and physical properties is essential. The particulars which will be given will be condensed as much as possible, and those desiring further information are referred to the text-books devoted to this subject. The textile fibres are usually divided, according to their origin, into vegetable fibres and animal fibres ] to these might be added artificial fibres^ but as all the artificial fibres in commerce are of vegetable origin, they will be considered under that classification (artificial silk manufactured from gelatine — ''Yanduara silk" — does not appear to find extensive employment at the present time). The vegetable fibres employed on the large scale are cotton, linen, china grass (ramie), jute, and hemp. Of these cotton is the most important, linen taking the second place. The animal fibres include wool, hair, and the different kinds of silk. Any or all of these fibres may be employed in the construction of a fabric ; e.g. satin is made with a silk warp and a cotton weft. In some cases the individual threads may be composed of more than one kind of fibre ; e.g. Viyella " fabrics are woven from warp and weft threads composed of threads containing wool and cotton spun together. The animal and vegetable fibres behave very differently towards acids, alkalies, and the other reagents employed in the processes of scouring, bleaching, and dyeing, and it may be taken as a general rule that the animal fibres are better able to withstand the action of acids, and the vegetable fibres to withstand alkalies. 1 2 DYEING AND CLEANING. I. Vegetable Fibres. Cotton. The employment of cotton in the making of fabrics dates back to 450 B.C., and probably much earlier. Allusions to cotton clothing are to be found in Herodotus (445 B.C.) ; a century later the Hindoos are referred to as wearing a fabric made from "a stuff which grew upon trees," and Pliny speaks of the Egyptians wearing cottons. Raw cotton as it comes into the market Fig. 1 . —Cotton Fibres consists of the hairy filaments which surround the seeds of various species of the cotton-plant {Gossypium)^ which belongs to the natural order of the Malvaceae or mallow-worts. The filaments attached to the seeds are enclosed in a capsule which when ripe bursts and exposes a ball of snowy-white down. The cotton is collected as soon as possible after ripening, and after separation from the seeds by ginning " it comes into the market. There are several species of the cotton-plant, but the following four include those cultivated for commercial purposes : — TECHNOLOGY OF THE TEXTILE FIBRES. 3 (1) Gossypium Barhadense. — This is the most valuable, produc- ing the long staple Sea Island cotton. The Gossypium hirsutum^ from which the bulk of the United States cotton is raised, is supposed to be a variety of this species. The true Sea Island bears a yellow flower, while that of the hirsutum is white or pale primrose. (2) Gossypium Peruvianum. — This is indigenous to South America, flourishing in Peru, Brazil, and the adjoining countries. It has a yellow flower. (3) Gossypium herhaceum. — This is a short, shrubby plant bearing a yellow flower. It is a native of Asia, and furnishes the Madras, Surat, short-stapled Egyptian, and other short-stapled cottons. (4) Gossypium arhoreum, — This is a tree-like plant bearing a reddish flower, and is found in India and China. It has a long and silky fibre, and yields nearly all the long-stapled varieties of Egyptian, Indian, and Chinese cottons. Bowman defines the typical cotton fibre as a long, tubular compound vegetable cell, from 1200 to 1500 times as long as it is broad. Viewed under a microscope (fig. 1) it appears as a twisted ribbon, the spiral shape being due to the drying up of the sap originally contained in the ripe fibre. The length of the fibre and its diameter varies considerably according to its origin, the following figures being given by Evan Leigh : — Description of Cotton. Length of Staple in inches. Diameter of Fibre in inches. Min. Max. Min. Max. New Orleans 0-88 1-16 0-000580 0*000970 Sea Island (long staple) 1-41 1-80 0-000460 0-000820 Brazilian . 1-03 1-31 0*000620 0-000960 Egyptian . 1-30 1-52 0-000590 0 000720 Indian 0-77 1-02 0-000659 0-001040 As the fibre matures the cell wall becomes thicker and the fibre whiter, while the central cavity gradually enlarges ; finally the sap in the cavity is withdrawn, passing back to the seed, the twisting referred to above resulting. This twisting is one of the most valuable features of the cotton fibre, as it adapts it for spinning purposes, and accounts for the elastic character of cotton as compared with linen fabrics. Immature or '^dead" fibres are almost transparent, have no central cavity, are flat and non-twisted, and are found in cloth in the form of knots or " neps " ; in indigo and alizarin-dyed calico they show up as white specks. 4 DYEING AND CLEANING. Chemical Composition and Properties of Cotton. — Cotton when freed from the five or six per cent, of natural impurities consists almost entirely of cellulose, a substance found throughout the vegetable kingdom, forming (sometimes in a modified form) the ligneous or woody fibres of plants. The impurities consist essentially of pectic acid, two or more colouring matters, cotton wax, cotton oil, and albuminous matter. Ultimate analysis shows that cellulose consists of carbon, hydrogen and oxygen, its simplest formula being CgH^oO^. Cellulose in the pure condition is a white translucent substance with a density of nearly 1*5, and is absolutely insoluble in water, ether, alcohol, benzol, etc. When heated to 90°-100° C. it loses water and is slowly destroyed, several days' exposure at that temperature being necessary to bring about complete destruction of the fibre. If the heating to 100° C. is not prolonged the cotton regains, on exposure to air, the water it has lost. At a temperature a little above 150° C. the fibre becomes rapidly charred and disintegrated. Mercer first observed that an ammoniacal solution of copper hydrate (Schweitzer's reagent) causes the fibre to swell up and slowly dissolve ; it appears to pass into solution in the form of oxy-cellulose. From this solution a blue hydrated compound of copper oxide and cellulose may be precipitated by the addition of sugar, gum, common salt, etc. Cotton fabrics immersed in the solution and dried, or impregnated with Schweitzer's reagent and dried, are rendered waterproof (" Willesden " canvas, etc.). Action of Acids. — Mineral acids have a more or less powerful action on cotton, depending upon the concentration of the acid, its temperature, and the duration of the action. Sulphuric Acid. — Cold concentrated sulphuric acid rapidly destroys cotton ; a brief immersion causes the fibre to swell up, contract in length, and become transparent ; it has also an increased afiinity for dyestufis. It is, however, difficult to avoid the destruction of the fibre. With acid of a lower specific gravity the action is more under control. Vegetable parchment is prepared by dipping unsized paper in cold sulphuric acid at 140° Tw. for a few seconds and rinsing in a plentiful supply of water. With acid of 115° Tw. the cotton becomes contracted (to a less extent than with concentrated sulphuric acid), is stiffened, and rendered more opaque ; it is also said to have an increased affinity for basic dyestuffs. Treatment with acid at this density has been patented for the production of a fabric for bookbinding cloth. By the continued action of strong sulphuric acid cotton is converted into dextrine ; by dilution with water and boiling, this is further changed into glucose (grape sugar). TECHNOLOGY OF THE TEXTILE FIBRES. 5 Nitric Acid. — Cotton is entirely decomposed by hot, strong nitric acid, the products of decomposition including oxalic acid. Cold nitric acid or a mixture of strong sulphuric and nitric acids do not alter the external appearance of cotton, but it is converted into a series of nitro-celluloses, the degree of nitration depending upon the strength of the mixture of acids and the duration of their action. The most highly nitrated product, represented in its simplest formula as CgH7(N02)305, is known as gun-cotton or insoluble pyroxylin. A less nitrated product is known as soluble pyroxylin ; it is soluble in a mixture of ether and alcohol and other solvents (toluene and wood spirit, acetone, etc.), its solution in ether and alcohol being known as collodion. The lower nitrated celluloses are employed in the manufacture of artificial silk (see p. 7). Hydrochloric acid when concentrated disintegrates cotton. Dilute mineral acids have little or no action on cotton in the cold ; if cotton is dried out of a dilute mineral acid solution the acid becomes concentrated in the fibre, which becomes tendered. Hence all cotton goods should be well washed after treatment with mineral acids. In calico printing processes, in which mineral acids may be formed during steaming or drying, it is usual to employ a certain quantity of sodium acetate in the printing paste ; this combines with the mineral acid forming the sodium salt and liberating acetic acid, which has no destructive action on the fibre. Organic Acids. — Those in general use are, acetic, citric, formic, lactic, oxalic and tartaric acids. In solution they have no action on the fibre ; dried direct from a solution of oxalic acid, tendering (with a 2 per cent, solution) or disintegration (10 per cent, solution) takes place. Acetic and formic acids under ordinary working conditions appear to have no action upon cotton. Action of Alkalies. — Mild alkalies, such as alkaline carbonates, soap, borax, sodium phosphate, etc., have no action upon cotton. Ammonia has no action at the ordinary temperature, but L. Yignon states that if cotton be heated in a sealed tube with ammonia or a solution of calcium chloride in aqueous ammonia to 200* C, an amido-cellulose is formed which behaves towards acid dyestuffs like an animal fibre. Experiments by the author do not appear to confirm these results. Dilute caustic alkalies, in the absence of air, do not afiect the fibre ; in the presence of air even heated lime-water may produce tendering. John Mercer in 1844 dis- covered that concentrated solutions of caustic soda and caustic potash had a remarkable action upon cotton, causing the fibres to become contracted in length, thickened, and more transparent. 6 DYEING AND CLEANING. No practical use of this process was made until about 1894, when it was employed in the production of crepon or crimped effects. These effects are obtained by printing the calico with a gum " resist " and immersion in caustic soda, or by printing direct on the fabric with thickened caustic soda. In either case the portion of the fabric acted upon by the caustic soda is contracted, the uncontracted portion being thrown up into folds, producing the crepon effect. Two years later it was found that cotton contracted with caustic soda and stretched to its original length whilst in a gelatinous condition, or treated with caustic soda under tension, the sub- sequent washing also taking place under tension, becomes highly lustrous ; the process was named " mercerisation," in honour of the first observer of the action of caustic alkalies on cotton. The action of caustic soda solutions on cotton has been exhaustively investigated by Hiibner and Pope (J.S.C.L, 1904). These investigators find that even dilute solutions of caustic soda (1° Tw.) produce some shrinkage and at the same time an increased affinity of the fibre for substantive dyestuffs. They found that the affinity for substantive dyestuffs and the degree of contraction increased with the density of the caustic solution up to a certain point (not quite the same in each case), after which a diminution in each property occurred with increased density of the caustic solution. They give the following table of contraction for hanks of 200 yards long in caustic soda of various densities : — Strength of Caustic Soda Length of Hank after Treatment. Strength, of Caustic Soda. Length of Hank after Treatment. °Tw. Yards. °Tw. Yards. 0 198-0 22 171-3 1 196*4 24 163*1 2 1957 26 160-3 3 195-6 28 160-0 4 195-5 30 158-2 5 195-2 35 150-2 6 194-2 40 143*7 7 193-7 45 141-0 8 194-2 50 142-2 9 194-0 55 142-7 10 194-2 60 145*3 12 194-5 65 149*2 14 192*7 70 150-3 W 190-4 75 152-8 18 158-7 80 154*2 20 186-8 TECHNOLOGY OF THE TEXTILE FIBRES. 7 Concentrated caustic potash has a similar action to caustic soda. Action of Reducing and Oxidising Agents. — Reducing agents have little or no action on cellulose, but oxidising agents (chromic acid, potassium permanganate, persulphates, chlorine, chloride of lime — bleaching powder, etc.) convert it into oxy -cellulose^ accom- panied by tendering of the fibre. In consequence of this tendering action oxidising agents employed in bleaching cotton must be used with care, as prolonged action or use in excess may entirely rot the fibre. Action of Metallic Salts and other Substances. — The cotton fibre has little or no affinity for normal metallic salts (alum, copperas, copper sulphate, etc.) ; it is capable of decomposing their basic solutions and loosely fixing the metallic hydroxides. It has a direct affinity for tannins which are largely employed as mordants for basic dyestufFs. Artificial Silk. This fibre is dealt with under Cotton, as the most important artificial silks in commerce are prepared from cellulose. That it is an article to be counted with in the future is shown from the fact that the present output is little short of eight tons per day (Dreaper, J.S.jD.C, 1907). Artificial silks prepared from casein and gelatin have been proposed, and the latter was introduced about ten years ago under the name of Vanduara silk, but it does not appear to be in extensive commercial use at the present time. All methods of preparing artificial silk from cellulose are variants of the same general principle. A solution of cellulose is prepared and forced through a very fine orifice into a medium precipitating the cellulose (or altered cellulose) in the form of a fibre, which is reeled off either alone or with several other fibres prepared in the same manner. The various artificial silks may be divided into those prepared from solutions of nitrated cellulose and those from unnitrated cellulose. The former are usually termed Chardonnet silks (after the inventor), and those usually prepared by the latter, Glanzstoff, The diameter of the ultimate fibre depends upon the size of the orifice and upon the method employed, the fibres of greater diameter being usually called artificial hair. Chardonnet silk is made by dissolving cellulose of suitable nitration in a mixture of ether and alcohol or other solvent (Du Vivier, Lehner, etc.), and forcing it through jets into water or other liquid, or direct into air. In either case solidification occurs, the fibre is reeled off continuously, and the solvent is recovered. To render the fibre less inflammable, it is denitrated " by treatment with dilute nitric acid, ammonium sulphide, etc. 8 DYEING AND CLEANING. The processes which do not depend upon nitro-cellulose, and which have passed the experimental stage, are the cwpr ammonium^ zinc chloride^ and viscose methods, which depend upon the solution of untreated cellulose ; to these we may possibly add the cellulose acetate process. GlanzstofF, the fibre produced by the solution of cellulose in an ammoniacal solution of copper hydrate (cuprammonium), closely approaches Chardonnet silk in output. The solution is forced through a fine orifice into the precipitating medium, the thread being reeled off continuously. By Dr Thiele's process threads are produced which are claimed to be practically indistinguishable from real silk in softness, appearance, elasticity, and covering power ; individual threads are producible containing ten times as many filaments as a real silk thread of the same size (Dreaper, J.S.D.C., 1907). The Linkmeyer process is also a modification of the cuprammonium method, and appears to give very good results. Zinc Chloride. — The employment of a solution of cellulose in zinc chloride has been patented by Dreaper and Tompkins : the solution is forced through suitable jets into alcohol, acetone, or other suitable precipitating medium, the thread being wound off continuously. This method is now employed on the commercial scale, and promises to give highly satisfactory results. Viscose (Cross and Bevan) is also employed in the production of fibres. The solution is prepared by treating finely divided cellulose with caustic soda, and submitting the compound formed to the vapour of carbon disulphide. Sodium xanthate is formed as a viscid liquid, continuous threads being produced from this by forcing it through an orifice into alcohol or a solution of common salt as the precipitating medium. Steam has also patented the production of threads from viscose, a solution of ammonium chloride or ammonium sulphate being employed as the precipitating liquid. Acetates of Cellulose. — The production of threads from cellulose acetates does not appear to have gone beyond the experimental stage at present. Bayer & Co. have patented the manufacture of artificial silk in this way, using a 15 per cent, solution in chloroform, precipitating in alcohol, benzine, or by other means. This method has the disadvantages attaching to the employment of chloroform, and, moreover, the raw material is very expensive. The processes w^hich are likely to prove com- mercially successful in the future are those depending upon the solution of cellulose in cuprammonium or in zinc chloride, as the raw materials and solvents are inexpensive when compared with the Chardonnet (ether, alcohol, carbon disulphide) or any other TECHNOLOGY OF THE TEXTILE FIBRES. 9 process involving the employment of expensive (chloroform) or inflammable volatile solvents in the production of the solution of cellulose. Linen. Linen, which is the product of the flax plant Limim usitatis- simum, is, next to cotton, the most important of the vegetable fibres. The flax plant is cultivated in nearly all parts of Europe ; it is a herbaceous plant, growing to a height of three to four feet, and bearing a blue flower. After becoming mature and in full seed, it is cut down and dried. The stalks are then rippled, or combed, to remove the seeds, which are employed in the preparation of linseed oil and oil-cake. The stalks at this stage contain only 20 to 27 per cent, of fibre, the remainder being wood, pith and rind. The separation of these from the fibre is a tedious process involving several operations. The first of these is i^etting, a fermentative process. It may be carried out in several ways ; viz. by steeping in stagnant or running water, by dew, by exposure to steam or hot water, or by treatment with mineral acids. After retting, the fibre is washed in water and dried ready for the mechanical operations which remove the woody portions of the stem ; these are known as breaking and scutching, and are followed by combing or heckling. The combed flax is technically known SiS Jlax-line. Properties. — Like cotton it consists essentially of cellulose ; the ultimate fibres average from | inch to 1^ inch in length and about w-^o inch in diameter. In the flax-line a large number of these fibrillcE are united together to form a fibre-bundle or filament, which may be of considerable length — 2 to 3 feet. Under the microscope the individual fibres are seen in the form of long cylindrical cells terminating conically at each end. The fibre is encrusted with impurities (pectic matters) amount- ing to 15 to 30 per cent. ; these render the operation of bleaching longer and more complicated than those required for cotton. When freed from these impurities linen is more lustrous and tenacious than cotton, but less elastic. It differs from cotton in being a better conductor of heat ; on this account linen fabrics always feel colder than cotton fabrics. Towards most chemical reagents linen behaves like cotton. It also behaves in the same way as cotton towards dyes, but is more difficult to dye than the latter; this is probably due to the presence of pectic matters and to the difference in physical structure. 10 DYEING AND CLEANING. Hemp. This fibre is obtained from the hemp plant, Cannabis sativa, which is cultivated in most temperate climates. The treatment of the hemp stalks involves the same processes as those described for linen. The fibre is usually employed in the manufacture of ropes, sacking, and canvas, and is rarely bleached or dyed. It is particularly adapted for the purposes named, as it is very tenacious and does not easily rot when immersed in water. The fibre is almost cylindrical, and has a large central cavity ; it difi'ers from linen and jute fibres in the frequent branching of the apices of the fibre stems into two forks. Jute. The fibre of jute is obtained from various species of Corchorus, the most common being the Corchorus tiliacece, which is largely cultivated in India, Turkey, Asia Minor. It is separated from the woody portions of the stem by operations similar to those employed for linen and hemp. Properties. — The fibres are polygonal in shape, and have a larger central cavity than linen. They vary in length from 0*03 to 0*17 of an inch, and have a diameter of 0*0004 to 0*0013 inch. The jute fibre is more readily acted upon by acid and alkalies than cotton and linen, being decomposed into insoluble cellulose and soluble tannin compounds. Cross and Bevan have suggested the name bastose for the fibre principle of jute, and the name corchorobastose for the compound of that substance and cellulose. Jute on treatment with sulphuric acid and iodine, or zinc chloride and iodine, is coloured brown ; treated with chlorine and then with sodium sulphite the fibre is coloured crimson (tanned cotton gives the same reaction). Jute readily absorbs chlorine and bromine, becoming chemically changed ; this renders it impossible to use the ordinary process of bleaching with chloride of lime. Basic dyestufis dye jute by virtue of the tannin matters which it contains in the same way as tannin-mordanted cotton. It has also some affinity for acid dyestufF from a sulphuric acid or alum bath. Jute is largely employed in the manufacture of carpets, matting, etc. China Grass. This fibre is also known as Ramie and Bhea ; it is obtained from plants of the order Urticacece or nettles, viz. Boehmeria nivea TECHNOLOGY OF THE TEXTILE FIBRES. 11 and Boehmeria tenacissima. It is grown abundantly in China, Japan, India, and other countries. When separated from the cementaceous pectic matters it is of great lustre and tenacity. The methods employed in separating the fibres from the stem and bark in linen, hemp, etc., cannot be employed, as the fibres them- selves are thereby separated into the ultimate fibres and cannot be recovered from the other portions of the stem. They are usually separated whilst the stems are still green by passing them through a machine which breaks up the stem and bark without affecting the fibres, the latter being easily separated by washing with a powerful jet of water. The fibre consists essentially of cellulose (80 per cent.), is polygonal in section, and contains a central cavity ; the ultimate fibres are about 1 inch long and have a diameter of 0*0016 to 0*0032 inch. It is easy to bleach, but is difiicult to dye full shades without injuring the lustre of the fibre. Other Vegetable Fibres. The vegetable fibres mentioned are practically the only ones finding textile application in this country. The following may be mentioned, but reliable data concerning them is difficult to obtain : New Zealand flax, Manila hemp, cocoa-nut fibre, fibres from the leaves of aloes, bananas, palms, etc. II. Animal Fibres. Wool. Strictly speaking, this is the hair of the sheep, but under the same category it is usual to class the hair of certain goats — e.g. Cashmere and mohair, as also that of the alpaca and of the camel, as they differ from wool only in physical structure. Archer distinguishes thirty-two different varieties of sheep, but from the dyer's point of view wool is only divided into the coarse and long-stapled lustre wools, most of which are produced in this country, and the finer qualities of merino or cross-bred wools, which are principally imported from Australia. The Cashmere wool is the product of a goat which abounds in Thibet; it sometimes reaches 18 inches in length. Mohair, the wool of the Angora goat, is characterised by its great lustre ; it is imported into this country from Turkey and the Cape. Alpaca is the hair of a genus typified by the llama. Gamers hair is collected when the camels shed their hair periodically. 12 DYEING AND CLEANING. Wool varies in quality with individual sheep, and according to the part of the body from which it is obtained. It is roughly classified according to the length of staple; fibres exceeding 1^ inch in length are termed long-stapled," and are employed in the spinning of worsted yarn, those less than 1| inch being termed short-stapled," and spun into woollen yarn. Physical Properties. — Observed under the microscope the wool fibres show a rod-like structure covered with broad scales project- ing in the same direction. The shape of the scales varies accord- ing to the origin of the wool, the structure being shown in figs. 2 and 3, which represent the various kinds of wool fibres. The outer scales cover the central or medullary cells, which in a, Fine merino ; 6, Lincoln wool taken from the coarsest part of the fleece after treatment with caustic soda and washing with alcohol and water ; c, Lincoln wool taken from the shoulders of the same fleece as h ; fZ, alpaca ; 6, mohair ; /, coarse hair from Cheviot fleece ; kemj)y fibre. the case of black or coloured wools contain organic pigment matter. If woollen or worsted fabrics are subjected to friction in the wet state, especially in the presence of alkalies, shrinkage takes place owing to the entanglement or interlocking of the scales. The degree of shrinkage is governed to some extent by the temperature, but still more so by the presence or absence of friction (see Jackson, Cantor Lecture, 1907). Wool differs from cotton, in that the longest fibres are usually those of greatest diameter ; the average length of fibre of the various classes of wool varies from 1^ inch to 7 inches, and the diameter from 0*004 to O'OOIS inch. The breaking strain varies directly as the diameter of the fibre from 4 ounce to nearly 1^ ounce, and the elastic limits from 0*25 to 0*4 per cent, on the length of the fibre. a. h. c. Fig. 2.— Wool Fibres. Fig. 3.— Wool Fibres. TECHNOLOGY OF THE TEXTILE FIBRES. 13 Wool is very hygroscopic ; in a damp atmosphere it will absorb lip to 40 to 50 per cent, of water without being palpably moist. When wool is dried at 100° C. it loses on an average 15*43 per cent, of moisture, being equivalent to a regain of 18*25 per cent. According to Bowman, the water is present in two conditions : (1) As water of hydration (about 8*25 per cent.); and (2) as hygroscopic water. At 100° C. wool becomes somewhat plastic, the form imparted to it then being retained when it becomes cold ; this plasticity is of great importance in certain methods of finishing yarn and piece- goods. Wool burns with difficulty on ignition, leaving a black car- bonaceous bead ; it emits the peculiar smell common to all animal nitrogenous substances (feathers, horn, etc.), which serves to distinguish it from cotton and other vegetable fibres. Chemical Properties. — The wool substance, which has been termed keratin^ consists of carbon, hydrogen, oxygen and nitrogen in approximately the same proportions as in gelatin, together with a small amount of sulphur. In the following table the figures for albumin are given for comparison : — Wool. Gelatin. Albumin. c . 49-25 50-0 52*8 H . 7-57 6-5 7-1 0 . 23-66 26-0 22-9 N . 15 86 17-5 15*6 S . 3*66 1-6 A considerable proportion of the sulphur may be removed without the appearance, tenacity, or other properties of the fibre being afi'ected. Action of Acids. — Dilute acids have but little effect on wool, although they are absorbed by the wool and retained with great tenacity. They have, however, a tendency to open up the scales or imbrications, giving the fibre a harsh feel. Concentrated mineral acids, particularly when hot, have a disintegrating action, destroying and dissolving the fibre. Dilute nitric acid when applied at the boil turns the wool yellow, due to the formation of xanthoproteic acid ; if the strength does not exceed 3° to 4° Tw., this formation only takes place slowly. Nitrous acid diazotises wool, the fibre becoming yellow in colour ; it is then capable of combining and forming coloured compounds with alkaline solutions of phenols {e.g. /^-naphthol gives a deep 14 DYEING AND CLEANING. red), and with acid solutions of amido compounds {e.g. a-naphthyl- amine gives an orange shade) (Richard, J.S.D.C., 1888, and Bentz and Farrell, J.S,C.L, 1897). Sulphurous acid has no action on the fibre, but exercises a bleaching action upon the yellow colouring matter which it contains. It is absorbed and retained very tenaciously by the fibre ; its removal may be effected by steeping in a dilute solution of soda, or by conversion into sulphuric acid by means of hydrogen peroxide. Organic acids are extensively employed in mordanting and dyeing wool, and have no destructive action upon the fibre. Action of Alkalies. —Wool is readily acted upon by alkalies. Caustic alkalies, even in very dilute solutions, exert a very in- jurious action upon wool, the extent depending upon the alkali employed, the concentration and temperature of the solution, and the time during which it is applied. Caustic soda and potash, even in dilute solutions, used in the cold have a destructive action, leaving the fibre harsh and tender, while hot solutions completely dissolve it. The alkaline carbonates (sodium and potassium carbonates) also exercise a destructive action on wool, but in a far less degree than the caustic alkalies. They may be employed in dilute solutions at temperatures not exceeding 120° F. The milder alkalies (soap, borax, etc.) have very much less action on wool, and with the exception of a tendency to felt the fibre, have practically no injurious action. Ammonia and ammonium carbonate have much less action than the hydroxides and carbonates of sodium and potassium. Action of other Substances. — Chlorine and hypochlorites act upon wool deleteriously, turning it yellow in colour and ultimately destroying the fibre. The regulated action of chlorine reduces the tendency to " felt," and is employed in the production of the so-called unshrinkable or "kymoed" under-garments. Chlorinated wool has an increased lustre, but becomes somewhat harsh to the feel ; it has an increased affinity for colouring matters, which is taken advantage of in printing wool and half-wool fabrics. The normal salts of the alkaline metals, such as common salt, sodium sulphate (Glauber's salt), potassium sulphate, calcium chloride, etc.;, are quite without action on the wool fibre. When boiled with solutions of metallic salts, such as the sulphates of aluminium, iron, chromium and copper, considerable quantities of the salt are taken up by the fibre. The chlorides and acetates of some of the metals act in the same manner. The mordanting of wool prior to dyeing with adjective colouring matters is performed in this way, but as garment dyers do not TECHNOLOGY OF THE TEXTILE FIBRES. 15 employ mordant dyestufFs on wool (with the possible exception of logwood on chromium or iron mordant), the matter will not be dealt with more fully. Wool appears to contain bodies of an amido-acid character, but whether this has any bearing on the fact that it dyes with either acid or basic dyestufFs appears to be open to question, as the removal of the amido group by diazotising and boiling does not appear to affect its affinity for acid colours (Bentz and Farrell, V.aS'.C./., 1897). SUk. Silk is the most valuable of the textile fibres ; it is excreted by the silkworm, which envelops itself in the fibre in the form of a cocoon when it enters into the transition or chrysalis period. The silks employed in the production of textile fabrics may be con- veniently classed as domestic or artificially reared, and wild silks. The former are by far the more important. The principal species of silkworm is the Bomhyx mori or mul- berry silkworm, which is reared in China, Japan, India, Italy, France, Greece, etc. It produces annually one crop of silk, the colour varying from white to golden-yellow according to the country from which it is obtained ; for example, China silk is white, Japanese greenish white, and Bengal silk deep golden- yellow. Fig. 4 represents the moth in the various stages of its existence. The threads of several cocoons are reeled to form a thread of raw silk, the hanks formed in this manner being imported into this country in the form of a twisted " book.'' These are reeled, several threads twisted a few turns to the inch forming organzine ; with less twist the threads are known as tram silk. Organzine is usually employed for warps, and is also frequently used for the weft or "shoot.'' Tram also is used for weft-threads. Spun silk is the name given to the threads produced by spinning silk waste in the same manner as cotton and wool threads are formed. Structure of the Silk Fibre.— As it comes into the market the raw silk has a harsh feel and but little lustre. The fibre drawn from a single cocoon varies in length from 400 to 2000 yards, and has an average diameter of 0*00067 inch. The fibre consists of two portions, the outer coating of silk gum or sericin, and the inner fibre or fibroin. The silk gum can be removed by boiling in solutions of alkalies or soap, the process being known as boiling off, during which a loss of about 25 per cent, occurs. With the removal of the gum the fibre becomes pliable and lustrous. Seen under the microscope two fibres (which have issued from 16 DYEING AND CLEANING. the two spinnerets of the silkworm) are found to be cemented together by the outer coating of silk gum (fig. 5) ; it presents the appearance of a structureless, transparent, rod-like fibre. Physical Properties. — Silk is very hygroscopic, and, like wool, can absorb considerable quantities of moisture (up to 30 per cent.) without feeling damp. Raw silk is always " conditioned " before buying, the standard of moisture on which the weight of the silk is calculated being 1 1 per cent. Silk has a specific gravity of 1*367. When dry it is a bad Fig. 4.— The Silk Moth. conductor of electricity, and easily becomes electrified by friction. It is very elastic, and can be stretched up to one-fifth of its length without breaking, raw silk possessing greater elasticity and tensile strength than the de-gummed silk. Action of Acids. — Silk is rapidly attacked and dissolved by concentrated mineral acids. Hydrochloric acid at a density of 27° Tw. contracts silk fabrics to about four-fifths of their original dimensions ; by printing gum or wax resists, crepon effects may be obtained (Farrell, J.S.D.C, 1905). Sulphuric acid at a density of 140° Tw. produces a similar TECHNOLOGY OF THE TEXTILE FIBRES. 17 effect, but the fabric is destroyed before the acid can be removed by washing in water. Concentrated nitric acid dissolves silk to a yellow solution, while dilute nitric acid turns the fibre yellow through the pro- duction of xanthoproteic acid. Fig. 5.— Silk Fibres. Nitrous acid turns the fibre yellow with the production of a diazo compound from which coloured compounds can be produced with alkaline solution of phenols, and acid solution of aromatic amido compounds. The silk-diazo compound is very sensitive to light, and a process for the production of photographs upon silk fabrics has been based on this property (Farrell, J.S.D.C., 1906). Silk absorbs acids from dilute aqueous solution and retains 2 18 DYEING AND CLEANING. them tenaciously ; at the same time the lustre of the fibre is increased and the silk acquires a peculiar feel or " scroop," emitting, when compressed in bulk, a crackling sound. To produce this effect the silk is worked in a dilute solution of acetic, formic, tartaric, or sulphuric acid, and dried without rinsing. Action of Alkalies. — In its behaviour towards alkalies, silk stands between wool and cotton. At low temperatures caustic soda and potash solutions up to 50** Tw. do not injure silk if the time of exposure is short, and the action is further reduced by the presence of glycerine or glucose. This method is employed in the production of crepon effects in silk and cotton fabrics, the cotton becoming contracted and throwing the silk into folds. In hot solutions of caustic alkalies silk is completely dissolved. The alkaline carbonates act upon silk in a less energetic manner than upon the wool fibre. Soap is usually employed in the "boiling off*" process, and has no action on silk. Borax may be also employed in ''boiling off," but prolonged boiling tends to weaken the fibre. Ammonia and ammonium carbonate have but little action on silk. Action of other Substances. — Metallic oxides may be deposited upon silk from suitable salt solutions; advantage is taken of this in the production of weighted " silks. White and coloured goods are usually weighted with tin compounds, immersion in stannic chloride being followed by immersion in sodium phosphate, sodium silicate, etc. Blacks are visually weighted with iron in combination with tannic acid. (Appendix A.) Chlorine and the hypochlorites turn silk yellow in colour and ultimately destroy the fibre. They must not be employed in bleaching cotton or linen fabrics trimmed or stitched with silk. Tannic acid is absorbed by silk, bleached sumach extract being sometimes employed in slightly weighting coloured silks in the production of "16-ounce" dyeings (i.e. 12 ounces of silk are weighted up to 16 ounces). Potassium permanganate is decomposed with the deposition of brown manganese dioxide, which may be subsequently removed by treatment with sulphurous acid, this method being sometimes employed in bleaching dark-coloured silks. Too strong a solution of potassium permanganate disintegrates the Hbre. Silk resembles wool in its behaviour towards colouring matters ; there are a few exceptions, which will be dealt with under ''Dyeing." Wild Silks. The only wild silk which comes to this country in considerable quantity is that known as Tussah or Tussore. It is imported TECHNOLOGY OF THE TEXTILE FIBRES. 19 into this country from India and China, very frequently in native woven pieces. The Indian Tussore is the product of Antheroea mylitta^ and the Chinese is the product of another species of the same genus, viz. Anther cea pernyi. The Tussore silk moth is larger than the Bomhyx^ and constructs a larger cocoon. The fibre has a brownish colour and a peculiar siliceous lustre. The brown colouring matter is very difficult to remove, although the fibre will withstand a very considerable amount of alkaline and acid treatment. The diameter of the fibre is about three times as great as that of mulberry silk. It appears under the microscope as a flat double fibre, each fibre being composed of several fibrillse (fig. 6). Fig. 6.— Tussore Silk Fibres. Raw Tussore contains a considerable quantity of mineral matter. Baston and Appleyard (J.S.D.C, 1888) found that the fibre contained 5-34 per cent, of mineral matter, of which about one- tenth was silica. Boiled with soap to remove the sericin, it loses in weight to the same extent as mulberry silk — about 25 per cent. After boiling off", the colour of the fibroin is still brown ; whereas many of the yellow mulberry silks (e.g. Bengal) give a fibre which is practically v hite. The brown colour may be reduced by bleaching with hydrogen peroxide, but the production of a colour even approaching a white " is a matter of very great difficulty. Tussore silk is more resistant towards acids and alkalies than 20 DYEING AND CLEANING. mulberry silk, and they may be employed in greater concentra- tion and at a higher temperature in bleaching the silk without any risk of injury. It is more difficult to dye than ordinary silk, especially in light shades (due to the colour) and very dark shades (due to the peculiar speckled appearance of the fibre). Other wild silks which may be mentioned are : — Eria silk, the product of Attacus ricini, which is found in various parts of India ; it resembles Tussore. Atlas silk, from Attacus atlas. Muga silk, from Anthercea Assami, a native of Assam ; the fibre is lighter in colour and easier to dye than Tussore. Yama-mai silk, the product of Anthey^oea yama-mai^ a native of Japan ; with the exception of its greater diameter, it closely resembles mulberry silk. CHAPTER II. DRY CLEANING. Reception of Goods. — Articles received for dyeing or cleaning are first carefully examined, to determine whether the customer's instructions can be satisfactorily and safely carried out. Owing to the fact that nearly all the articles submitted to the dyer and cleaner have had a certain amount of wear and exposure, it is the custom of the trade to undertake all orders at the "owner's risk." The following wording has been adopted by the Incorporated Association of London Dyers and Cleaners, and with minor verbal alterations is printed on the price lists, etc., of dyers and cleaners throughout the kingdom : — " Non-liability. — In accordance with the custom of the trade, no responsibility can be accepted for shrinkage or for damage to any article, or for defects becoming apparent during treatment, which are due to defective manufacture, to adulteration and deterioration, or to wear and exposure." If an examination renders it obvious that a satisfactory result is very unlikely, the customer should be advised, and permission to proceed at his risk and expense obtained. The following are some points concerning which it is found necessary to communicate with customers : — Obvious frailty of lace and other curtains from exposure, etc. Selection of unsuitable shades for re-dyeing articles (suitable alternatives must be suggested). Extra expense involved through the necessity to unpick and re-make articles which can generally be treated whole — e.g, chintz curtains, etc., fitted with linings dyed with fugitive colours or with woollen linings which would be spoilt in the cleaning and finishing processes. Marking. — When the articles have not been marked at the receiving shop, they must be allotted a number or other mark 21 22 DYEING AND CLEANING. corresponding with the entry in the book (or where the Card Index System is employed, on the card) wherein the customer's name and address, Hst of articles, instructions, etc., are recorded. This mark may be in ink, where the dry cleaning process is to be adopted, or in marking cotton where the goods are to be wet cleaned or dyed. For dyed goods tinsel thread is sometimes employed, as the tinsel remains bright and easily decipherable after the dyeing operation, whereas the marking cotton is frequently dyed the same shade as the goods, rendering it somewhat difficult to determine the mark, thus leading to confusion and errors. The mark in either case may be placed direct on the article {e.g. with marks on gloves) or on a separate piece of tape, which is sewn or otherwise fixed on to the article. The mark allotted should convey to the worker as much information as possible ; it should combine the registered number of the article, the number of pieces or articles in the batch, and with articles which have to be finished a certain size, e.g. window blinds, casement curtains, etc., the size of the article. For example, in a set of chintz curtains and covers, comprising thirteen pieces, each piece would be marked — \"'q^^^ • ^^i^ 1 o case the letter would indicate the receiving shop, van district, etc. A window blind belonging to a set of eight to be finished 46| inches wide (the width is the important dimension in this case) would be marked ^ ^^^? . 8 X Articles for dyeing are frequently marked with a letter or letters indicating the colour which they are to be dyed. All articles are now thoroughly examined, and any trimmings or attachments likely to become damaged during treatment, or to cause damage to any articles, must be removed and marked for subsequent identification. For example, rings, hooks, and pins must be removed from curtains, draperies, etc.; glass, china, enamel, and metal buttons, and metal and paste buckles from costumes and blouses, and buttons and buckles from waist- coats. Dress hooks must be knocked down, as they are liable to catch in lace or trimmings, etc., in the cleaning machines, causing considerable damage. They can be raised again in the process of finishing. (Hooks need not be removed if a piece of tape or calico be tacked over them.) Garments, etc., received for dyeing in an unpicked state (or which have to be unpicked at the works — a very rare occurrence) must be tacked together, as otherwise small pieces may be lost in the dye vats, etc. DRY CLEANING. 23 The processes to which articles are submitted by the dyer and cleaner may be roughly classified as follows : — Dry Cleaning, Wet Cleaning, Dyeing (including Dry Dyeing); these processes being followed by suitable methods of Finishing. Of these processes the most important at the present time is that known as Dry Cleaning. Dry Cleaning. This process is known variously as Dry, French, and Chemical Cleaning, and by its French equivalent Nettoyage a sec. It is based on the fact that a considerable amount of the dirt and dust on articles of wearing apparel, curtains, draperies, etc., is held in position by greasy or fatty substances. If this grease or fat is removed by a suitable solvent, the dirt is readily removed mechanically. The term "dry" cleaning does not appear to be easily understood by the layman. He does not understand how a process which involves immersion of the articles in a liquid can be a "dry" one. Articles immersed in the liquids usually employed in the "dry" cleaning process are not " wetted" in the ordinary acceptance of the term ; an elaborately trimmed gown washed in petroleum benzine, for example, retains its shape in every way ; the same article immersed in water would become a shapeless mass ; a piece of accordion-pleated material retains the pleating in benzine, but loses it in water. This is due to tw^o principal causes : first, most of the substances employed in the dressing of finished fabrics are soluble in water ; and secondly, the fibres absorb the water, becoming hydrated and considerably modified in their physical properties. The water causes the fibres to become limp and to alter (in many cases) in shape and size, the diameters of the ultimate fibres increasing, and the lengths of the threads (especially where they are at all highly spun) contracting considerably. Thus the relative positions of the fibres and threads are altered, and with them the shape of the fabric. Benzine and the other liquids employed in dry cleaning are chemically inert as regards the fibres, as also are other liquids not containing water — e.g. ether, chloroform, carbon tetrachloride, turpentine, etc. On the other hand, methylated spirit, which contains a certain percentage of water, produces in a reduced degree much the same effect as water. If this water is removed by 24 DYEING AND CLEANING. dehydration and distillation, the absolutely dry alcohol produced acts in the same manner as benzine. This indicates that the chemical and physical changes which take place when a fabric is 'Svetted" in water are not due to the mere fact that water is a liquid^ but to the inherent and peculiar chemical properties of water, and are only produced by water or by liquids containing water. Consequently the immersion of articles in a liquid which does not produce the ordinary effects of wetting " may be quite correctly termed a '"dry" process. The ^*dry'' process appears to have been first employed com- mercially about the middle of the last century. M. Jolly, President of the Paris Syndicate of Dyers, made a special com- munication on behalf of the author to the Syndicate, and states that the old members recall having worked at dry cleaning with ''essence" about 1856, but his father recalled the employment of the process as early as 1848. At this earlier date it would appear that the spirit employed was not petroleum benzine, or benzol, but ''camphene," an oil of turpentine specially distilled for burning in lamps. Thomas Love, in his Practical Dyer and Scourer^ published in London in 1854, gives directions for cleaning articles with camphene (describing the process as " Dry " or "French" cleaning); but he does not appear to have been acquainted with the use of any other spirit. It would therefore appear probable that the date mentioned by M. Jolly, viz. 1856, indicates the first introduction of benzine or benzol. Dry cleaning was first introduced into the United Kingdom by Messrs. J. Pullar & Sons of Perth in 1866, both petroleum benzine and benzol (or solvent naphtha) being employed, the methods and men being taken from the Paris house of Petit-Didier ; but whereas the process had only been carried out by hand in Paris, machinery was very quickly introduced at Perth, thus forming the basis of the huge industry which now exists. The liquids employed in the dry cleaning process are petroleum benzine, coal tar benzene (benzol), and, in a minor degree, carbon tetrachloride. Other solvents which could be employed, but are either too costly or are offensive in odour, are turpentine, ether, chloroform, acetone, and bisulphide of carbon. Petroleum Benzine. — This is the most important liquid employed in dry cleaning, and is obtained during the refining of American, Borneo, Sumatra and Scotch shale petroleum. The benzines from American and Borneo petroleum are most largely employed. Benzine is a light, mobile spirit having a specific gravity of from '700 to '780. Formerly spirit of specific gravity •700 was principally employed for gloves and '730 to '740 spirit for other work ; but owing to the great demand for light spirit DRY CLEANING. 25 for motors many cleaners now employ '780 spirit solely, as the heavier spirit is lower in price than the lighter ones. It is highly dangerous to use, giving off an inflammable vapour at the ordinary temperature, and must therefore be used with every possible precaution against fire. It has not a stationary boiling point, but consists of a series of hydrocarbons boiling over a wide range of temperature ; the spirit employed for dry cleaning begins to distil at about dO" C, and portions remain undistilled at 150° C. The following table (Garry and Watson, J.S.C.L, 1904) gives comparative analyses by fractional distillation of samples of petroleum benzine from various sources, and shows the variation in the range of boiling-points : — American Benzine. Sumatra Spirit. Scotch Shale Spirit. Borneo Spirit. Specific gravity at 15' C. . 0727 0-710 0-739 0-782 Condensation commenced at 64° C. 60° C. 65° C. 65° C. Volume distilling below 60° C. „ 70° C. 80° C. 90° C. 100° C. „ 110° C. 120° C. 130° C. „ 140° C. . 150° C. : above 150° C. Per cent. 0- 5 1- 5 8 18 36 16 8 6 4 2 Per cent. 15 17 20 9 14 9 3 2 1 Per cent. '0-5 1 1-5 5 12 24 18 20 10 8 Per cent. 1-5 1-5 3 14 26 22 12 10 6 4 100 100 100 100 Apparatus Employed. — Glinsky's dephlegmator ; rate of distillation, one drop per second ; Liebig condenser ; flask, 200 c.c. capacity; thermometer in vapour only ; sand bath with flask immersed to height of liquid in flask ; Bunsen burner. The best and most economical spirit for dry cleaning is that with a large percentage distilling between 80° C. and 120° C. The portions distilling below 80° C. are very volatile and lead to losses during the cleaning processes from volatilisation ; the high boiling portions (i.e. above 120' C.) involve a long period of 26 DYEING AND CLEANING. drying before the articles are free from smell, and (where vacuum distillation is not employed in the recovery of the spirit) a larger quantity of water to be separated from the condensed spirit. Of the samples shown in the above table it will be seen that the percentages distilling between 80° C. and 120° C. are as follows : — American benzine . . .78 per cent. Sumatra spirit . . .52 Scotch shale spirit . . . 42*5 Borneo spirit . . .65 Other things being equal, their value would therefore be in this order : American benzine, Borneo spirit, Sumatra spirit, Scotch shale spirit. (This order, of course, only refers to the samples in question.) Particular attention is directed to the large percentage of Sumatra spirit distilling below 80° C, viz. 32 per cent. This would involve a heavy loss from volatilisation during usage. Analyses of benzine by fractional distillation must always be carried out under precisely the same conditions, as otherwise widely divergent results may be obtained. In the following table the results are given of tests on a sample of '730 sp. gr. spirit employing different forms of apparatus^ : — A B. c. D. E. F. G. Condensation com- menced at 63°-C. 68° C. 58° C. 58° C. 73" C. 64° C. 88° C. Below 70" C. . 80" C. . 90° 0. . „ 100° C. . 110° C. . „ 120° G. . 130° C. 140° C. . „ 150° C. . Above 150° C. 0-5 3-5 40 32 16 5 1 1 1 0 0-5 2-5 44 28 15 5 3 2 1 0 2-5 9-5 37 27 15 3 3 2 1 0 2 17 26 30 15 4 2 2 2 0 4 38 34 15 5 2 1 1 0 1 12 35 28 15 4 2 2 1 0 1 44 43 5 2 2 1 2 100 100 100 100 100 100 100 A, Engler flask ; B, Ladenburg's flask ; C, Le Bel-Henninger's dephlegmator (three bulbs) with glass-head substituted for platinum gauze cones ; D, Le Bel-Henninger's dephlegmator (three bulbs), no obstruction whatever ; E, Bannow's method ; F, Glinsky's dephlegmator (five small bulbs), vapour readings for temperature ; G, as F, with liquid readings for temperature. 1 Garry and Watson, J. S.C.I. , 1904. DRY CLEANING. 27 The rate of distillation in each case was 2^ c.c. per minute. The above results indicate that distillation analyses may be very misleading unless carried out in exactly the same manner, but if this is done they are of great value to the dyer and cleaner. Trotman (J.S.C.I.^ 1906) suggests the following apparatus and conditions, and finds that very consistent results are obtained. One hundred cubic centimetres of the sample are placed in a round-bottomed flask of 150 c.c. capacity and having a short neck 1 inch in length. The latter is connected to a Young's rod and disc fractionating column with sixteen chambers, the distance from the neck of the flask to the lateral exit tube being 13 inches. The bulb of the thermometer is placed 1 inch below the lateral exit tube. The fractionator having been connected to a condenser with adapter, the flask is placed upon a piece of asbestos with a circular hole, and heated with a shaded direct flame from a small Bunsen burner, the gas supply being controlled by a screw clamp placed on the supply tube. The rate of distillation is arranged at approximately one drop per second. The distillation is started with a flame which will produce the required rate, and its height is only altered when the temperature or rate of distillation shows any inclination to fall. He gives the following as examples of good and inferior spirits : — Fraction Distilling. Good. Poor. Below 80° C 3-0 25-0 6-0 Between 80° C.-90° C. . 12-0 33-0 14-0 90° C.-lOO" C. . 82-0 16-0 33-0 100° C.-110° C. . 3 0 14-0 26-5 Above 110° C 12 0 20-5 The results indicate that the ^'good'' sample is an extremely satisfactory one. A sample of spirit distilled according to the above conditions with not more than 5 per cent, coming over below 80° C. and not more than 10 to 15 per cent, remaining undistilled at 120° C, may be passed as a satisfactory one. With spirit of the higher specific gravity now frequently em- ployed the percentage remaining undistilled above 120° C. is frequently much higher than 15 per cent. Where a vacuum dis- tilling plant is employed in the purification of the dirty spirit the higher boiling-point is not so objectionable, the loss due to the high boiling fractions retained by the grease and dirt being very much less than where the distillation is carried on at atmos- 28 DYEING AND CLEANING. pheric pressure. The following results obtained by the author from a sample of Borneo spirit sp. gr. '762 may be taken as typical of a heavy spirit of fairly good quality : — Fraction Distilling. Borneo Spirit '762 sp. gr. Below 80° C. . . . Between 80°-130° C. . Over 130° C. . . . Per cent. 4 74 22 100 It is very important that benzine employed in dry cleaning shall leave the articles free from smell and in the shortest possible time. A very simple test for the impurities causing the unpleasant odour in some samples of benzine consists in placing in a clean glass test-tube 10 c.c. of the sample and 1 c.c. of pure concen- trated sulphuric acid, agitating for a few seconds, and then allowing to stand for ten minutes. The layer of sulphuric acid becomes coloured, the shade varying from a very pale yellow in good samples to a deep brown in bad ones. If the test is carried out as stated above, one in which the acid is not rendered deeper than a pale lemon yellow may be taken as indicating that the sample of benzine is a satisfactory one. (The impurities to which the odour is due are principally sulphur compounds, which may be removed by agitating the benzine with sulphuric acid, drawing off the acid and washing either with water alone or with caustic soda, and distilling.) It is very unlikely that benzine will be found to be adulterated, but if the relative prices of benzine and benzol were such as to render adulteration with the latter profitable, it can be detected by nitration of the sample, and separation of the nitrobenzene by fractional distillation. It has been stated by many writers on this subject that benzine possesses a considerable germicidal power. Farrell and Howies (J.S.D.C., 1908) investigated this subject, testing at the same time benzol and carbon tetrachloride. Using a pure agar-agar culture of Bacillus typhosus^ which was absorbed by sterile threads of silk, they found that immersion in petroleum benzine (sp. gr. •765) at the ordinary temperature for as long as 6| hours did not kill the organism. With the addition of 1 per cent, by weight of benzine soap (Saponine) the same result was obtained. Benzol at the ordinary temperature did not kill the organism after 6^ DRY CLEANING. 29 hours' immersion ; not only do benzine and benzol possess no germicidal power at the ordinary temperature, but they do not appear to act as antiseptics, the organism in no case showing signs of attenuation, but growing as vigorously after 6J hours' immersion as the original culture. Carbon tetrachloride, on the other hand, killed the organism in all cases, with an immersion of thirty minutes. Employing benzine and benzol at 60° C. the organism was in all cases killed by immersion for five minutes, but subjection to air at the same temperature kills the organism almost as rapidly ; this would appear to indicate that it is the heat only which is responsible for the sterilisation. Benzene (Benzol) is obtained as a product of the distillation of coal tar and coke oven tar, each of which contains from 0*8 to 1 per cent, of benzene. The first fraction, known as the '4ight oil," consists of that spirit which passes over up to 150° C. and contains benzene, toluene, xylene and smaller quantities of other substances. It is purified by washing with dilute acids to remove basic substances (pyridine, etc.), and with dilute alkalies to remove phenols, etc. It is finally washed with strong sulphuric acid, and is then submitted to fractional distillation. (The boiling-points of the chief constituents are benzene 81° C, toluene 111° C, xylene 142° C). The commercial benzols obtained are defined according to the percentage distilling over below 100° C, those of most interest to dyers and cleaners being described as 90's and 50's. The proximate composition of these are given by Kraemer and Spilker as follows : — 90 per cent. Benzol. 50 per cent. Benzol. Per cent. Per cent. Water ...... 0-060 0-100 6-25 Carbon disulphide .... 0-686 0-39 Substances absorbing bromine, in- 1-202 1-23 cluding thiophen and the like Thiophen per se . . . . 0-264 0-264 80-922 45-37 Toluene ...... 14-850 40-32 Xylene ...... 2-180 12-44 Excess of sulphur compounds causes the benzene to impart an unpleasant odour to articles cleaned in the spirit, which is only removed on prolonged stoving. 30 DYEING AND CLEANING. The following figures give the average specific gravities of commercial benzols : — 90 per cent, benzol 0-880-0-883 50 per cent, benzol 0-875-0-877 Solvent naphtha, 90 per cent, at 160° C. . 0-874-0-880 Pure benzene 0-883-0-885 Toluene 0-870-0-871 Xylene 0-867-0*869 Benzene is a highly refractive, colourless, mobile liquid, and is very inflammable, the following being the flash points of benzols, etc.: — Pure benzene . . . . . . — 8° C. 90 per cent, benzol . . . under — 4° C. Toluene . + 5° C. Xylene. + 21° C. Solvent naphtha, 90 per cent, at 160° C. . +21° C. In making fractional distillation tests with commercial benzol the same precautions must be observed as with petroleum benzine, as otherwise variable and misleading results will be obtained. F. Frank (J.S.C.I., 1901) gives the percentage composition of commercial benzols ascertained by distilling 1 kilo of the sample in a specified copper flask fitted with a Le Bel-Henninger dephleg- mator 60 cm. in length as follows : — Percentage Composition. 90 per cent. Benzol. 50 per cent. Benzol. Up to 79° C 79° to 85° 85° to 105° 105° to 115° Residue (xylol) .... Loss by distillation .... 1- 0 78-8 100 8-0 2- 0 0-2 0-3 18-3 47-5 23-7 10-0 0-2 Thiophen can be detected by the blue colour produced on shaking the sample with sulphuric acid and a small quantity of isatin. Schwalbe (Chem. Zeit., 1905) states that this test is perfectly trustworthy when employed quantitatively within the limits of 0-5 per cent, and 0*05 per cent., which are said to be the maximum and minimum proportions of thiophen found in commercial benzols. The requisite solutions are a number of test solutions of benzene containing the following percentages of DRY CLEANING. 31 thiophen: 0*5, 0*25, 0*1, 0-075, 0-05, 0025, O'Ol. A solution of 0*5 gramme of isatin in 1000 grams of pure concentrated sulphuric acid. Two 100 c.c. measures are each charged with 25 c.c of isatin solution and 25 c.c. of pure concentrated sulphuric acid. To one of the measures 1 c.c. of one of the thiophen test- solutions is added, and to the other 1 c.c. of the benzol to be examined. Both solutions are then shaken for five minutes and the colours viewed on a white base. Carbon disulphide is tested for by the addition of a few drops of phenylhydrazine, giving when present a crystalline precipitate on standing. It is determined quantitatively by conversion into potassium xanthate with alcoholic caustic potash, separation with water, and estimation in the washings by acidifying with acetic acid and titrating with a solution of copper sulphate (12*475 grammes of crystallised salt in 1 litre of water, 1 c.c. = 0*0076 CSg). The end reaction is ascertained by the red colour produced when a drop of the liquid is brought into contact with a drop of potassium ferrocyanide on filter paper. The presence of hydrocarbons of the paraffin series (petroleum benzine, etc.) can be detected by the nitration of the sample with nitrosulphuric acid. If benzine is absent no unnitrated hydro- carbon will be obtained on distillation in steam. To ascertain the presence of unsaturated compounds (hydro- carbons of the ethylene series) 5 c.c. of the sample are shaken for five minutes with 15 c.c. of pure concentrated sulphuric acid, when the acid layer should only be slightly darkened. Benzol (preferably 90's because of its lower boiling-point) is an excellent solvent of grease, and gives highly satisfactory results in dry cleaning. It is not so extensively employed as petroleum benzine, as the latter is generally lower in price (except under abnormal local conditions). Moreover, Goehrig (Soc. Ind, de Mulhouse, 1903) states that petroleum benzine is better for the workers, as the vapour of benzol has dangerous toxic properties ; also that a mixture of benzol and petroleum benzine produces analogous effects to those produced by benzol alone. Carbon Tetrachloride. — In recent years the price of carbon tetrachloride has been considerably reduced, rendering it possible to employ it to some extent in dry cleaning. As its name implies, it is methane in which all the hydrogen atoms have been replaced by chlorine — CCl^. It is closely allied to chloroform, which con- tains one atom of chlorine less — CHCI3. It is a stable, colourless liquid, and does not decompose even with boiling alkalies. Its odour is very similar to that of chloroform. It has a specific gravity at 15° C. of 1*604, and it boils at 76**- 77" C. The latent heat of vaporisation is 51 calories as com- 32 DYEING AND CLEANING. pared with benzine = 90 calories. Goehrig {Soc. Ind. de Mulhouse, 1903) considers that it is unsuitable for degreasing fabrics, stating that it produces upon the workmen anaesthetic effects similar to those produced by chloroform, but the author has not observed any ill effects upon workmen using it continuously over a long period, provided the workrooms are well ventilated. The com- plaint most frequently made by workers is that they cannot get rid of the "taste" of carbon tetrachloride; e.g., at meals, taken several hours after working with it, all the foods taste of carbon tetrachloride. It is important that it should be free from chloroform, as the latter in the presence of air and light gradually undergoes de- composition with the formation of carbonyl chloride (phosgene gas, COCI2), which is very poisonous. It is possible that some of the ill effects attributed to carbon tetrachloride are due to the formation of this substance. Carbon tetrachloride is an efficient degreasing agent, and (if hydrochloric acid and free chlorine are not present) has no action upon the most delicate colours and fabrics. Its advantages are : — (1) Its absolute non-inflammability. (2) Its low heat of vaporisation, ensuring small cost for distilling and condensing. (3) It is a definite chemical compound with a definite boiling- point, and can be completely evaporated at normal pres- sure by means of closed steam. (4) It has a greater solvent power for some substances, e.g. resins, than benzine. Its disadvantages are : — (1) Its high cost, volume for volume, as compared with benzine (about8:'l). (2) Its high specific gravity, rendering it necessary to employ twice as much by weight to do the same amount of work as benzine. (3) Its low boiling-point and greater loss in working (by volatilisation). (4) The possibility of ill-effects on the health of the workers, particularly if it is not pure. Its non-inflammability outweighs its disadvantages for some purposes, as it may be employed when it would be quite impossible to employ benzine, e.g. in cleaning silk, panels, furniture, etc., in situ. It has been stated that benzine and benzol may be rendered DRY CLEANING. 33 non-inflammable by the addition of a varying quantity of carbon tetrachloride, and an English patent has been taken out to cover its use for this purpose. Experiment, however, has shown that while the liquid produced by the addition of 20 to 40 per cent, of carbon tetrachloride to benzine may be non-inflammable, when the articles which have been immersed in the liquid are dried the carbon tetrachloride (with its low^er boihng-point) evaporates first. The vapour coming off* subsequently contains increasing quantities of benzine or benzol, and is highly inflammable. It is therefore desirable that samples of so-called non-inflammable benzine should be exhaustively tested under working conditions. An English patent (1202, 1905) has also been taken out by E. B. Barboni, for " Improvements in the Manufacture of Non- inflammable Products of Benzene " ; this invention consists in the main in passing chlorine into a solution of iodine in a mixture of benzene and carbon bisulphide. It is asserted that poly- chlorinated derivatives of benzene are thus obtained which are non-inflammable. Dry Cleaning. — Machinery and Methods. The goods which are submitted to the dry-cleaning process include nearly all articles of wearing apparel, household drapings and furnishings, fancy articles, etc., of which the following may be mentioned as examples : — Ladies' Apparel^ etc, — Costumes, evening -gowns, tea-gowns, blouses, dust-coats, jackets, furs, gloves, fancy shoes, laces, scarves, fichus, parasols, and hats. Children's Apparel. — Frocks, pelisses, capes, jackets, boys' suits, etc. Gentlemen's Apparel. — Suits, overcoats, fancy vests, ties, gloves, soft felt hats, gaiters, etc. Household. — Curtains and draperies in nearly all fabrics (satin, plush, velvet, damask, repp, tapestry, cloth, cretonne, tissue, etc.), furniture covers, cushion covers, tablecloths, table centres, anti- macassars, lamp-shades, eiderdown quilts, carpets, rugs, etc. The special advantages of the process are that no shrinkage takes place, no dressing or stifl'ening is removed from fabrics, no alteration or running of colours occurs (with rare exceptions), and the most delicate fabrics, garments, and trimmings are not damaged or altered in shape or finish. After the preliminary examination during the marking process {vide ante)^ when glass buttons, metal buckles, etc., were removed, the pockets of all garments must be thoroughly searched for matches and — with boys' garments — explosive caps. These may 3 34 DYEING AND CLEANING. inflame or explode through the friction produced when handling into or out of the washing machines, during the rinsing process, hanging up, etc. The bottoms of the linings of coats, waistcoats, etc., must be carefully gone round by hand, as matches occasionally get through small holes in the pockets into the space between the cloth and the lining. Special care must be taken in searching for pockets, as they are sometimes found in unexpected places, e.g. ticket pockets (which frequently contain matches), in the sleeves of overcoats, inside other pockets, etc. Matches have also been found in such unlikely places as the folds of curtains and draperies, inside the pocket of a sheepskin perambulator rug, etc. All the pockets of garments should be turned quite inside out ; the bottoms of trousers, double cuffs on overcoats, etc., should be turned down, and articles which are liable to have accumulated fluff", etc. (e.g. the bottoms of knee-breeches, etc.), should be turned inside out. The articles are now roughly sorted according to their colour, fabric, and condition into several classes : — White and cream silks, flannels, etc. White or cream articles with dark trimmings {e.g. ladies' cream serge coats with dark velvet collars and cuffs). Light colours (fancy silks, delaines, etc.). Dark-coloured cloths, tweeds, etc. (costumes, suits, etc.). Black garments. Light-coloured curtains, draperies, etc. (damask, cretonne, etc.). Dark curtains, draperies, etc. Gloves, sunshades, lamp-shades, shoes and other articles treated by hand, or by special methods. The trimmings on articles must be very carefully examined, as there are many fancy trimmings now on the market which are only stuck together and which come apart during the cleaning process. Feather trimmings are very frequently made in this way, as also are chenille medallions, etc. Spotted fabrics, particularly plain cloths with velvet and cloth spot effects, are often produced l3y sticking spots of other fabrics or even a mass of loose fibre on to the base fabric. These must not be cleaned, as the result is invariably disastrous. Light articles with dark velvet trimmings, e.g. cream coats with dark violet or dark green velvet collar and cuffs, must be carefully tested, as the velvet is sometimes found to have been dry-dyed ; some portion of the colour may be dissolved by the benzine in the cleaning process and discolour the light fabrics in the same batch. Also where such trimmings have been dyed with basic colours, or with a substantive colour " topped " with basic colours, the latter is sometimes found to be soluble to an appreciable extent in a solution of benzine soap in benzine, with the same effect on light- DRY CLEANING. 35 coloured fabrics in the batch as if the velvet had been dry-dyed. Dress preservers " containing indiarubber must be removed from blouses, bodices, etc., as the rubber will be wholly or partially dissolved in the cleaning process and may produce stains. The superficial dust is now removed from all gentlemen's clothes, cloth and tweed dresses, curtains, draperies and all other articles not liable to be damaged or " broken " in the process (as are silk- faced frock and dress coats, etc.), by revolving them in a dust wheel (fig. 7). This machine may be either cylindrical or star-shaped, the latter being employed only for carpets, rugs, heavy curtains, etc. It is FiG. 7.— Circular Dust Wheel. essentially a revolving cage, varying in diameter from 5 feet to 14 feet, being constructed of wooden bars or rods set slightly apart so that the dust, etc., loosened by the articles rubbing against each other in the slow process of revolution may fall between them. It is advantageous to enclose the dust wheel in the chamber through which a current of warm air passes (some firms hang up all work in a drying room before putting into the dust wheel). This serves the double purpose of carrying away the dust (which can afterwards be separated in a " vortex " filter or similar device) and of removing any moisture from the contents of the machine. This ensures a more rapid penetration of the benzine, with quicker and more efficient cleaning, and keeps the spirit in a " dry " condition. The removal of the superficial dust 36 DYEING AND CLEANING. by the dust wheel enables the benzine to be employed for a longer period before redistillation becomes necessary. The portions of articles which are unduly dirty are now brushed on a slate or marble slab, with a strong solution of benzine soap to remove or loosen the dirt before the articles are placed in the machine. This is most frequently necessary with the bottoms of skirts, petticoats, trousers, etc., which are very much stained with mud. Brushing slabs are slightly inclined, and fitted with a trough at Fig. 8 — Horizontal Tumbler. the back to collect the spirit running off the slab and to lead it by means of a pipe to a tank or other closed receptacle. The machines generally employed for dry cleaning may be divided into three classes ; special processes such as the " Barbe,'' etc., will be dealt with separately. (1) Tumbler type. (2) Inclined cylinder — " Sunflower " type. (3) Ordinary horizontal type. Tumblers. — The older type of tumbler machine consists of an iron cylinder from 3 to 4 feet long and about 1 foot 6 inches diameter, revolving or oscillating upon bearings as shown in the illustration fig. 8, whereby its contents tumble from one end to the DRY CLEANING. 37 other. The tumbler revolves through an arc of 180°, one com- plete cycle comprising the passing of the cylinder from a vertical Fig. 9.— Vertical Tumbler. 38 DYEING AND CLEANING. position to a similar position with the other end of the cylinder upwards, and back along the same path to the original position. A spirit-tight door fastened with wing nuts enables the goods to be introduced and removed, and a vent pipe passing through one of the bearings to about 1 inch above the highest point of the machine prevents the accumulation of gases under pressure inside the machine. The oscillating motion of this type of machine is usually obtained by means of a rack and pinion. To economise space it may be mounted vertically against a wall ; it is then necessary to unkey the pinion, move it round through 90" and re-key it on the shaft after cutting a new key way ; less space also is taken by the tumbler mounted on the vertical framework shown in fig. 9. Machines of this type are found to be convenient for cleaning small articles such as gloves, furs, blouses, etc., and for the rapid cleaning of " specials " — i.e. articles required in a specially short time, and are very economical, as they require a comparatively small volume of spirit. They possess, however, the great dis- advantage of leaving all the dirt removed from the soiled articles in suspension in the spirit. This finely-divided dirt tends to get ingrained in the fibres of fabrics and in the glove skins, producing a greyness which is extremely difhcult to remove. This will be referred to again later. The defect has been partially reduced by the introduction of a modified form of tumbler (fig. 10), with a well in which the dirt may to some extent settle. Sunflower Type. —The inclined cylinder or Sunflower " type of machine (fig. 11) is also very convenient for cleaning small articles. It is a very suitable machine for use with hand power, being of light construction and requiring very little power for driving. For dry cleaning the cylinder is generally constructed of copper, tinned iron or galvanized iron. The diameter of the cylinder is rather greater than its length, and the angle at which it is inclined and the size of the door are so arranged that the spirit is a few inches below the lower edge of the door when the machine is charged for working. Ribs are fitted on to the inside periphery of the cylinder to produce the necessary rubbing action between the articles in the machine during the cleaning process. The cylinder makes three revolutions in each direction, the belt- shifting gear being operated by a worm and worm-wheel. The lid is fitted with a small stopcock, which is kept open during the cleaning operations to prevent accumulation of pressure in the machines. This type of machine labours under the same disadvantage as the tumbler type, in that the dirt removed from the garments remains in suspension in the benzine. Both types also bear the DRY CLEANING. 39 great disadvantage that it is impossible to make permanent con- nections for feeding and discharging the benzine, and there is consequently a greater fire risk. Horizontal Cylinder Type. — The type of machine generally employed in dry cleaning is the ordinary cylindrical washing 40 DYEING AND CLEANING. machine revolving or oscillating about its axis. It consists of a fixed outer cylinder of metal, inside which is the revolving cylinder of slightly less diameter, in which are placed the articles for cleaning, a suitable door being provided for their introduction and withdrawal. The outer cylinder is provided with a door giving access to the inner cage. The material of which the DRY CLEANING. 41 inner cage is constructed depends to some extent upon the class of work for which it is intended, those generally employed being wood (maple or beech), sheet or tube steel (plain, tinned or galvanised), brass and alummium. Wooden cages are con- structed of rods with intervening spaces of from ^ inch to | inch, or perforated segments with or without intervening spaces. If constructed of perforated sheet metal the holes (j^^ inch to ^ inch in diameter) should be well countersunk, so that there should be no possibility of rough edges coming in contact with the contents of the machine. When metal tubes are employed care must be taken by the makers that no split tubes are used, and the ends must be plugged to prevent dirt extracted from articles accumulating in them. This is liable to come out into the clean spirit employed on a subsequent batch, and if white or light-coloured articles are being cleaned they may be discoloured. This trouble is more frequently experienced in smaller w^orks, where the same machine has to be employed for both light and dark-coloured articles. Machines with open tubes must be particularly avoided in the cleaning of white woollen goods, or the dirt in the tubes will turn certain fabrics, and especially white and cream serges, a greyish shade which is very difficult to remove. Wooden machines are not satisfactory for w^hite work unless they are employed upon it exclusively, as some of the dirt and colouring matter extracted from darker goods is absorbed by the wood and may be dissolved out again by the clean spirit employed for a batch of white goods, resulting in the discoloration experienced with tube machines. Satisfactory results on white goods are obtained with perforated tinned steel cages, but the best results are given by cages con- structed of perforated sheet aluminium. With these machines there is no possibility of metallic stains being produced, aluminium oxide being w^hite. As the cage is quite white, a visual examina- tion of the inside of the cage will at once show if it is quite clean. In all machines of this type baffles or " rubbers ^' are fixed around the periphery, which help to turn over the goods during the revolution of the cage and facilitate the rubbing of the articles one against the other ; this loosens and removes the dirt after the grease has been dissolved by the benzine. The annular space between the inner and outer cages must not be too large, as an unduly large volume of spirit would then be required for each load of work ; on the other hand, it must not be so small that the dirt which is separated and falls to the bottom is stirred up into the goods again. It is usual for the cage to perform three revolutions in each 42 DYEING AND CLEANING. direction, though many cleaners are becoming convinced that oscillation backwards and forwards — i.e. about three-quarters of a turn in each direction — is equally eflficient in cleaning and does not crease or entangle the contents to the same extent. Where the former method is adopted, the reverse motion is usually obtained by means of fast and loose pulleys with a direct and cross drive, the belt-shifting forks being actuated by a worm and worm-wheel. Where the oscillating motion is adopted the Fk;. 12. — Rotary Machine (front view). worm and worm-wheel may also be employed, but it is better to use a rack and pinion motion. This lias the advantage of being "positive," whereas the degree of "slip" on the direct and cross belts is not the same ; consequently with a quick reverse (as in the three-quarter revolution) the cage will probably revolve the full three-quarters of a turn on the cross drive, but only half a turn on the direct drive. This unequal revolution has a tendency to cause the articles to become more entangled than where the degree of revolution in each direction is exactly the same. DRY CLEANING. 43 Other well-known methods of obtaining the reversing action may be employed, but the methods described are those most generally in use. Figs. 12 and 13 give front and back views of the ''Ibis" benzine washing-machine. The inner cage is of wood, the revers- ing gear is arranged for driving from below, and is fitted at the back of the machine to economise floor space. FIG. N-' 507 Fig. 13. — Rotary Machine (back view). In fig. 14 a pair of machines by (jorrie & Son of Perth is shown, each being driven from the same overhead reversing shaft, which may be extended for any number of machines. This arrangement is more economical than fitting the reversing gear to each machine, and saves a considerable amount of space. Still further space may be saved by running the reversing shaft behind the machines and driving by means of a spur wheel through an intermediate pinion direct on to the large spur wheel, each machine being thrown in or out of gear by a friction or other clutch. DKY CLEANING. 45 Fig. 15 shows the Ibis machine fitted with the rack and pinion reversing motion. This being a positive motion, gives exactly the same degree of rotation in each direction. Fig. 16 gives the same type of machine by Gorrie & Son, and fig. 17 the same makers' automatic reversing motion, which is also positive and takes up less space than the ordinary worm and worm-wheel reversing motion. Rinsing Tank. — Rinsing is generally carried out in the washing Fig. 15.—" Ibis" Rack-driven Machine. machines, but it is necessary to provide rinsing tanks, as articles are frequently dealt with which cannot be cleaned in machines. The one usually employed is shown in fig. 18, and consists of a galvanised or tinned iron receptacle with or without a false bottom, and provided with pins or pegs over which the articles are thrown to drain ; it is fitted with a lid, which should be made to close automatically in case of fire (vide '*Fire Precautions"). Hydro-extractors. — The hydro-extractors employed are gener- ally of the under-driven type, as a tight-fitting lid may then be 46 DYEING AND CLEANING. employed. The most satisfactory results are obtained with balanced cages, as higher speeds may be attained and consequently Fig. 16.— Gorrie's Rack-driven Machine. a larger quantity of benzine recovered. The machine made by Watson, Laidlaw & Co., shown in fig. 19, and in section in fig. 20, Fig. 17.— Gorrie's Automatic Reversing Machine. is of this type, and takes less power to drive than a machine of the same size and speed made with a fixed spindle. The spirit extracted runs away and is collected. The speed of the cage depends upon the diameter, but the usual rate for a 26- inch diameter machine is 1200 revolutions per minute, down to DRY CLEANING. 47 about 700 revolutions per minute for one with a diameter of 48 inches. Efficient means of kibrication must be provided to Fig. 18.— Rinsing Tank. minimise the risk of overheating. If the hydro-extractor is con- nected to the spirit tank, a gauze interceptor of the "Nonex" or 48 DYEING AND CLEANING similar type must be provided to prevent any flame passing down the pipes into the storage tanks. Arrangement. — The arrangement of the washing machines, rinsing tanks, hydro-extractors, clean spirit tanks, dirty spirit tanks, and still, should be such that as little pumping as possible is employed. One plan is to have the levels so arranged that the soiled spirit can run by gravity from the machines, by hydro-extractors, etc., to the dirty spirit (settling) tanks, thence by gravity to the still, whence it is delivered by gravity to the clean DRY CLEANING. 49 spirit storage tanks. From these it is pumped to a distributing tank with a sufficient head for the spirit to be suppHed to the various machines by gravity. The dirty spirit tanks, which are also employed as settling tanks, are so arranged that the spirit, after settling, can be pumped to within about 4 inches of the bottom 4 50 DYEING AND CLEANING. of the tank up into a grey " spirit distributing tank. By this arrangement the cycle of handling the spirit is performed with only one pumping, and that with the clean (or partially clean--" grey " ) spirit, which is the easiest to handle, there being no grit or dirt to get into the valves of the pump as is tlie case where dirty spirit has to be raised to a higher level. Each washing machine is fitted with a trap or strainer box at Fig. 21. — Diagrammatic Illustration of General Arrangement. the dirty spirit outlet to intercept any buttons, bones, fluff, etc., which are liable to collect in the bends, T-pieces, etc., in the pipes and cause blockage. The strainer box consists of a metal box with an easily removable spirit-tight lid for cleaning, fitted with a wire gauze partition which holds back any large articles such as those referred to. Fig. 21 illustrates the arrangement diagrammatically, showing washing machine A, distributing tanks B and C (clean and "grey" respectively), pump D, settling-box E, dirty spirit tank F, still and condenser G, and clean spirit tank DRY CLEANING. 51 H. The valves shown in the diagram enables the operator to charge tanks B and C with clean spirit from H or "grey" (or settled) spirit from F, or, if desired, the tanks B and C can be dispensed with and clean or grey " spirit pumped direct into the washing machine A. Dry-cleaning Soap. — Soaps soluble in benzine are employed for the dual purpose of assisting the cleaning process and to minimise the risk of fire. Their application for the latter purpose will be dealt with under " Fire Precautions." The soaps generally employed are anhydrous (or almost anhydrous) stearates or oleates of potash, soda, or ammonia, one of the best on the market being that made by Griinwald & Stommel and sold under the name of Saponine. According to the specification (English patent 8798, 1895) this is made by melting together equal or nearly equal parts of oleic acid and soap, the heating being continued until a clear liquid is obtained, after which it is allowed to cool. The patentees term the product an "acid oleate of alcali." Very satisfactory soaps freely soluble in benzine to a clear solution may be made by dissolving caustic soda or caustic potash in the smallest possible quantity of methylated spirit and stirring it into the theoretical quantity of oleic acid or melted stearic acid and heating the mixture on a water-bath. In place of soda or potash, ammonia ('880 sp. gr.) may be employed with or without the addition of methylated spirit. The following quantities give satisfactory results : — I Methylated spirit . . . . .4 These quantities are arranged to produce a slightly superfatted soap freely soluble in benzine. By increasing the quantity of oleic acid, the solubility of the soap in benzine is increased. For brushing on the slab an ordinary hard oil soap may be employed, green olive oil soap being perhaps the most satisfactory. A brush dipped in benzine and rubbed on a bar of this soap dissolves enough to produce a plentiful lather when brushing the goods. When a solid or semi-solid benzine soap is employed, e.g. Saponine, it is usual to make a stock solution (a 5 per cent, or 10 per cent, solution by weight) and to add the necessary amount of the stock to the machine. For use in the Barbe process neutral soaps must be employed, those containing free acid being found to attack the galvanised fittings at the temperature to which the machine is raised. Method. — The articles for dry cleaning having been ^sorted as described on p. 34, the white goods are always cleaned with Oleic acid. Parts by weight. . 5 . 1 52 DYEING AND CLEANING. freshly distilled spirit. These are the most difficult to turn out satisfactorily, as, if the spirit is not perfectly clean and dry, they are liable to become greyish in tone. They should therefore be cleaned in a type of machine which can be kept perfectly clean, and the cleaning operation should be as short as possible. To this end very soiled white goods requiring a longer period of machining, and also tending to soil the spirit, should not be mixed with white goods which are but slightly soiled. The necessary amount of benzine is run into the machine, and if there is a proba- bility of the spirit being slightly damp, a piece of clean soft calico, taken direct from a warm drying room, is put into the spirit and the machine is run for a few seconds. The calico will absorb a considerable portion of the water which may be dissolved in the benzine. A sufficient quantity of the stock solution of benzine soap is now added to give a solution of from '5 per cent, to 1 per cent, by weight and the goods are introduced. The door of the machine is closed, and it is run for from ten to fifteen minutes. If the goods are very much soiled it may be necessary to machine them for as long as half an hour, but this is rarely necessary with white goods ; if found essential, it is better to run for a second period of fifteen minutes with fresh benzine and soap as before. Another very satisfactory method of cleaning white goods is to machine them for about ten minutes in benzine containing no soap and then to run them from ten to fifteen minutes in benzine and soap as before. This divides the removal of the dirt into two stages, that which is easily removed coming away in the first stage, and the smaller amount of dirt mixed with the benzine at each stage minimises the risk of discoloration, clearer whites being produced. If the rinsing is done in the machine, two separate rinses of clean benzine (without soap) are given, the machine being run in each case for about five minutes. The goods are then hydro-extracted, shaken out, and hung in a steam-heated stove room until quite free from benzine.^ White goods are not usually ^ The necessity for efficient hydro- extracting is shown by the following figures giving the weight of benzene retained by various fibres after dipping in the spirit and allowing to drain without pressure. For comparison the figures for water are also given (L. Vignon, Comptes Hendus, cxxvii. [i], 73-75). Weight absorbed by 100 parts by Weight of the Textile. Liquid. Silk. Wool. Cotton. Water 574 559 497 Benzene . 592 571 506 DRY CLEANING. 53 hydro-extracted to the same extent as other articles, as it has been found that leaving a fair amount of spirit in them improves the colour. It is more general to rinse the goods by hand ; they are hydro extracted to remove as much dirty spirit as possible and are then rinsed in a tank by hand, in clean benzine (without soap), allowed to drain, squeezed, hydro-extracted, shaken and dried. The spirit and soap employed for a load of white goods may now be employed without any purification for cleaning light or medium-coloured articles, and so on until the supernatant liquor from very dirty spirit, which has been allowed to settle, may be employed for very dark or black articles. In this way a considerable saving in soap is effected, and the loss which occurs on distillation is reduced to a minimum. For heavy goods and for articles liable to contain free acid {e.g. articles containing a considerable amount of perspiration, or hangings and draperies which are smoke-begrimed) a larger amount of soap must be employed than that specified for white goods, and if the articles are very much soiled the duration of the machining must be prolonged. Care must be taken that articles liable to be damaged in a rotary machine are cleaned by hand. Those which may be specially mentioned in this connection are articles made, trimmed or lined with glace or other weighted silks, which are usually very tender and particularly liable to be cracked or broken, or to drop into holes in the machining. Glace silks which have not been unduly weighted, and which have not had any hard wear, may be cleaned by machine ; but if on examination they appear to be cracked, to have had a fair amount of wear, or to be much stained under the arms with perspiration, it is safer to brush them by hand on a slab with a strong solution of benzine soap (5 to 10 per cent.), and finally to thoroughly rinse them in a rinsing tank. Jute curtains which have had a fair amount of exposure are frequently very liable to " drop in the machine. If sufficiently sound to be cleaned by hand, that method may be employed, but otherwise they should be returned to the customer. Chiffon trimmed with sequins, beads, or other articles liable to catch on the threads of this delicate fabric should be cleaned by hand. In certain classes of silk fabrics the fibres are very liable to slip or " fray," if rubbed even to a slight extent. This generally occurs in the shiny fabrics, such as brilliantes, and is due to the silk threads employed in the weaving having very little twist (in order to produce the brilliant effect in finishing). The fibres are thus able to slide one over the other with the greatest ease, the slight rubbing of a rotary washing machine being frequently quite sufficient for this purpose. In such cases the articles must 54 DYEING AND CLEANING. either be cleaned by hand or in a machine in which the rubbing is reduced to a minimum [e.g, an oscillatory machine), and the time occupied in cleaning must be as short as possible. Other articles which must be cleaned by hand are sunshades, shoes (leather, silk, etc.), fancy boxes covered in silk and other fabrics, lamp-shades in silk, etc. ; in fact, all articles which will obviously be damaged in a rotary machine. The method is the same in all cases. The article is brushed with a solution of benzine soap, special brushes being employed in some cases ; for example, a triangular brush is employed to get into the pleats of a lamp shade. After brushing, they are rinsed and allowed to drain (hydro-extracting being impossible), and are then dried in the stove room. Special care must be taken with sunshades, which are liable to be very frail from exposure to the sun ; and lamp- shades, which are frequently very tender from exposure to heat. Mention must be made of white furs, which are frequently dry- cleaned. If these have not became yellow from exposure, clean- ing by hand or machine (tumbler or sunflower) gives very satis- factory results ; but if discoloured by exposure, after rinsing, rub well into the hair a paste of benzine and french chalk, and allow to dry in the ordinary way. When dry, brush or shake out the french chalk, when the fur will generally be found much whiter. The methods of dry cleaning which have been described do not remove the whole of the dirt and stains from garments, etc. After drying in the stove room, all articles are carefully examined and, if quite clean and free from stains, are passed on for the process of finishing. Those which are not satisfactory are retained for brushing or for spotting, which will be dealt with later under " Spotting." Glove Cleaning. — A very considerable business is done in glove cleaning, some portion of it being in the hands of those confining their operations to this section of the trade. Glove cleaning, especially amongst the smaller firms, is done largely by hand, but in recent years machines have been introduced to reduce the manual labour as far as possible. The spirit employed in glove cleaning is generally of a lower specific gravity than that employed in garment cleaning, '700 spirit being frequently used. The object of using a lighter spirit is to reduce the time by which the gloves are free from smell to a minimum, especially in the smaller firms where steam is not available for drying and they have to be dried at the ordinary temperature. It is, however, quite possible to use heavier spirit with satisfactory results ; though it is not advisable to employ one having a higher specific gravity than -740. It is necessary to bear in mind that the majority of the white gloves now worn are alum tanned and that the tannage is very DRY CLEANING. 55 soluble in water ; consequently water or liquids containing water should not be brought into contact with them. The tannage is frequently extracted by perspiration or by rain, and the portions affected are left hard and brittle. In cleaning gloves by hand the following appliances are requisite : Vessels to hold the cleaning spirit, glove sticks, brushes, glove hands (for finishing) and cloths (for rubbing). The vessels to hold the cleaning spirit should be of zinc or tinned or galvanised iron, and each should be fitted with a tight-fitting, self-closing lid. Satisfactory results are obtained with a rect- angular vessel constructed with a lid fitted w^ith a chain of such length that the lid will not open so far as to remain open when the hand is removed. By this means the loss of benzine by evaporation is minimised, and with it the risk of fire. The glove stick consists of a round tapered stick of hard wood, and about 18 inches in length. The smaller end takes the finger of the glove, and the degree of taper is such that the wrist is on the thicker portion (about H inch in diameter). Glove sticks are also made with a small round end to take the finger, and a broader flat portion to take the wrist. The brushes employed in glove cleaning are made of best black bristle fastened into the back with string (wired brushes are not satisfactory, as the bristles are cut through and readily come out ; bristles fixed in position with pitch are of course useless, as the pitch is readily dissolved by the spirit). Glove hands for shaping the gloves are made of hard wood with four pieces to take the fingers, the thumb being shaped by the operator. It is general to employ glove hands with slots between the fingers to accommodate nickel slides which fold the sides of the fingers into the slots, shaping the gloves in the same manner as new ones. The gloves must first be sorted according to colour, the white ones (forming by far the larger portion) being separated from the fancy colours, greys, browns and blacks. The white gloves are immersed in a solution of benzine soap in clean benzine, the time depending upon the condition of the gloves, but with those in average condition twenty minutes to half an hour is generally sufficient. They are then squeezed by hand to remove the dirty benzine, and brushed on the slab with a stronger solution of benzine soap. They are then placed on a glove stick, and the tips of the fingers and thumb and the creases of the wrist portion, which are generally more soiled than the rest of the glove, are well brushed. Perspiration marks, which are generally stiff and hard, must be carefully softened by hand or with a pair of glove stretchers, and may be brushed with benzol containing about 25 per cent, of alcohol and a small amount of ammonia. The gloves 56 DYEING AND CLEANING. are now thoroughly rinsed in clean benzine, and allowed to soak for a short time in spirit containing about 5 per cent, by weight of lanoline (wool fat) or white vaseline, which replaces the natural oil (extracted in the cleaning process), and tends to preserve the suppleness and strength of the leather. They are well squeezed to remove as much benzine as possible, placed on a glove hand fitted with the nickel slides, and rubbed with a clean cloth until nearly dry. The thumb is then carefully shaped and the glove- hand with the glove on it is hung up until quite dry and free from smell. The glove is then polished and softened by rubbing with french chalk or white talc powder, and removed from the hand in a finished condition. Coloured gloves are cleaned in the same way, except that with greys, browns and other dark colours clean spirit need not be employed, the spirit from white gloves being employed to clean greys, following with browns, and so on. The final polishing with french chalk and talc powder is also omitted, as also is the rinsing in lanoline or vaseline if the colours are rendered streaky thereby. In cleaning by machine two methods are employed, viz. : — 1. Washing in tumbler or similar machine, followed by hand or machine brushing. 2. Washing and brushing simultaneously. In cleaning gloves in a tumbler or sunflower machine they must be sorted in the same way as when cleaning by hand. The gloves (from 100 to 200 pairs) are washed in a solution of benzine soap (about 1 per cent.), great care being taken that the time in the macliine does not exceed ten to fifteen minutes. If a longer time be taken there is a possibility of the finely divided dirt in suspension in the spirit becoming ingrained in the leather, rendering it greyish in colovir. Some skins appear to be more liable to be affected in this way than others, and it is sometimes found that a glove may be made from more than one skin and the thumb may be discoloured while the remainder of the glove remains quite white. The discoloration is very difficult to remove, even by prolonged brushing. The gloves are now placed in a calico bag and hydro-extracted to* remove as much dirty spirit as possible, and are now proceeded with in the manner described under hand cleaning, being brushed on the slab, on the stick, rinsed, allowed to soak in a solution of lanoline or vaseline, shaped, dried and polished. The amount of brushing required is less than with hand cleaning, the tumbler removing more dirt than a simple soaking in benzine and soap. Brushing on the slab by hand may be to a large extent replaced by brushing by macliine (fig. 22), DRY CLEANING. 57 and polishing by hand may be replaced by Gorrie's polishing machine, consisting of renewable swansdown and calico mops Fig. 22. — Glove Brushing Machine. driven by belt, and against which the glove is lightly held (fig. 23). The drying may be done in the ordinary steam-heated drying-room. Fig. 23.— Glove Polishing Machine. When the gloves are washed and brushed simultaneously very good results are obtained with Gorrie's oval machine (fig. 24), 58 DYEING AND CLEANING which is made to take from a hundred pairs upwards. It is fitted with an oval well in the centre to take the one bearing of the brush spindle, leaving an elliptical annular space in which is fixed the revolving paddle, on each blade of which is fixed a brush, and an adjustable brush is fixed on the bottom of the machine against which the other brushes rub when revolving. The machine is filled to about one- third its depth with benzine and soap in the usual proportions, and the requisite number of gloves being placed in it, the revolving paddle is started. The gloves and Fig. 24. — Gome's Oval Glove-cleaning Machine. spirit are thus kept rotating, the gloves passing between the brushes at each revolution. With gloves of average condition it is found that only from 5 per cent, to 10 per cent, require hand-brushing after passing through this machine. Brushing (where necessary), rinsing, etc., follow as already described. The Barhe System. — The Barbe system of dry cleaning, the patents for which are held by the firm of Robatel, Bufiaud & Co. of Lyons, is dealt with separately, as it differs in principle from the methods already described. In this process the benzine operates in a closed circuit, the DRY CLEANING. 59 whole of the operations being carried on under seal, the articles to be cleaned being washed, rinsed, hydro-extracted and dried in the same machine ; also these processes, instead of being applied in the presence of air, take place in an atmosphere of an inert gas, viz. carbon dioxide. The washing cylinder, which is of specially strong construction, is arranged for driving at two speeds, viz. a slow speed for the washing process, and a high speed (about 300 revolutions per minute) as a centrifugal extractor. In the diagrammatic illustration fig. 25, A represents the washing machine, the clean spirit tank, G^, Gg and G^ the tanks for settled benzine, C and D air pumps, F a tank for dirty benzine, J a cooler, M a receptacle for separating the benzine and carbon dioxide, K a steam heater (for carbon dioxide), L a still leading by way of a condenser to a clean benzine tank 0, S a gas- holder for carbon dioxide, and E a holder for compressed carbon dioxide. The articles to be cleaned by this process are first dried and freed from surface dust, etc., by means of a dust-wheel in a hot-air chamber. This operation takes from thirty to forty minutes, according to the class of goods under treatment. The articles are then sorted according to colour and fabric in the ordinary way, a load consisting of about 100 lbs. of light silk goods up to 200 lbs. of heavy woollen materials. The inner cage having been filled with the requisite quantity of goods, the door is closed and then the air-tight door of the outer casing. By means of the vacuum pump the pressure of the air is reduced to 60 cm. below zero (i.e, the pressure is reduced by about three-fourths). Carbon dioxide is pumped from the gas-holder S to the vessel E in which the gas is stored for distribution at a pressure of about four atmospheres. The gas- holder conduit is then opened to admit carbon dioxide, and after- wards the benzine is run in to the required level (clean spirit from or " settled " spirit from G2, Gg and G^, according to the colour of the goods) ; the gas-holder connecting pipe is left open. Run the machine (on the slow speed) from ten to fifteen minutes, according to the articles, and afterwards remove the spirit by centrifuging at the high speed for three or four minutes. (The soiled spirit runs through a filter which intercepts buttons, flufi', etc., into the tank F, whence it is lifted by pressure into the tanks Gg, G3 and G^.) Replenish the washing machine with benzine from G-^, and run again for ten or fifteen minutes. Empty while running slowly, and when the benzine is almost entirely rim out, transfer to the high speed and run as an extractor for three or four minutes. (This rinsing process may be repeated if necessary.) 60 DYEING AND CLEANING. The benzine still remaining in the goods is now removed by passing a current of hot carbon dioxide through the machine while it is revolving slowly. The following circuit is opened for this purpose : From the machine A to the cooler J, by way of the filter (shown in fig. 26), which removes fluff and dust. From the cooler J by way of the vessel M (which is fitted with DRY CLEANING. 61 a gauge-glass) where the condensed benzine collects. From the vessel M by way of the pump D to the heater K and thence to the machine A. Steam is admitted into the steam jacket of the outer casing of A, so as to heat the machines up slowly to 60°-100°C., according Fig. 26. — Barbe Cleaning Machine. to the nature of the articles. The pump is started and causes the carbon dioxide in the circuit to pass through the heater K to the machine A ; it then passes with the vaporised benzine through the filter E to the cooler J, where the mixed gases are cooled, the benzine being condensed and collected in the receptacle M. To make sure of the proper operation of the plant, the liquid must be seen to circulate through the inspection glass m fitted 62 DYEING AND CLEANING. at the inlet to M. The cooled carbon dioxide now passes through the pump and heater back to the machine A, and the circulation is allowed to continue until observation at the glass m shows that evaporation is completed. The goods are now ready for removal. To do this the pump is stopped and all cocks in the circulating system are closed and the rotation of the washing machine is stopped. The machine A is connected with the suction pump and the gas-holder, and is exhausted to the extent of 25 to 30 cm. (reduced to about 8 lbs.), T Fig. 27. — Barbe Machines — showing Spirit Tanks. the carbon dioxide being returned to the holder. The pump is now stopped, all cocks are closed, and the small cock fitted on the door is opened, admitting air until the gauge returns to zero. The outer door is now opened, and, after brushing away any fluff, the inner cage is opened and the goods are removed. From six to ten loads of work can be cleaned in each machine daily. The spirit tanks G2, G3 and are connected with the still where the dirty benzine is purified ; the condensed fluid, after passing through a receiver N, running into the tank 0, whence it is lifted by pressure to the clean spirit tank G^ . Figs. 26 and 27 show the general arrangement, the former DRY CLEANING. 63 being installed for the tirm of Nannucci in Florence and the latter for the firm of Plat in Buenos Ayres. The advantages claimed by the makers may be summed up as follows : — 1. The risk of fire is eliminated. 2. The annual losses of solvent are reduced by 80 per cent. 3. The cost of labour is reduced by 60 per cent. 4. Elimination of drying-rooms and delivery of the goods two hours after their receipt. 5. The articles retain no odour. 6. More volatile solvents can be employed, which clean more .effectively. 7. The operators work under better conditions, owing to the absence of benzine vapour. The makers claim a reduction of 80 per cent, of the annual loss of solvent when benzine is employed, as a small portion of the light boiling fractions cannot be condensed and a very small amount of the high boiling fractions may remain in the goods which have been cleaned. There is also, of course, a small loss from leakage. The disadvantage of the system is undoubtedly the heavy initial outlay compared with the cost of the ordinary benzine cleaning plant and the relatively small number of loads which can be treated daily, but the advantages accruing from the greatly reduced risk of fire and the great saving of solvent are worthy of very serious consideration (see p. 74, re distillation in connec- tion with Barbe system). Scott System, — Another process of dry cleaning which operates in a closed circuit is that recently patented by G. Scott & Son, Ltd. In this process the articles, which are of such shape or construction that they cannot go into a rotary machine, are suspended from rods mounted on a trolley. It is claimed that articles of dress, etc., may be cleaned in the same way. The illustrations figs. 28 and 29 show a four-chamber installation capable of a large output. The chambers are provided with special carriages on which the goods are arranged after being dealt with on the slab. They are then run into the empty chamber, which is provided with rails for that purpose, and the counter-balanced door swings into place and is made fast and air-tight by swing bolts. Benzine is now run into the chamber through one or more automatic spreaders which receive a rotary motion from the egress of the spirit, thus equally distributing it over the whole of the interior and its contents. On falling to the bottom of the DYEING AND CLEANING. 66 DYEING AND CLEANING. chamber, which is provided with a steam-heating coil, the benzine is heated up previous to passing to the benzine pump, which forces it again (quite hot in most cases) over the goods. It is claimed that the hot spirit and vapour play an important part in the cleaning. A connection is provided in the chamber to a pair of patent condensers, so that loss of benzine in this way is prevented. The benzine employed is changed several times during the operation, and is used progressively in the earlier changes of a subsequent batch. When completely soiled the benzine is dis- tilled in the ordinary way. The goods in the chamber, now degreased but saturated with benzine, are subjected to the drying operation. All the benzine is first pumped out of the chamber, and the air-duct valves are opened up on top and below the chamber. A circulating fan is placed in the pipes, which form a completely closed circuit, and by this means the air is passed through a double- flow water-cooled condenser. This removes the bulk of the benzine from the air, which is then passed through a heater and thence to the top of the chamber again, w^here it removes a further quantity of benzine from the goods and the circuit until the goods are free from spirit and dry. The door is then opened and the goods removed. This method of cleaning is also claimed in combination with a modified form of the ordinary rotary wash- ing machine. The author has no practical experience as to the efficacy of this plant, as it is only now being introduced, the above description being based upon particulars supplied by the patentees. In the illustrations the references are as follows : — A. Cleaning chambers E. Purifier condensers. B. Storage tank for benzine. F. Fan. C. Benzine pumps. G. Condenser. D. Purifier. H. Heater. The advantages claimed for this process are : (1) The use of hot benzine and its greater cleaning power ; (2) the completely enclosed process with practically complete recovery of benzine ; (3) no intermediate handling with hydro- extractors ; (4) no dry- ing rooms are required ; (5) risk of fire is greatly reduced. Purification and Eecovery of Benzine. — The only satisfactory manner of purifying and recovering soiled benzine is by distil- lation, but as some of the smaller firms cannot use this means, methods for purification other than by distillation will be described. The soiled benzine contains (in a state of solution) benzine soap, oils, fats, waxes, and some colouring matters, and (in a state of suspension) dirt (i.e. organic and inorganic insoluble matters) and DRY CLEANING. 67 fibrous substances, and sometimes water (in solution or partly in solution and suspension). Matters in suspension may be removed by allowing the spirit to stand and drawing off the dirt from the bottom or syphoning off the supernatant liquid, followed by pass- ing the spirit through a vessel containing dry common salt, which removes any moisture. The settlement of the insoluble matters Fig. 30. — Benzine Purification by Settlement. is facilitated by slightly warming the spirit, when the Gorrie apparatus shown in fig. 30 may be employed. The dirty spirit is pumped or run by gravity into either of the heaters A A and warmed to about 87° F. by steam coil. After settlement, the cocks B B are opened and the very dirty liquor at the bottom is ran off into another receptacle. The cocks are closed, and cocks C C are opened and the liquor is run through the 68 DYEING AND CLEANING. cooling worm and thence through the salt tanks E E to absorb any moisture from the spirit. The disadvantage of this process is that it does not remove the dissolved grease, etc., which in- creases each time the spirit is employed. A method which removes the soluble and insoluble impurities (except such soluble matters as cannot be saponified, e.g. paraffin wax) depends upon the de- composition of the benzine soap with sulphuric acid, followed by saponification of the dissolved fats with caustic soda. To purify soiled benzine in this way an earthenware jar must be employed. To 10 gallons add | lb. of concentrated sulphuric acid (about three-eighths of a pint), stir thoroughly and allow to settle all night ; the top liquid will now be comparatively free from dirt and will contain the fatty acids, etc. Remove by syphon and add 1| lbs. of caustic soda solution 70° Tw. (about a pint), and stir well from time to time. Then allow to stand for some hours and syphon off the clear liquid, which will be ready for use. This method will be found quite satisfactory for small users where steam for a still is not obtainable, but where any quantity of spirit is employed the only satisfactory method of purification is by distillation. Two methods for purification by distillation are employed, viz. distilling at normal pressure and at reduced pressure. The former method is usually employed in the smaller works, owing to the increased capital outlay necess-^ry for a vacuum distillation plant. The spirit usually employed (see pp. 24-31) boils over a range of from 80° C. to 150° C. and even higher, and as the temperature of steam at the pressure employed is very seldom higher, and is generally lower than 150° C, it is obvious that the heating of the spirit by coils will result in the higher boiling fractions remaining undistilled ; the boiling point is also raised by the matters in solution. It is therefore necessary to take advantage of the fact that live steam blown through benzine will vaporise and carry over with it spirit which has a boiling-point higher than the temperature of the steam employed. (Liquids boiling at a much higher temperature than benzine may be distilled in a current of steam in the same way; e.g. aniline BP 182" C, quinoline BP 239° C, etc.). This action depends on the fact that in distilling a mixture of two (or more) liquids boiling at diff*erent temperatures — e.g. liquid A with a boiling-point of 60° C. and B with a boiling- point 150° C. — all the fractions between 60° and 150° will contain both liquids, the lower fractions containing principally A and the higher fractions principally B. In this case the vapour of A boiling at 60° C. has been able to carry over a certain amount of B at temperatures much below the boiling-point of the latter. The larger the proportion of high boiling fractions contained in the benzine the greater will be the amount of steam necessary to DllY CLEANING. 69 distil it ; involving, of course, increased cost and an increased proportion of water in the mixed distillate. The essential portions of a distilling plant (fig. 31) are : Still (with steam coil and "live" steam supply). Condenser. Separator. The still consists of an iron (or copper) vessel varying in capacity from 20 gallons upwards, the size depending upon the volume of spirit requiring distillation. It is fitted with a steam coil for closed steam, and a pipe or perforated coil for live steam, a gauge glass to indicate the amount of liquid in the still, an inlet Fig. 31.— Distilling Plant. for the dirty spirit, an outlet at the bottom for the undistilled residue, and at the top a swanneck leading to the condenser. The condenser consists of a copper coil in a cylindrical vessel through which water passes, the water entering at the bottom of the vessel and leaving near the top. The amount of cooling surface in the copper coil depends, of course, upon the capacity of the still. The separator serves to separate the mixed distillate of water and spirit, and the method of employment is shown in the sectional drawing fig. 32. The capacity of the separator depends upon the size of the still, but for 100 gallons it should hold about five gallons and so on in proportion (the larger the separator in proportion to the work it 70 DYEING AND CLEANING. has to do, the more effective the separation of the benzine and water). The benzine and water not being miscible, the two liquids entering the separator form in two layers, the water with its higher specific gravity (1-0) being at the bottom, the benzine floating on the top. Coming out of the bottom of the cylinder is a U-tube B which acts as the outlet for the water ; the benzine outlet A is slightly higher than the point at which the water overflows. If we now take the height of B as 10 inches and the height of A as 12 inches, it will be seen that a column of water 10 inches high can support a column of water and benzine {i.e, the Fig. 32.— Sectional View of Separator. liquids in the cylinder) 1 2 inches high when the proportions are as follows : — Benzine ('780 sp. gr.) Water, 3 inches. Benzine, 9 inches. Benzine ('750 sp. gr.) Water, 4 inches. Benzine,. 8 inches. Varying proportions of benzine and water in the distillate cannot affect the proportions in the separator, which depend solely upon the difference in height between the water overflow and the benzine overflow and the specific gravity of the benzine employed. In practice it is found advisable to have one or more gauze partitions in the separator, so that the distillate entering it may not stir up the liquid which is separating. The soiled spirit having been agitated is run into the still, the distillation is carried as far as possible with closed steam, after DRY CLEANING. 71 which the live steam is blown through the spirit until the gauge glass indicates that no spirit is floating on the surface of the water which has condensed in the still, and a sample of the distillate collected in a glass test-tube shows no indication of benzine. The spirit leaving the separator still contains a small quantity of dissolved water and some in a finely divided state in suspension, which may be removed by passing the spirit through a receptable containing dry salt before running it into the clean spirit storage tanks, or by standing in settling tanks for several hours. The salt must, of course, be changed periodically (it can be employed again after drying). The water from the separator and the undistilled residue must not be run down the drain direct, as they may contain small quantities of benzine, but into a receptacle whence the semi-solid grease and dirt can be removed and disposed of, and the dirty water remaining may, after ex- amination, be pumped into the drain, using a steam ejector for the purpose. That benzene is soluble in water to an appreciable extent is shown by E. Mtiller {Journal fur Gasheleuchtung^ 41 [27], 433- 435). The quantity dissolved depends upon the temperature of the water, and, in scrubbing a mixture of air and benzene vapour, upon their relative proportions. With the temperature of the water at 16° C. the benzene dissolved ^amounts to 0*145 gram per 100 c.c. of water, and at 10° C. to 0*190 gram per 100 c.c. of water. Vacuum Distillation. — In distilling under reduced pressure the boiling-point of the liquid is lowered by lessening the atmospheric pressure on the liquid with a vacuum pump, thereby rendering it possible to distil the soiled spirit without the employment of live steam. The form of apparatus usually employed is that of Messrs G. Scott & Son, Ltd., shown in fig. 33, and the plants in operation vary in capacity from 25 gallons per hour to 1500 gallons per hour. The cylindrical vessel on the right hand side of the illustration is the still, the heating surface being composed of a number of vertical tubes of different diameters so disposed that an extremely vigorous circulation is obtained, thus presenting a continually changed body of spirit to the heating surface. The vapour is conducted through a special heater-condenser (the horizontal cylindrical vessel at the top of the illustration). This is cooled by the in-going dirty spirit, thus performing part of the condensation, while at the same time the in-going spirit is heated up practically to the same temperature as the contents of the still. This is, of course, accomplished by the out-going vapour, and therefore efl'ects a double economy. Fig. 33. — "Scott" Vacuum Distilling Plant DRY CLEANING. 73 The vapours are then directed through a tubular condenser which is arranged so that the condensed spirit in the Hquid form is directed over that part of the surface cooled by the coldest in-going water. The cooled condensed spirit is then delivered into a receiver. This receiver is connected with a vacuum pump by a vapour pipe through which the vacuum on the whole apparatus is produced. The vacuum pump supplied is usually steam driven, and is of the displacement type, the piston working under a column of water. Another pump is provided for removing the benzine from the receiver ; this is generally arranged to be driven by a side crank from the main crank-shaft of the engine of the vacuum pump. The advantages claimed by the makers for this apparatus are : — 1 . Great economy in space, time, labour, steam, water, spirit. 2. No loss of product. 3. Safety from fire. Whole operation entirely enclosed ; lower boiling-point ; cooler distillate. 4. Only exhaust steam necessary (except with high - boiling benzines). 5. No open steam used. 6. Superior distillate — bright, white, and dry. They give as the mean figures taken on several trials of one hour's duration the following : — Solvent naphtha distilled . Natural boiling-point Specific gravity . Steam used Condensing water used Temperature of condensing water In, 52° F. ; out, 184° F. Temperature of distilled spirit . 54° F. The hot water from the condenser can, of course, be employed in the dyehouse or in any operations where a regular supply of heated water is required. The process is a continuous one, the benzine being fed in by a regulating feed valve, so that the feed just compensates for the distillation. In recovering benzine by either method of distillation a certain amount of ammonia comes over with the distillate, being produced in distillation by the decomposition of ammonium salts and albuminoid matters extracted from the clothes, etc. Where live steam at normal pressure is employed in distilling, this is largely washed out of the spirit in the separator, owing to its great 400 gallons per hour. 230° F. 0-860. 420 lbs. 270 gallons. 74 DYEING AND CLEANING. solubility in water. In distilling under reduced pressure a considerable proportion of the ammonia remains dissolved in the condensed spirit. It is not particularly objectionable when the spirit is employed in the ordinary type of cleaning machine^ as, owing to its volatility, it readily escapes. When, how^ever, the cleaning operations are carried on in a closed circuit, as in the Barbe process, and the distillation is carried on under a vacuum, the ammonia cannot escape, and increases slightly with each batch of articles cleaned with the spirit. The quantity of ammonia then present (especially when heated) may attack the copper in the fittings of the machine or the colours in fabrics when the latter are such as are readily affected by alkalies. It will be found that the ammonia can be neutralised by the addition of a small quantity of oleic acid to the benzine, ammonium oleate being formed (see p. 51). Stain Removal, or " Spotting." Articles which have been dry-cleaned according to any of the methods described are frequently found to have retained stains which have not been affected (or only partially affected) by the benzine, and in addition to stains, a certain amount of ingrained road dirt may be found round the bottoms of skirts, skirt linings, petticoats, etc. Among the stains which are frequently met with, the following may be specified : — Paint, tar, wax, resin, pitch, and varnish stains. Milk, water, white wine, scent, and other colourless liquid stains. Stains from coloured food stuffs, as fruit, wine, beer, tea, coffee, etc. Ink stains from marking, writing or copying inks. Dyestuff stains (frequently colours which have "marked off" or "run," from other garments). Blood stains. Perspiration. Iron-mould. Mildew. Grass stains. Articles are frequently found which have been stained with mud or with water to such an extent that local treatment is of little value. If there is any prospect of a satisfactory result being obtained, mud-stained articles are brushed on the slab with a strong (10 per cent.) solution of benzine soap, with or without the addition of methylated spirit (which is miscible with a strong DRY CLEANING. 75 solution of benzine soap in benzine), and with or without the further addition of ammonia, subsequently rinsing in clear benzine. With coloured goods care must be exercised in em- ploying methylated spirit or ammonia, particularly the latter, as many colours are wholly or partially decolorised by it. A small portion of the article should first be tested, especially if basic violets or green colouring matters appear to have been employed. It is therefore important to note that the following colours are wholly or partially decolorised by aqueous ammonia (25 per cent. NHg) [Cain and Thorpe] ; the fabric employed in the test is indicated in brackets Patent Blue V (silk). Red Violet, 4 RS and 5 RS (wool). Acid Violet, 2 B (wool). Acid Violet 4 BN (wool) ; colour returns in air. Alkali Violet (wool). Water Blue (wool). Methyl Violet B (wool). Azo Green (with chromium-mordanted wool). Light Green, yellowish (wool). Light Green, bluish (wool). Malachite Green (wool). Brilliant Green (wool). Neptune Green S.G. (wool). Acid Magenta (wool). Magenta (wool and cotton). New Magenta (wool and cotton). If brushing in the manner described does not produce a satis- factory result, nothing further can be done with fabrics which cannot possibly be treated with water ; but with plain dyed or printed muslins, and soft silks, delaines, serges, etc., the articles are subjected to water brushing." All the grease having been removed by the benzine, the cold water readily penetrates the fibres, rendering the use of soap unnecessary. With coloured articles it is advisable to add a small quantity of acetic acid to the water. When ladies' skirts are mud-stained it is frequently only the loose slip lining which is stained ; in such cases the outer skirt can be sheeted-up in a clean dry cloth, and only the lining requires brushing. The articles to be water brushed must be done as quickly as possible — that is, brushed, rinsed, sheeted up, hydro-extracted, and dried without delay. In this way many articles which could not possibly be wet-cleaned with ordinary soap, and which are but slightly improved by dry cleaning, yield very good results. We now come to the removal of stains or spotting, and in this connection it is of interest to note that the art of spotting is DKY CLEANING. 77 of considerable antiquity, a book on this subject having been pubHshed as early as 1583, being entitled A Profitable Boke Declaring Dyiiers Approoued Remedies to take out Spottes and Staines in SilJces, Veluets, Linnen, and Woollen Clothes . . . taken out of Dvtch and Englished by L. M. [Leonard Mascall]. Spotting should be done in a well-lighted room, and the reagents employed may be applied by a glass wash bottle (similar to those shown in the illustration of Gorrie's spotting table, fig. 34), or may be applied with a small glass pipette or a piece of glass rod. It is sometimes necessary to heat a small portion of fabric under treatment ; this is best done with a small steam jet with a vulcanite or other non-conducting holder, fitted to a flexible metallic steam pipe. The agents employed in spotting must be very carefully selected, as they must not affect the colour or colours of the fabrics ; the fibres must not be injured in strength or appearance ; and no sweal mark or stain must remain after the original stain has been removed. Whenever possible, organic solvents must be employed, as they are less liable to affect the colours, and they have no deleterious effect upon the fibres. In employing inorganic liquids or solutions it must be borne in mind that acids have an injurious action upon vegetable fibres and alkalies upon animal fibres ; whereas vegetable fibres w^ill withstand the action of alkalies, and animal fibres will withstand acids. The principal organic solvents employed in spotting are — Acetone. Benzol. Alcohol (methylated spirit). Carbon tetrachloride Amyl acetate. Chloroform. Amyl alcohol. Ether. Aniline. Turpentine. Benzine. These liquids are employed alone or in combination. Of inorganic substances (in fact, of all spotting agents) the most useful is water — hot or cold. A very large number of stains can be removed by its use — e.g. blood-stains, food-stains, etc. The stained place is laid upon a clean cloth or, if possible, is stretched upon two closely fitting concentric rings (such as are employed in darning by machine, etc.). The stained place is carefully sponged with cold or warm water, care being taken to avoid the use of more water than is absolutely necessary ; after the removal of the stain the place is rubbed as dry as possible with a dry cloth to avoid the production of sw^eal mark in dyeing. With silk fabrics a small quantity of acetic acid is used in the water ; this preserves the scroop and lustre of the fabric. The other substances 78 DYEING AND CLEANING. employed in spotting will be referred to in the following summary of the methods employed for removing the various stains which are encountered. Grease, Oil, and Wax Stains. — These are generally removed during dry cleaning, unless the wax is present in any quantity, or the oil is one that has been rendered insoluble by oxidation {e.g. linseed oil). Wax may be removed by scraping carefully, after- wards employing benzol. Oils rendered insoluble in benzine by oxidation must be dealt with in the same way as paints. After the removal of oil stains it is frequently found that an iron stain remains. This is dealt with in the manner described under " Iron Mould.'' Faint, Enamel, and Varnish Stains, — The removal of these stains, which frequently contain oxidised oils, depends to a large extent upon the age of the stains. Fresh stains may be some- times removed by benzine or benzol, or by the application of turpentine. The latter should, however, be avoided, if possible, as the odour imparted to the garments is sometimes difficult to remove. If benzine or benzol will not remove paint stains the following solvents may be employed, viz. chloroform, carbon tetra- chloride, ether, acetone, aniline, or nitrobenzine. Of these ether is the most satisfactory, particularly with old stains, but should not be employed unless the other solvents fail, owing to its low boiling-point and the consequent loss by evaporation. Acetone is not so volatile as ether, and generally softens old paint stains satisfactorily. The solvent which gives the most satisfactory results in practice is aniline, as it is not so mobile as ether and acetone, and with its high boiling-point does not evaporate quickly. Enamels frequently contain nitrocellulose, and are readily removed with a mixture of acetone and amyl acetate in equal parts or by acetone alone. This method is better than the employment of a mixture of ether and methylated spirit, which will not dissolve all nitrocelluloses. Resin varnish and resin stains in general may be removed with aniline. Shellac varnish stains (and sealing wax) may be removed with methylated spirit in which the shellac is readily soluble. Tar and Pitch. — If these stains have not been removed by benzine they should be treated with benzol. For pitch stains the most satisfactory solvent is aniline. Failing these reagents the stains may be removed by the use of ether. - Blood. — The stains are generally removed with water; with white linen and cotton goods this treatment can be followed by treatment with sodium hypochlorite solution ; wool and silk goods may be treated with a solution of neutral soap in methylated spirit. DRY CLEANING. 79 Fruit, Tea, Coffee, Wine and Beer. — These must first be sponged with warm water, followed in linen or cotton goods by treatment with a solution of sodium hypochlorite. White wool or silk goods are treated with a solution of potassium permanganate ; this oxi- dises the colouring matter and leaves a brown stain of manganese dioxide, which, after sponging with water, is remoA^ed by treatment with a solution of sulphurous acid. Coloured goods must be carefully tested by taking a few threads from a seam or other portion which does not show, and if the colours are fast to dilute sulphurous acid, the stained portions may be treated with that reagent ; in the same way hydrogen peroxide may be employed, after first testing the colours for fastness to oxidation. If neither of these methods can be employed, sponging with warm water alone or with the addition of soap, and treatment with a solu- tion of soap in methylated spirit, are the only safe processes to adopt. Iron Stains. — These stains may be removed from white cotton and linen goods by spotting with titanous chloride, with or without the addition of a small quantity of hydrochloric acid. The titanous chloride must then be thoroughly rinsed out of the fabric. Iron stains can also be removed from linen and cotton goods with oxalic acid, but the method described will be found more ex- peditious. With woollen and silk fabrics oxalic acid may be employed, the stains being spotted with a strong aqueous solution ; or the spot may be moistened with warm water and a mixture of equal parts of powdered citric acid and cream of tartar rubbed into it. After the removal of the stain the place is well rinsed. White wool or silk fabrics may be treated with a warm dilute solution of hydrochloric acid to soften the stain before treating as above. Inh Stains; Marking Ink. — These inks may be divided into two classes, viz. silver inks and aniline black inks. The former may be removed by treating with a solution of potassium cyanide (poisonous) ; the latter is usually regarded as very difficult to remove without the destruction of the fabric ; it may, however, be removed with perfect safety by means of aniline, or with a solution of benzine soap in chloroform. The former process yields the most satisfactory results, the marks being spotted with the cold liquid until removed, or with stains of considerable age the aniline may be made lukewarm. Copying Inks. — Violet and other copying inks generally consist of a solution of glue, glycerine (or other hygroscopic substance) and a basic colouring matter. They can generally be removed or decolorised by treating with a mixture of methylated spirit and ammonia '880 (5 : 1) on silk goods; and on white cotton and 80 DYEING AND CLEANING. linen goods with a dilute solution of caustic soda or a 25 per cent, aqueous solution of ammonia. Writing Inks. — These are generally made from iron and sub- stances containing gallic and tannic acids. They can be removed from silk and woollen goods by treatment with warm dilute sulphuric acid or oxalic acid. The same method may be employed for cotton and linen goods, but greater care must be exercised, owing to the destructive action of sulphuric acid on cellulose ; for this reason it is better to spot the stains with strong acetic or formic acid, and allow the goods to lie for some time. This will frequently soften the stain and enable it to be removed without unduly long treatment with mineral acids. Grass Stains. — These are removed by ether, in which the colouring matter of grass — chlorophyll — is soluble. Colour Stains, — With white cotton and linen fabrics employ titanous chloride. For white woollen and silk articles the best results are obtained with one of the stable hydrosulphites (Hyral- dite, Decroline, Rongalite, etc.), with the addition of acetic acid and warming by means of a steam jet, etc. If the stains are from basic colours a mixture of four parts of methylated spirit and one part of ammonia ('880) may be employed (see p. 75 for list of colours decolorised by ammonia). In removing colour stains from coloured goods great care must be exercised, as the colours of the fabric may be more susceptible than the stain to the agents employed. It is generally possible to determine by experience the dyes which are likely to have been employed by the style of fabric, etc., but in case of doubt a few threads can be unravelled from a seam and tested with the reagent to be employed. Colour stains in coloured linen and cotton goods may be removed by immersion for a few minutes in a 10 per cent, solution of titanous chloride. General Notes. — Articles from which stains have been removed by organic solvents can be dried off at once ; but if there is a possibility of a sweal mark remaining, the goods can be rinsed through benzine in all cases where the spotting agent is soluble in benzine. Care must be exercised in using very mobile solvents such as ether, as they will very readily spread over a considerable area of the fabric, carrying with them in solution some of the substance which is to be removed, making the small stain into a very much larger one. After treatment with solvents the fabric should be carefully rubbed with a dry cloth to avoid the produc- tion of a well-defined edge to the area which has been treated. It must be made to merge gradually into the surrounding fabric so as to be imperceptible, or practically so. Where mineral acids have been employed on cotton or linen DRY CLEANING. 81 goods, or on fabrics containing these fibres, the place must be sponged with a weak solution of sodium acetate, which produces the sodium salt of the mineral acid and liberates acetic acid, which is quite harmless. This treatment is safer than merely sponging with water, which does not always remove all traces of sulphuric acid. All inorganic spotting agents employed in stain removal must be thoroughly removed by sponging with water, and in all cases (as with organic solvents) care must be taken to prevent a sweal-mark being left on the fabric. After the removal of a stain it is sometimes found that the colour of the fabric has been discharged or reduced, or in many cases the stained place is found on examination to be a spot where scent or other colourless liquid has discharged the colour of the fabric. In such cases the colour may sometimes be revived by sponging with acetic acid. If this has no effect the dried fabric may be carefully touched up with a solution of a suitable solution of colour in benzine (see *'Dry Dyeing"). As a convenient form for reference the methods which have been indicated are given in tabulated form {see pp. 82, 83). Regulations and Fire Precautions. Petroleum benzine and benzol being highly inflammable, their transport, storage and use are regulated under the Petroleum Acts (1871 to 1881) by the various authorities in which their administration is vested. The following abstracts from the Petroleum Act 1871 indicate the points which affect dry cleaners : — 1. This Act may be cited as " The Petroleum Act 1871." 3. For the purposes of this Act the term " petroleum " includes any rock oil, Rangoon oil, Burmah oil, oil made from petroleum, coal, schist, shale, peat, or other bituminous substance, and any products of petroleum, or any of the above-mentioned oils; and the term "petroleum to which this Act applies" means such of the petroleum so defined as, when tested in manner set forth in Schedule I of this Act, gives off an inflammable vapour at a temperature of less than 73° of Fahrenheit's thermometer. 7. Save as hereinafter mentioned, after the passing of this Act, petroleum to which this Act applies shall not be kept, except in pursuance of a licence given by such local authority as is in this Act mentioned. (Remai'hs. — The exemptions relate to the storage for use or for sale of small quantities of petroleum, not exceeding three gallons, under certain conditions, and to the storage of 6 82 DYEING AND CLEANING. Nature of Stain. Silk Goods. Woollen Goods. Cotton and Linen Goods. Grease, oil, wax. Benzine, benzol (see also Paints and Iron mould). As silk goods. As silk goods. Paint. Ether, aniline, acetone, nitrobenzene, chloro- form, carbon tetra- chloride. As silk goods. As silk goods. Enamel. As paint, or with a mix- ture of acetone and amyl acetate. As silk goods. As silk goods. Varnish (oil). (resin). (shellac). As paint. Aniline, or methylated spirit, or carbon tetra- chloride and a little methylated spirit. Methylated spirit alone, or with carbon tetra- chloride. As silk goods. As silk goods. Sealing wax. Methylated spirit. As silk goods. As silk goods. Tar and pitch. Benzine, benzol, aniline, or ether. As silk goods. As silk goods. Blood. Water, followed by solu- tion of neutral soap in methylated spirit. As silk goods. Water, followed by sodium hypochlorite. Sugar, glue, etc. Water. As silk goods. As silk goods. White Silk. White Goods. Fruit, tea, coffee, wine, beer. Water, followed by potass- ium permanganate and removal of the brown stain produced with sulphurous acid. Coloured Silk. Water, followed by sul- phurous acid or hy- drogen peroxide if the colours are fast to these reagents ; other- wise methylated spirit and soap. As silk goods. Water, followed by sodium hypochlorite. Coloured Goods. Aqueous soap solution and ammonia. DRY CLEANING. 83 Nature of Stain. Silk Goods. Woollen Goods. Cotton and Linen Goods. Iron mould. Aqueous solution of oxalic acid. Cream of tartar and citric acid. As silk goods. Titanous chlor- ide, with or without hy- drochloric acid. Oxalic acid. Ink stains. (1) Marking ink (silver). Marking ink (aniline black). (2) Copying pad inks. (3) Writing inks. Solution of potassium cyanide. Aniline ; or a solution of benzine soap in chloroform. Methylated spirit and ammonia. Dilute mineral acids or oxalic acid. As silk goods. As silk goods. As silk goods. As silk goods. As silk goods. As silk goods. As silk goods, or, on white goods, dilute caustic soda. Acetic or for- mic acid, fol- lowed by di- lute mineral acids or ox- alic acid. Grass stains. Ether, or soap in methyl- ated spirit. As silk goods. As silk goods. Colour stains (substantive and basic). White Goods. Decroline (or other stable hydrosulphite), and acetic acid, or methylated spirit and ammonia, or hydrogen peroxide. Coloured Goods, As above, if colours are not affected thereby. As silk goods. White Goods. Titanous chlor- ide (warm). Coloured Goods. Titanous chlor- ide (cold and dilute). Scorch stains. Potassium permangan- ate followed by sul- phurous acid, or hydrogen peroxide. Hydrogen per- oxide. Hydrogen per- oxide or sodium hypo- chlorite. 84 DYEING AND CLEANING. petroleum for motor cars in conformity with the Regulations in Appendix IX.) 8. Remarks. — This section defines the local authority referred to in section 7, and may be summarised as follows : — In the city of London . In the county of London In any harbour In any borough in England or Ireland Scotland. — In any borough In any place not a borough or part of a borough In any other place in England in Scotland in Ireland The Corporation. The London County Council. The Harbour Authority. The Corporation. The Town Council. The Police Commissioners or Trustees. The District Council. Two or more Justices of the Peace for the county. The Justices in Petty Sessions, 9. Remarks, — This section relates to the conditions which may be attached to licences (a copy of the form of licence of the London County Council is given on p. 92). 10. Remarks. — This section relates to appeals in the event of a local authority refusing a licence. 13. Remarks. — This section relates to the right of entry of an officer appointed by the local authority. He can only claim a right of entry into factories where he believes petroleum is kept under warrant unless the premises are licensed and there is a term in the licence requiring the occupier to allow him free access. 15. Remarks. — This section relates to proceedings for offences and penalties. The Petroleum Act 1879 relates to the mode of testing petroleum so as to ascertain the temperature at which it will give off an inflammable vapour, and the Petroleum (Hawkers) Act 1881 regulates " the hawking of petroleum and other substances of a like nature." These Acts are always quoted as "The Petroleum Acts 1871 to 1881." In 1896 a Departmental Committee (of the Home Office) on Certain Dangerous Trades issued an interim report [C — 8149], 1896, of which the following sections relate to dry cleaning. DRY CLEANING. 85 Interim Report of the Departmental Committee on Certain Dangerous Trades. [Copy.] [C— 8149] 1896 Dry Cleaning. 70. The process of "dry cleaning," sometimes called "French'' or " chemical " cleaning, originated in France, where it is known as " Nettoyage-a-sec." As carried on upon a small scale in many works in London and elsewhere, this is an extremely simple process. The gloves or garments are scrubbed with a small brush, soap, and benzine ; they are then rinsed in benzine, and " made up." The Committee are informed that this has been carried on in kitchens and small rooms where cooking was going on at the same time, and in rooms above the ground floor, from which escape in case of fire would be sometimes impossible. When done on a large scale it becomes an elaborate business, involving the use of much and carefully devised machinery, employing large numbers of workpeople, and necessitating most careful precautions. The Process. 71. Two forms of benzine are used in the dry-cleaning process ; one is the spirit of petroleum or manufactured mineral oil, and the other the spirit distilled from coal tar. 72. When the goods arrive at the works all the pockets and linings are searched for matches or for any article which might produce a fire. They are then sorted, as different fabrics have to undergo different processes. Some with ink, coffee, or other stains go to their separate department, while others, costly and valuable goods, or those with tinsel trimming, are treated with special care. When the sorting process is finished, the goods, with the spirit, are placed in a machine which either revolves on a horizontal axis, or which itself remains stationary while cylinders inside it revolve. The latter is the commoner form of machine ; it is covered over with a lid which, in the best factories, is not fastened down. The lid should be provided with a counter weight by which it is easily opened and shut. From these machines the garments, tablecloths, curtains, etc., go to the hydro-extractor, which is a simple centrifugal machine revolving on a vertical axis ; there the surplus spirit is removed and run off by a pipe to settlers, where the dirt is allowed to fall to the bottom. The spirit is decanted off, either by a syphon or some other means, and is redistilled. The goods from the hydro-extractor are rinsed 86 DYEING AND CLEANING. in clean spirit, put through the hydro-extractor again, dried, finished and sent out. In describing a process such as this, one is met by the difficulty that no two firms employ exactly the same means to perform practically the same work. And even in the same works the operations vary with the nature and the texture of the articles to be cleaned. For example, some forms of goods are not allowed to go into a machine at all ; some articles have lo be treated with one spirit, some with the other. The Dangers of Working. 73. As in the case of inflammable paints the risks encountered by the operatives in this trade are: (1) The danger of fire; (2) the injurious effects of inhaling volatile spirit. 1 . The Danger of Fire. 74. All naphtha and spirit stores in Great Britain are under the permissive control of the local authority. The Committee have found them in London to be carefully and efficiently controlled and protected. In the provinces, generally speaking, this control and protection were absent. 75. It is not an uncommon thing in dry-cleaning factories for small fires to take place. They are in most instances extinguished in a few minutes. In spite of all precautions which can be, and usually are, taken, in the larger and more carefully conducted factories — among others, searching the workpeople's pockets — small fires seem to be inevitable. Sometimes they result from carelessness ; a match is left in the pocket or lining of a garment, or is dropped on the floor by a worker emptying his own or somebody else's pockets. But they also not infrequently originate from an electric spark, generated by the friction of rinsing or rubbing a silk fabric on a close, thundery day. The spontaneous combustion of benzine may be avoided by the addition of a small quantity of oil soap. 76. Having regard to these circumstances it seems most necessary that every precaution which reason and experience can suggest sliould be adopted by dry cleaners. As has been indicated, the best firms come up to a very high standard in the manner in which the health and lives of their workpeople are safeguarded, and, in the opinion of the Committee, there seems no reason why other less careful employers should be permitted to expose the lives of their employees to incalculable risk, and to compete unfairly with their more humane and provident neigh- bours by saving the expense involved in such precautions. DRY CLEANING. 87 77. As an example of the number of fires which occur, the owner of a dry-cleaning establishment in Liverpool informed the Committee that in fifteen years there had been eight fires. Accidents resulted in two cases ; in one case two men were burnt, in the other one man, though neither fatally. 78. To illustrate the want of system and the carelessness brought to the notice of the Committee, the following incident may not be without interest. A carpet, which was valued at a high figure, had been sent to be cleaned by the dry process, to a firm in London. It had been cleaned and rinsed, only just before closing time arrived. The foreman, knowing it to be valuable, took it home, after it had been hanging up only about half an hour at the factory. He seems to have placed it in front of the fire to dry, where his two children of eleven and six years respectively were playing. The carpet caught fire, and both the children were so severely burnt that they died in the course of twelve hours. He had only brought it home for ten minutes when it took fire. Other fatal accidents have come to the knowledge of the Committee where the work has been done in unsuitable premises. 2. The Dangers to Health, 79. Similar effects are noticeable in this trade as have been traced in indiarubber works to the inhalation of naphtha fumes, and in docks to the use of inflammable paints. The workers complain of giddiness, nausea, vomiting and headache, sometimes of tasting the spirit, and usually loss of appetite, intoxication with hysterical symptoms, sleepiness, and, in the more severe cases, of loss of consciousness. These effects are more noticeable and severe among the young workers, and in some people than others. Men who have been fifteen and twenty-four years in the trade say that they have felt no bad effects from it, and after a little questioning and examina- tion they have generally admitted either that their eyes smarted while at work, or that, in heavy weather, they experienced a certain giddiness and headache, which they have attributed to pressure of w^ork, owing to the fact that the busy season is from Ap'ril to July, when the weather is hot. In nearly every case these men, who go on working at it for years, admit that it is not a healthy trade. In one place visited by the Committee, the girls in the glove- cleaning department told them that they had to come out for fresh air "pretty often," that the spirit got into their heads and made them " act silly." One of the girls said this might occur twice a day, another three or four times a day. Only one of the 88 DYEING AND CLEANING. four girls examined at this factory suffered from headache, and, although they tasted the spirit in the morning and also in their food, they said they had good appetites. The girl who suffered from headache said the intoxicating effect was more frequent on the days when she was so suffering. She felt very tired and sleepy in the evenings. Recommendations. 80. If a machine in which a fire takes place has a carefully constructed lid, very often the force of the expanded atmosphere has pushed the lid up with sufficient violence to cause it to close down again immediately, by which means the fire is extinguished, without any of the goods in the machine being even singed. Evidence confirming this, as an actual experience, was given by several witnesses from different factories. (i.) The Committee recommend that all machines, tanks, vessels for rinsing, or hydro-extractors, should be provided with a balanced lid or cover, which should be closed, but not fastened down, during the operation of cleaning or rinsing. They should be so constructed that upon the occurrence of an explosion or fire they will, after being forced open, fall down again by their own weight. The Committee are aware that in the process of rinsing it is not often practicable to keep the vessel covered over. In such cases there should be attached to the ceiling, pillar, or beam above the rinser a cover door of iron. This should be so constructed and adjusted that in case of fire, by pulling a string or touching a catch it will instantly fall down upon the vessel, and cut off the supply of air from the burning spirit. In practice advantage has been derived from having the string or catch at some distance from the extinguishing cover. (ii.) The soiled spirit from all washing and rinsing machines and hydro-extractors should, whenever practicable, be run off to the settlers or distilling apparatus in closed pipes, (iii.) Sand should be kept in abundance close to all places in which benzine or naphtha is used. (iv.) Blankets should also be kept in readiness in case of fire. (v.) Men working in the processes in which spirit is used should wear woollen shirts and clothing. (vi.) All rooms above the ground floor in which any of the processes of dry cleaning, involving the use of spirit, are carried on, should be provided with an outside emergency staircase. DRY CLEANING. 89 vii.) All dry-cleaning factories should be provided with hydrants, hoses, and an efficient water supply, (viii.) Wherever possible, incandescent electric light should be used. Each incandescent light should be enclosed not only in the small glass globe which usually surrounds it, but also in an outer airtight envelope of glass. In cases where electric light cannot be procured, the rooms in which mineral spirit is used should be lit from the outside, the light being separated from such a room by a thick airtight partition of glass. (ix.) Ventilation and air space in these processes are of para- mount importance. In all places, rooms, or shops in which spirit is used there should be not less than 500 cubic feet of space to each worker. There should also be ventilators both near the floor and the ceiling of such rooms. (x.) All young persons and women should be examined once per month by the certifying surgeon for the district, who shall have powder to order temporary or total suspension. (xi.) A register should be kept of the date and result of his visit, and any requirement made by him. (xii.) No food should be eaten in a place or room in which benzine, naphtha, or volatile spirit has been used, or in which goods saturated with such spirit have been placed, during that day. (xiii.) Where more than twenty people are employed, the occupier should provide a dining-room for the w^orkpeople. 81. In place of the permissive powers conferred upon local authorities by the Petroleum Acts and the Explosive Substances Acts, the Committee recommend that the duties of controlling and regulating the storage and use of benzine or other mineral spirit should be made compulsory. This report has been followed in October 1906 by a memo- randum on Dry Cleaning, issued by the Chief Inspector of Factories under the Factory and Workshop Act 1901. Form 824:.— October 1906. Factory and Workshop Act 1901.— Memorandum. Dry Cleaning. In 1896 a Departmental Committee reported upon the pre- cautions necessary for the safety of persons employed in the process of dry cleaning. The recommendations of the Committee 90 DYEING AND CLEANING. have been largely adopted, with satisfactory results, but accidents of a severe and sometimes fatal character are still reported from time to time. In the light of further experience it is now possible to suggest additional measures of precaution, directed more especially against the risk of ignition by electric sparks, which is now recognised as the cause of most instances of so-called spontaneous firing of benzine. Danger of Electric Sparks, Textile fabrics (especially undyed wool and silk) and many other materials become electrified when rubbed or when moved quickly in benzine, and sparks may result causing explosion. The risk of sparking is greatly increased when the air is exceptionally dry, e.g, in frosty weather ; and if the relative humidity of the air falls much below 70 per cent, of saturation,^ moisture should be added, by steaming or otherwise. This can easily be done if steam jets are available. Benzine may be rendered less liable to ignition by electric sparks by the addition of small quantities of certain soaps or other chemicals. For example, antibenzinpyrin " or the oleate soap mentioned in the Committee's Report ; ^ the proportion to be added does not exceed 1 part in 1000 of spirit. The use of soap in benzine appears to have become general except in rinsing, and to have contributed to the immunity from fire. Exclusion of Air. All vessels (hydro-extractors, washing and rinsing machines, etc.) containing inflammable spirit should have adequate covers, and should, as far as practicable, be kept closed during use. The covers should moreover be balanced, so that if forced open by explosion they will fall back by their own weight and cut off the air supply from the burning spirit ; or in the case of rinsing vessels which cannot be kept closed during use, an iron cover should be suspended from above by a cord passing to a catch at some distance from the vessel, when in emergency it can be ^ The degree of moisture or dryness of the air can be determined readily by means of the hygrometer. There are several forms of this instrument, obtainable at small cost. The one in common use is known as the wet and dry bulb hygrometer ; instructions as to its use will be given on application to H.M. Inspectors. 2 "To prepare such a soap, dissolve 1 kilo, of caustic potash or caustic soda in 4 kilos, alcohol. To each litre of this solution add If litre oleic acid and heat the mixture. To keep the salt in solution add to every 100 parts of the mixture, either before or after heating, 250 parts carbon tetrachloride, benzol, benzine, or other suitable solvent. Any other soluble oleate may also be employed." DRY CLEANING. 91 immediately set free so that the cover will fall. Attention is also directed to the special safety appliances, such as the Nonex, which are now available for the storage of inflammable spirit. Used spirit should be conveyed in closed pipes, without ex- posure to air, to the settlers or still, which should be in a room set apart for the purpose. Artificial Lighting. Naked lights should not be used in a benzine room. Where incandescent electric light is available, the burners should be in a double airtight glass cover. Failing electric light, the room should be lit from outside, through an airtight window. Preventing Extension of Fire. Extinguishing Burning Spirit. By such means the risk of fire and explosion can be greatly lessened, but it is still necessary to make provision for minimising these effects. There should be an ample water supply, with hydrants and hose, in order to prevent the extension of flames, but water should not be used in attempts to extinguish burning spirit. For the latter purpose blankets and a supply of sand should be kept in readiness. Steam jets will be useful in the event of fire, as well as for the preventive purpose of humidifi- cation when the air is dry. Woollen Garments. All persons employed should wear woollen or other non- inflammable outer garments. Means of Escape. As a fire may cut off the ordinary exit by the door, there should be alternative means of escape by an outside staircase, if the room is not on the ground floor. All persons employed should have clear instructions what to do in case of fire. Air-space and Ventilation. Ample space and free ventilation, desirable on other grounds, also tend to lessen the risk of accidents. Effects of Breathing the Fumes. Medical Examination. Apart from the risk of fire and explosion, injury to health may result from breathing the fumes of benzine, etc., and care should be taken to make the exposure to those fumes as brief as possible. Meals should not be taken in rooms in which inflammable spirit 92 DYEING AND CLEANING. is used, and suitable accommodation should be provided else- where. It is desirable that women and young persons exposed to the fumes should be periodically examined by the Certifying Surgeon, in order that if their health is found to suffer from their occupation they may discontinue it either permanently or for such a time as he may direct. H.M. Inspectors of Factories will be glad to advise in further detail if desired. B. A. Whitelegge, Chief Inspector of Factories. Home Office, October 1906. It is necessary to comment on one or two points in this memo- randum : in the first place, the formula given for the preparation of benzine soap would produce a highly caustic soap which, if employed in strong solutions for brushing, etc., would materially affect many colours. For 1 kilo, of caustic potash from 4 to 5 kilos, of oleic acid should be employed. Referring to the addition of moisture to the atmosphere when the latter is exceptionally dry it is, of course, the object of the dry-cleaner to keep his work and spirit as free from moisture as possible, in order to produce satisfactory results. If, however, the addition of some moisture to the atmosphere is insisted upon, the standing in the room of an open vessel containing water will suffice. Regarding the conditions which may be enforced by the local authorities the copy of the form of licence employed by the London County Council may be taken as a model. London County Council. Petroleum Acts 1871 to 1881. Petroleum Licence. Pursuant to the provisions of the Petroleum Acts 1871 to 1881, the London County Council doth hereby grant Licence to A. B. for the period of one year from the to keep petroleum,, to which the Acts apply, and as defined in the said Acts, on the premises C. D, in the Metropolitan Borough of and within the County of London, subject to the conditions folio wing^ that is to say : — That the total quantity of petroleum (including substances containing petroleum) kept upon the premises hereby licensed do not at any time exceed seven thousand gallons. That such petroleum be kept only in the manner and at the places herein- DRY CLEANING. 93 after specified, viz. in strong metal tanks sunk underground and partly under- ground in the yard, and in metal tanks in brick and iron store in yard, and in stills, condenser and agitators, tanks or other vessels in dry-cleaning rooms. That such petroleum be run or pumped from one vessel to another by means of metal pipes. That the outer clothing of persons em})loyed in the cleaning rooms in which petroleum is being used be of a woollen or other non-inflammable material and without pockets, and that such persons do not wear boots or shoes with exposed iron thereon when in such rooms. That fire or such artificial light as would ignite inflammable vapour be not within or nearer than twenty feet of the openings of tlie cleaning rooms in which petroleum is being used. That explosives, matches, or other inflammable or explosive substances be not in or near any store, workroom, or other place where petroleum is kept or used. That petroleum be not kept or used in any ])art of the premises other than as specified in this Licence. That due precautions be at all times taken for the prevention of accident from fire, and that fire or such artificial light as will ignite inflammable vapour be not within or nearer than twenty feet of the openings of buildings, or places where petroleum is kept. That buildings or workrooms in which petroleum is kept or used be at all times thoroughly ventilated into the external atmosphere, and that sufficient sand to extinguish fire be kept in such buildings or workrooms. That the Licensee do take effectual precautions for preventing unauthorised persons, and all persons under the age of 15 years, from obtaining access to the place of storage, or to any })etroleum on the premises. That vessels containing petroleum be at all times securely closed except for the time absolutely necessary for the purposes of the business, and that every precaution be used for preventing the leakage of petroleum or the escape of inflammable vapour. That petroleum or any product or residue from petroleum be not allowed to enter any inlet or drain communicating with a public sewer. That the arrangements for the storage or use of petroleum as approved by the Council and as seen by the Council's Inspector last before the granting of this Licence, be in all respects kept and maintained, unless the consent of the Council is given in writing to any departure therefrom. That every authorised Ofiicer of the Council be at all times allowed free access to the premises of the Licensee, for the purpose of ascertaining if the above conditions are properly observed ; and that the Licensee do, by himself or his representatives, give any assistance for that purpose which such Officer may require, and furnish samples of substances alleged to be petroleum. By order of the Council. Spring Gardens, S.W. Clerk of the Council. Section 9 of the Petroleum Act 1871 provides that any '"Licensee violating any of the conditions of his Licence shall be deemed to be an unlicensed person." This Licence is not Transferable. The following report presented to the Sanitary and General Purposes Committee of the London County Council in 1890, on the Petroleum Acts, emphasizes the precautions which must be adopted. 94 DYEING AND CLEANING. London County Council. report as to licensed premises in the county of london upon which petroleum under the acts is used in trade or manufacture. Presented to the Sanitary and Special Purposes Committee^ l^th November 1890. Petroleum Acts. In accordance with the instructions of the Committee, at their meeting on the 31st October, that I should prepare a report submitting a list of the businesses carried on in London in which petroleum spirit is used in manufacturing processes or otherwise, I have to report as follows : — The following is a list of the businesses in which petroleum is SO used, carried on in the County of London, under the licences of the Council — Dry Cleaners (21 licensed premises). Helmet Manufacturers (5 licensed premises). Tennis Shoe Manufacturers (4 licensed premises). Indiarubber Manufacturers (12 licensed premises). Waterproof Garment Manufacturers (41 licensed premises). Glass Silverers (14 licensed premises). Paint Manufacturers (6 licensed premises). Glove Cleaners (41 licensed premises). The licences granted in respect of all these businesses have special conditions attached, with a view to safety, and in some cases these conditions appear to be fully adequate, as they probably reduce the danger in the particular processes carried on to the minimum. In some of the businesses, however, it may be desirable to make some addition to the existing precautions. Whenever mineral spirit or its inflammable vapour is liable to be present in workrooms in dangerous quantity, the following precautions should wherever possible be adopted — (a) The workroom should be a detached fireproof building on a level with the ground. (b) The workroom should be well ventilated, both at the ground and ceiling levels. (c) The workroom should be provided with doors opening outwards, in order to facilitate the escape of the work- people in case of accident. (d) The process in which mineral spirit is used should be carried on in closed vessels, and where that is not DRY CLEANING. 95 possible, the exposure of spirit should be reduced to a minimum in order to lessen the formation of in- flammable vapour. (e) Such artificial light as would ignite inflammable vapour should be wholly excluded from workrooms in which mineral spirit is used. The only artificial light allowed should be incandescent electric light, or a form of gas- light where the light is so enclosed as not to be in contact with the air of the workroom. Taking the businesses in the order in which they appear in the above list, the first to be dealt with is — 1. Dr2/ Cleaners. — In this business mineral spirit is used, generally in large quantity, in the cleaning of dress material and other substances. The spirit is kept in specially constructed stores, and the cleaning takes place in specially constructed buildings. Practically, all the conditions for safety already indicated are insisted upon by the conditions attached to licences granted to dry cleaners in London. Formerly there were numerous accidents in connection with this business, but for the past few years, since the adoption of the indicated precautions, only one fire has occurred in London ; and fortunately, on account of the isolation of the building and the precautions imposed by the licence, no fatality, or even personal injury, resulted, nor did the fire extend beyond the actual building in which it broke out. It may be mentioned, as an instance of the value of precautions in businesses of this nature, that on one of the dry cleaner's premises, before the present stringent con- ditions were insisted upon, the cleaning room was burned out five times in six years ; but that since the adoption of these precautions, some seven years since, no fire has occurred on the premises. 2. Helmet Manufacturers. — In this business a quantity of petroleum spirit, in no case exceeding 45 gallons, is used for the purpose of dissolving indiarubber, to form a solution used in cementing and waterproofing some forms of helmets. I do not consider the conditions attached to licences for premises in which this business is carried on are sufficiently stringent. Difficulty was experienced in obtaining adequate arrangements for safety, both on account of the situation and construction of many of the premises. In every case, however, the petroleum spirit is kept, and the indiarubber solution is made, in a store which is as far as possible detached from the workrooms. The solution is used for cementing and waterproofing helmets, and in the room in which this is done, as well as in the place in which the helmets 96 DYEING AND CLEANING. are afterwards dried, a considerable amount of inflammable vapour is given ofl'. This vapour is to some extent carried off by ventila- tion, but at present artificial light is used in some of the work- rooms ; and, looking to the recent fatal accident at a helmet manufacturer's in Cloth Fair, I think that such a method of lighting should no longer be permitted. No special provision is made upon any of the licensed helmet maker's premises for the escape of workpeople in case of accident, and the Committee may consider it desirable in future to licence only premises where adequate means of escape have been provided. I may, however, point out that no serious fire, or any fire involving loss of life, has occurred in recent years upon any of the licensed premises. The recent fatal fire on Messrs Rowley & Brock's premises (which are in the City, and under the jurisdiction of the Corporation of London) probably arose from the very grossest carelessness and the neglect of the most elementary precautions. An uncorked can containing a solution of naphtha and indiarubber was placed in the drying stove, and on the door of the stove being opened a volume of the vapour escaped and ignited. Although no accident can be traced to the use of naked lights in the workrooms where solution is used, it would undoubtedly reduce the danger if the Council insisted on the abolition of such lights, and the substitution of the incandescent electric light, or some perfectly safe form of gas-lighting. In every case where a drying stove by fire-heat is used, such stove should unquestionably be separated from the workrooms, and ventilated into the external air, or, in other words, it should be a distinct fire risk. 3. Tennis Shoe Makers. — In this trade an indiarubber solution is used for cementing indiarubber soles to the uppers. The danger and the conditions are very similar to those in the case of helmet makers, and whatever the Committee decide as to the one trade should apply to the other. 4. Indiarubber Manufacturers. — In this trade indiarubber in bulk is dissolved in mineral spirit and then mixed with other ingredients to form a plastic substance, which is worked up into various forms of indiarubber goods. T think the arrangements for the storage of the naphtha and for dissolving the rubber are probably adequate at all the premises under the Council's licence ; after being taken out of the vessels in which it is dissolved, the indiarubber is of the consistency of dough, and it is so termed by the trade. It subsequently passes through a variety of machines for manufacture into different articles, and during these processes some inflammable vapour is given off", but probably not in sufficient quantities to be liable to ignition. I recommend the Committee to in future attach a DRY CLEANING. 97 condition excluding fires and unsafe forms of artificial lighting, not only in the stores and mixing rooms as at present, but also in any workroom where there is a liability to the presence of inflammable vapour. 5. Waterproof Garment Makers. — This business is in some cases on a very large scale, in very large buildings, and in others on a small scale, and sometimes in dwellings. No matter how many or how few hands are at work, each of them requires a small quantity of solution and a small quantity of spirit. This is used for cementing the seams of the garments to be manufactured, and as there is but a small amount of vapour given off in the operations of each work-person, it is only where a large number of workpeople are employed in one room that there is a liability to the formation of a large amount of inflammable vapour. The two points for the consideration of the Committee appear to be — (1) Whether fires and exposed artificial light should not be prohibited in all such workrooms. (2) Whether facilities for escape, in case of accident, should not be insisted upon, wherever a considerable number of hands are employed in one building. By requiring both the solution and the naphtha to be used from suitable vessels, and by regulating the storage of the naphtha and the mixing of the solution, the Council has reduced the danger in these places ; but the other points indicated are matters for serious consideration. I may point out, however, that there might be great difficulty in the case of the smaller makers, and of the workpeople who carry on this business in their own homes, in providing a special artificial light, or special means of heating the rooms. 6. Glas8 Silverers. — In this business mineral spirit is used in the manufacture of the paint which covers the back of silvered glass. The spirit is usually kept and the paint mixed in the basement of the building in which the business is carried on, and it has been impracticable to obtain in such cases external places for the storage and the mixing. There is probably little danger in the process of applying the paint to the glass ; and the point for the consideration of the Committee appears to be whether in future the storage and mixing should be allowed in the building in which the workrooms are situated. 7. Glove Cleaning. — In this business only small quantities of mineral spirit are used, and in a large number of cases the trade is so small it can be carried on under the exemption contained in section 7 of the Petroleum Act 1871, which permits three gallons of spirit to be kept without a licence, provided it is kept in 7 98 DYEING AND CLEANING. stoppered bottles which contain not more than one pint. The practice in London is, that where only one of these bottles is open at a time, no licence is necessary, but whenever any larger quantity than one pint is opened for use at one time, a licence is requisite. Although the quantity of petroleum used in glove- cleaning is small, there is a considerable escape of inflammable vapour, and consequent danger. Upon every premises licensed by the Council glove-cleaning is required to be carried on in buildings either detached or external to the house or shop, and the presence of a fire or artificial light is forbidden. It is probably unnecessary to add to the restrictions already imposed on this business. In addition to the foregoing, there are also a few^ other busi- nesses in which petroleum spirit is used and which are under the licence of the Council, as follows : — 1 Bone Boiler. 1 Bedstead Manufacturer. 1 Photographic Chemical Manufacturer. 1 Manufacturing Chemist. 1 Brass Fitter (Asbestos packing). 1 Paraffin Scale Maker. 1 Electrician (4 licences). 1 Colour Printing Works. I believe the conditions imposed in each of the above cases are adequate for safety The only remaining trade in w^hich it is known that petroleum spirit is used is that of toy balloon maker. Two premises upon which this trade is carried on are licensed, and at each five gallons may be kept. In both cases the store is a sunk pit in the garden at rear of the dwelling, and this method is quite safe. The spirit is, however, taken, in quantities of not exceeding half a gallon, into a workroom in the upper part of the dwelling, where it is put into an open vessel, into which the indiarubber is dipped. No fire or light is allowed in this room, and the work is done with open windows, and it is probable that no further precaution can be adopted, except to require that the work be done in out- buildings only. The licensees are, however, so poor that they are unable to provide these. These premises have been under licence for some years, and the Inspector reports that he has always found the business being conducted with care. Alfred Spencer, Deputy Clerk of the Council, The London County Council have also (under their General DRY CLEANING. 99 Powers Act 1894) issued a warning concerning the discharging of petroleum or products of petroleum into the sewers : — Inflammable Liquids in Sewers and Drains. L.C.C. Warning. The London County Council has noted with great concern that on several occasions recently explosions have occurred in sewers in which men were working, as a result of which explosions many lives might have been lost. It has been proved that these ex- plosions were caused by the discharge into sewers, in contravention of the order made by the Council under section 10 of the London County Council (General Powers) Act 1894, of petroleum or of some product of, or residue from, petroleum or other liquid liable to give off inflammable vapour. Any violation of the above-mentioned order is punishable by a fine not exceeding £20, with an additional fine not exceeding £b for every day on which the offence continues. The Council fears, however, that it is not generally recognised that persons contra- vening the provisions of the Act are seriously endangering human life. In fact, in ordinary circumstances, an explosion of the kind referred to must be attended by injuries of a grave and, very possibly, fatal, character to men engaged in the sewer. They therefore have asked firms who are licensed under the Petroleum Acts to give such instructions and to make such arrangements as will prevent the escape from their premises into drains or sewers of matter or liquid of a dangerous nature. Construction of Premises. — In designing and constructing premises for dry cleaning the two important factors to be borne in mind are: (1) The materials employed must be fireproof; (2) the premises may be so arranged that if a fire occurs it is confined to the place or room in which it breaks out. The selection of materials which are fireproof is a comparatively simple matter. Confining the fire to the area in which it breaks out is facilitated by splitting the various sections up into separate units connected only by way of the open air. Where the units are connected together, all doors must be fireproof and self-closing in case of fire. As this is the usual method of constructing fireproof doors no description of them is required. Floors are usually constructed of concrete, but this material has the great disadvantage of sparking when struck with iron {e.g. nails in workers' boots, etc.) ; asphalt and wood cannot be employed, owing to the solubility of the former in benzine, and absorption of spirit by the latter. The most satisfactory floor material for dry-cleaning premises is slate, as it 100 DYEING AND CLEANING. does not spark when struck with iron, is not absorbent, and, more- over, it has excellent wearing qualities. It is, of course, a non- conductor, but if all machines, etc., are efficiently " earthed this is not a disadvantage. Whereas the walls are usually strongly built and constructed of fireproof materials, the roofs of dry-cleaning rooms are generally lightly made, so that in the event of an explosion taking place it will give way readily and without doing very much damage ; the fire can then burn itself out without spreading to adjoining buildings. If the roof is strongly constructed, it is highly probable that the walls will give way, and by the collapse of the building the fire area may be enormously increased. All rooms should be fitted with steam pipes, the valves being situated outside the benzine area, so that if a fire breaks out the unit or units affected may be flooded with steam. This displaces a considerable portion of the air, rendering the combustion of the benzine more difficult. Where the rooms are isolated the walls should be of sufficient height to prevent the flames being blown on to other buildings, and w^here the benzine section of the works adjoins other portions of the premises the party wall should be higher than either section. Glass employed in windows should be made with embedded wire, which may crack in case of fire, but will not fall to pieces so as to allow flames to pass. Where underground storage tanks are employed it is very important that they should be so placed and protected that water cannot enter them under any circumstances^ as instances have occurred where, owing to openings, water has entered tanks and pushed out the spirit with serious results. To this end, pipes communicating with such tanks should be so placed as not to be liable to damage ; the filling-hole should be kept closed with a screw-plug, and any vent-pipe should be carried to such a height that it would be impossible for water to obtain access to the tank thereby. The tanks sunk in the ground and embedded in concrete should be arranged so that they are above the general ground level, and if placed in an underground chamber, the latter must be mechanically ventilated. Artificial Light. — Only incandescent electric light should be em- ployed, the wires being laid in screwed iron barrel (efficiently "earthed" in case of a short-circuit occurring); all fuses and switches should be outside the benzine area. All lamps should be fitted with a strong glass cover (ship's pattern). When it is impossible to employ electric light the gas or other form of lamp employed must be outside the windows of the room, the windows being glazed with rolled glass with embedded wire. Ventilation. — The most effective means of preventing fire and explosion in dry-cleaning works is to have thorough ventilation DRY CLEANING. 101 whereby the vapour of the benzine is never allowed to accumulate in sufficient quantities to form an inflammable or explosive mixture with the air. In arranging for the ventilation of the rooms, the fans or outlets must be placed on the floor level, the vapour of benzine being considerably heavier than air. The duct for dis- charging the mixture of air and vapour must be above the roof level of the building. Efficient ventilation fulfils the double purpose of minimising the risk of fire and of rendering the process more healthy for the operators. Drying-room. — After thorough extraction, the goods still retain a considerable quantity of benzine. In an actual test, goods weighing 750 lbs., after hydro-extracting were found to have lost 150 lbs. of benzine during the drying process. The drying-room is heated w^th steam pipes, or by an indepen- dent heater of the Sturtevant type. In either case the ventilation must be such that the air in the room is changed so frequently that an explosive mixture of air and benzine vapour may not exist. The loss of benzine in drying being so considerable, it has been suggested that the vapour might be recovered by condensation. To this end the use of a closed stove and condenser attachment, similar to that employed by felt hat manufacturers in the recovery of methylated spirit, has been devised by Gorrie of Perth. Another arrangement which would in all probability yield satisfactory and economical results would be to employ several stoves in series, the air passing from one to another, the percent- age of benzine vapour gradually increasing. For example, we will assume an arrangement of four stoves. A, B, C, and D. A is being emptied, B has just been filled with goods, the contents of C are half-dried, and those of D are nearly ready for removal. Warm dry air will pass from a heater to D, thence to C, and finally to B, so that the air free from benzine will come in contact ^ith the goods nearly dry, and the air when most saturated will come in contact with the goods containing the greatest quantity of benzine. Thus when the contents of D are ready for removal the air in that chamber will be free from benzine. A being now charged with w^ork, and D ready for unloading, the air ducts will be so arranged that the fresh air passes to C, thence to B, and finally to A, and so on throughout the day in any desired order. By this means the cost of condensation would be materially reduced, and the greater the percentage of benzine vapour present in the air, the less will be the loss of benzine.^ Machinery and Fittings. — In all moving parts where there is a possibility of electricity being generated by friction, the machines ^ In a recent test with the condensing apparatus of the Volatile Solvents Recovery Co., Ltd., 93 per cent, of the benzine was recovered. 102 DYEING AND CLEANING. or parts in question must be efficiently earthed ; i.e. they must be connected by copper wire with a copper plate buried in the earth (in the same manner as with a lightning conductor). As most dry-cleaning rooms are fitted with concrete floors, it will be found that unless earthed through pipe fittings the machines are insulated and wdll store up any current generated until it is of sufficient potential to produce a spark when approached by a body of lower potential, e.g. an operator who may be earthed through holding on to a pipe or machine which is earthed ; the spark, of course, ignites any benzine vapour mixed with air through which it passes. Special attention must be paid to overhead hydro- extractor counter shafts, as electricity is frequently generated by the " slip " of the belt when first thrown from the loose to the fast pulley. Certain classes of silk and wool fabrics, when dry, are readily electrified by friction ; and as dry benzine is a non-conductor, the goods w^hen brought in contact with the edge of the machine in unloading may produce a spark. This risk is largely reduced by the fact that benzine may be converted into a conductor by the addition of a small quantity of magnesium oleate. Any electricity is conducted as soon as generated to the metal of the machine, and at once dissipated if the latter is efficiently earthed. This property of magnesium oleate was discovered by M. M. Richter in 1893, who found that the addition of 0*02 to 0'05 per cent, rendered the benzine incapable of (so-called) spontaneous combustion. Other oleates act in the same way though in a less degree, a larger amount than 0-02 per cent, being required. The quantity of potassium oleate (or other soluble oleate) employed as a benzine soap is more than sufficient to convert the benzine into a conductor of electricity. It is in the process of rinsing, where, of necessity, no benzine soap is employed, that " spontaneous " fires usually occur, as certain articles become electrified in the friction of rinsing, and spark when brought in contact with the edge of the machine w^hen being withdrawn. To reduce this risk as much as possible when rinsing in open tanks, a metal plate or grid should be placed inside the tank and be properly earthed. Each time the goods are raised or lowered in rinsing they should be drawn over this plate to remove any current which has been generated. The lids of all machines should be counter-balanced, and in the length of cord or chain employed there should be a unit consisting of two pieces of brass soldered together with fusible alloy" melting at a low temperature — say 110° C. to 120° C. In the event of a fire occurring the solder would melt and the lids of all machines would close at once. The damage in case of fire is not so great as that caused by DRY CLEANING. 103 an explosion due to the flames passing down the pipes, etc., to tanks containing benzine and air. This danger may be removed by the employment of the Nonex " fitting, manufactured by the Nonex Safety Tank Syndicate, Ltd. This consists of a combina- tion of the Davey safety-lamp principle with a fusible or oravity plug and plunger, which automatically releases the gases from the benzine before the pressure, hot or cold, can cause the tank or machine to w^rench, leak, or explode. It is in the form of a cylinder, and is fitted to the inlet and outlet of each machine or tank ; no flame can pass it. The illustration fig. 35 show^s diagramatically the various points in the system at which the device is fitted, and fig. 36 shows the device fitted to a storage tank. Leakage. — The benzine must be distributed to the various machines under seal in pipes, and where permanent fittings cannot be employed (as in the Sunflower machine), flexible metallic couplings, fitted with screw caps when not in use, must be coupled and uncoupled each time the machine is filled or discharged. All joints must be well made to avoid leakage, and in this connection it is necessary to point out that ordinary jointing material (e.g. red lead) cannot be employed, owing to the solubility in benzine of the oil which it contains. Glue wath or without the addition of a small quantity of potassium bichromate or chrome alum (to render it insoluble in water) gives the best results in pipe and other joints where benzine is employed. It is better to avoid all joints in pipes and in tanks by employing welded pipes and welded tanks, when leakage (except from faulty workmanship) is impossible. The advantage of the balanced hydro-extractor over the fixed spindle type is noticeable here, as with the reduced vibration of the outer casing the risk of joints being broken is minimised. Regarding general provisions in case of fire the use of non- inflammable clothing by the workers has already been referred to in the Home Office reports and the London County Council form of licence. Special attention may, how^ever, be directed to the necessity of wearing boots or shoes free from exposed iron. In this connection it may be mentioned that shoes with jute soles have been found very satisfactory. Blankets or asbestos sheets and vessels containing sand must be provided, and must be readily accessible ; if a fire occurs water must not he used ; in a machine or rinsing tank the lids of all machines must be closed, if possible ; and sand blankets or asbestos sheets may be used to smother the flames. If the various precautions in construc- tion which have been indicated have been adopted, there is very little likelihood that the fire will spread, but will burn itself DRY CLEANING. 105 Storage Tank Fig. 36. — Tank showing " Nonex " Cylinder. purpose. In conclusion, it may be stated that most fires occur through the carelessness of operatives : therefore it cannot be too often impressed upon them to exercise every possible pre- caution, and each one should clearly imderstand what to do in the event of a fire occurring. CHAPTER III. WET CLEANINa. It may be taken as an axiom in cleaning that no article is soap cleaned if it can possibly be dry cleaned. The branch of wet cleaning known as " fancy " cleaning is now almost extinct, having been replaced by benzine cleaning alone or followed by water- brushing. There are, however, many articles which can only be wet cleaned, e.g. muslin, lace, Swiss net and guipure curtains, chintz curtains and covers, window blinds in holland, coutil, etc ; in fact, any articles in which the removal of the old starch and re-starching forms part of the cleaning process. Muslin, lace, and other cotton and linen dress fabrics frequently require wet cleaning, as the dirt is generally ingrained and is not removed by dry cleaning. Blankets, white flannels (cricket trousers, etc.), are generally wet cleaned, as in addition to their being soiled they are frequently discoloured and have to be re-bleached. Cretonne, tissue and similar printed fabrics in the form of curtains, bedspreads, and chair coverings give satisfactory results by dry cleaning, but if soiled to any extent must be wet cleaned. This is especially the case with furniture covers, which are some- times discoloured by dye, dirt, etc., rubbed off black or other dark-coloured dresses. Wet cleaning may be roughly divided into hand cleaning and machine cleaning. For hand cleaning it is necessary to provide earthenware or wooden vessels, it being usual to employ a series of earthenware vessels of about ten gallons capacity for small articles and rectangular wood vats (or frequently barrels with one end sawn off) for the larger articles. Slate or marble slabs are also provided for hand brushing. For machine cleaning the ordinary rotary washing machine with a brass inner cage is employed. Fig. 37 shows the type of machine usually employed. For curtains, blinds, and other articles which are liable to be frail from exposure, Messrs Hill & Herbert's 106 108 DYEING AND CLEANING. " open-end " washer (figs. 38 and 39) has been found to give very satisfactory results, as there is not the same tendency for the articles to become entangled during the rotation of the machine, and also the cage may be unloaded without straining the goods. A series of wood vats with a pair of squeezing rollers between each pair is employed for rinsing (e.g. blankets), and a starch trough with a pair of rubber-covered rollers for starching curtains, etc. Fig. 38.— Open-end Washer. Other appliances will be described when referring to their mode of employment. Soap. — As most articles for wet cleaning have to be treated at a low temperature (from the ordinary temperature up to about 90° F.), it is necessary to use a soap which will not gelatinise at the ordinary temperature. For this reason tallow soaps (curd, mottled, primrose, etc.) should not be employed in wet cleaning ; the most satisfactory soap is a neutral oil soap, of which there are many on the market. A soap of this type being perfectly neutral may be safely employed on woollen articles and on most coloured WET CLEANING. 109 articles : it does not gelatinise on cooling, and is readily rinsed out of the articles which have been cleaned with it. A liquid detergent has been recently introduced by the Bayer Co., Ltd., under the name of Tetrapol, which should find some application in wet cleaning, as it is a very efficient solvent of grease, and it is claimed that it has no action on the most delicate colours. It consists of a mixture of Monopol soap and carbon tetrachloride, and is miscible with water in all proportions. Monopol soap is a superfatted sulphonated castor-oil soap, and differs entirely from ordinary soaps, as will be seen from the following list of its properties : — Fig. b9. — Open-end Washer (showing Gearing). (1) It gives, even in very hard water, a clear solution, as it does not form an insoluble lime soap, but will actually dissolve lime soap. (2) It is unaffected by the acids generally used in textile processes. (3) It cannot be salted out, except with great difficulty and by the use of a very large amount of salt. (4) It is capable of dissolving and retaining in very large quantity, other oils and fats, especially mineral oils. (5) It will wet out and penetrate goods to an exceptional extent, and imparts to them a soft and full handle. 110 DYEING AND CLEANING. (6) It opens the fibre, increasing its power of capillary attraction, and leaves it in tlie best condition for finishing. (7) Goods which have been treated with it can be stored almost indefinitely without acquiring an objectionable smell or unduly absorbing moisture. (8) Colours are improved in appearance and brightness by its use. Tetrapol may be employed without any addition, but in practice it is found more economical and equally satisfactory to use it in conjunction with ordinary soap. Fancy Cleaning. — Wool and silk articles of wearing apparel in white or colours, and cotton and linen articles in colours, must be cleaned at a low temperature (not exceeding 90° F.), which is known to cleaners as a ''hand" heat. This tends to prevent shrinkage of woollen articles and the running of colours in print and dyed fabrics. If experience shows that the colours of a fabric are particularly loose, it must be cleaned quite cold. The articles are first rinsed in water to remove surface dirt and any acid from wool and silk goods. They are then entered into the soap bath and are squeezed through the soap liquor by hand, the order of the articles being so arranged that white and cream goods are cleaned first, followed by light and finally dark colours. After squeezing through the soap several times they are placed on the slab and any very dirty places brushed with soap solution by hand. They are then rinsed in two or more waters, followed by a rinse in dilute acetic acid to " harden " the colours, and in the case of silk fabrics to brighten the fibre and to impart to it the necessary " scroop." White silk and cotton goods may be cleaned at a higher temperature if necessary (with the exception of weighted silks, which are rarely wet cleaned). Crepe de chine and other soft silks may even be boiled in neutral soap with perfect safety, as these fabrics are aways woven "in the gum" — i.e. the silk in its natural state w4th the sericin coating on the fibre or fibroin, and are "boiled off" in soap solution after weaving. Bleaching. — White wool, silk and cotton goods frequently become discoloured during wear, and it is necessary to make them a good white after cleaning. With silk and cotton goods which are only very pale cream tint this may be effected by "blueing," the colours employed being ultramarine or Alkali Blue 4 B for cotton and a clear violet for silk (usually a basic violet), a very minute quantity being required in each case to produce the desired effect. Woollen goods cannot be " blued " in this manner. When the colour of the fabric is of such a depth that blueing" is not satisfactory bleaching must be resorted to (followed, if necessary, by "blueing"). WET CLEANING. Ill Wool and Silk. — The old-fashioned method of bleaching wool and silk by means of sulphur is rarely employed by dyers and cleaners at the present date, and will not be described in detail. Briefly, it consisted in hanging the goods in a closed chamber in which sulphur was burnt, the bleaching being effected by the resulting sulphur dioxide. The white produced is not permanent, as the colouring matter is not destroyed by the sulphur dioxide, but only reduced and decolorised, the original colour gradually returning on oxidation taking place. Moreover, the goods have an objectionable smell and a harsh feel, owing to the retention of sulphurous acid. The most satisfactory results are produced with hydrogen peroxide, which oxidises and destroys the colouring matters ; con- sequently the results produced are quite permanent. Hydrogen peroxide is usually supplied in ten and twelve-volume strength, and is generally acidified to assist its keeping qualities ; one of its dis- advantages is the rapidity with which it decomposes, particularly in sunlight. It should therefore always be stored away from direct sunlight, as is shown by the following figures giving the percentage decomposition of a sample of ten-volume hydrogen peroxide kept in direct sunlight for one month (July 1895) and another sample kept during the same period in diffused sunlight (C. A. Fawsitt, J.S.C.L, 1902) Original strength ... 9 vols. Loss in sun . . . .22*0 per cent. Loss in shade . . . 1*1 per cent. The cost of hydrogen peroxide and the introduction of sodium peroxide have restricted its use to a large extent ; but the ease with which it may be employed as compared w4th the latter, and the entire absence of risk, give it a certain limited application. The ten- volume strength is diluted to a suitable working strength by the addition of two or three times its volume of water, and the bath is made faintly alkaline with ammonia or sodium silicate. Wooden or earthenware vessels must be employed, and for heat- ing with steam, an indiarubber (not wired) or lead pipe must be used, the latter being the only commercial pipe metal not affected by the bleach. The goods are entered in the cold bath and the liquor is gradually raised to a temperature of about 50° C, and are allowed to remain in the bath for several hours. As the oxygen liberated tends to lift the articles above the surface of the liquid, they must be pushed below from time to time. If left in the bath over night it is advisable to keep the articles below the surface of the liquid by means of one or more clean wooden 112 DYEING AND CLEANING. sticks. After bleaching, the goods are rinsed and dried in the ordinary way. Sodium Peroxide. — This substance is supplied in the form of a greyish-yellow granular mass, which readily dissolves in water with the generation of a considerable amount of heat and some loss of oxygen. It cannot be employed without first neutralising the caustic soda formed, the usual method being to dissolve it in cold water containing sufficient sulphuric acid to neutralise all the caustic soda with the formation of hydrogen peroxide and sodium sulphate (Glauber's salt). The sodium peroxide is sprinkled slowly on to the water with constant stirring, from one to two pounds being required for every ten gallons of water. The bath must be rendered neutral to litmus paper by adding sul- phuric acid or sodium peroxide, according as the bath is found to be alkaline or acid to the indicator. The method of working this bath is exactly the same as that described for hydrogen peroxide. In place of sulphuric acid de Haen recommends the use of magnesium sulphate (Epsom salt), which yields with the sodium peroxide, by double decomposition, magnesium peroxide and sodium sulphate. The bath is made by dissolving three parts of mag- nesium sulphate in the requisite quantity of cold water and gradu- ally stirring in one part of sodium peroxide. The bath becomes turbid, and is employed in that condition ; it is a quick and satisfactory bleaching bath for silk goods, but is not recommended for wool, owing to its alkalinity. In place of ammonia or silicate of soda, as additions to the sulphuric acid-sodium peroxide bath, the use of ammonium phos- phate has been recommended to increase the stability of the bath and to cause the evolution of the oxygen to be slow and regular. It has the advantage of yielding a perfectly neutral bath, and for this reason is recommended for the finest woollen goods. The quantities recommended by the makers are — Water . . . . .100 gallons Sodium peroxide . . . 7| lbs. Sulphuric acid . . . . 8 ,, Ammonium phosphate . . 3 ,, The soluble hydrosulphites now on the market (Decroline, Hyraldite, etc.), whilst not yielding such permanent results as hydrogen peroxide, may with advantage be employed upon articles frequently in the hands of the cleaner — e.g. flannel cricketing trousers, etc. They are easily applied, and much cheaper and quicker in use than hydrogen peroxide. Taking Decroline as an example, from one to four ounces are taken for every ten gallons of water, with the addition of a quarter of a pint of acetic acid. AVET CLEANING. 118 The goods are entered cold and are gradually brought up to about 50" C, and, after remaining at this temperature for a short time, are well rinsed and dried in the ordinary way. Cotton and Linen. — These fibres are generally bleached with hypochlorites, the sodium salt being usually employed. Solu- tions of sodium hypochlorite are sold under various trade names — e.g. chloros, parozone, yarnite, lavozone, etc. ; or may be made from bleaching powder by double decomposition with sodium car- bonate or by the electrolysis of sodium chloride solution. Bleach- ing solution made by the cleaner from bleaching powder is not altogether satisfactory, as it usually contains free alkali and some calcium salts in solution. The proportions of bleaching powder and sodium carbonate, " 58 per cent, alkali,^' are about 6 : 5 parts by weight respectively. Each is dissolved in water, and on mixing the solutions, calcium carbonate is precipitated, and may be separated by settlement and decantation, followed by filtration. One method of bleaching curtains is to add the hypochlorite to the soap in the "boil." This cannot be done with bleach made from bleaching powder, as the calcium salts in solution decompose the soap with the formation of insoluble lime soaps. Hypo- chlorites made by the electrolysis of sodium chloride may be quite safely employed in this manner, as they contain no lime. The electrolysis of salt solution may be easily and economically carried out on the small scale, and various forms of apparatus have been designed for the purpose. Of these the most satisfactory and most extensively employed appears to be that of Haas and Dr Oettel. The size designed for cleaning works is shown in figs. 40 and 41, and can be run direct off the electric lighting circuit at 110 volts continuous current ; with a higher voltage two or more cells can be run in series or a resistance can be employed. The apparatus consists of the circular brine dissolver of wood with agitator and tap for supplying the brine to the cell. The cell (fig. 41) is of stoneware with carbon electrodes, which require renewing about once a year ; and the collecting tank is also of stoneware. Salt (common freezing salt) is dissolved at the rate of about half a pound to each gallon of water by stirring for about five minutes, and is then allowed to settle for an hour. The brine is drawn off a few inches above the bottom of the vessel to avoid the impurities which have settled, the rate at which it passes through the electrolyser being from ten to thirteen gallons per hour. The bleaching liquor produced contains about three grammes per litre of free chlorine, and the cost of production, including salt, electric current (at power rates), and depreciation of 8 114 DYEING AND CLEANING. electrolyse!', but not labour (which is very small), may be taken at about Jd. per gallon. Blankets. — These may be cleaned by machine, but it is advis- able to employ the oscillatory motion, as too much rubbing tends to "felt" woollen articles. Neutral oil soap should be employed, and if an alkali is used in addition, it must be either ammonia or potassium carbonate. The temperature throughout the cleaning, rinsing and drying must be the same, viz. about 90° F. ; higher Fig. 40. — Haas and Oettel Electrolyser. temperature or a change of temperature {e.g. cleaning at 90° F. and rinsing in cold water) tends to produce shrinkage. The blankets are introduced into the machine containing the water and soap (the latter being in sufficient quantity to produce a good head of lather when running), and the machine is run for ten minutes. The blankets are then passed through a rubber wringer, and are treated in a similar way in fresh soap liquor for another ten minutes (this soap liquor can be used as the first liquor for another batch). They are now finished by one or two methods, viz. by immersing in a "thin liquor" {i.e. a dilute solution of soap), wringing, hydro-extracting, and drying, or by WET CLEANING. 115 rinsing thoroughly in water at 90° F., to remove all traces of soap, running through a dilute acid bath (sulphuric or acetic acids) to brighten the colours on the borders, rinsed in water, hydro-extracted and dried. Instead of brightening the colours in an acid bath, a broken soap bath may be employed ; this is made by adding a small amount of acid to a solution of oil soap, whereby a fine Fig. 41. —Cell of Electrolyser. emulsion is produced. The blankets are rinsed in this, wrung, hydro-extracted, and dried. After they are taken from the hydro-extractor they must be thoroughly shaken by hand, and must be hung up quite square in the drying-room. (The hydro-extracting is sometimes omitted.) Curtains (Lace, Swiss Net, Guipure, etc.) — Curtains may first 116 DYEING AND CLEANING. be sorted into wliites and creams ; and those which are obviously frail from atmospheric exposure must be cleaned by hand. Those which are sufficiently sound for machine cleaning may be placed direct in the washing machine cage ; but it is safer to put them into openwork string bags, as, altliough by so doing they take somewhat longer to clean, the strain on the curtain-net is very much reduced. The machine having been run up with water (about half-way up to the door) the curtains are run for about ten minutes, with the addition of one pound of 58 per cent, alkali, in the cold. This is known as the " breakdown, and serves to remove some of the starch and a large amount of surface dust. This liquor is run off and the " first wash " is prepared by running in about half the quantity of water employed in the "breakdown," and adding a sufficient quantity of stock soap solution (which is made by dissolving equal quantities of soap and 58 per cent, alkali). This is heated by steam to about 140** F., and the machine is run from fifteen to twenty minutes. Run off the liquid, add the same amount of water as in the " first wash," and sufticient stock soap solution ; run for a few minutes at about 140° F. ; bring up to the boil, and run for from fifteen to twenty minutes. With white curtains requiring bleaching, electrolytic sodium hypo- chlorite may be added to the second wash ; but, as already stated, bleaching solution prepared from bleaching powder must not be added at this stage. The soap solution is now run off, and the curtains are rinsed in hot water for a few minutes, followed by a warm-water rinse of similar duration, and finally by a cold blue rinse. If the bleaching solution is not added in the second wash the bleaching follows the hot rinse, and after bleaching the curtains must have two warm rinses and one cold rinse. They are now hydro-extracted and are ready for starching. In place of a rotary washing machine, curtains are sometimes sewn end to end in rope form and are cleaned in an open vessel over a power- driven winch. When this is done the curtains can be made to pass continuously from one process to the next : but the duration and sequence of the various processes are the same as when cleaning by means of a rotary machine. Cream and ecru curtains are frequently treated in the same way as w^hite curtains, it being generally necessary to remove the old colouring matter ready for re-tinting on account of fading. Suitable substantive colours, chosen on account of their fastness to light, are usually employed in re-tinting curtains ; though, for cream and ecru, "red iron liquor" (basic nitrate of iron) is frequently employed, as the colours produced thereby are exceptionally fast to light. The curtains are passed through a dilute solution of " nitrate of iron," followed by treatment with a WET CLEANINPt. 117 weak solution of sodium carbonate which " raises the colour " — that is, it precipitates hydrated ferric oxide in the fibre. Counterpanes, bedspreads, dimity and other white cotton and linen goods are cleaned in the same manner as white curtains. Printed muslin curtains, net curtains with coloured embroidery, etc., are cleaned in neutral soap without the addition of 58 per cent, alkali, and the temperature must not exceed 1 20° F. After cleaning and hydro-extracting, the curtains are ready for starching and finishing. The starch employed for this purpose is " boiled " starch ; that is, the starch is boiled with water to burst the granules before it is applied to the curtains, though dextrin or farina may be employed in place of starch. Where starch is employed maize starch is frequently used, as it is generally lower in price than rice starch and wheat starch. The last mentioned, owing to its high price, is seldom, if ever, used for curtain starching. Maize starch has the advantage of boiling up thinner than rice starch, and is consequently absorbed by the curtains more readily ; on the other hand^ it possesses the disadvantage of being more hygroscopic than rice starch (whereby the curtains dressed with it readily become limp in damp weather), and it is generally more yellow in shade : this defect can be remedied to some extent by the use of a slightly increased amount of blue. A very good result may be obtained by combining a cheap pearl maize with rice starch in equal quantities, this mixture giving a solution which can be worked into the curtains readily ; the curtains so finished are not affected by moisture to the same extent as when maize starch only is employed. The starch is stirred with cold water, and is then brought to the boil while stirring. The proportions of starch and water employed depend upon the nature of the curtains being starched, and vary from a few ounces to each gallon of water up to twelve ounces to the gallon. A trough fitted with a pair of rubber rollers and with a small live steam pipe is employed for the opera- tion of starching, the curtains being run through the starch solution and thence to the rubber rollers, where the superfluous starch is removed. Curtains are sometimes starched by immersion in the starch solution followed by hydro-extracting, the starch removed by the latter process being collected and returned to the stock solution. It is usual to add blue (ultramarine or a soluble aniline blue) to the starch, as the hot starch solution removes from the curtains some of the blue which they have taken up in the "blueing" operation. Occasionally insoluble weighting materials (such as china clay) are mixed with the starch solution, being kept in suspension by stirring from time to time. They add a certain amount of "body" to the curtains, though it is usually at the 118 DYEING AND CLEANING. expense of the colour, which becomes somewhat greyish in tone. The framing of curtains will be dealt with under "Finishing." Cretonne, Tissue, Toile ombre, etc.— Curtains, fitted furniture covers, bedspreads, etc., are now very largely made in printed fabrics, such as plain and figured cretonne, which are piece- printed ; shadow tissue (toile ombre), which is yarn-printed (with a printed warp and a plain weft) ; and similar fabrics in linen, linen and cotton, and cotton ; the majority of the effects in the better-class goods are produced in half-linen fabrics. If these are but slightly soiled they may be dry-cleaned, but in the greater number of cases wet-cleaning has to be resorted to. They must be handled with very great care, as the colours employed (particu- larly the greens) are not at all fast to alkalies ; consequently they are usually cleaned by hand, as they are then under observation the whole time. They may, however, in many cases be safely cleaned in a rotary washing machine ; they are first run for a few minutes in cold water to remove surface dirt, and are then run for ten minutes in cold neutral-oil soap. The second wash, also in cold neutral-oil soap, may take place in the machine, but is better done by hand in a wood vat, as the articles can then be carefully examined, and any places which are specially soiled may be hand brushed on the slab. The goods are then rinsed in separate lots of lukewarm water, follow^ed by a rinse in dilute acetic acid. (Sulphuric acid is sometimes employed to brighten the colours, but it must be well rinsed out of the goods in cold water.) The articles are now sheeted up, well hydro-extracted and dried, ready for finishing. Some classes of cretonne are occasionally slightly starched ; in such cases the starching follows the acid rinse. Chintz Curtains and Covers.— Chintz articles are but rarely unpicked for cleaning ; occasionally, however, linings dyed with loose colours, or woollen linings, are employed, or the curtains are trimmed with an expensive silk ball fringe. In such cases the articles must be unpicked and re-made after finishing. Chintz is cleaned in the same way as cretonne, with the difference that the old starch must be removed from it by means of lukewarm water before it is soaped. After rinsing, the chintz is ready for starch- ing : this may be done in several w^ays, as a large quantity of starch has to be absorbed by the fabric to produce the necessary degree of stiffness and gloss in the finished fabric. It used to be the practice to starch all chintz twice, that is, to starch and dry the material and then to re-starch it ; as an alternative method the chintz was dried after rinsing, and entered in this condition into the starch solution, the quantity of starch absorbed by the dry fabric being greater than that absorbed by the wet material, the necessary stiffness being thus produced in one operation. In WET CLEANING. 119 recent years starches have been made which produce a "thin" solution when dissolved at the rate of two pounds of starch to each gallon of water, thus rendering it quite possible to starch the hydro-extracted chintz quite satisfactorily in one operation. The strength usually employed is about one poiuid of starch to each gallon of water, but it varies to some extent ; work which can be finished on a friction calendar requiring less starch than work which must be finished on a reciprocating glazing machine ; also unlined chintz requires more starch than lined chintz. The starch usually employed is a mixture of wheat starch and maize starch, the proportions being one part by weight of the first to two parts of the latter. Maize starch may be used without any addition, but, as already noted under curtain starching, it is rather hygroscopic. Maize and crystal rice starch, or maize and thin boiling rice starch, may be employed, and produce satisfactory results ; but the use of too large a proportion of rice starch tends to make the work somewhat brittle. Japan wax is frequently added to 'the starch solution. The boiled starch is worked into the chintz in a punch tub, being rubbed well into the fabric by hand. After draining and squeezing, the chintz is hydro-extracted to remove the surplus starch and is then laid on the slab, and the starch is rubbed in by hand until the surface is perfectly clear and free from any smeariness. The articles are then hung in the drying-room, lined goods being well " picked out " — that is, the linings are separated from the chintz. If the linings are not separated in this way, or if the chintz is hung so that two pieces or two parts of the same piece stick together and dry in that condition, it is very difficult to separate them without damaging the fabric. The chintz when thoroughly dry is ready for finishing (see p. 204). Window Blinds.— Window blinds are usually made of white or cream hoUand, linen, union, or coutil, with or without lace trimming and insertion. They are occasionally made in the same materials in red, blue, and other colours. They have necessarily had a considerable amount of exposure to the sun (depending in degree on the aspect of the window) and to atmospheric influences in general. The lace and insertion and the bottom of the blind have generally been subjected to more exposure than the remainder of the blind, which is protected to a large extent by being rolled up on the blind roller during the greater part of the day. White and cream blinds without trimming or insertion may be cleaned in a rotary machine, if careful examination shows that they are quite sound. Blinds trimmed with lace and insertion must invariably be cleaned by hand ; as also must plain blinds not strong enough to stand machine-cleaning. WET CLEANING. 121 Oil soap with or without the addition of soda ash is employed, followed by thorough rinsing in clean water. Plain blinds are starched in the same manner and with the same 122 DYEING AND CLEANING. kind of starch as chintz. Insertion blinds, and blinds with lace ends in which the lace is not to be so stiff as the remainder of the blind, are starched on the slab, the solution of starch being brushed into the fabric and finally equalised by rubbing with a clean damp cloth. The blinds are now ready for framing. Other methods of finishing blinds will be given under Finishing.''' Hydro-extractors. — The extractors employed for wet-cleaned work are similar to those for dry-cleaned work (figs. 19 and 20). If preferred, over-driven suspended hydro-extractors may be employed, figs. 42 and 43 showing one of Watson Laidlaw's machines of this type. Belt-driving may be replaced by a direct electric motor drive or by a water turbine. CHAPTER IV. DYEING. The articles submitted to the "job dyer" comprise all descriptions of wearing apparel and all kinds of household furnishings — curtains, carpets, draperies, etc. The job dyer has to overcome many difficulties which are not experienced by the piece dyer of new goods. In the first place, he does not deal with a white or "grey" fabric, but with one which is already dyed with colours which may or may not be fast to washing, etc. Moreover, this colour is very frequently faded in the portions which have been most exposed to light, the faded portion being not only different in colour, but behaving differently towards certain dye- stuffs owing to the oxidation of the fibre or fibres at the exposed portions. The fabrics may contain any or all of the fibres generally employed in the production of woven textile fabrics, viz. wool, silk, cotton, mercerised cotton, linen, artificial silk, ramie, jute, etc. For example, a ladies' dress is very frequently made with the combination of fibres : half-wool (wool and cotton) dress fabric with a cotton lining, stitched with cotton and trimmed w^ith silk and possibly, in addition, with an artificial silk lace. If it is a coat and skirt, the coat will probably be lined with glace silk with sleeve linings of the same material, or with a linen or cotton " glissade " lining. This complexity of composition renders it necessary for the garment dyer to exercise a considerable amount of judgment in deciding the process to be adopted for every article submitted to him. Lace and other trimmings which can be readily removed and which would otherwise complicate the method of procedure, must be unpicked, dyed separately or (in the case of lace) cleaned, and replaced on the finished garment. The considerations which guide the dyer in determining the method which will be employed and the alternative methods which he has at his 123 disposal will be duly dealt with. It is now necessary to consider the appliances and raw materials used by the dyer. Appliances. — The vessels employed in job dyeing are of wood DYEING. 125 or copper ; wood vats being usually employed where large capacity is desired, and copper pans up to about 120 gallons capacity. The wood vats or "barks" usually employed are of about 200 gallons capacity, and are rectangular in shape. A perforated steam pipe is fitted on the bottom of the vat and is generally covered with two perforated pieces of wood in the form of an inverted V known as the " feather," which prevents the articles I Fig. 45.— Jacketed Pan (Tilting). being dyed coming in contact with the steam pipe. Each vat is fitted with an adequate water supply and with a plug for running off the contents. Copper pans are made for heating with live steam or are fitted with a steam jacket. In the smaller sizes of jacketed pans (up to about 40 gallons) the contents are removed by tilting the pan, but in the larger sizes an outlet valve is fitted. Figs. 44 and 45 show jacketed tilting pans, and fig. 46 a similar type of pan to which a valve is fitted for emptying the pan. 126 DYEING AND CLEANING. Where large quantities of articles are to be dyed a given colour {e.g. black, navy blue, etc.) an oval dyeing machine may be employed. Fig. 47 shows Gorrie's garment dyeing machine, which can deal with batches weighing up to 300 lbs. at a time. The paddles keep the liquor and the garments in circulation and reduce the amount of manual labour very materially. The machine may be fitted with an arrangement for removing the garments at the end of the operation ; the garments may be taken by a conveyor to a similar machine for rinsing. Colouring Matters. — The dyestuffs employed in the process of dyeing may be divided into the classes — 1. Natural colouring matters. 2. Artificial colouring matters. The natural colouring matters (logwood, cudbear, etc.) are seldom employed in the garment dyeing industry, as the artificial colours are easier to apply, cheaper, and give a range of colours and shades impossible to attain with natural dyestuffs. The artificial colouring matters may, chemically, be divided into a considerable number of groups ; but from the dyer's point of view of their behaviour towards the various fibres they may be divided into six groups : 1. Direct or substantive cotton dyestufis. 2. Acid dyestuffs. Fig. 46.— Jacketed Pan. DYEING. 127 3. Basic or tannin dyestuffs. 4. Mordant dyestuffs. 5. Vat dyestuffs. 6. Developed dyes. Of these groups the first two are of the greatest importance to the garment dyer ; the other groups, with the exception of the basic colours, which find a limited application, are rarely, if ever, employed. 1. Direct or Stihstantive Cotton Dyes. — This is an extremely valuable group from the garment dyer's standpoint, as it includes the colours of the Diamine, Benzo, Congo, Titan and similar series. Fig. 47. Gorrie's Oval Dyeiiif^- ^lacliine. The majority of the colours of this group are azo compounds derived from benzidine or from bases of similar constitution. They dye vegetable fibres direct from an aqueous bath containing the dyestuff, with the addition of common salt, sodium sulphate, etc. Many of them dye animal fibres from a neutral or slightly acid bath, some of them, in fact, being better adapted to dyeing wool and silk than cotton Their classification according to their behaviour towards the various fibres will be dealt with later. Many of the substantive colours which contain free amido groups are employed in the production of ingrain colours. In such cases the dye on -the fibre is treated directly with nitrous acid, which converts the amido group into the diazo group, this being com- 128 DYEING AND CLEANING. bined with suitable naphthols or amines. The shades produced in this way are generally very fast. A notable example of a dyestufF yielding ingrain colours is primuline. For example, on diazotisa- tion and development with alkaline /3-naphthol a bright red is produced. 2. Acid Dyestuffs. — These are the sodium salts of sulphonic acids and the nitro-colours. They are substantive to the animal fibres, which they dye from an acid bath. Certain acid colours, however, will dye wool and silk from neutral salt-baths, and are termed neutral-dyeing acid colours. These are very useful to the garment dyer, as they can be dyed in conjunction with substantive cotton dyestuffs. With a few exceptions they have little affinity for vegetable fibres. 3. Basic Dyestuffs. — These are substantive to wool and silk, but will only dye cotton on a tannic acid or oil mordant or " topped " on to a substantive cotton dyestuff. Some of the basic dyestuffs will dye cotton without the employment of a mordant, but the colours produced are very fugitive and of little practical value. They are but seldom used in garment dyeing, as the colours produced are not so fast to light and to rubbing as the same shades dyed with the acid dyestuffs usually employed. The colours are, however, very bright, and are not changed by artificial light to the same extent as the other groups ; they may therefore be employed when fastness to light is not so important as the production of a bright gaslight shade. They are sometimes ^' topped " on to substantive cotton dyestuffs for shading purposes, or are employed for "filling up" cotton linings on an iron-tannin mordant. Their advantages and disadvantages for these purposes will be referred to later. 4. Mordant Dyes. — These are not usually employed in garment dyeing owing to the difficulty of application. Wool and silk are dyed by one of two methods : (a) The fibre is mordanted and subsequently dyed. {h) The mordant and dye are fixed in one operation. Cotton is not largely dyed with mordant colours, with the notable exception of Turkey-red, which is produced from Alizarine and an alumina lime and fatty acid (Turkey-red oil) mordant. 5. Vat Dyes. — This group is not employed in garment-dyeing, again owing to the difficulty of application. The dyestuffs, of which the chief example is indigo, are not soluble in water, but can be reduced to leuco compounds soluble in dilute alkalies. In this condition they are applied to the fibre, the leuco compound being re-converted to the dye by oxidation. (Indigo extract is a sulphonated indigo, and acts as an acid dyestuff.) DYEING. 129 6. Developed Dyes. — These dyes are produced in the fibre from substances which are not dyestufFs, and may be divided into two classes : (a) Those produced by the combination of naphthols, etc., wdth diazotised amido compounds. (h) Aniline black. (a) The fibre is impregnated w^ith the ^'developer," e.g. fS- naphthol, and the colour is produced by immersion in an ice-cooled solution of a suitable diazotised amido compound. For example : jo.-nitraniline diazotised and developed with ^-naphthol gives scarlet. dianisidine diazotised and developed with /5-naphthol gives blue. (b) Aniline black is produced by the oxidation on the fibre of an aniline salt or by heating the fibre in a solution of an aniline salt and an oxidising agent. This black is only produced on vegetable fibres, and is largely employed in the manufacture of marking inks. The table on p. 130 (SchaposchnikofF) gives a chemical classi- fication of the dyestulfs in relation to their behaviour towards the fibres. For further particulars the reader is referred to Cain and Thorpe's Synthetic Dyestuffs and to W. P. Dreaper's Chemistry and Physics of Dyeing. Assistants, — The assistants usually employed in garment dye- ing are neutral salts and acids. Neutral Salts. — The salts usually employed are sodium chloride (common salt) and sodium sulphate (Glauber's salt). The latter, especially when calcined, is not always absolutely neutral, but may contain traces of acid sodium sulphate or hydrochloric acid ; common salt, on the other hand, is free from this defect. Sodium phosphate is sometimes recommended as an assistant, but any advantages which it may possess over common salt or sodium sulphate are not commensurate with its increased price. Soap may also be employed as an assistant where clear pale shades are dyed on cotton with substantive dyestuffs. Acids. — The acids usually employed in dyeing with acid dyes are sulphuric acid, acetic acid and formic acid. Hydrochloric acid may also be employed, and has the advantage of being volatile. Mineral acids are rarely employed alone, sodium sulphate being also used with the formation in the bath of acid sodium sulphate. The dyeing generally takes place more quickly with mineral than with organic acids and the baths exhaust better, but the colours produced, in many cases, are not so level and the penetration is 9 CP rJ t ill Q O fH o o o o . .11 t-H Ph 03 J3 CO +3 o M 03 03 03 ■-d 6 ^ N ce O O 03 ?3 5 .s ' 3 ^ 2 a. 3 .CO Pi 03 c3 o ye in baths. from deri- 03 E5 <:« ,co 03 ^ 0 .CO 53 ^ ?3 CO TO 'r-l {>, 03 ^ 03 r2 r-H .CO 03 32 H 03 >^ ^03 'B ^ O CO 03 4-5 -t-> c3 CO 4-5 03 03 -2 r2 r5 >i 03 ^ g.s N3 ^ P 03 03 B o o f3 EC 'B ^ cr' CO o q3 03 <^ ^ B d ^ <^ oT 03 O t3 rd o o 00 03 ^ ^ CO O CO O .H CO o3 '"d Oh 03 5G o3 ^ ,co Q ^ !^ d O +2 ^ ;5 o d d CO J3 d O 03 2 Ph Pnr-H 03 f P. 03 in 03 O 03 N d o3 Q nd 'o o -^^ CO « ^ 03 o DYEING. 131 not so good. It may be taken as a general i^ule that the level- dyeing and penetrative qualities of a dye are inversely pro- portional to the rate of dyeing ; that is, they are poor with a quick dyeing bath and good with a slow dyeing one. For this reason it is advisable to employ organic acids whenever there are thick seams, etc., on a garment. Sulphuric acid is generally preferred by dyers because the old colour (which in many cases is not previously removed by a stripping agent) is stripped off to a much greater extent than when organic acids are employed ; consequently with slightly faded work a more level result is obtained. The organic acids have the great advantage over the mineral acids that they do not tender the cotton threads in a wool or silk garment, and with articles trimmed with black, or with black woven stripes, the colour is not removed. The organic acid most largely in use is acetic acid, w^hich is usually sold in 30 per cent, and 40 per cent, strengths, the specific gravities being respectively 1*0412 and 1*0523. In some cases the dyeing- is done with acetic acid as an assistant until the bath is nearly exhausted, when sulphuric acid is added to complete the ex- haustion. During the past few years the price of formic acid has been reduced very considerably, until it can successfully compete with acetic acid. It has many advantages over the latter, from the garment dyer's point of view, the principal one being that better penetration is obtained. This is of great importance in the dyeing of garments with thick seams, etc. For example, a light coloured cloth coat dyed dark brown with acid colours which do not level easily with the addition of sulphuric acid, may not be thoroughly penetrated in the thick portion where the sleeve joins the body of the coat, and the light coloured portion may become visible if the sleeve is pulled during the process of finishing. The same article dyed with the addition of formic acid would show^ very much better penetration, and the pulling of the seams in stretching would not reveal light-coloured portions of the fabric. Formic acid also exhausts the bath more completely than acetic acid, and produces, in many instances, brighter and purer shades. Rusby (J.S.D.C., 1907) states that formic acid 90 per cent, is equivalent to about an equal quantity of sulphuric acid and to four and a half or five times the quantity of 30 per cent, acetic acid. He made comparative dye trials with Cyanole, Lanafuchsine, Rhodamine, etc., employing sulphuric, acetic, and formic acids, the last-named always yielding brighter and purer shades. Experiments as to the penetration of the dye were made on a very thick hard- twisted carpet yarn, with the result that with sulphuric acid the middle of the yarn was 132 DYEING AND CLEANING. almost nndyed, with acetic acid the penetration was not quite satisfactory, but with formic acid perfect penetration was obtained without any special precautions, such as the gradual addition of the acid, etc. Formic acid is usually supplied in tw^o strengths, viz. 40 per cent, and 90 per cent. ; the latter, being less than twice the price of the former, is more economical in use. It will be seen that formic acid is likely to take an important place in the garment dye-house, its advantages over acetic acid being summarised as follow^s : Better penetration. Brighter colours. More even dyeing. No increased cost. Better exhaustion. In common with acetic acid it has the great advantage over mineral acids that the cotton and linen portions of mixed fabrics are not damaged in the slightest degree. Preparation of Goods for Dyeing. — The garments, etc., received for dyeing have to undergo some preparation-, the nature of which depends upon their texture, condition, and colour, and the shade which they are to be dyed. They are usually soiled, more or less stained with grease, road dirt^ etc., and the colour is frequently uneven from fading. In some cases it is only necessary to remove the dirt, grease, stains, and dressing from any article, the colour selected for dyeing being such that none of the colour need be removed, or only such as may be removed in the cleaning of the goods. Stripping the old colour is not resorted to if it can be possibly avoided, as the process is somewhat expensive and tends to im- poverish the material. When it is only necessary to clean the goods without the removal of the colour (except such as may be incidentally removed in the cleaning process), wool or half wool is treated with a cold or warm soap solution with or without the addition of soda or ammonia, followed by thorough rinsing in warm water. The rinsing is very important when the goods are to be subsequently dyed in an acid bath, as the fatty acid precipitated in the goods froui any soap which has not been thoroughly rinsed out of them tends to impart an unpleasant odour which can only be removed with difficulty. If used wdth care in dilute solutions, and either cold or at a moderate temperature, soda alone (Brunner Mond's 58 per cent, alkali) may be employed, and gives very satis- factory results, and there is no possibility of any fatty acid being fixed in the fibres. In pressing new garments (particularly men's clothes) soap is frequently employed to assist the process ; this must be well worked out during the cleaning, as otherwise the DYEING. 133 precipitation of fatty acids in the thick portions (round the button- holes, etc.) may prevent the penetration of the dye. Silk goods are usually dyed with acid colours, which are easily removed in a soap bath, boiling being resorted to if necessary. Unweighted silks (crepe de chines, spun silks, china silk, etc.) can be boiled in soap with perfect safety ; but weighted silks (glace, etc.) must be handled with great care in lukewarm soap baths. The latter, however, are very seldom wet-dyed, as they are generally in such a tender condition that even cleaning causes them to become more or less disintegrated. Silks are sometimes dyed with basic colours to produce bright gaslight " shades, and in some cases these are but little affected by boiling soap {e.g. Night Blue). Stripping by reduction must be employed in such cases. Mordant colours are sometimes dyed upon silk ; such colours are invariably skein dyed and woven as stripes, floral "swivels," etc., in crepe grounds, and may be removed by the method employed in stripping mordant colours from woollen goods {q,v,). Cotton and linen goods may be boiled in alkaline solutions, such treatment being usually sufficient ; if it is not, stripping must be resorted to. Stripping Processes. — The methods generally employed may be divided into four classes : 1. Stripping in alkaline baths. 2. Stripping with oxidising agents. 3. Stripping with reducing agents. 4. Stripping in acid baths followed by alkaline baths. The woollen articles received for dyeing are principally ladies' dresses, curtains, draperies, etc. These have (in the majority of cases) been dyed with acid colours, though dress materials are sometimes dyed with mordant dyes. When acid colours have been employed, it is frequently possible to remove sufficient of the colour by treatment with warm soap with the addition of soda, or by the use of soda alone. (In some cases boiling in a solution of sodium sulphate will remove a considerable amount of colour.) The class of fabric and the colour will frequently be sufficient for the dyer to decide, from his general knowledge, what dyes have been employed in any given fabric ; but further information, together with a systematic method of determining the colouring matters on a fabric, is given in Cain and Thorpe's Synthetic Dyestuffs, to which reference should be made. Where dark colours, especially blues, browns and reds, require stripping, a knowledge of the dyes employed in producing the colours is of very great assistance, and where an alkaline bath has no effect. 134 DYEING AND CLEANING. the blues and browns will probably have been dyed with mordant colours and the reds with substantive colours (owing to their fast- ness to washing). Blues dyed with the Sulphon Cyanines are also but little affected by a soap and soda bath. Mordant colours can only be removed by the decomposition of the colour lake. This can be effected by boiling in a dilute solution of hydrochloric acid, afterwards removing the colouring matter proper in a warm solution of alkali. The demands upon the garment dyer are now very much more exacting than was the case a decade or so ago, and he is now expected to match patterns exactly ; frequently this can only be effected by the almost complete removal of the colouring matter from the fibre, which frequently involves the decomposition of the dyestuff in the fibre by means of oxidising or reducing agents. The oxidising agents which may be employed for this purpose are — Nitric acid. Chromic acid (potassium bichromate and sulphuric acid). Hydrogen peroxide. Hypochlorites. The reducing agents usually employed are — Stable hydrosulphites (Rongalite, Hydrosulphite, Hyraldite, Decroline, etc.). Stannous chloride. TitanoQS chloride. Oxidising Agents. — Of the oxidising agents, nitric acid was at one time very largely employed on woollen goods, but is now less frequently used. Its advantages were its economy, and the fact that it " cut up the fades " — that is, it oxidised the fabric evenly, so that the faded and the unfaded portions of the fabric could be dyed a level shade. Its disadvantages were the deep yellow colour which it imparted to the goods, rendering it impossible to produce many colours, and the destructive action of the bath upon the cotton threads, linings, etc. The cotton stitching was frequently tendered to such an extent that the various portions of the garment would come apart. The nitric acid bath is made with about one gallon concentrated nitric acid to every ten gallons of water, earthenware or vulcanite vessels being employed with lead steam pipes. The oxidising bath usually employed for stripping woollen goods is that made from potassium bichromate and sulphuric acid. It cuts up the fades in the same way as nitric acid, without tendering the cotton threads to quite the same extent. Like nitric acid it has the disadvantage of leaving the goods a brownish- 135 jellow shade, which may, however, be reduced to i^ome extent by after-treatment. The bath is made by adding about 5 per cent, of potassium bichromate, and about twice the quantity of concen- trated sulphuric acid, and is usually employed at the boil ; finer goods may be entered at the boil and the bath allowed to cool oft' with occasional turning of the goods. Goods stripped in this manner can be dyed most dark and medium shades of which yellow is a component, but the range may be increased by further treatment. They are rinsed and passed through a w^arm acid bath and thoroughly rinsed and treated, first, in a dilute bath of hydrogen peroxide ; second, in a hydrosulphite and acetic acid bath. The latter is preferable, as there is not so much risk of tender- ing. The method of applying the hydrosulphite will be given under Reducing Agents.^^ Potassium permanganate and potassium persulphate may also be employed as oxidising stripping agents, but the risk of tender- ing the fibre prevents their use to any extent. The safest oxidising agent is undoubtedly hydrogen peroxide ; but its employment as a stripping agent is limited by its cost and by the fact that it is much less energetic than chromic acid, many colours not being affected by it. It finds a useful application, however, in the preparation for dyeing of white and cream woollen goods. These have very frequently been sulphur-bleached, and the original yellow colour reappears gradually, probably through the oxidation of the reduced pigment. This reappearance of the yellow colour is not always even, those portions of the garment most exposed to the sun being more affected than those which are more or less pro- tected. Such articles are very difficult to dye pale or medium shades, unless they are bleached in a bath of hydrogen peroxide. The bath is made up in a wooden or earthenware vessel with ten gallons of hydrogen peroxide (ten vols.) to every hundred gallons of water, and made faintly alkaline with ammonia. The goods are put in the bath overnight, and in the morning are squeezed and rinsed in w^ater. Cotton and linen goods are usually bleached with sodium hypo- chlorite where an oxidising agent is employed. For this purpose the solution of sodium hypochlorite prepared electrolytically (see p. 113) will be found very satisfactory and perfectly safe in use. It can be employed in the full strength as taken from the electrolyser (three grammes available chlorine to the litre), or may be diluted. The treatment with hypochlorite is usually followed by a "sour" or dilute acid bath (generally hydrochloric acid) and subsequent rinsing in water. Hypochlorites must not be used on articles containing wool or 136 DYEING AND CLEANING. silk, which are turned a yellow colour by a short treatment and destroyed by a prolonged immersion. It is therefore necessary to examine articles which may be stitched with silk {e.(j. white waistcoats) before bleaching them wuth hypochlorites. Reducing Agents. — Sodium hydrosulphite is not employed to any extent as a stripping agent, owing to the trouble of making it and its instability when prepared ; it oxidises very rapidly and must be preserved in w^ell-filled bottles or barrels tightly fastened to exclude air. It is prepared from sodium bisulphite by the action of zinc dust, and the quantity made should not exceed one week's requirements. With the introduction of stable derivatives of sodium hydrosulphite its use has been very largely extended. These derivatives are compounds of sodium hydrosulphite and formaldehyde, the reaction w^hich takes place being expressed in the following equation (Green, J.S.D.C., 1906) : ^ Sodium hydrosulphite is represented as an anhydrous salt derived from equal molecules of sulphurous and sulphoxylic acids, according to the researches of Bernthsen : It was at first thought that this product was a compound having the empirical formula It is on the market under the trade names of Hyraldite A (Cassella) and Hydrosulphite NF (Meister Lucius & Briining), forming white fused lumps readily soluble in water. It was fovmd soon after its introduction (Baumann, Thesmar, and Frossard, Bull, de la Soc. ind. de Mulhouse, 1904, 348) that it was a mixture in molecular proportions of sodium bisulphite- formaldehyde NaHSOg, CHgO, and a new compound to wdiich Bernthsen has given the name sodium sulphoxylate-formaldehyde, NaHS02, CH2O. The latter can be separated by fractional crystallisation, and is sold under the trade names of Rongalite C (B.A.S F.) and Hydrosulphite NF cone. (M.L.B.), and has double the reducing powder of the mixture. Decroline (By, and B.A.S. F.) is the zinc salt of formaldehyde- sulphoxylic acid, and is more stable than the sodium salt. /S— ONa \S0— ONa. This salt in aqueous solution reacts w^ith formaldehyde : Nsi^S^O,, 2CH2O, 4H2O DYEING. 137 Rongalite C is soluble in water, and is employed as a discharging agent in calico-printing, but decomposes too quickly in the acid stripping bath to be employed for that purpose economically. Decroline is insoluble in water but is soluble in acids, and is only decomposed in the boiling bath. It is supplied in the form of a heavy grey powder, w^hich keeps for an almost unlimited time, even if exposed to moist air. The methods of application of all the stable hydrosulphite derivatives are the same ; therefore the particulars will only be given for Decroline."^ The goods are first cleansed in a dilute lukewarm solution of soda, follow^ed by a good rinsing, and are then entered into a bath containing the following quantities (calculated on the weight of the goods) : 3 to 5 per cent. Decroline ; 1| to 2^ per cent, formic acid 90 per cent. ; or 5 to 7| per cent, acetic acid 30 per cent. In place of the organic acids, sulphuric acid may be employed, but it is not recommended. The bath is lukewarm when the goods are entered, and is gradually raised to the boil and maintained at that temperature for ten to fifteen minutes. The bath must remain acid to litmus paper the whole time, further quantities of acetic or formic acid being added if required. The vessel employed must be of wood, and any exposed steam pipes must be wrapped in cotton cloth. During the rinsing, w^hich follows the stripping, some colours revive and must be put into the stripping bath again for a few minutes. By this means nearly all aniline colours (except mordant colours) may be stripped without risk of injury to the fibre, in many cases being reduced to very pale buff or cream "bottom," on which pale and medium fancy shades may be produced. Stannous chloride finds but little application as a stripping agent in garment dyeing, especially since the introduction of titanous chloride (or sulphate). Titanous chloride is a powerful reducing agent, and may be employed both for animal and vegetable fibres, but is principally employed for decolorising dark shades on cotton and such colours as are not affected by chlorine. It comes into the market in concentrated solutions containing free acid, and will reduce nearly all cotton substantive colours and acid colours in wool. It is applied in a hot aqueous solution, the quantity used varying from 1 per cent, (in the weight of the goods) for pale shades up to 10 per cent, for dark shades. An equal volume of hydrochloric acid is added to prevent the precipitation on the * The trade names of the stable hydrosulphites are given in Appendix C (p. 229). 138 DYEING AND CLEANING. fibre of titanic oxide or hydrate, which represents a loss in bleaching power, soils the goods, and frequently interferes with the subsequent dyeing operations (especially if basic colours are to be employed). The deposition of titanic hydrate is due to the instability of the titanic salts formed by the oxidation of the titanous chloride : 2TiCl3 + 2HC1 + 0 = 2TiCl4 + H^O. The titanic chloride is readily hydrolysed, yielding the insoluble hydrate TiCl^ f 4H2O = 4HC1 + Ti(OH)^. Hibbert (J.S.D.C., 1906) states that the tendency of the fibre to take up titanic hydrate may be overcome by the addition to the stripping bath of potassium oxalate, as the double titanic potassium oxalate which is formed does not undergo hydrolytic decomposition. It is stated that in some cases (e.g. Benzopur- purine) the addition of the potassium oxalate slightly retards the stripping action, whereas in others (e.g. Chrysophenine) its action is rather beneficial than otherwise. A bath containing oxalic and sulphuric acids is occasionally employed as a reducing stripping bath (for goods dyed with cochineal or cudbear). Selection of Process. — The selection of the process for pre- paring and dyeing the various articles handled by a garment dyer requires a considerable amount of judgment and experience. As already stated, stripping processes must be avoided if possible ; but very frequently the removal of the old colouring matter is essential to produce the shade desired by the customer. Where goods are badly faded it is necessary in any case. Woollen or half-woollen fabrics which are faded must be stripped by an oxidising agent ; as, if a reducing agent is employed, the faded portion (having been oxidised by the combined action of light and air) will dye very differently to the unfaded portions. Stripped with chromic acid (for example), the unfaded portions are oxidised to the same extent as the faded parts, and an even result may be obtained if acid dyestuifs are employed. These ^' cover the fades " very much better than the "direct" colours, w^hich tend to make the faded portions dull and heavy. Half-wool Fabrics. — In dyeing half-wool goods there are, at least, five distinct methods which may be employed : (1) The wool is dyed w4th "acid dyeing" acid colours, the cotton being dyed in a separate bath at a low temperature with direct colours which do not colour the wool (or only go on to it slightly). DYEINCx. 139 (2) The wool is dyed with a "neutral dyeing" acid dyestuff {i.e. one which dyes it in a salt bath), the cotton being dyed (generally in the same bath) with a direct colour principally dyeing the latter. (3) The wool and cotton may be dyed in one bath with a direct colour, giving a practically uniform shade on both fibres. (4) The wool and cotton may be dyed different shades as follows : (a) The wool is dyed with an acid colour, leaving the cotton white ; the cotton may be subsequently dyed a different shade with a direct colour which does not go on to the wool. (b) The cotton may be dyed with a direct colour, the wool being left white. (5) The " three bath process " is occasionally employed, in which the wool is dyed with acid colours, the cotton being su.bsequently mordanted with iron and tannic acid, and dyed with basic colours. The first method is frequently employed in re-dyeing damask tablecovers and curtains, and in dyeing wool garments trimmed with lace made from cotton or artificial silk. The first method is employed in cases where the proportion of cotton is very small, as in the case of woollen curtains or garments with cotton stitchings, braids or linings. It is also employed whenever articles are badly faded ; the goods must in such cases be stripped with an oxidising agent (usually potassium bichromate and sulphuric acid), and they should only be accepted for colours which can be dyed on the " bottom " thus obtained. In dyeing the wool with acid colours the shade must be kept a little lighter than the pattern, to allow for any direct dyes tuff' which may go on to the wool from the cotton dye bath. Before entering into this bath all traces of acid must be rinsed out of the goods, as the presence of small quantities of acid increases the amount of direct colour which goes on to the wool, causing the latter to become too dark, particularly in the faded portions. To overcome this difficulty some dyers fill up the cotton in faded goods with basic colours dyed on a tannic acid — nitrate of iron mordant. There is, however, the danger of some of the basic dyestuffs going on to the wool and producing bronziness." This can generally be removed by a warm water rinse. The method adopted for dyeing wool or half-wool goods with cotton linings depends to a large extent upon the method which was 140 DYEING AND CLEANING. employed in dyeing the latter. They are generally found to have been dyed by one of the following methods : (a) Substantive cotton colours with or without a basic colour " topping." (b) Direct dyes diazotised and developed. (c) Sulphur dyes (katigen, immedial, etc.). (d) Basic dyes on a tannic acid mordant. Of these four methods the first three are principally employed. When linings have been dyed by (b) or (c) the colours obtained are usually extremely fast, and a dress with acid-dyed wool and a lining dyed by either of these methods will show, after cleaning in warm dilute alkalies, that the lining has been but slightly affected. Such goods may be re-dyed in an acid bath. In a similar dress with the lining dyed according to method (a) the colour of the lining will have been less affected by cleaning than the wool ; but if dyed in an acid bath the colour will come off in the boiling bath and go on to the wool, causing it to become dull and heavy. If, therefore, it is proposed to re-dye such a dress in an acid bath, the colour must be removed from the lining by means of a reducing stripping bath (hydrosulphite or titanous chloride). The stripping bath may be avoided, however, by dyeing in accordance with method (2), employing "neutral dyeing " acid colours in a salt bath combined with substantive colours, which principally dye the cotton. This method is largely employed in dyeing unfaded (or slightly faded) articles containing a large proportion of cotton, in cases where a pattern has to be matched. The matching of the wool can be more easily done with acid colours than with direct colours, owing to the ease with which the former can be removed from the animal fibre, if too deep a shade has been produced. Moreover, it is easier to obtain level and deep shades on the cotton with substantive colours at or near the boil. This method also gives the best results when artificial silk trimmings are present, as, being dyed somewhat darker than the wool, the trimmings are not very noticeable if they become broken or frayed, as frequently happens. Method (3) is employed to a considerable extent, as there are now available a large number of substantive dyestuffs giving practically uniform results on both wool and cotton. The adjust- ment of the colour on the two fibres is a comparatively simple matter, as it may be taken as a general rule that at low tempera- tures the cotton takes up more colour than the wool, whereas at or near the boil more colour is taken up by the wool. It is therefore usual to dye the wool almost the required depth and DYEING. 141 to allow the bath to cool off until the cotton is sufficiently dyed, the wool in the meantime taking up sufficient colour to bring it to the required shade. As already stated, this method is not quite so satisfactory as the second method, where exact matches to patterns have to be produced ; but it is very useful in pro- ducing shades fast to washing. Method (4) is frequently employed in producing cross-dyed effects on union damask, etc. It is also used in dyeing light shades, wool blouses, and dresses trimmed with cotton or artificial silk lace and trimmings, the latter, if left white, producing a pleasing effect. Blouses, dressing-gowns, etc., in light shades are usually made with white cotton linings, coloured materials being rarely employed. In such cases it is always desirable to select acid colours which will not stain the cotton. In fact, the garment dyer should always endeavour to reproduce the combinations usually found in new garments, as the result is always more pleasing and acceptable to a customer than the possession of an article which obviously has been re-dyed. Method (5) is occasionally employed in the dyeing of faded goods. Wool, Silk and Cotton Mixtures. — This combination is very frequently met with by the job dyer in garments and in curtains, etc. In garments, a wool or half-wool dress is frequently lined or trimmed with silk, or the dress fabric may be composed of wool and silk and the lining of cotton. A typical wool and silk dress fabric is a crepe fabric with a wool warp and silk weft, the crepe effect being produced by the contraction of the hard twisted wool. In curtains and draperies many half-wool and silk fabrics are employed (roman satin, etc.), frequently in combination with cotton (or part cotton) trimmings or linings. The dyeing of those fabrics is very similar to the dyeing of half-wool articles. If badly faded, an oxidising stripping agent is employed, followed by dyeing the wool and silk in an acid bath, the cotton being dyed in a subsequent bath with a direct colour. The precautions given under the heading of Wool and Silk Unions must be observed. If the articles are not faded, the best results are obtained by dyeing with "neutral dyeing" acid colours com- bined with direct colours which principally dye the cotton. Where no pattern has to be matched, direct colours dyed in a salt bath may in some cases be employed. As a general rule the cotton and silk are sufficiently dyed at about 160° F. and the wool at the boil, uniform shades being obtained by carefully adjusting the temperature. Wool. — All-wool fabrics are not frequently met with in garments, which usually have more or less cotton interwoven, or 142 DYEING AND CLEANING. in the form of linings, etc. ; but they are frequently employed in curtains, e.g. wool repp, wool damask, etc. These are almost invariably re-dyed with acid colours, a reducing agent being employed for stripping, if they are not faded ; or an oxidising bath, if they are badly faded. Cotton or Linen. — Cotton fabrics are prepared for dyeing by removing the old colour by (1) alkalies; (2) hypochlorites; (3) titanous chloride, the processes being selected in the order named : they are always re-dyed with substantive colours in neutral baths. If bright colours are desired, they may be topped in a separate bath with basic colours. It must, however, be remembered tliat basic colours dyed in this way are not very fast to light. Silk. — Unweighted silks (crepe de chine, etc.) may be cleaned in soap baths, and dyed in acid baths with acid colours without any special precautions, but weighted silks (glace, etc.) should not be touched before testing a small piece of the fabric. These and heavy unweighted silks (bengalines, etc.) should be handled as little as possible during the processes of cleaning and dyeing, the best results being obtained by dyeing on frames w^hich are let down into the dye bath. Basic colours are only employed on silk fabrics in the production of bright "gaslight" shades. The colours produced are not fast to light, but this is not always of importance. The most satisfactory results on expensive silk fabrics, especially in light and medium shades, are obtained in many cases by "dry-dyeing" (see p. 166). Silk and Wool Unions (Gloria, etc.). — If faded, these goods are stripped in an oxidising bath ; otherwise, hydrosulphite is employed. They are usually re-dyed with acid colours, the silk taking a darker shade at a moderate temperature, and the wool being darker at or near the boil. The silk, in fact, after being darker at a moderate temperature loses some of its colour at the boil. After the wool is dyed nearly dark enough the bath is allowed to cool off until the silk is sufficiently dark ; the best effect being produced when the silk is a little lighter than the wool. By selection of the dyes, cross-dyed effects may be obtained on silk and wool fabrics. For closely woven goods which are difficult to penetrate, uniform results are obtained with certain cotton substantive colours dyed in a neutral bath (with the addition of sodium sulphate). Silk and Cotton (Satin, etc.). — Preparing with boiling soap is usually sufficient, but if a stripping agent is required use hydro- sulphite (or titanous chloride). The dyeing is usually done with substantive colours in a neutral bath, followed, if necessary, by topping in a separate acidified (acetic acid) bath with acid or basic DYEING. 143 colours, the former dyeing the silk only, the latter going on to both the cotton and the silk. Cross-dyed effects may be obtained by employing acid colours on the silk, the cotton remaining white ; it may be subsequently dyed in a separate cold bath with suitable substantive colours. Useful effects may be obtained in this way by dyeing pale shades in silk blouses with lace insertion, the latter being left white or tinted cream in a separate bath. In pale shades the cotton stitching will not show very much, but a similar effect in medium shades can only be obtained if the article is stitched with silk. This method is also frequently employed in re-dyeing silk casement curtains, which are usually made with cream cotton lace insertion. Selection of Dyes. — To determine the relative value of any dyestuff the following properties must be considered : 1. Solubility in water. 2. Equalising (or levelling) power. 3. Fastness to light. 4. Behaviour towards other influences — perspiration, rubbing, ironing, and washing. Solubility. — Colouring matters should be dissolved in pure water when possible, but if this cannot be done the lime must be corrected by the addition of acetic acid or soda, according to the properties of the dyestuffs, as some dyestuffs form insoluble compounds with lime. The precipitation of dyestuffs in standing baths is generally due to the use of hard water, unless the dye- stuff has been "salted out," by excess of sodium sulphate or sodium chloride in the bath. Equalising Power. — This depends upon the affinity of the dyestuffs for the fibres. Colours which are taken up by the fibre slowly, generally yield more even dyeings than those which exhaust quickly. The addition to the bath of common salt or sodium sulphate tends to retard the absorption of colouring matters possessing strong affinity for the fibre ; consequently, more even dyeings are obtained. Of the acid dyestuffs, the yellow and orange colouring matters equalise better than the reds, blues, and violets. The "neutral dyeing" acid colours generally dye more level than those requiring the addition of an acid, the equalising powers of the acids usually employed being in the following order, the first named giving the most satisfactory results : (1) Formic acid ; (2) acetic acid ; (3) sulphuric acid. The production of level dyeings depends largely upon the regulation of the temperature of the dye-bath ; good results can always be obtained if the temperature is carefully raised during the process. 144 DYEING AND CLEANING. Fastness to Light. — This is very important, particularly in the dyeing of curtains, etc., which are more or less continually exposed to direct sunlight. Only dyestuffs possessing good fastness to light should be employed ; as a rule the red, yellow, brown, and black dyestuffs surpass the green, blue, and violet dyes. Many of the acid and substantive dyes are very fast to light ; whereas the basic dyes are, on the whole, fugitive. (Where no colours are particularly fast, e.g. violets on half-wool fabrics, the best available dyestuffs are given.) The following acid dyestuff^s may be recommended for their fastness to light : Reds.—kmidiO Naphthol Red, 2 B, 6 B, G (M.L.B.), Azo Acid Carmine B (M.L.B.), Azo Fuchsine B, G (By.), Azo Acid Magenta B, G (M.L.B.), Brilliant Cochineal 2 R (C), Brilliant Croceine (By.), Chromotrope 2 R (M.L.B.), Cloth Red B, G (By.), Cloth Red 0 (M.L.B.), Guinea Red 4R (Ber.), Lanafuchsine 6B (C), Ponceau 6 RB (Ber.), Victoria Scarlet (Ber.). Oranges. — Croceine Orange G (By.), Orange IIB (By.) [not so fast as Croceine Orange G], Orange EN, ENZ (C), Orange GG (C). Yellows.— k(^i^ Yellow AT (C), Acid Yellow G (Ber.), Fast Light Yellow G (By.), Fast Yellow, extra (By.), Fast Yellow S (C), Flavazine L (M.L.B.), Milling Yellow 0 (C), Tartrazine (By.). Greens. — Alizarine Cyanine Green E, G (By.), Cyanole Fast Green G (C), Cyanole Green 6 G (C.) [these are somewhat faster than Acid Green extra cone. (C.)], Fast Green bluish (By.), Fast Light Green (By.). Blues. — Acid Cyanine B, R (By.), Alizarine Sapphirole B (By.), Cyanole extra (C.) [moderately fast], Fast Blue for wool (Ber.), Lanacyl Blue BB, R (C), Peri Wool Blue B (C), Sulphon Cyanines (By.). Violets. — Azo Acid Violet B extra (By.), Azo W^ool Violet 7 R (C), Fast Acid Violet A 2 R, B, R (M.L.B.), Patent Acid Violet 4R (B.A.S.F.). ^/ac'^'s.— Naphthol Black B (C), Naphthylamine Black 4 B, 6 B, S (C), Nerol Black (Ber.), Phenylamine Black 4 B (By.), Victoria Black B (By.), Wool Black GR (Ber.). The following substantative cotton dyestufi's give practically level shades, moderately fast to light, on half-wool fabrics : Reds. — Diamine Bordeaux B (C), Diamine Fast Red F (C.) [faster on wool than on cotton], Dianil Claret Red B, G (M.L.B.), Dianil Red 4 B, 10 B, R (M.L.B.), Geranine G (By.). Oranges. — Congo Orange R (Ber.), Diamine Orange B (C.) [the fastness is materially improved by after-treatment with copper sulphate], Dianil Orange N (M.L.B.). Yellows. — Aurophenine 0 (M.L.B.), Chloramine Yellow M (By.), DYEING. 145 Chrysamine G (By.), Chrysophenine G (Ber.), Diamine Fast Yellow FF (C), Diamine* Gold (C), Diamine Yellow CP (C.), Dianil Yellow 3G, R, 2R (M.L.B.). Greens. — Diamine Green B, G (C.). Blues. — Diamine Blue RW (C.) [especially by after-treatment with copper sulpliate], Diamine Fast Blue C (C.), Dianil Indigo 0 (M.L.B.). Violets. — Diamine Violet N (C.) [faster on w^ool than on cotton], Oxy Diamine Violet B (C.) [not so fast as Diamine Violet N]. Blacks. — Benzo Fast Black (By.), Diamine Black HW (C.), Dianil Black N (M.L.B.), Patent Dianil Black FF (cone.) (M.L.B) ; by diazotising and developing, or by after-treatment with copper sulphate, many direct blacks are made very fast to light. In addition to the substantive colours mentioned above as specially suitable for dyeing shades fast to light on unions, the following direct colours are recommended for their fastness to light on cotton goods : ^^f?5._Benzo Fast Scarlet 4 BS (By.), Columbia Red 6 B (Ber.), Diamine Rose BD (C), Erika (Ber.). Oranges. — Chloramine Orange G (Ber.), Diamine Orange G (C.), Dianil Orange G (M.L.B.), Mikado Orange (Ber.). r^/^om. -Brilliant Yellow (By.), Cresotine Yellow G (M.L.B.), Diamine Fast Yellow A, AR, B (C), Diamine Yellow N (C), Dianil Direct Yellow S (M.L.B.), Oxydianil Yellow G, 0 (M.L.B. ), Primuline (after-treated with chloride of lime). Greens. — Benzo Dark Green B (By.), Benzo Olive (By.), Dianil Green G (M.L.B.). Blues. — Brilliant Azurine 5G (By.), Congo Fast Blue R (Ber.), Diamine Fast Bhie C, CG (C), Dianil Blue H 2 G, H 6 G (M.L.B.) ; many direct blues are made very fast to light by after-treatment with copper sulphate. F^'o/e^s. —Benzo Fast Violet R (By.). Browns. — Benzo Chrome Brown G, 3 R (By.), Diamineral Brown G (C), Dianil Brown G, B, D (M.L.B.), Dianil Chrome Brown G (M.L.B.), Dianil Fast Brown B (M.L.B.). Blacks. — Diamine Jet Black 00, SS, Cr, RB (C), Diaminogen extra (C), Dianil Black CR, ES (M.L.B.), Pluto Black CR (By ). Fastness to Perspiration. — Most of the colours mentioned are sufficiently fast with the following exceptions : Brilliant Croceine, Eosine, Erythrosine, and Phloxine on cotton. Fastness to rubbing can be attained by avoiding basic dyestuffs. Fastness to Ironing. — Many dyes change in shade during the process of ironing, but in nearly all cases the change is not per- manent ; the exceptions include a few of the direct reds — e.g. Diamine Red 4 B and Diamine Scarlet 3 B. 10 146 DYEING AND CLEANING. Fastness to Washing. — Half-wool garments for outdoor wear should be dyed with colouring matters fast to washing. Most of the substantive cotton dyestuffs are satisfactory for this purpose in combination with suitable neutral dyeing" acid colours such as the following : Reds — Acid Rosamine A (M.L.B.), Scarlet B extra (M.L.B.). Orange, — Orange IIB (By.). Yellotvs. — Azo Acid Yellow (Ber.), Indian Yellow G (By.). Greens. — Brilliant Acid Green 6 B (By. ), Brilliant Milling Green B (C), Fast Green extra (By.) [fairly good]. Blues. — Alkaline Blue (all brands), Formyl Blue B (C.), Fast Acid Blue R (M.L.B.), Lanacyl Navy Blue B (C.), Patent Blue A (M.L.B.), Sulphon Cyanine G, GR extra, 3 R, 5 R (By.), Thio- carmine R (C.). Violets.— kQid Violet 5 BN, 7 BN (M.L.B.), Alkali Violet LR (By.), Formyl Violet S 4 B (C.). Blacks. — Amido Naphthol Black 4 B (M.L.B.), Naphthylamine Black 4 B (C.). Dyeing of Half- wool (Wool and Cotton) Fabrics. Method 1. — This is a two-bath process, the wool being dyed with an acid colour in an acid bath, the cotton being subsequently dyed with direct colours having little or no affinity for wool. It is one of the oldest methods of dyeing half- wool garments, etc., but is now usually employed with goods which are faded. The assist- ants employed are sulphuric acid and sodium sulphate (Glauber's salt) ; or, with goods w^hich are difficult to penetrate or to dye evenly, acetic acid or formic acid replaces the sulphuric acid with advantage (the risk of tendering the cotton is also removed by the employment of the organic acids). The amount of dyestuff em- ployed depends upon the tinctorial power of each colouring matter ; it averages from *! per cent, for light shades up to 2 to 6 per cent, for dark shades (calculated upon the weight of the goods), with the addition of 10 to 20 per cent, of Glauber's salt and 4 to 5 per cent, sulphuric acid (or equivalent amounts of acetic or formic acids). With colours which do not equalise well the acid may, with advantage, be added a little at a time as the process proceeds ; in such cases the quantity of Glauber's salt may also be increased. When organic acids are employed the bath may be cleared by the addition of a little sulphuric acid w^ien it appears to be nearly exhausted. The goods are entered into the bath at 120° to 150° F., the tem- perature being slowly raised to boiling-point and maintained at that temperature for half an hour to one hour. Faded goods must not be boiled too much. DYEING. 147 The following acid dyestufFs are suitable for dyeing wool in the manner described, those marked * being specially recommended for their level-dyeing properties : — Beds. — Acid Magenta (C, etc.), Azo Acid Carmine B (M.L.B.), Azo Acid Magenta B, G (M.L.B.), Azo Crimson S (By.),* Azo Fuchsine G (By.),* Azo Phloxine 2 G (By.),* Brilliant Cochineal 2 R (C), Brilliant Croceine (By., etc.). Brilliant Scarlet 3R (C), Chromotrope 2 R (M.L.B.), Cloth Red B, G (By.), Cloth Red 0 (M.L.B.), Croceine Scarlet 2 Bx (By.), Fast Acid Magenta B (M.L.B.),* Guinea Red 4 R (Ber.),* Guinea Carmine B (Ber.),* Lanafuchsine 6 B (C), Lanafuchsine SG (C.),* Ponceau 6 RB (Ber.), Rosazeine B (C.),* Victoria Scarlet (Ber.), Victoria Scarlet 2 R, etc. (M.L.B.). Orange. — Brilliant Orange G (M.L.B.),* Croceine Orange G* (By.), Mandarin (Orange II) (Ber.),* Orange IIB (By.),* Orange EN, ENZ (C), Orange G (M.L.B.),* Orange GG (C.),* Orange extra (C.),* Orange RO (By.). Yelloivs.—KQ\^ Yellow AT (C.),* Azo Yellow 0 (M.L.B),* Fast Light Yellow G (By.),* Fast Yellow extra (C), Fast Yellow S (C.),* Indian Yellow G, R (all makes),* Metanil Yellow (C.),* Milling Yellow 0 (C), Naphthol Yellow S (all makes),* Quinoline Yellow (all makes),* Tartrazine (By.), Tropseolin 00 (C.).* Greens. — Acid Green extra cone. (C.),* Acid Green 5 G (C.),* Alizarine Cyanine Green E, G (By.), Alkali Fast Green G (By.),* Brilliant Acid Green 6 B (By.),* Cyanole Fast Green G (C),* Cyanole Green B, 6 G (C.),* Fast Green Bluish (By.),* Fast Light Green (By),* Fast Light Green G (C). Blues. — Alizarine Cyanine B, R (By.), Alizarine Sapphirole B (By.),* Azo Wool Blue SE (C),* Cyanine B (M.L.B.),* Cyanole extra, AB, FF (C.),* Fast Blue for wool (Ber.), indigo extract (sulphonated indigo), Indigo Blue N, SGN (C.),* Lanacyl Blue BB, R (C), Patent Blue V, etc. (M.L.B.),* Peri Wool Blue B (C), Sulphon Cyanines (By.), Tetra Cyanole V (C.),* Thiocarmine (C). Violets.— kcidi Violet 6 BN (By.),* Acid Violet N (M.L.B.),* Azo Acid Violet B extra (By.),* Azo Acid Violet AL (By.), Azo Wool Violet 4 B, 7 R (C.),* Fast Acid Violet A 2 R (M.L.B.),* Fast Acid Violet R (M.L.B.),* Fast Acid Violet B (M.L.B.), Fast Acid Violet 10 B (By.),* Formyl Violet S 4 B, 10 B (C), Patent Acid Violet 4 R (B.A.S.F.). Blacks.— km Merino Black BE, 6 BE (C.),* Naphthol Blue Black (C), Naphthylamine Black 4 B, 6 B, S (C), Nerol Black (Ber.), Sulphon Cyanine Black B (By.), Victoria Black B (By.), Wool Black GR (Ber.). (Blacks are very rarely dyed on unions by this method.) Dyeing by this method, only the wool is dyed ; the cotton 148 DYEINCx AND CLEANING. threads, linings, etc., generally become lighter in shade owing to the colouring matters being stripped off in the boiling acid bath. When organic acids are employed in place of sulphuric acid the stripping of the cotton is very much reduced. The goods must be thoroughly rinsed to remove all traces of acid, the presence of which w^ould cause some of the direct colour in the " filling up bath to go on to the wool. In any case it is advisable to leave the shade of the wool a little lighter than the pattern to allow for the small amount of dyestuff which it may take up. The wool may be brought up to pattern by slightly warming the bath. The dyeing of the cotton is usually done w ith direct colours which have little or no affinity for wool in a cold or lukewarm bath, common salt or Glauber's salt being employed as an assistant. As such baths do not exhaust, it is usual to keep " standing " baths of the colouring matters principally employed for dark and medium shades. The dyeing of the cotton should not take place in the vessel in which the standing liquor is stored, but in a clean vat or copper. The most satisfactory method is to transfer about one quarter of the standing liquor to the dye vessel, and the necessary quantity of previously dissolved dyestuff, and bring to boil ; then add nearly the whole of the remaining standing liquor and fill up with cold water. By adopting this mode of procedure, the standing bath is continually freshened up. An excess of salt or Glauber's salt must be avoided, as it may ^' salt " out the dyestuff. F. E. Robertson {privately communicated) finds that the stand- ing dye-bath when used cold should not register more than about 1*5° Tw. ; if a larger proportion of salt is employed, bringing the density of the bath up to 2*5*' Tw., the wool is found to be coloured to a greater extent, and the slightly deeper shade found on the cotton has a tendency to be uneven, due to the " salting out " of the dyestuff. He found that dyeing with a bath of about 1° Tw. (cold) made up with — 3 2Tams Brilliant Azurine B ) .-i. a 14. r per litre, 0 grams common salt J ^ immersion for two hours gave a somewhat deeper shade on the cotton than dyeing for one hour only, the wool taking up only a trace more colour during the longer immersion. Dyeing cotton, wool, and faded wool in the above bath at 35° C. for one hour gave a much deeper shade on the cotton, whereas the wool and the faded wool (which had been exposed for six weeks uncovered), did not take up any more colour than when dyed cold for two hours. If the dyestuff is in excess of the salt in a cold bath registering DYEING. 149 2°-3° Tw., a considerable quantity of dyestuft' will go on to the cotton without being properly fixed, with the result that bronzi- ness will be noticeable after drying, and in addition the wool is found to absorb a considerable quantity of colour. He found that a large excess of salt in the cold bath causes the dyestuff to go on to the fades. In a range of experiments with dyebaths varying from 1*5° Tw. to 10° Tw., it was found that the cotton became lighter and less level as the proportion of salt increased ; the wool showed but little variation, but the faded wool absorbed an increasing amount of dyestuff with the increas- ing density of the bath. With a bath of 2° Tw. the faded wool w^as darker than the unfaded wool, and with greater densities it w^as actually darker than the cotton. As the result of these experiments he recommends that filling- up baths should never exceed 2^ Tw. in density. The direct dyestufFs suitable for "filling up" the cotton after the wool has been dyed with acid dyestufFs are as follows (those marked thus do not tint the wool, or only slightly so, and give the best results) : Reds, — Benzo Red SG (By.), Cotton Red A (C), Diamine Red 4 B, 10 B (C), Diamine Rose BD (C.),^ Erika BN (Ber.). Orange. — Chloramine Orange G (By.),"^ Diamine Orange G, D (C.),^ Dianil Orange G (M.L.B.), Mikado Orange 4 RO (Ber.).^ Yellows. — Chloramine Yellow HW (By.),"^ Diamine Fast Yellow A (C.),'' Diamine Fast Yellow B, FF (C), Dianil Yellow 2 R (M.L.B.), Direct Yellow R (By.). Greens. — Columbia Green (Ber.), Diamine Green B, G (C). Blues.— Qhics^go Blue 6 B (Ber.), Columbia Black HWD (Ber.)/ Columbia Bhie G, R (Ber.),^ Diamine Black BH, BMW (C.),^ Diamine Sky Blue (C), Diamineral Blue R (C), Dianil Blue G, R, B (M.L.B.), Diazo Black BHN (By.)^. Browns. — Benzo Dark Brown extra (By.), Diamine Catechine B (C.),"^ Diamine Brown M (C.),^ Diamine Nitrazol Brow^n B (C.),^ Dianil Brown R (M.L.B.). Violets, — Benzo Violet R (By.), Diamine Heliotrope 0, B, G (C.) Oxy Diamine Violet B (C). Blacks, — Those given under " Blues." Method 2. — This method consists in dyeing half-w^ool fabrics with direct colouring matters (principally dyeing the cotton) and ^' neutral dyeing " acid dyestuff in one bath. It is employed when direct dyestuffs will not produce sufficiently bright shades, especially when the goods contain but little cotton, and w^hen it is necessary to match a pattern exactly, as already explained under Selection of Dyeing Process. The dyeing is performed at, or near, the boil, with the addition 150 DYEING AND CLEANING. of 1 lb. of Glauber's salt per ten gallons of liquor for pale shades up to double the quantity for dark shades, or w ith an equivalent amount of common salt. The goods are entered lukewarm and the bath gradually brought up to the boil. Most of the " neutral dyeing " acid colours equalise well (especially in a neutral bath), and may be added at the boil for shading purposes. The bath is allowed to cool off towards the finish in order to bring the cotton up to the correct shade. The advantage of this method in " pattern dyeing " over the dyeing of unions with direct colours alone depends on the ease with which some of the colour may be removed from the wool if the shade produced is too dark. This is done by entering in a fresh bath with Glauber's salt, bringing to the boil, whereby a considerable amount of the acid dyestufF is removed, and bringing up to the pattern with the necessary quantity of dyestuff. Standing baths may be employed in this method for standard colours. The following acid dyestufFs dye wool in a neutral bath : Reds. — Acid Alizarine Red 3 B (By.), Acid Anthracene Red G (By.), Acid Rosamine A (M.L.B.), Azo Red A (C.), Brilliant Croceine 3 B (By.), Croceine AZ (C.), Fast Red 0 (M.L.B.), Rhodamine B (By., etc.), Roccelline (C.), Rosazeine (C., etc.). Scarlet B extra (M.L.B.). Orange. — Croceine Orange G (By.), Orange extra, ENZ (C), Orange No. 2, No. 4 (M.L.B.), Orange RO (By.). Yellows.— kzo Yellow 0 (M.L.B.), Indian Yellow G, R (C. etc.), Sulphon Yellow 5 G, R (By.), Tropseoline 00 (C), Victoria Yellow 0 (M.L.B.). Greens. — Brilliant Acid Green 6 B (By.), Brilliant Milling Green B (C), Fast Green CR (By.), Naphthalene Green Y (M.L.B.). Blues. — Alkaline Blue, all brands (all makers). Blue for half- wool BD (M.L.B.), Formyl Blue B (C), Fast Blue (M.L.B.), Lanacyl Blue 2 B, R (C), Lanacyl Navy Blue B, 2 B (C), Naphthol Blue G R (C), Neutral Blue 0 (M.L.B.), Patent Blue A (M.L.B.), Sulphon Cyanine GR extra, 5 R extra (By.), Thio- carmine R (C), Wool Blue N extra, R extra (By.). Violets.— kcidi Violet 5 BF, 7 BN, N (M.L.B.), Alkali Violet LR (By.), Alkaline Violet CA (C), Formyl Violet 6 B, 10 B, S 4 B (C), Fast Acid Violet A 2 R, B, R (M.L.R.), Neutral Violet 0 (M.L.B.). Blacks.— ChromQ Black B, T (M.L.B.), Naphthol Blue Black (C), Naphthylamine Black 4 B, 6 B, D (C), Wool Black N 4 B (By.). The various brands of Alkaline Blue are dyed near ITS'* to 195° F., with the addition of 4 to 5 per cent, borax ; after dyeing, the goods are rinsed in water, and the colour is "raised'' in a hot bath containing a small quantity of sulphuric acid. The substantive cotton dyestuffs which are used in combination DYEING. 151 with the cibove " neutral dyeing " acid colours are preferably those which have little or no affinity for wool, a list of which will be found on page 149. Method 3. — This method resembles the preceding one in being a " neutral bath " process, the dyestufis employed being sub- stantive cotton colours which dye practically level shades on cotton and wool. It may be combined with the previous method by largely depending upon the direct colours for the production of the colour desired, but shading or brightening the wool by the addition of a small quantity of a " neutral dyeing " acid colour. There is now a very large range of direct dyestuffs available for the production of practically solid shades on half- wool goods. Though the shades obtainable are not so bright as those dyed with acid colours, this is not always of primary importance, and the simplicity of the process has led to its employment to a very considerable extent, especially in the production of dark shades. Blacks are almost invariably dyed on half-wool by this method. The dyeing takes place with the addition of 20 to 30 per cent. Glauber's salt or the equivalent amount of common salt, and it may be taken as a general rule that the wool is dyed a fuller shade at the boil, and the cotton a fuller shade at a lower tempera- ture (160° to 180° F.). The production of a solid shade depends upon the careful regulation of the temperature of the bath. In all cases when wool is dyed in a neutral bath special care must be taken in rinsing out the alkali employed in the preparatory cleaning of the goods, as its presence, even in small quantities, has a detrimental action on the wool in the boiling bath. The goods are usually entered into the bath at about 140° F., the temperature being gradually raised to the boil and allowed to cool down towards the finish. The following dyestuffs give practically solid shades on wool and cotton fabrics : Reds. — Benzo Bordeaux 6 B (By.), Benzo Fast Bed FC, L (By.), Benzopurpurine 4 B, 10 B (all makers). Diamine Bordeaux B (C.), Diamine Rose BD, GD (C), Diamine Fast Red F (C.), Dianil Fast Red PH (M.L.B.), Geranine G (By.), Oxy Diamine Red S (C.). Orange, — Benzo Fast Orange S (By.), Congo Orange R (Ber.), Diamine Orange B (C.), Dianil Orange N (M.L.B.). Yelloivs. — Chloramine Yellow M (By ), Chrysamine G (By.), Chrysophenine G (Ber.), Diamine Fast Yello^v B, FF (C), Diamine Gold (C.), Diamine Yellow CP (C), Dianil Yellow 3 G, R, 2 R (M.L.B.), Oxy Diamine Yellow GG (C), Thioflavine S (C). Greens. — Benzo Dark Green B, GG (By.), Benzo Green BB, C (By.), Diamine Green B, G (C), Union Green (Ber.), Union Leaf Green (C). 152 DYEING AND CLEANING. Blues.— Beuzo Blue RW (By.), Brilliant Benzo Blue 6 B (By.), Diamine Blue RW (C), Diamine Dark Blue B (C.), Diamine Fast Blue C (C), Dianil Blue BX (M.L.B.), Dianil Indigo 0 (M.L.B.), Navy Blue for half-wool (By.), Oxy Diamine Blue R, G, 3 G, 5 G (C.), Union Blue (C.). Brotvns. — Benzo Chrome Brown B, G, 5 G, MC, R (By.), Benzo Dark Brown extra (By.), Diamine Brown M (C), Diamine Catechine G (C.), Dianil Brown 3 GO, 3 R (M.L.B.), Dianil Copper Brown 0 (M.L.B.), Oxy Diamine Brown G (C), Union Brown (C). Violets. — Diamine Heliotrope G, B, 0 (C), Diamine Violet N (C), Oxy Diamine Violet B (C.) [the two latter dye the cotton a fuller shade than the wool], Union Violet B (Ber.). i^/ac^'s.— Dianil Black N, E (M.L.B.), Direct Deep Black E, EW, RW (By.), Half-wool Black LS, BGS (By.), Oxy Diamine Black A, D, JW (C), Patent Dianil Black FF cone. (M.L.B.), Pluto Black BS, F (By.), Union Black (C), Union Black S, P, BG, special (C). The blacks may be shaded with any of the above mentioned direct greens, or the addition of a small quantity of Gloria Black (By.) ; Naphthylamine Black 4 B, will add ''bloom " to the wool. In any of the three foregoing methods the cotton may be brightened by "topping" in a separate bath with a basic dyestufF with the addition of acetic acid. If too large a quantity of basic colouring matter is employed, the colour produced is liable to rub. The colouring matters usually employed for this purpose are : Auramine 0. Magenta. Brilliant Green crystals. Methyl Violet. Chrysoidine. Methylene Blue. This process must not be employed for "topping" cotton dress linings, as the colour will rub on to white undergarments ; nor should it be employed for curtains and other articles liable to continued exposure to light, as the basic colours dyed in this way are very fugitive to light. Method 4. — Two-colour effects are produced by this method, by dyeing the wool with acid colours which do not stain the cotton, the latter being left white or subsequently dyed a different shade to the wool with direct colours which do not go on to the wool ; most of the acid dyestufis leave the cotton white or practi- cally so. In dyeing the wool the white on the cotton becomes purer as the bath is made more acid ; the best results are ob- tained by using the acid colours given under Method 1 on p. 147, which equalise well in a sulphuric acid bath. If the cotton is to be kept white (e.g. lace on wool blouses, etc.) the final rinse should contain a small quantity of acetic or formic acid. The cotton may be " cross-dyed " with direct colours in cold baths DYEING. 153 with the addition of salt or Glauber's salt, the dyestuffs referred to on p. 149 as having little or no affinity for wool giving the best results. Cross-dyed effects may be obtained in one bath by employing " neutral dyeing " acid colours and suitable direct colours, but the two-bath process is recommended. Some dyes possess the property of dyeing wool and cotton different colours in the same bath ; e.g. Benzo Olive (By.) dyes cotton green and wool brown. Method 5. — This is one of the oldest methods of dyeing half- wool goods, and though not in general use is occasionally employed in dyed faded goods in medium and dark shades of brown, blue, green, maroon, etc. It is usually known as the "three bath" process, and consists in dyeing the wool with acid dyestuffs, the cotton being subsequently filled up by mordanting with iron and tannic acid (see p. 157), and dyeing with basic colouring matters at a low temperature. There is a tendency for the faded wool to become darker than the unfaded wool, but not to so great an extent as may occur in Methods 1, 2, or 3. There is also a tendency for the colour on the wool to "rub " ; this is due to the presence of imperfectly fixed basic dyestuff on the wool. Wool, Silk, and Cotton Fabrics. — The fabrics are dyed by the same methods as half-wool fabrics ; if dyed according to Method 1, care must be taken to avoid acid dyestuffs which do not dye the silk {e.g. indigo extract, Azo Phloxine 2 G (By.), etc.). The following acid colours give practically level shades upon silk and wool ; at the boil the colour goes more on to the wool, and at a lower temperature on to the cotton, uniform shades being obtained by the regulation of the temperature of the bath. The goods are entered at 140" F. and the bath is slowly raised to the boil, maintained at the boil for fifteen to thirty minutes, and then allowed to cool off to bring the silk to shade. All the colours mentioned are dyed with the addition of Glauber's salt and sulphuric acid, with the exception of those marked thus "^j which are dyed with acetic acid or formic acid and Glauber's salt or common salt. Reds. — Acid Anthracene Bed 3 B, G (By.),"^ Acid Magenta (all makes), Bordeaux extra (By.), Brilliant Croceine 3 B (By.), Croceine AZ (C.), Erythrosine B (C.),"^ Fast Red A (By.), Rosa- zeine 13 (C.),^ Scarlet B extra (M.L.B.). Orange. —Orsiuge extra (C.), Orange No. 2 (M.L.B.). Yellows.— Azo Yellow 0 (M.L.B.), Indian Yellow G (By.), Tropgeoline 00 (C.). Greens. — Acid Green extra cone. (C.), Brilliant Acid Green 6 B (By.), Fast Green, blue shade (By.). Blues. — Alkaline Blues (for dyeing process see p. 150), Brilliant 154 DYEING AND CLEANING. Wool Blue G extra (By.), Cyanole extra, FF (C), Indigo Blue N (C), Patent Blue V (M L.B.), Thiocarmine R (C), Wool Blue 2 B (Ber.). Violets.— Add Violet N (M.L.B.), Fast Acid Violet A 2 R, B, R (M.L.B.), Fast Acid Violet 10 B (By.), Formyl Violet S 4 B, 6 B (C), Guinea Violet 4 B (Ber.). Blacks.— Q\oYi2. Black B (By.),* Naphthylamine Black 4 B, 6 B (C.),^ Victoria Black B (By.), Wool Black GR (Ber.). To add " body " to the silk small quantities of basic dyes tuffs may be added to the bath towards the finish, or in a fresh luke- warm acetic acid bath (the wool will take up some of the dyestufF). Only very small quantities of basic colours must be used or the goods will be liable to rub, and the following are suit- able for this purpose : Bismarck Brown, Chrysoidine, Brilliant Green, Indazine M (C.), Magenta, Malachite Green, Methylene Blue, Safranine, Tannin Orange R (C.), Thioflavine T. The cotton is dyed cold in a neutral bath with direct colours which do not go on to the wool or silk (see p. 149). The simplest method of dyeing goods containing wool, silk and cotton, consists in employing direct colours in neutral baths with or without the aid of "neutral dyeing" acid colours (see p. 150). The cotton substantive colours given on p. 151 as dyeing full shades on cotton and wool give in many cases solid shades on silk also, but where the silk is " thin " {e.g. when using Union Black 8) it can be topped with acid colours in a lukewarm bath with acetic acid {e.g. with Naphthylamine Black 4 B). The dye- stuffs given in the following table give practically level shades in all three fibres ; it may be taken as a general rule that the cotton and silk dye best at 160" to 180* F. and the wool at the boil. The goods are entered at 120° F. and brought to the boil in a quarter of an hour ; after boiling ten to fifteen minutes the steam is turned off and the dyeing is continued in the cooling bath. Reds. — Benzo Fast Red FC (By.), Benzo Purpurine 4B (all makes). Diamine Rose BD, GD (C.). Orange. — Congo Orange G (By.). Yellows. —Diamine Fast Yellow^ B (C.), Diamine Yellow CP (C), Dianil Yellow 3 G (M.L.B.), Thioflavine S (C). Greens. — Benzo Green G (By.), Diamine Green B, G (C), Union Leaf Green (C). Blues. — Diamine Brilliant Blue G (C), Diamine Blue RW (C), Diamine Dark Blue B (C). Browns. — Diamine Brown 3 G, M (C). Blacks.— D'miiW Brown N (M.L.B.), Union Black S (C). The substantive colours which dye fuller shades on cotton than DYEING. 155 on wool and silk (see p. 149) in combination with "neutral dyeing " acid colours give very good results, and the following may be taken as typical combinations : Wool Fabrics. — All wool articles are rarely found in dress materials, as cotton stitchings, linings or trimmings are almost invariably present. They are, however, frequently employed as curtains, draperies, etc., in repp, etc. Dyeing with acid colours in acid baths is employed, the mode of procedure being the same as that described for dyeing the wool under Method 1 for half- wool fabrics. If, for any special reason, it is desirable to use direct colours in a neutral bath, any of the dyestufFs which give level shades on half- wool may be employed. This method is only used when it is necessary to produce shades fast to washing on all-wool flannel, etc. Wool is not usually dyed by garment dyers by the other w^ell-known methods, viz. mordant colours, basic colours and vat dyes ; it is therefore unnecessary to describe the methods employed. Cotton or Linen. — Fabrics consisting solely of vegetable fibres are but rarely dyed by the garment dyer ; if, however, they come into his hands they are dyed with direct colours, follow^ed in some cases by topping with basic colours. If particularly fast colours are required direct colours are chosen, which can be after-treated Avith copper or chromium salts or by diazotisation and development. This method is useful, more especially in dark colours and black, as shades of exceptional fastness to light and washing can be produced. The usual method is to dye with the addition of 20 to 40 per cent. Glauber's salt or common salt and 1 per cent, of 58 per cent, alkali, entering the goods at the boil, then shutting off the steam and allowing them to dye in the cooling bath. Very pale shades — e.g.^ sky blue, pale pink, etc. — may be dyed with the addition of soap in place of the alkali, clearer shades being pro- duced thereby ; soap is also added to the bath in dyeing linen and half-linen goods which are difficult to penetrate. For dark \ Formyl Violet S 4 B, topped ( with Methyl Violet. i Benzo Brown MC. I Sulphon Cyanine GR extra. I Diamine Black BH. ) Sulphon Cyanine GR extra. 156 DYEING AND CLEANING. shades the soda may be omitted, and as the baths do not exhaust well, standing liquors are usually kept (see p. 148). Full ranges of direct dyestuffs suitable for cotton dyeing have been given under half- wool dyeing on pages 149 and 151. The following dyestuffs (which include some of those already mentioned) are specially recommended as suitable for after treatment by — 1 . Copper sulphate (marked ■^). 2. Potassium bichromate and copper sulphate (marked f). 3. Diazotisation and development (marked J). 1. Copper Sulphate. — The dyed goods are well rinsed in water and are then treated for ten to fifteen minutes at 120° to 140° F. in a bath containing 1 to 3 per cent, copper sulphate and a little acetic acid. The shade is in some cases dulled somewhat, but all the colours named are made very fast to light. 2. Bichrome. — The bath is prepared with — 2 to 3 per cent, potassium bichromate. 2 to 3 per cent, copper sulphate. 2 to 4 per cent, acetic acid 30 per cent. This bath is brought to the boil and the goods are treated for twenty to thirty minutes and then rinsed. This after-treatment improves their fastness to washing, in addition to rendering them fast to light. Diazotising. — This method is employed occasionally in garment dyeing, especially in the production of fast navy and black {e.g, on velveteen). After rinsing, the diazotising is done in a cold nitrous acid bath prepared by dissolving 3 per cent, sodium nitrite and stirring in 9 per cent, hydrochloric acid (or an equivalent quantity of sulphuric acid), wooden or earthenware vessels being employed (these quantities are calculated on the w^eight of the goods). The goods are immersed in this bath (which must be freshly prepared) for ten to fifteen minutes, care being taken to avoid direct sunlight, as the diazo compounds of the dyestuifs which are formed are very quickly decomposed by light, patchy results being obtained. The goods are quickly rinsed in cold water and are transferred to the " developing " bath (usually beta-naphthol or metaphenylene diamine) (^'phenylene diamine"). If beta-naphthol is employed, 1 per cent, is dissolved in its own weight of caustic soda solution 70° Tw. With " phenylene diamine " '6 per cent, is dissolved in 2 per cent, alkali. After development the goods are rinsed and soaped hot, if necessary, to remove bronziness. Direct colours suitable for after-treatment : Reds. — Diamine Fast Red F (C.) (after treated with chromium DYEING. 157 fluoride is made faster to washing), Primiiline I (beta-naphthol ; fast to washing, but not to light ; further treatment with copper sulphate gives a duller shade very fast to light). Orange. — Dianil Orange N (M.L.B.)."^ Yellows.— Chrjs'dmine G, R (By.),^t Diamine Yellow N (C.),^ Dianil Yellow R (M.L.B.) * Greens. — Benzo Olive (By.)t, Diamine Green G (C.) (as Diamine Fast Red F). Blues. — Benzo Azurine G (By.),*t Benzo Indigo Blue (By.),"^t Diamine Blue RW (C.),* Diamine Brilliant Blue G (C.),"^ Diamine New Blue R (C.),^ Diamine Sky Blue FF (C.),^ Diamineral Blue R (C.),"^ Diaminogene Blue BB (C.)| (with beta-naphthol), Dianil Blue, all brands (M.L.B.).^ Broivns. — Benzo Chrome Brown B, G (By.),t Cotton Brown A, N (C.)t (beta-naphthol or phenylene diamine), Dianil Brown B (C.),t Diamine Brown M (C)tJ (beta-naphthol or phenylene diamine), Dianil Brown 3 GO (M.L.B.),^t Dianil Fast Brown B,*t Pluto Orange G (By.).-^t Violets.— km Violet (By.),^ Chloramine Violet R (By.),"^ Diamine Blue 3 R (C.).'' Blacks. — Benzo Chrome Black B, N (By,),t Diamineral Black B, 3B, 6B (C.),t Diamine Black BH (C.)J (beta-naphthol or phenylene diamine), Diaminogene B, extra (C.) % (beta-naphthol or phenylene diamine), Dianil Black CR (M.L.B.).*t Topping with basic colours on direct dyeings on cotton has already been described. Dyeing with basic colours on mordanted cotton is rarely employed in garment dyeing, but as it is used occasionally by some dyers for filling up cotton linings in wool dresses which have been dyed with acid colours, the mode of procedure will be described. Tannic acid or sumach extract is employed, the former for light shades and the latter for dark shades, the mordanting bath containing from 2 to 5 per cent, tannic acid according to the depth of shade (four to five times Sumach Extract, about 23 per cent. Tannin ; or eight times the quantity of sumach powder, about 12*5 per cent. Tannin). The goods are worked in the bath for a short time at 120° F., and are then allowed to remain in the bath for several hours (or over night). The goods are then squeezed out and fixed" in a cold bath with 1 to 3 per cent, tartar emetic if tannic acid has been employed, or nitrate of iron 2 to 4° Tw. if sumach extract has been used. The goods are rinsed w^ell and are ready for dyeing. The dyeing takes place with the addition of 1 to 2 per cent, acetic acid or 5 per cent, alum, and owing to the rapidity wdth which the mordanted fibre absorbs the dyestuif, the goods must be worked cold until the 158 DYEING AND CLEANING. bath is almost exhausted ; otherwise, uneven shades are produced. As a further precaution it is advisable to add the dyestutf solution in several portions. When the bath is practically exhausted the temperature is slowly raised to 100° to 120° F. In employing this method to dye the linings of wool dresses, etc., the mordant- ing and dyeing must take place in the cold in stronger liquors than those given for cotton alone. Even with these precautions the surface of the wool may take up some of the dyestuff : it may be " cleared " with weak hydrochloric acid or a lukewarm bath of soap, or soap bark (quillaia). Cotton piece goods are now largely dyed with " sulphur colours (katigen, immedial, and similar series) in alkaline baths ; but it does not appear probable that these will be applied in the garment dyeing trade. To produce economical results, standing baths of considerable strength must be employed in regular use. The dyestuffs are dissolved in sodium sulphide and dyed with the addition of soda and Glauber's salt or common salt at the boil. They may be rendered faster to light and washing by after treatment with copper sulphate or potassium bichromate. Silk Dyeing. — The silk fabrics submitted to the garment dyer may be divided into those which are not adulterated and those which are weighted " with tin and other weighting matters. The former class includes, as a rule, those fabrics which have been woven "in the gum" and have been "boiled off" and dyed in the piece, whereas the weighted fabrics, in nearly all cases, have been dyed and weighted in the skein. Examples of un- weighted silks are crepe de chines and fancy crepon fabrics, which depend upon highly twisted threads for the production of the crepon effect, chiffons, soft china silks, "spun silk" goods, Tussore fabrics, etc. Weighted silks include nearly all those employed as linings, such as glace and other " rustling " silks, also heavy dress silks, some bengalines (these are sometimes piece-dyed and consequently unweighted), silk-backed satins, etc. (See Appendix A.) Weighted silks are usually very tender, particularly if they have been exposed to any extent, and it is very rarely that they can be dyed satisfactorily, the best results being obtained after a pre- paratory scalding. If received in an unpicked condition they are frequently dyed on frames, but in any case they must be handled as little as possible and with very great care, and always at "owner's risk." On the other hand, unweighted silks (such as crepe de chine) are very strong, and with the exception of a tendency to " fray " in certain fabrics {e.g. brilliantes), no special precautions need be taken in dyeing them. Articles consisting entirely of silk are DYEING. 159 almost invariably dyed with acid dyestiiffs, basic colours and substantive cotton being employed for special purposes only, which will be duly referred to. In dyeing with acid colours the goods are entered at about 120'' F. and the temperature of the bath is gradually raised to about 190° F., acetic, formic, or sulphuric acid being added. In nearly all cases acetic or formic acid will replace sulphuric acid with advantage, the better exhaustion produced by the latter being negligible in silk dyeing, whereas the organic acids produce better levelling baths. Silk fabrics are usually easy to penetrate, but hard portions are sometimes found in closely woven fancy fabrics (e.g. silk shawls and scarves with a chiffon ground and heavy stripes or borders). In such cases a substitute for boiled-ofF liquor " (which is not obtainable in a garment dye-house) may be made by dissolving one pound of neutral oil soap and 2| ounces leaf gelatine in four gallons of water. A sufficient quantity of this solution is added to the dye-bath (usually 4th the volume of the bath), and sulphuric acid is gradually stirred into the bath until it is slightly acid and the emulsion produced is made lukewarm. The goods are well wetted out in this bath and then lifted, while the dissolved filtered dyestufF is added ; the goods are again entered, the bath being slowly raised to 190° F. All silk goods, after rinsing in water, are scrooped" in a dilute acetic acid bath to impart to them the peculiar "handle" or scroop" possessed by all silk fabrics. With a few^ exceptions, all the acid colours dye silk satisfactorily, but the following dyestufFs may be recommended : Reds, — Azo Rubine A (C), Croceine AZ (C), Fast Red A (By.), Rhodamine B, Rose Bengale extra N (C), Scarlet, all brands (IM.L.B.). Oi'anges. — Orange extra (C), Orange II. (M.L.B.), Orange II. B (By.), Tropseoline 00 (C). Yellows.— Acid Yellow AT (C), Indian Yellow G (By., etc.), Quinoline Yellow (M.L.B., etc.). Greens. — Acid Green extra cone. (C.), Acid Green GG (By.), Fast Acid Green BN (C.). Blues. — Alkaline Blue (all makes ; for method of dyeing, see p. 150), Brilliant Wool Blue G (By.), Cyanole extra (C.), Patent Blue AN, superior, V (M.L.B.), Silk Blue B.E.S. (By.), Solid Blue R (C.). Violets.— Acid Violet 4R (By.), Acid Violet 4 RS, 5 BN (M.L.B), Formyl Violet S 4 B, 10 B (C.). Blacks. — Naphthylamine Black 4 B, 6 B (C.) (shaded with Indian Yellow and Acid Green). Basic colours are only used upon silk fabrics when it is desired 160 DYEING AND CLEANING. to produce shades which are fast to washing, or shades which are particularly brilliant in artificial light. Certain basic colours, especially Night Blue, are very fast to hot neutral soap baths, provided they have been dyed at the boil in broken soap baths. (See also Dreaper and Wilson, J.S.C.L, 1907.) Basic colours are usually dissolved in water to which a little acetic acid has been added, or in some cases in a small quantity of hot 30 per cent, acetic acid, hot water being added after the colour has dissolved. The dyebath is made up with 10 per cent, (on the weight of the goods) of neutral oil soap, if ^^boiled-otF liquor " is not available, and 1 to 2 per cent, acetic acid. The requisite amount of filtered colour solution is added, and the goods are entered at about 85° F. and slowly brought up to 140° to 160° F. If colours fast to washing are required, the goods must be brought up to the boil. After dyeing, the goods are well rinsed and scrooped " in an acetic acid bath. The basic colours are more fugitive to light than the majority of the acid colours, and should only be employed for special purposes. Direct colours are also employed in the production of shades fast to water and to w^ashing ; their fastness to soaping, however, is very inferior to that of many of the basic colours. For example. Night Blue which has been dyed at the boil will, even in pale shades, withstand boiling in a weak neutral soap bath for over an hour. The direct colours are dyed on silk in a soap bath broken with acetic acid, excess of acid being avoided ; those suit- able for diazotisation and development are treated in the manner described for cotton fabrics. Silk is also dyed with alizarine colours on various metallic mordants (chiefly aluminium, chromium, and iron) ; but as this method is of no interest to garment dyers, no details of the methods employed will be given. Tussore silk should only be dyed bright luminous shades, and should not be accepted for blacks, as it is very difficult to produce a full shade. Wool and Silk. — These goods may be dyed in acid or neutral baths, the latter method being the one usually employed. In dyeing level shades with acid dyestuffs the colours and method shown on p. 150 must be employed. Neutral baths are used for goods which are very closely woven and hard to penetrate ; the dyestuffs given on p. 153 give level shades on wool and silk. Whether dyed in neutral or acid baths, the goods are finally rinsed in a weak acetic acid bath to brighten the silk. By selecting acid colours w^hich leave the silk white, cross-dye effects may be produced. For this purpose the goods are dyed at the boil with the addition of 10 to 20 per cent, acetic acid, well DYEING. 161 rinsed, and treated for half an hour at 100° F. in a wheat bran bath to clear the silk; after rinsing, the goods are "scrooped" in acetic acid and dried. Another method of ''clearing" the silk is to work the goods in dilute acetate of ammonia ; in some cases warm water alone suffices. The following acid dyestufis employed in the manner described above leave the silk practi- cally white : Reds. — Acid Magenta (in pale shadeu), Azo Fuchsine G, 6 B (By.), Azo Phloxine 2 G (By.), Fast Red NS (By.), Lanafuchsine SG (C.), Scarlet 6 R (M.L.B.), Victoria Scarlet 3 R (M.L.B.). Orange. — Orange GG (C.). Yelloius. — kci^ Yellow A.T. (C.), Fast Yellow extra (By.), Naphthol Yellow (all makes), Tartrazine (By.) Greens. — Acid Green extra cone. (C.) (for pale shades only), Naphthol Green B (C.) (dyes the wool in an acid bath containing ferrous sulphate). Blues. — Alizarine Sapphirole B (By.), Azo Acid Blue B (M.L.B.), Cyanole FF (C.) (for pale shades), indigo extract paste. Violets.— kQid Violet 3 RS (M.L.B.), Azo Wool Violet 7 R (C.), Victoria Violet 4 BS (By.). Blacks.— kcidi Chrome Black WS 23250 (By.) (after-treated in a fresh bath with 2| to 3 per cent, potassium bichromate and 3 to 5 per cent, acetic acid), Naphthylamine Black EFF (C.) (after- treated in a bath 5 per cent. Decroline — or other hydrosulphite derivative — and 10 per cent, acetic acid at 120° F. for twenty minutes, and thoroughly rinsing, the second rinse containing 5 per cent, sulphuric acid). The silk may be subsequently dyed in a cold bath with the addition of acetic acid, basic or suitable acid colours being em- ployed. For this purpose the following acid colours may be given as examples: Fast Acid Eosine G (M.L.B.), Rosazeme B (C, etc.), Turquoise Blue G (By.), Rhodamine B (all makes), Indigo Blue N (C). Silk and Cotton Fabrics. — This combination of fibres is frequently met with in satins (silk face and cotton back), silk blouses trimmed with cotton lace or with cotton stitching, silk curtains with cotton lace, embroidery or trimming, etc. They may be dyed solid shades, or the silk may be dyed leaving the cotton white, or the cotton dyed leaving the silk white ; in either of the two latter cases the white fibre may be cross-dyed another colour. In dyeing solid shades the one-bath or two-bath method may be used, the process selected depending upon the amount of cotton which shows plainly and upon the shade. In cases where the silk is most prominent (as in cotton back satins) or when pale bright shades are to be dyed, the silk is dyed with an acid colour, 11 162 DYEING AND CLEANING. and the cotton in a separate bath with a direct colour. In this process either fibre may be dyed first ; but when it is necessary to match the silk to a pattern (particularly in pale shades) it is advisable to dye the cotton first in a lukewarm soap bath, after- wards dyeing the silk in a cold or lukewarm acetic acid bath. In dyeing with direct colours giving level shades on cotton and silk, the bath to which Glauber's salt or common salt and a little soap, soda, or borax has been added, is kept just below the boil (195° to 205° F.); lowering the temperature causes the cotton to become darker, whilst boiling deepens the shade of the silk. It is advisable in any case to keep the cotton a little darker than the silk in case it is found necessary to " top " the silk in a separate bath with acid colours. The following direct colours give practically solid shades on cotton and silk : — Reds. — Benzo Fast Red FC (By.), Benzo Purpurine 4 B (all makes), Congo Corinth B, G (By.), Diamine Rose BD, GD (C.), Diamine Scarlet B (C), Union Bordeaux B (Ber.). Oranges, — Congo Orange G (By.), Diamine Orange D (C). IWto^'s. — Chrysophenine G (By.), Cresotine Yellow G (M.L.B.), Diamine Fast Yellow B (C), Diamine Yellow CP (C), Diamine Yellow 3 G (M.L.B.), Thioflavine S (C). Greens. — Benzo Green C, G (By.), Brilliant Benzo Green (By.), Diamine Green B, G (C), Union Leaf Green (Ber.), Union Leaf Green (C). Bhtes.—BQnm Blue RW (By.), Diamine Brilliant Blue G (C), Diamine Blue RW (C), Diamine Dark Blue B (C), Union Navy Blue BR (Ber.). Browns. — Benzo Brown MC (By.), Diamine Brown 3 G, M (C), Dianil Brown 3 GD (M.L.B.), Union Brown F (Ber.). Violets. — Chloramine Violet R (By.), Benzo Violet LR (By.), Diamine Violet N, Union Lilac R (Ber.) Blacks.— J}va.m\ Black N (M.L.B.), Pluto Black TG (By.), Union Black S (C). In dyeing blacks a small quantity of green or yellow may be added for shading purposes and the silk may be topped, if necessary, in a separate bath with Naphthylamine Black 4 B. Any of the above colours may be topped in an acid bath with basic or acid dyestufFs. In dyeing bright pale shades, the best results are obtained by dyeing the cotton in a cold or lukewarm soap bath and the silk in a separate cold bath w4th acid colours. For example, sky-blue may be obtained by dyeing the cotton with Diamine Sky Blue and the silk with Cyanole. Other combinations can readily be made from the following tables, which may be employed for the purpose DYEING. 163 of producing solid shades or for cross-dyed effects. The first table gives direct colours which, dyed in a soap and soda bath (10 per cent, and 1 per cent, respectively) leave the silk practically white, and the second table gives acid colours which dyed in an acetic acid bath at the boil leave the cotton white. In each case the same dyestufFs may be employed in cold baths for cross-dyeing. Direct colours which leave the silk practically white when dyed in a soap bath : — Reds. — Benzo Fast Scarlet 5 BS, 8 BS, GS (By.), Diamine Bor- deaux B (C), Erika BN, GN (Ber.). Omri^^res. — Chloramine Orange G (By.), Diamine Orange G (C), Dianil Orange G(M.L.B.), Mikado Orange 4 BO (Ber.). Yellotvs. — Chloramine Yellow GG (By.), Curcumine S (Ber.) Diamine Fast Yellow A (C.), Diamine Direct Yellow S (M.L.B.). lilues, — Benzo Sky Blue (By.), Brilliant Azurine B (By.), Chicago Blue 6 B (Ber.), Diamine Sky Blue (C.), Diamine Sky Blue FF (C.), Diamine Black BH (C.), Dianil Dark Blue R (M.L.B.). Blacks.— BmnnnG Black BH (C), Diazo Black BHN (By.), in each case followed by diazotisation and development with meta- phenylene diamine. Acid colours which leave the cotton white when dyed in acetic acid baths : — For this purpose nearly all acid colours may be employed, of which the following may be particularised : Azo Kubine A (C.), Acid Magenta (all makers), Azo Crimson S (By.), Brilliant Croceine 3 B (By.), Orange GG (C), Orange IIB (By.), Orange No. 2 (M.L.B.), Trop^oline 00 (C), Indian Yellow G, Fast Yellow S (C), Naphthol Yellow S, Quinoline Yellow, Acid Green extra cone. (C), Brilliant Acid Green (By.), Acid Green cone. (M.L.B.), Brilliant Wool Blue G (By.), Cyanole extra (C), Patent Blue V'(M.L.B.), Keton Blue, 4 BN (M.L.B.), Indigo Blue SGN (C), Formyl Violet S 4 B (C), Acid Violet 4 B (By.), Fast Acid Violet 10 B (By.), Naphthylamine Black 4 B, S (C). Two-colour effects may be produced in one bath by combining the above direct colours with neutral-acid dyeing colours. Artificial silk is dyed in the same way as cotton and linen, but, having a somewhat greater affinity for basic colours, pale shades may be dyed, without mordanting in acetic baths. Ramie is dyed in the same way as cotton and linen fabrics. Jute. — This fibre is seldom handled by the garment dyer ; it may be dyed with basic colours in an acetic bath, with or without the aid of a mordant with acid colours with the addition of a small quantity of acetic acid to correct the hardness of the water and (if necessary) 2 to 5 per cent, alum, or with direct colours 164 DYEING AND CLEANING. with the addition of Glauber's salt or common salt. The usual method is to dye with acid colours with the addition of acetic acid. General Notes. — In the foregoing tables a large number of dyestuffs have been given from which the garment dyer may make his selection. For most purposes a stock of from thirty to forty dyestuffs will meet all the requirements ; whenever possible, the dyer should select colours which will serve more than one purpose. For example, acid dyestufis may be selected which will dye in acid or neutral baths, have good equalising qualities, are fast, or comparatively fast, to light, and are, moreover, economical in use. By careful collation of the tables, dyers will find that they can fulfil their particular requirements with a comparatively small number of dyestuffs. All articles containing silk should be given a final rinse in a weak acetic acid bath to brighten and " scroop " the silk ; this bath must, however, be omitted when dyestuffs sensitive to acid have been employed (e.g. Benzopurpurine 4 B). It is rarely, if ever, necessary to stiffen silk fabrics ; if a slight stiffening is required, gelatine or gelatine and white dextrine may be employed. Dresses with cotton linings require stiffening in nearly all cases, as the dyer should always endeavour to reproduce as closely as possible the appearance of new goods. For this purpose starch cannot be employed, as, although it stiffens the lining of a wool dress satisfactorily, it also adheres to the surface of the wool fabric, producing an unpleasant effect. This difficulty may be overcome by using a soluble starch which has been introduced under the name of gum feculose. This dissolves to a clear solution of which a small quantity is added to the last rinse water, and while stiffening the lining sufficiently it does not affect the colour, feel, or appearance of the wool. In rinsing articles containing wool, they must not be taken direct from the boiling bath to a cold rinse w^ater, or shrinkage will occur; if thrown over a "horse" and allowed to "cool off" before rinsing, the risk of shrinking is very much reduced. After rinsing and stiffening, if necessary, the goods are hydro- extracted, with the exception of velvets, heavy satins, and any other articles which are liable to permanently retain creases. Such articles are shaken out to remove as much moisture as possible and then dried off. The drying-rooms employed for dyed work may be divided into stationary and continuous. The stationary room is usually a steam-heated chamber, exhaust steam being generally employed, and suitable means for hanging up the garments, etc., is provided. The most satisfactory method where any quantity of work is being handled is the continuous process.. DYEING. 165 The articles are carried by clips on an endless chain or band through a heated chamber in which the air is kept circulating by means of a fan. At the other end of the chamber the clips open automatically, and the dried goods fall into a basket or other receptacle. This method of drying is quicker, takes up less space, and requires much less steam than any other process. Various makes of continuous drying-rooms are on the market, and while all are more economical than stationary drying, the best type appears to be that manufactured by Vincent Roberts & Marr. In most forms of apparatus the air is kept in motion by means of a fan ; but in Vincent Roberts & Marr's drying-room the air follows a definite path. It enters at the outlet of the machine (where the goods are quite dry) and passes down through the goods, through a heater, thence to the top of the chamber, down through the goods, and so on until it reaches the feeding end of the machine completely saturated with water vapour, and is dis- charged. This type of drying-room is also suitable for wet- cleaned work. After drying, the goods are ready for finishing. In some cases goods are not dried, but are taken direct to the finishing ; these will be referred to under that heading. CHAPTER y. DRY DYEING. The process known as " dry " dyeing bears the same relation to ordinary or "wet" dyeing as "dry" cleaning does to aqueous or " wet " cleaning ; that is to say, the articles are not wetted in the ordinary sense of the word, benzine or benzol being employed as the dyeing medium. Methylated spirit had been employed as a medium in the process known as " spirit " dyeing, but the results obtained were very unsatisfactory, and were, moreover, very expensive to produce. The employment of methylated spirit with pleated and other fabrics liable to lose their shape or finish by immersion therein is quite impossible. Whereas many coal-tar colours are soluble in methylated spirit, very few are soluble in benzine or benzol, and in most cases in such small quantities that the colour solutions obtained are of no practical value. Cain and Thorpe {Synthetic Dyestuffs) give the following acid and basic dyestuffs as being " soluble in traces " in benzol : Ponceau 4 GB, Chrysoidine, Scarlet for silk, Biebricli Scarlet, Brilliant Green, Methyl Violet B (moderately soluble on heating), Acid Violet N, Fast Acid Violet B, Eosine BN, Erythrosine, Phloxine, and Rose Bengale 3B; Crystal Violet is "somewhat soluble," and picric acid and Induline (spirit soluble) are readily soluble in benzol. The basic colouring matters which, as hydrochlorides, are only " soluble in traces " may be rendered readily soluble in benzine or benzol by conversion into oleates, stearates, or resinates. These colours, known as "fat colours," may be obtained from nearly all the colour manufacturers, or they may be made from the basic dyestuffs by double decomposition with the sodium or other soluble salts of the fatty acids. The usual method of preparation is to dissolve the basic colour in water, adding the solution obtained to a solution of a tallow or oil soap ; or the colour and soap may be dissolved together. 166 DRY DYEING. 167 Hydrochloric acid is added to the cold mixture, which precipitates a mixture of fatty acid and " fat colour " ; this rises to the surface and may be collected, washed, and dried. The drying is performed by melting, and separating from any contained water by cooling and removing the solid fat layer. The quantities employed vary with the colouring matters em- ployed, but the following figures may be taken as an example : — Dissolve in 100 parts of hot water 1'25 parts Methyl Violet, 5 parts curd or white oil soap. When cold, add 2*5 parts concen- trated hydrochloric acid. The resinates are prepared in a similar manner. Resin is dissolved in a solution of caustic soda, mixed with an aqueous solution of basic colouring matter, a mineral acid, or a solution of alum being employed to precipitate the "fat lake." Gouillon {Manuel Methodique du Teinturier-Degraisseur) recommends the following quantities : — Colophony ..... 500 grams. Soda crystals . . • . . 150 ,, Caustic soda . . . . . 50 ,, Water ...... 5 litres. The colour solution is made by dissolving Magenta (or other suitable colouring matter) 30 grams, in Water ....... 2 litres. These solutions are mixed, and the colour resinate is precipitated by adding a solution of Alum . . . . . . .100 grams, in Water 500 „ The " fat colours " prepared by either of the above processes dissolve very readily in benzine or benzol, but the production of satisfactory results from the solutions is a matter of considerable difficulty. The dyeing takes place immediately the previously cleaned goods are entered, and the production of level dyeings requires consider- able manipulative skill. After dyeing it is very difficult to remove the superfluous colour solution without obtaining patchy results, as any folds, creases, or thicker portions of the fabric retaining the colour solution for a longer period than any other portion become darker, owing to the concentration of the colour solution, due to the rapid evaporation of the solvent. The removal of the super- fluous colour solution by hydro-extracting is not satisfactory, the most level results being produced by rinsing out and well shaking by hand while drying. Rinsing in a bath of clean benzine to remove the adhering 168 DYEING AND CLEANING. colour solution also removes the dyestufF from the fibre ; in fact, continued rinsing removes practically the whole of the colour. It has been found that more satisfactory results may be obtained with the *'fat colours" by the addition of 5 to 10 per cent, of benzine soap (e.g. Saponine) or oleic acid to the dye bath ; these substances tend to retard the dyeing, giving more even results and placing the operations more under control. It has also been found (Farrell and May, J.S.D.C., 1908) that the basic colours will dissolve direct in a 10 per cent, solution of benzine soap in benzine, thus avoiding the separate preparation of the " fat colours." Although the process of "dry dyeing" with "fat colours" has been in vogue for several years, it has not been found satisfactory except for a limited application in the dyeing of alum-tanned gloves, etc. In dyeing fabrics its great disadvantages have been the difficulty of production of level dyeings, the readiness with which the colours "rub," the extremely fugitive character of the colours towards light, and the difiiculty of rinsing in benzine without the removal of a considerable portion of the colour. These difficulties have now been overcome by the employment of acid dyestuffs in "dry" dyeing in the process described by Farrell and May {J.S.D.C., 1908). Many acid dyestuffs are freely soluble in alcohol (absolute or methylated); but whereas absolute alcohol is miscible in all pro- portions with benzine or benzol, methylated spirit (64 o.p.) is practically insoluble therein. Solutions of suitable acid dyestuffs {e.g. Fast Acid Violet A 2 R) in absolute alcohol are miscible with benzol or benzine in all proportions, and the colour solutions thus obtained may be employed for dyeing silk and other fabrics. The employment of absolute alcohol is, however, debarred by its very high price. It was found that although methylated spirit 64 o.p. is insoluble in benzine and benzol, it is miscible with solutions of benzine soap in benzine or benzol, the quantity of methylated spirit which will dissolve depending upon the amount of the soap present. The soap employed in most of the experiments was Griinwald and Stommel's Saponine, and the following tables show the number of volumes of methylated spirit (64 o.p.) dissolved by ten volumes of the soap solution (benzine, benzol, and carbon tetrachloride). It will be seen from the solubility table for benzine solution of soap that with 25 per cent, of soap present, methylated spirit (64 o.p.) is soluble in all proportions. These tri-solutions, con- taining benzine, methylated spirit and soap, may be diluted with benzine without separation occurring, provided that by such dilution the reduction in the ratios of soap to benzine and methy- DRY DYEING. 169 lated spirit to benzine are not at variance with the figures given in the table. Temperature 15°-16° C. Percentage of Saponine Volumes of Methylated Spirit (64 o.p. ) dissolved in Benzine {'7Q5). by 10 Volumes of Benzine Soap Solution. 0 Trace. 1-25 0-35 vol. 2-5 0-4 „ 5-0 0-6 „ 7-5 0-7 „ 10-0 0-8 „ 15-0 2-3 vols. 25-0 All proportions. Temperature 11°-12° C. Percentage of Saponine Volumes of Methylated Spirit dissolved by in Benzol. 10 Volumes of Benzol Soap Solution. 0 Trace. 1 Trace. 2 0-8 vol. 2-5 0-85 3 and above. All proportions. Temperature 10°-11° C. Percentage of Saponine in Carbon Tetrachloride. Volumes of Methylated Spirit dissolved by 10 Volumes of CCI4 Soap Solution. 0 1 2 3 4 and above. Trace. 0-3 vol. 0-5 „ 0-75 ,, All proportions. For example, a 25 per cent, solution of soap in benzine will dissolve an equal volume of methylated spirit (64 o.p.). The addition of 7*5 c.c. of benzine to 10 c.c. of this solution would reduce the soap to 10 per cent, on the benzine present ; we see 170 DYEING AND CLEANING. from the table that a 10 per cent, sohition is capable of dis- solving only 8 per cent, of methylated spirit, whereas there is present 5 c.c, or 28*5 per cent. ; consequently separation takes place. On the other hand, a mixture of 9 c.c. of 25 per cent, ''soap" solution and 1 c.c. methylated spirit diluted with 13*5 c.c. of benzine gives a solution containing 10 per cent, of benzine soap on the benzine present and 4*2 per cent, of methylated spirit, against 8 per cent, which can be dissolved by a 10 per cent, solution ; hence no separation occurs. The presence of colouring matters in solution in the methylated spirit does not affect its solubility in solutions of soap in benzine, consequently by this process colouring matters soluble in methy- lated spirit can be obtained in benzine containing but a small percentage of methylated spirit. The acid dyestufFs which are soluble in methylated spirit belong principally to the sulphonated triphenylmethane series. Azo colours are on the whole but slightly soluble, though there are a few exceptions, such as Indian Yellow, Orange XL, etc. Rhodamine B, Eosines, and other members of the phthale'in group are readily soluble in methylated spirit. The following table contains the colouring matters giving the most satisfactory results : — Acid Green, extra cone. Fast Acid Violet A 2 R. Acid Magenta. Formyl Violet S 4 B and 10 B. Acid Violet 10 B. Indian Yellow G and R. Alizarine Sapphirole. Metanil Yellow. Azo Rubine A. Orange II. Croceine Scarlet B and 3 B. Patent Blue A. Cyanole. Phloxines Eosine extra. Rhodamine B. In order to use the minimum quantity of methylated spirit the solutions of the colours should be as concentrated as possible. After dissolving, the solutions are filtered to remove insoluble impurities, diluents, etc., and the necessary quantity of the colour solution is mixed with several times its volume of a 25 per cent, solution of Saponine in benzine. This solution is then added to a 10 per cent, solution of Saponine in benzine, the solution obtained being the bath employed for dyeing. In most cases the quantity of methylated spirit present in the dye bath does not exceed one or two per cent., but in no case should it be greater than 10 per cent. The goods having been cleaned in a strong solution (5 to 10 per cent.) of benzine soap, are entered direct into the dye bath. The dyeing, unlike " dry " dyeing with fat lakes, takes place slowly. DRY DYEING. 171 and is easily controlled. It is advisable to prepare the colour solution of such strength that the dyeing is not complete in less than half an hour, as the results produced by more rapid dyeing have a greater tendency to be uneven, and are not quite so fast to rinsing. The greatest advantage of this process is that the goods may be taken direct from the dye bath to a clean benzine rinsing bath. In this the goods are quickly rinsed, after draining to remove the superfluous colour solution, and are then taken to a second benzine rinse in which no further colouring matter is removed. The goods may now be hydro-extracted and dried. The dye baths do not exhaust, and a considerable number of articles may be dyed in the same bath with little or no replenish- ing. If they are allowed to stand for any length of time the baths must be filtered before using, as a small amount of dye- stuff may have separated out (particularly in cold weather). The process of dry dyeing cannot, on account of its cost, be recommended in cases where the ordinary process of dyeing gives good results, but it can be used with great advantage for all silk and wool fabrics which will be injured by wet-dyeing, such as glaces, silk, velvets, poplins, satins, bengalines, etc. It is also very useful for dyeing made-up articles, such as silk lamp- shades, etc., which it is impracticable to unpick, dye and remake. Leathern articles (gloves, shoes, belts, bags, etc.) are readily dyed by this process, either by brushing or by immersion. Furs also may be dyed, though the process is much slower than with silk and wool goods. Unlike the ordinary method of dyeing fabrics, the colour already on the goods can very seldom be removed. If the articles have been dyed with basic colours a considerable portion of the dyestufF is removed by immersion in a 10 per cent, solution of Saponine in benzine ; colouring matters of other groups cannot be removed in this way, and the colour on the fabric must always be allowed for in "dry" dyeing. Acid dyestuffs dyed by this process are found to be equally fast to light and other influences as the same dyestuffs dyed on the same fabrics by the wet process. The spent dye baths may be distilled in the ordinary way, the benzine being recovered and the small amount of methylated spirit which is present in the distillate being washed out with the water in the separator. CHAPTER VI SPECIAL METHODS— CLEANING AND DYEING SKIN RUGS, FEATHERS AND HATS. The articles mentioned above require special methods of treatment, owing to their peculiar physical and chemical properties. They do not represent a very large section of the garment cleaner's busi- ness, and many of the smaller firms do not carry out the work themselves, but send such articles to firms which specialise in fur dyeing, feather cleaning, dyeing and curling, or hat cleaning, dyeing and blocking ; consequently they will only be dealt with briefly. Skin Rugs. — White and light coloured rugs if not soiled or faded to any great extent may be cleaned by the dry process (see p. 54). In wet-cleaning skin rugs it must be remembered that they have usually been alum-tanned, and this tannage is not fast to water at a temperature higher than 40° C. The operation of cleaning skin rugs by the wet method is per- formed with neutral oil soap. If the rugs are fitted with linings the latter must be removed and cleaned separately, dry cleaning woollen linings, and wet cleaning, starching and glazing canvas linings. A solution of soap is prepared and a bath is made at a temperature of about 40'' C. (lOO*" F.) in which the skins are worked. (Shallow troughs are employed in this and in all other operations with skin rugs to economise the liquors, or the cleaning may be done on the slab.) The soap is worked into the skin by hand, repeating the process (with fresh soap with the addition of ammonium carbonate if necessary), and finally rinsing in water. Skins which have been cleaned in this way are generally white enough for dyeing ; but if they are to be finished white or very pale shades, bleaching must be resorted to. For this purpose, sulphur, sulphurous acid, potassium permanganate (followed by sulphurous acid), and hydrogen peroxide may be used. The last gives the most satisfactory results, as the white produced by sulphur bleaching is not per- 172 SPECIAL METHODS. 173 manent, and the permanganate process is not so safe as the use of hydrogen peroxide. The peroxide bath is prepared in the same manner as for bleaching woollen fabrics as described on p. 111. The skins are placed in the faintly alkaline cold bath for one hour, after which they are rinsed in a dilute (y^y per cent.) solution of sulpliuric acid; and if they are to be finished white they are to be rinsed in water, hydro-extracted, and re-tanned, if necessary, by painting the flesh side with a tepid solution of alum or basic alum and salt (5 per cent, aluminium sulphate and 15 per cent, common salt). A suitable basic alum is prepared by slowly mixing, with constant stirring, separate solutions of one part of 58 per cent, alkali for every ten parts of aluminium sulphate. The skins are then tacked or stretched on frames, and dried at a low temperature. When dry they may be worked on the flesh side with a special knife to soften them ; oil (castor or other non-oxidising oil) is sometimes rubbed into the flesh side of the dried skins to soften them. The fur is then combed out and the skins are trimmed and re-mounted. Skins which have been cleaned or bleached for dyeing are chlored " to increase their aflinity for dyestuffs. This consists in immersing them in a clear dilute solution of bleaching powder (about 5 per cent.) ; the solution must be cold, and the immersion may last for several hours. They are then rinsed in dilute sul- phuric acid, excess of which must be subsequently neutralised if the rugs are to be dyed with basic colours. Owing to the solubility of the alum tannage at temperatures exceeding 40° C. the basic dye- stufls are generally employed with or without the addition of Glauber's salt to the dye bath. Any of the basic dyestufts men- tioned in other sections may be employed, but the results produced are not very fast to light or to rubbing. The tendency to rub may be overcome by passing the articles through a sumach bath. When acid colours are employed formic acid is to be recom- mended as an assistant in preference to sulphuric acid and Glauber's salt. The following acid dyestuffs are recommended by Lamb {J.S.D.C., 1905):— Fast Red, Azo Fuchsine, Acid Brown, Old Gold G, Quinoline Yellow, Alkaline Blue, Acid Green, Naphthol Green, Silver Grey N, Naphthylamine Black. Cassella & Co. recommend the following (patented) process for dyeing with acid dyestuffs. The skins, well cleaned with soap, are rinsed in water and dipped in a solution containing — 1*8 ounces chromium oxychloride 3*6 ,, basic sulphate of alumina 3*6 ,, common salt 5*4 ,, acetate of soda (cryst.) 174 DYEING AND CLEANING. After leaving the skins for a few hours in the liquor (which is sufficient for ten skins), the leather is tested by cutting, in order to see whether it has been properly saturated by the liquor ; if this be the case, another 3 '6 ounces chromium oxy chloride are added, and the skins are left in the liquor for twenty-four to thirty-six hours, being given an occasional turn. They are then lifted, thoroughly rinsed, and hydro-extracted. The skins are then entered into a cold bath of 1| pints hydrochloric acid per 22 gallons water, where they are left for a quarter of an hour, and are then put into a clear bleaching powder bath. Having worked them in the liquor for twenty minutes, | pint hydrochloric acid is added, and they are worked for a further ten minutes ; they are then put back for another quarter hour in the first bath of hydrochloric acid, which has been strengthened in the meantime by the addi- tion of a pint of acid. The skins are then well rinsed. To the last (lukewarm) rinsing water, 3 to 4| ounces of hyposulphite of soda (sodium thiosulphate) per ten gallons are added, which is followed by a final thorough rinsing. After hydro-extracting it is stated that the skins may be dyed with any acid dyestuffs in baths up to 167" F., without fear of damaging the leather. The dyestuff's must, however, be added slowly, and the temperature must be low in the beginning, slowly rising to 167° F. In all methods of dyeing, the skins, after hydro-extracting, should be painted on the back with alum and salt as described under the cleaning of skins. Blacks are dyed with logwood by the one-bath or two-bath process. The following quantities are recommended by Lamb {J.S.D.C, 1905):- One-Solution Method, — 100 lbs. logwood extract, 18 lbs. fustic, 10 lbs. copper acetate, dissolved in 400 gallons water. The bath is maintained at a temperature of 40° C, and the skins are entered and allowed to remain in this liquor for three to four hours, and the three gallons of acetate of iron (black iron liquor) is added, and the goods are kept in the solution until black, usually requir- ing an immersion of thirty to forty hours. Other single-bath liquors may be prepared as follows : — {a) 200 lbs. logwood extract, 3 lbs. potassium bichromate, 3 gallons lactic acid, 300 gallons water. {h) 15 parts logwood extract, 10 parts sumach extract, 2 parts copper acetate, 5 parts iron liquor. Two-Solution Method. — In this the goods are placed in a solution made in the following proportions : Logwood, 50 lbs., fustic extract, 12 lbs. ; water, 500 gallons. After remaining in this for four to five hours, they are transferred to a solution of potassium bichro- mate. If a sufficiently intense black is not obtained, the skins are SPECIAL METHODS. 175 placed in the first bath again, after strengthening it, being finally finished in the bichromate bath. The skins dyed by any of the above methods are drained and allowed to oxidise for some time. They are then well washed in warm water and scoured with neutral oil soap and ammonium carbonate to obtain the necessary gloss. After washing and draining they are re-tanned with alum and salt, framed and dried. The blacks dyed with potassium bichromate have a tendency to become greenish in shade. The gloss of coloured rugs is much improved by passing them through a warm "fat liquor" or fat emulsion. This is made by emulsifying a suitable oil (castor, neatsfoot, or olive oil) with a solution of a neutral potash soap. After passing quickly through a weak emulsion the skins are dried, softened, combed out, beaten and trimmed ready for mounting. Light coloured fur necklets, muffs, etc., may be very satisfactorily re-dyed by the dry process ; e.g, pale greys give very good results by this method. Feather Cleaning and Dyeing. — Feathers are cleaned in soap baths to which mild alkalies (ammonia, sodium carbonate, etc.) may be added, at a temperature of 100° to 120° F. If a creamy white is obtained in cleaning soiled white feathers they may be "blued " with Methyl Violet. If bleaching is necessary, hydrogen peroxide gives the most satisfactory results, and is applied in the same manner as for wool (see p. 111). Sulphur bleaching is also used to some extent. In dyeing feathers they are first cleaned in an alkaline bath and are then dyed with acid or basic colours, the natural dyestuffs being rarely employed (blacks are sometimes dyed with logwood). The basic colours are used to a considerable extent, but the shades produced are very fugitive to light ; and, whenever possible, acid colours should be employed. Basic colours are dyed in neutral baths at a temperature of 80° to 100° F., acid dyestufls are dyed near the boil for dark shades and at 120° F. for pale shades, with the addition of sulphuric, acetic, or formic acids. Many feather dyers select colours soluble in alcohol and make stock solutions in methylated spirit, but there does not appear to be any advantage in this mode of procedure. Feathers must be handled with care, and excess of acid and violent boiling must be avoided, as the flue of the feathers is easily injured. All the acid dyestuffs mentioned as suitable for silk may be used for feathers. For blacks, Naphthylamine Black 4 B (C.) and Feather Black GS (C.) give good results, and may be shaded, if necessary, with Indian Yellow G and Acid Green, acetic or formic acids being employed as assistants. The baths shovdd be small in size (fig. 48), and in dark colours standing liquors may be kept. 176 DYEING AND CLEANING. In dyeing blacks with logwood, several methods may be em- ployed ; the following is an iron-chrome black : The feathers having been thoroughly freed from grease, are placed in a cold bath prepared by adding one part of red iron liquor (nitrate of iron) 80° Tw. to three parts water, and allowed to remain therein over night. They are then well washed, the last rinse containing a little ammonia. The logwood bath is made up with — Logwood extract . . .'6 parts Fustic extract ... 1 part Water ..... 200 parts (Soap also may be added to the bath.) The feathers are worked in this bath just below the boil until the black is developed ; they are then rinsed in water, followed by a warm soap bath. After rinsing in warm water, tliey arc DXOf^|^ltS*SO,«. E^HOmtERS. PCJ^TH, SCOTLAND, Fig. 48. —Feather Dye Pans. placed for two or three minutes in a cold bath of potassium bichromate (^ per cent, solution), and are then well rinsed. Other mordanting baths for feathers are made with (a) copperas (ferrous sulphate), potassium bichromate and tartar, (b) copperas blue-stone (copper sulphate) and tartar. The dye bath is made in the same way as in the above method. Various methods have been suggested for dyeing feathers (and likewise furs), depending upon steeping them in solutions of certain compounds of the aromatic series, followed by oxidation. They do not, however, appear to have been adopted to any extent. Of these methods the following may be selected as one which has been recommended for the production of fast blacks on feathers (J.S.B.C, 1907) : A bath is prepared containing 2 per cent, of paraphenylene diamine (or 3 per cent, of the hydrochloride of that base with sufficient caustic soda to combine with the hydro chloric acid). The feathers are steeped in this for several hours SPECIAL METHODS. 177 and the black is developed in a 30 per cent, solution of hydrogen peroxide. Feathers are sometimes dyed in graduating shades, beginning at one end with a very pale shade and finishing in a dark shade of the same colour. Two methods are employed in the produc- tion of these effects. In the first a weak dye bath is prepared Fig. 49. — Feather Starching Machine. and the whole feather is dyed a pale shade ; the bath is then slightly strengthened and three-quarters of the length of the feather is dipped in it, and so on, gradually strengthening the bath and then immersing less of the feather, until only the end is dyed in the last bath. In the second method the bath is made up sufficiently concentrated to dye the dark shade on the end of the feather, and the strength is reduced in stages by diluting 12 178 DYEING AND CLEANING. with water and immersing more and more of the feather. In this method a more even graduation is effected. Feathers and articles made of feathers (boas, stoles, etc.) which have been cleaned or dyed have a very bedraggled appearance Fig. 50. — Feather Drying Machine. when wet, the " flues " of the feathers being matted together. To open up the "flues," the feathers are dipped in cold water, containing starch or farina. After drying, the starch is gently beaten or shaken out, and the flues open up to their original condition and are ready for curling. When a large number of SPECIAL METHODS. 179 feathers are handled the machine shown in fig. 49 can be used to work the dry starch or farina into the wet feathers, the machine ilhistrated in fig. 50 being employed for drying off the feathers and shaking out the starch or farina. It consists of a woven wire cage which oscillates in a current of hot air, the starch or farina being collected in a receptacle at the bottom. Feathers are curled by hand with a special knife after being slightly steamed to soften them, the curl being fixed by drying before a suitably heated stove. Feather boas, which consist of flat feathers stitched together and twisted (and incidentally shortened in length) to give them the round, full appearance, open out flat again when wetted and Fig. 51. — Feather Boa Curler. must be retwisted. For this purpose a small appliance has been made, the ends being clipped and the centre being held out by hand (fig. 51). Feathers may be successfully "dry dyed" in pale shades {q.v.). This method is very useful in dyeing wired pom-poms, etc., which cannot be wetted without taking to pieces, and subsequently re- making ; in most cases the price which could be obtained would not prove remunerative if this had to be done. Hat Cleaning and Dyeing. —Hats are manufactured in a great variety of materials, without reckoning those made of ordinary fabrics (velvet, cloth, etc.), made up on wire frames. The materials usually met with are — Straio of various kinds — e.g., ordinary wheat straw, Tuscan, Italian, etc. 180 DYEING AND CLEANING. Grass. — Panama, etc. Chip. — Usually willow, though other woods are employed. Satin Chip. — Wood chip combined with artificial silk and other fibres. Felt. Beaver. Artificial silk — e.g. crinolines, which consist of artificial silk stiffened with glue, etc. The dyeing and cleaning of hats is not, on the whole, very csatisfactory, as, before they are submitted to the garment dyer, they have usually had a considerable amount of exposure to direct sunlight and to the usual atmospheric influences. Straw. — This material is very resistant to cleaning and dyeing operations, owing to the natural siliceous coating, which prevents liquids penetrating readily to the centre. Preparatory to bleach- ing or dyeing, straw is cleaned in a 2 per cent, solution of soda ash. The materials employed in bleaching straw are sulphur (as sulphur dioxide in a sulphur stove), oxalic acid, and hydrogen or sodium peroxide. As in all cases where sulphur is employed, the decolorisation is not permanent, but the process is still employed to a considerable extent. When straw hats are not very badly discoloured, oxalic acid alone will generally give satis- factory results. In employing peroxides, the following process is recommended by Konigswarten and Ebell : — Dissolve 1| lbs. oxalic acid in 10 gallons cold water, and add, while constantly stirring, 1 lb. sodium peroxide. The bath reacts acid, and suflicient silicate of soda (1| lbs. at bb'' to 75° Tw.) is added to cause the liquor to become slightly alkaline. (To produce quicker bleaching, about twice the strength may be employed.) Enter the goods at 60** to 80** F. and allow^ to lie in the bath until a satisfactory bleach is obtained ; then rinse in soft water and dry at the ordinary temperature. Straw must always be dried cold, as otherwise it becomes brittle. Straw^ is usually dyed with basic colours, being entered luke- warm and raised in half an hour to the boil, and maintained at the boil for an hour. Cotton substantive colours are sometimes em- ployed, being applied in the same way as basic colours. Chip is very much easier to dye than straw, basic, acid, and substantive colours being employed. For light shades, the chip should be bleached with sulphurous acid. Basic colours are applied without any addition to the bath, the dyeing taking place at the boil. With acid dyestuffs the bath is slightly acidified with sulphuric acid, dyeing at the boil. After dyeing, the chip must be rinsed free from acid. Substantive colours are dyed at the boil with the usual addition of Glauber's salt or common salt. SPECIAL METHODS. 181 Satin Chip, — The lustrous appearance of this substance is obtained by causing threads of artificial silk to adhere side by side with glue, and plaiting the band so obtained with ordinary chip. As soon as the resulting plait is immersed in water, the glue is dissolved and the threads separate, the plait falling to pieces. The glue may be rendered insoluble prior to wetting by exposing it for about half an hour to the vapour of formaldehyde, after which it may be dyed (but at not too high a temperature) with basic colours. Artificial silk alone is now employed in the production of '^crinolines." These are stiffened with glue, and before they are dyed this should be made insoluble with formaldehyde ; otherwise, imless handled very carefully, the artificial silk may break or fray during the process of dyeing. It may be dyed with basic colours, but the best results are obtained with substantive colours (see p. 163). Felts and heavers are dyed like ordinary wool fabrics with acid colours (see p. 155). In pale shades, when slightly faded, they may be very successfully re-dyed by the "dry" process. This method gives very good results in re-tinting gentlemen's grey felt hats which have faded slightly. Hats are stiffened with gums, resins, starch, soluble starches (feculose, etc.), glue, etc., according to the materials of which they are made. After sizing (if necessary), the hats are dried, damped, blocked, and (if necessary) wired. CHAPTER VII. FINISHING. Articles which have been cleaned or dyed must be finished before they can be returned to the customers. Those which have been dry cleaned or dry dyed require the least finishing, as they have not altered materially in shape, and they retain the original dress- ing and finish of the new fabrics of which they are composed. On the other hand, articles which have been dyed frequently require careful and skilful finishing, as in most cases they have been boiled during the dyeing process, and have, consequently, lost the dressing, appearance, and shape of the original fabric ; and, in addition, they may have become shrunken to some extent, due, in many cases, to the original cloth having been over-stretched by the maker. These and any other defects must be remedied if the article is to please the customer. Examination. — The goods on reaching the finishing department are first carefully examined to see that the processes of cleaning or dyeing have been carried out in a satisfactory manner. In cleaned work, stains which have escaped the notice of the spotter may be discovered, and in dyed work the colour is compared with the pattern, examined for evenness and freedom from bronziness, etc. If there is a possibility of effecting an improvement (some- times, owang to some peculiarity in the fabric or to the original shade the result produced is the best possible under the circum- stances) the goods are rejected for further treatment. (Defects sometimes develop in the subsequent finishing processes; stains frequently reappear during the process of steaming or ironing.) Although there is no sharp dividing line, it will be found con- venient to divide the finishing into tw^o classes : 1. The finishing of articles of wearing apparel. 2. The finishing of furnishings (blinds, curtains, draperies, etc.). 1. Wearing Apparel. — The majority of articles of wearing apparel are finished by hand ironing, supplemented in varying x82 FINISHING. 183 degrees by other processes. The ironing takes place on ordinary ironing tables or skirt boards, the latter being employed in most cases. The boards are covered with one or more layers of a Fig. 52. Skirt Board (with Sleeve Board). specially manufactured grey ironing felt and a layer of fine calico (also specially made for this purpose). The skirt boards may be fixed permanently to the wall, or may be self-contained as shown in fig. 52. The latter are very useful in a business having busy and slack seasons, as they may be taken to pieces and put on Fig. 53.— Sleeve Board. one side when not in use. For sleeves and small articles (bonnets, etc.) a sleeve board is used, which is padded in the same manner as the skirt board. A sleeve board is shown with the portable skirt board, or it may be separate (fig. 53). The irons, which weigh about 10 lbs. each (except tailors' and 184 DYEING AND CLEANING. "crown" irons, which are much heavier), may be heated by separate coke or gas stoves, by internal combustion of gas, or by electricity. Stove irons are still used to a considerable extent, as the worker is not hampered by any tube or other connections ; they admit of variation of the temperature over a wide and easily controlled range, and are fairly economical. Internal combustion irons and electric irons are very satisfactory for cleaned work, but the latter do not appear to be employed to any extent on dyed work, where a much higher temperature is necessary to produce a good finish. Electric irons do not appear to be so economical as the other types, unless the dyer is generating his own current at a very low cost (e.g. by suction gas Gas irons may be used with very good results, especially in large works where the finishers are engaged on one class of work continuously requiring a more or less constant temperature. In small works where the finishers have to do dyed, wet-cleaned, and dry-cleaned work, the stove-heated iron will be, on the whole, found very satisfactory. The most easily controlled and most economical gas iron is the Keith-Blackman or other make of pressure gas-iron." The gas is compressed by a small belt,, water, or motor-driven compressor ; the air is not mixed in the ordinary "mixer" and led to the iron through the flexible tube, as the compressed gas jet acting as an injector draws it in through adjustable holes on the gas-iron fittings. This allows of a flexible tube of much smaller diameter being employed, and consequently the ironer is hampered by the tube in a less degree than with any other gas iron. The Keith-Black- man iron also has a by-pass, enabling the ironer to reduce the temperature of the iron without turning off the gas. Over the end of each skirt board it will be found very con- venient to fix a length of chain to which the waists of skirts, etc., can be attached whilst other portions of the garment are being finished. Each board should also be provided with a basket or other receptacle to prevent portions of skirts, etc., which are being finished becoming soiled by touching the floor. Nearly all articles (with the exception of dry-cleaned silks) are prepared for finishing by the process of steaming. This is carried out with the perforated apparatus shown in fig. 54. In use the board is covered with one or more layers of calico. The process of steaming is a most important one, as properly carried out it reduces the labour and time of finishing to a very large extent. Whilst the steam is passing through the garments they are w^ell brushed to remove creases, hydro-marks, etc., are carefully pulled into shape, the lapels, folds, etc., are "set" by pressing with a small wooden block, and the garment is then hung on a wooden FINISHING. 185 hanger " ready for the finisher. Woollen goods must not be over-steamed, or shrinkage may occur. The articles, whether previously steamed or not, are not ironed direct, but put through a piece of damp calico. Dry-cleaned work rarely requires much finishing, and in the case of silks the steaming must be omitted. Plain skirts are very frequently finished on a gas-heated body ironer, an example of which is shown Fig. 54.— Steaming Table. m fig. 55. It consists of a gas-heated top roller and a padded roller, both being belt-driven ; and in some cases they are reversed by the operator pressing a foot-lever. Normally the rollers are a few inches apart, but are brought together on pressing a foot lever ; consequently the operator can place a skirt in position w^hile the top roller is running, the skirt being gripped by the rollers, when the depression of the lever raises the bottom roller and throws it into gear. Releasing the foot-lever separates the rollers 186 DYEING AND CLEANING. and enables the operator to change the position of the skirt or to withdraw it. The steam-heated cone is also largely employed in skirt finishing, especially for dyed skirts which have shrunk slightly (shrinkage is plainly indicated by the linings of lined skirts). The steam cone is made of tinned copper and is heated with steam at a few pounds pressure, a reducing valve, pressure gauge and safety valve being generally fitted to each cone or set of FINISHING. 187 cones. The cone shown in the illustration fig. 56 is that of Gorrie & Son, and is fitted with a stretching device ; the Holder- ness stretching device is shown in fig. 57, and consists of short lengths of curved metal pinning attached by adjustable strapping to a rail or rod at the end of the cone. Fig. 56. — Cone with Sprays. Hand sprays (on the ordinary " scent-spray " principle, fig. 58) fitted to an air compressor and to tanks for the supply of water or other liquids are employed in conjunction with the cone. The waist of the skirt having been fastened or pinned so that it will not slip over the small end of the cone, the body of the skirt is drawn over the cone and the hem is gripped by the pinning. 188 DYEING AND CLEANING The skirt having been sprayed to dampen it, the fulness under the cone is drawn tightly by hand on either side, and the stretchers are drawn up until the material is quite taut, the tension employed depending upon the shrinkage — if any. When quite dry (in a few seconds in most cases) another portion of the skirt is treated in the same way, and so on until the whole skirt has been finished. The number of operations depends, of course, on the fulness of the skirt, but in most cases two or three suffice. After hand-ironing the hem, to remove pin marks, the portion of the skirt gathered into the band, and smoothing the lining, if necessary^ the skirt is finished. If desired, the lining of the skirt may be stiffened by spraying it with starch or gelatin solution before coning ; in many cases this method of stiffening linings is more satisfactory than the method described under Dyeing " (p. 164). If a skirt has shrunk to a considerable extent it cannot be sufficiently stretched on a steam cone, and the Knollman apparatus will be found to give very good results. The skirt is not dried, but is taken direct from the hydro-extractor, and can be stretched in all dimensions, dried and practically finished in one operation. The skirt is finished with the waist downwards, the bottom being attached to a circuit of movable pins, so arranged that they can be moved in any desired direction, and can be altered in number according to the circumference of the bottom of the Fig. 57. — Gone with Holderness" Clips. FINISHING. 189 skirt. Before this is completed the waist is fitted with a wooden body which is connected to a lever, so that when ready the skirt can be stretched without difficulty to its original length. It dries quickly under tension, and only requires ironing to remove the pin marks. In finishing all descriptions of wearing apparel steam bolts of various shapes and sizes are found to be very economical. They are extremely simple in use, the articles being held tightly by hand on the heated surface for a few seconds. They are employed in finishing the shoulders of coats, the sleeves of blouses, etc., the ''fulness" or irregularly-shaped surfaces of any articles which cannot be ironed satisfactorily, small frills of ribbon, lace, etc.. FiCx. 58.— Gome's Hand Spray. trimmings on babies' bonnets ; in fact, there are not many articles of ladies' dress in which some portion is not finished on a bolt. They are made in a very large number of shapes and sizes to meet various requirements, some of which are illustrated in figs. 59 and 60. When gentlemen's suits are being finished in considerable quantities the " Eastman-Keston " bust finishing machine and the " Hill ik Holttum " flat plate pressing machine will be found very economical. The bust-pressing machine is shown in fig. 61, and is employed in shaping and finishing the bust, shoulders and collars of gentlemen's coats. The upper crosshead of the machine contains an inverted polished mould, heated by steam, and shaped to fit 190 DYEING AND CLEANING. over the collar, shoulders, and bust of the coat. The lower plat- form is fitted with a perforated iron bust, more or less fitting the inverted mould in the crosshead. Covering this perforated bust is a loosely fitting indiarubber bag, the lower edges of which Fig. 59.— Steam Bolts. are fitted to form a water-tight joint with the top of the platform. The bag is filled with water and communicates with a pump, .the object of the perforated bust being to prevent the bag from collapsing when the water pressure is reduced. In working, the bag is slightly inHated, and the coat^ previously damped by Fig. 60.— Steam Bolts. steaming or spraying, is placed over it, and shaped by hand to remove creases ; the platform is now raised by a lever, the coat being lifted into the heated mould and locked there by another lever. Water is then forced into the bag by a small hydraulic pump and the coat is forced into every part of the mould, the FINISHING 191 pressure (10 to 20 lbs. per square inch) varying with the class of work in hand. The coat remains in position until dried and Fig. 61. — " Eastman -Keston" Bust Finishing Machine. pressed. If necessary, calico cloths can be used between the coat and the heated mould. FINISHING. 193 The sleeves and flat portions of coats and trousers are finished on the flat plate pressing machine (fig. 62). This apparatus has a flat steam-heated bed, polished on the under surface, and two swing tables on which the articles are placed, one table being filled whilst the goods on the other are being hydraulically pressed. The top of each table is covered with an indiarubber sheet about a quarter of an inch in thickness, hermetically sealed by bolts to the under-side of the table. This sheet encloses a layer of air about a quarter of an inch in thickness, the cushion of air acting as a substitute for the ordinary ironing felt. At the centre of the vmder-side of each table is a projecting boss, so that when the table is swung round under the polished heated bed, it coincides with the top of the hydraulic ram. A few strokes of the pump raises the table at any desired pressure against the heated bed, where it is locked. While this is in position the work is being arranged on the second table. On the water being released from the first table it drops an inch, and the second table is swung into place and raised as before. For pressing gentlemen's clothes heavy irons, to which foot pressure can be applied, are sometimes used. This type of machine is shown in fig. 63, which is fitted with a heavy gas-heated tailor's iron (20 lbs. weight), which is shown on a larger scale in a separate illustration (fig. 64). Many articles of dress, either whole or unpicked, are finished upon machines, which are principally employed for draperies, etc., and will be described under that section. 2. Furnishings. — The articles employed in furnishing cover a very wide range of articles which are finished according to the fabric employed and the preliminary treatment which it has undergone. The principal machines and appliances employed are as follows : — Curtain frames (for lace, Swiss net, guipure and other curtains, window blinds — preparatory to glazing, etc.). Silk frames (for pile fabrics of all descriptions — velvet, plush, etc., in curtains and draperies, unpicked or partially unpicked dresses, capes, etc., dyed curtains in various fabrics, especially such as have shrunk in dyeing, etc.). Steaming table (for dyed and cleaned fabrics ; e.g. serge cur- tains, etc.). Cylinder (for unpicked dresses, ribbons, laces, small curtains, embroidered net curtains and window blinds [alternative to framing] ). Glazing machines (for glazing chintz and druggets, glazing cretonne on the back, or fitted with felt roller and steam block for finishing cretonne, satin, etc.). 13 194 DYEING AND CLEANING. Glazing calender (for glazing window blinds, lengths of chintz, drugget, etc.). -■I Fig. 63. — Pressing Machine. Decoudun {or similar calender) (for finishing lace curtains after framing, lengths of material, dimity, etc.). Gofferiiig machines (for goffering the frills of curtains, etc.). Carding machines (for raising the nap on blankets). Hand ironing with ordinary or special irons (for cretonne, soft silk curtains, etc.). 195 FINISHING. Hot press (ior dsim?isk, etc.). The articles which may be sent for dyeing and cleaning from the household cover such a very wide range, varying from small 1 03 articles such as curtain bands, fancy table centres, etc., to large curtains and draperies in every possible fabric, that it is im- possible to specify every article and the method or methods of finishing the same, but the principal methods in use and the 196 DYEING AND CLEANING. chief articles for which they are employed will be given, and from these the processes to be adopted for allied articles can be deduced. Cu7 tain and Window Blind Finishing, — Frames are employed in drying curtains in Nottingham lace, Swass net, guipure, muslin, etc., window blinds in holland, linen, coutil, etc. They may be divided into horizontal and vertical frames, these terms referring to the position taken by the frames during the drying process. A **set" of frames varies from five upwards, the number being generally so arranged that the workers can frame the curtains, etc., continuously; e.g. with a set of five frames the drying power is such that by the time the fifth frame is filled and placed in the drying chamber, the curtains on the^rs^ frame are dry and ready for removal. The question as to whether horizontal or vertical frames shall be employed depends to a considerable extent upon the space available and on the w^orkers who are to operate the frames. Vertical frames which are to be emptied and filled in a horizontal position are somewhat heavy for female labour to lift into the vertical position ; but, on the other hand, a very much larger number of frames can be accommodated in a given space. Fig. 65 shows a vertical frame in position on the rail leading to the drying chamber. It consists of a rectangular frame fitted on one side with a flanged wheel at each end to fit on to the overhead rail. The top and left hand side are fitted with steel pinning" with a wood guard to prevent it from being damaged in running in and out of the drying chamber. There are also a movable horizontal rail and a movable vertical rail fitted with "pinning," which can be fixed by thumbscrew^s or other device in any position, so that the frame will take any curtain smaller than the dimensions of the full-sized frame. Frames are also made wdth a second horizontal rail between the fixed and the movable sets of pinning, bearing upon it a double set of pinning. When narrow curtains are being framed, two sets can be put on one frame by this appliance, the first set being framed on the fixed pinning and one side of the centre bar ; and the second set on the other side of the centre bar and the outside movable pinning. To ensure the movable side being quite parallel with the fixed side, the table on which the frame is placed during framing may have two parallel lengths of angle iron or wood, which may be moved in either direction by racks and pinions, the latter being keyed on a rod which is turned by a handle from the end of the frame. The parallel lengths, by resting against the fixed and movable sides, ensure the latter remaining absolutely parallel, 198 DYEING AND CLEANING. and, moreover, afford a means of stretching blinds, etc., which may have shrunk in cleaning. The curtains, starched and wet from the cleaning house, are sorted into pairs and placed on the frames by means of brushes which " tap " the edges or points of the curtains on to the pins. Usually one pair is placed on each frame, bat if there are others of exactly the same size, two pairs may be placed on one frame. The movable side and end having been fixed, the frame is lifted on to the rail, the door of the drying chamber corresponding with that rail is opened, and the frame is pushed into the chamber, which is heated with steam pipes, and may or may not be fitted with a fan. Still air is frequently employed, as the dust, which is drawn in and kept in movement by a fan, readily adheres to the damp starched curtains. When the contents of the frame are dry the frame is withdrawn from the drying chamber, placed upon the table, and the movable side and end are slackened so that the curtain may be readily removed without risk of damage. Horizontal frames differ from those described in that the drying chamber is fitted with rails, on which the frames rest one above the other, in a horizontal position. A frame fitted with a pair of rails is arranged outside the drying chamber, and is counterbalanced so that it can be raised or lowered and locked opposite any of the pairs of rails inside the chamber. The curtain frame is then drawn out on to the movable frame and raised or lowered to a convenient height for taking off or putting on curtains. In these curtain frames two wheels on each side are provided, but in all other respects they do not differ from the vertical frames. They do not, however, possess the advantage of the parallel stretching device, which can be fitted to the table used for the vertical frames. Curtains which have been framed should have tlie points and the " headings " ironed by hand to remove the pin marks, or, with the exception of frilled and heavily embroidered net curtains, they may be passed through a decoudun or similar calender to remove the slightly rough surface left by framing. Figs. 66 and 67 show the *'Ibis" decoudun; it consists of a steam-heated bed and a steam-heated padded roller revolving in the bed, the curtains or other articles being fed through a ''lip," and passing between the roller and the bed. Curtains which are to be calendered sub- sequent to framing may with advantage be taken off the frames while they still contain a small amount of moisture. Curtains with frills are not calendered ; but the frills and the headings of the frills are ironed out and goffered by hand or by machine. The latter is not usually found satisfactory for muslin and light fabrics, as the result is not so permanent as that pro- duced by goffering with hand tongs. The machine is made with 0. 200 DYEING AND CLEANING. various sized flutings on a stand or to fit on a table (figs. 68 and 69), and produces fairly satisfactory results where the fabric is of heavier material {e.g. Nottingham lace). 2 Curtains with highly raised embroidery are sometimes starched on the curtain frames to keep the raised portions quite soft. The unstarched curtain is placed on the frame with the embroidered face downwards, and the back is carefully sponged with a solution FINISHING. 201 of boiled starch. Such curtains may also be finished on the steam cylinder, being brushed on by hand with starch solution. This method is also employed for finishing curtains which are of special value, or which are too frail to stand the slight tension of framing. It is not, however, economical for general curtain and blind finish- ing, owing to the large condensing surface and consequent heavy steam consumption. Window blinds in holland, etc., may be framed or cylindered, the former being the more satisfactory process, as it affords a Fig. 68.— Table Goliering Machine. means of stretching to their original dimensions blinds which have shrunk in the process of cleaning. Window blinds are cleaned and finished with or without unpicking the side hems. If un- picked, the pin marks are not so obvious ; and in the case of blinds which have shrunk the hem may be made a little narrower in re-making, permitting the blind to be re-made to the original size. On the other hand, the unpicking atid re-making add to the cost of the process. When the slight additional cost is not of paramount importance, it is advisable to unpick the hems, as there is a possibility of the ''paper" bowl of the glazing calender 202 DYEING AND CLEANING. becoming indented by the double thickness of the hemmed portion. If possible, blinds which are to be glazed on a friction calender should be framed about a half inch wider than the finished width to Fig. 69. — Stand Goffering Machine. allow for the slight contraction in width which takes place. The blinds having been framed, are steamed or sprayed to dampen them slightly, and are then ready for glazing. The friction calender consists of a chilled steel top roll heated by steam, a centre bowl of highly compressed paper or cotton, and a bottom FINISHING. 203 roll of steel to enable heavy pressure to be placed on the centre bowl. The top bowl is geared to run at a higher speed than the centre roll. Fig. 70. — Downham "Lifting" Calender. In the "Downham" calender shown in fig. 70, the top bowl lifts about an inch from the centre bowl by means of belt-driven cams. This is very useful in glazing blinds trimmed with lace at the ends, as the lace end may be passed through the opening, the top bowl dropped into place and the machine started, thus 204 DYEING AND CLEANING. glazing the holland and leaving the lace untouched. Blinds are usually passed through the calender twice, each side being glazed. In other glazing calenders the bowls are arranged to reverse by operating a lever ; lace-ended blinds are then fed in with the plain end first, and the bowls are reversed just as the lace reaches the nip " of the calender. Calenders are also made with over- hanging bowls, one end of the machine is open (in the same way as a "body ironer," fig. 55); by means of such machines, blinds wider than the rolls may be finished by glazing one-half at each operation. It is, however, somewhat difiicult to finish a blind absolutely " square " by this means. Duchesse blinds, in which the embroidery does not finish in a straight line, may be glazed on a calender as far as the embroidery, the rest of the holland being finished on the ordinary reciprocating glazing machine. In some cases blinds are finished without any glaze {e.g, coutil), in which case they are taken direct from the frame or cylinder, and after topping up the lace (if any) by hand, are ready for re-making. The glazing calender is also employed in finishing straight lengths of drugget, chintz, and linings which have been unpicked, etc. If the paper bowl of the calender becomes accidentally marked or indented, the places, if small, may be worked out by damping with cold water or a weak solution of neutral soap in water and run- ning cold for some time and afterwards with the top bowl heated, the water or soap solution being applied from time to time. By this means the surface" of the bowl may be gradually worked up again. If the bowl is deeply indented it must be placed in a lathe and turned down until the marks are removed. Chintz Glazing. — The finishing of unpicked chintz by the glazing calender has been referred to briefly ; in most cases chintz is not unpicked, but is finished in the form' of curtains, hangings, chair covers, seat covers, ottoman and sofa covers, etc., in the made-up condition. When received from the drying-room the chintz is very stiff" and must not be handled carelessly, as in this condition it readily cracks and tears. It is damped with water by an atmospheric pressure spray, and when it has laid by for a short time and has become softened it is pulled into shape, if necessary, and is rolled up tightly for some hours to allow the slight amount of moisture in it to equalise, after which it is ready for glazing. The glazing tools shown in figs. 71 and 72 consist of a com- pressed felt bed about 2 inches wide and of varying length, which may be raised by a foot lever. The polishing tool is a piece of flint with a round surface and rounded edges of the same width FINISHING. 205 as the felt bed ; it is fixed in the reciprocating arm of the machine, the length of stroke depending on the throw of the eccentric on the driving shaft, and is the same as the length of the felt bed. The machines are usually supplied in sets of four, the smallest having a stroke of 2 inches, being employed in finishing frills, covers, etc., and the largest having a stroke of about 2 feet, being used for curtains, etc. The intermediate sizes are used for chair covers^ etc., though frequently the same curtain or cover will have various parts glazed on all four machines. Care must be taken to avoid "pinching" — i.e. the formation of small pleats in the Fig. 71. — Glazing Machine. Fig. 72. — Glazing Machine and Roller and Steam Block. fabric, as these are liable to show as cuts when the fabric is cleaned again. The machines are frequently used for finishing cretonne, tissue, and similar fabrics in curtains, covers, etc. ; in such cases the hack of the fabric is glazed, giving a smooth unglazed finish on the face. They are also supplied with a compressed felt roll in place of the flint and a steam-heated bed instead of the felt block for finishing cretonne, etc., on the face, a better finish being obtained in this way than that producible by hand ironing (fig. 72). This machine is also employed in finishing dyed satin goods, etc. A rotary glazing machine (fig. 73) is now being experimented FINISHING. 207 with, and, if satisfactory, should permit of less skilled labour being employed ; it consists of a gas-heated polishing roller and a com- pressed cotton bowl, and is in elTect a miniature glazing calender. Cretojine is also finished by hand ironing, using ordinary irons or the large surface or " Crown " irons shown in fig. 74. These are economical in use and easy to operate ; they are not lifted on to a stand when not required, but are slid on to a sloping rest which is fixed on the ironing table (fig. 75). Pile Fabrics. — Velvet and other pile fabrics which have been 208 DYEING AND CLEANING. dry cleaned can generally be finished by brushing on a steaming table of the pattern shown in fig. 54, or the table pattern shown in fig. 76. Those which have been dyed cannot be finished in this manner, as the pile is not sufficiently raised thereby ; they can only be done satisfactory on a silk frame." This consists of a metal framework, the two sides of which are fitted with metal pinning, which is usually fitted into a metal strip instead of wood (as in curtain frames), to allow of considerable tension being employed. The underframe is fitted with rails on which run two trolleys fitted respectively with gas burners and steam jets fitted in pans running transversely on the trolleys, the gas and steam being supplied by flexible tubes. By this means the gas pan or the steam pan may be brought under any portion of the fabric which is upon the frame. Articles which are not rec- tangular in shape have " tacking cloths" — i.e. pieces of calico — stitched round them ; these are fixed on to the pins so that the Fig. 75. — Stand for Crown Iron. velvet (portion of a dress, etc.) may be stretched quite evenly. Crossbars fitted with pinning are provided for the ends of the curtains, etc., to which they are attached direct or by means of tacking cloths. Velvet curtains which are too long for the frame may be finished one half at a time ; the finished portion must be carefully protected while the other half is being treated. A curtain having been placed on the frame, the latter is tightened by means of the hand screws provided, and steam is blown through the fabric, working from one end to the other and brushing the whole time by hand. By means of a circular motion w^ith the brush the pile is disentangled and opened up, and is finally brushed one way — up to the heading of the curtain, when no marks or broken places should be visible. The fabric is then dried by means of the gas pan, brushing the pile at the same time towards the top of the curtain. Velvet pile table covers, etc., which have been dry- cleaned are frequently finished by steaming, followed by brushing FINISHING. 209 with fine emery cloth ; this " cleans " the pile by removing adhering particles of fluff, fibre, etc. The silk frame may also be used with advantage in finishing any dyed curtains which have become cracked or "broken " during the dyeing — e.g. satin, silk damask, roman satin, etc. It is also used for stretching dyed curtains which have shrunk to any extent in dyeing (felt, etc.). Satins, velvets, and other fabrics having a " face " side are sometimes slightly stiffened on the back while on the frame by sponging with a weak solution of gelatine 14 210 DYEING AND CLEANING. containing a little acetic acid (feculose and similar soluble starches may also be employed). Serge^ Chenille^ etc. — Curtains in these fabrics which have been cleaned or dyed may be finished in many cases on the steaming table, followed by topping up by hand where necessary. Damask (if it is not trimmed with fringe, etc.) may be finished on a decoudun or similar machine, any undesirable gloss imparted to the fabric being removed by a slight steaming. Where possible, however, damask is finished by hot pressing in the ordinary hydraulic press. Soft silk curtains and small articles, such as curtain bands, table centres, sideboard cloths, etc., are usually finished by hand. Embroidered linen cloths of various kinds are also finished by hand or on the cylinder. Cylinder. — This is a tinned copper cylinder made in various sizes, the most generally used being 12 feet in length and about 4 feet in diameter (fig. 77). The steam is supplied through a reducing valve, and the cylinder should be fitted with a safety valve and pressure gauge. As already pointed out, it is an expensive machine to use, owing to its large steam consumption. It is, however, very useful in finishing embroidered articles of all descriptions — curtains, bedspreads, counterpanes, tray cloths, etc., as the raised portions are not flattened in the slightest degree. It is also used for finished shaped articles — lace, ribbon, pieces of unpicked dresses, etc., as the articles are brushed on to the cylinder whilst wet and arranged in the correct shape, and are not removed until dry and set in that shape. The wet articles are brushed on to the surface of the cylinder with a brush or sponge damped with water, starch water or gelatine solution, according to the finish required, and remain in position until quite dry, when they are peeled off". Lace which is to be finished quite soft must not be cylindered. It must be pinned out on a padded table and not remoyed until quite dry. Fig. 77.— Cylinder. 212 DYEING AND CLEANING. Blankets, — These must be " carded " to soften them and to raise the nap. This process may be carried out by hand or by machine ; in the former process the blanket is stretched on a frame and the carder'' (a piece of wood on which has been tacked "carding cloth " — i.e, cloth fitted with fine metal pins inclined at an angle, such as is employed in carding raw cotton) — is drawn by hand down the blanket, raising a nap with a practically negligible loss of wool to the blanket. In carding by machine the " carding " is mounted on a roller (fig. 78) the result produced being the same as that in the hand process. The descriptions which have been given cover practically the whole of the finishing appliances in general use. While it is impossible to specify every article which may come into the hands of the dyer and cleaner, he may deduce the mode of procedure in any particular case from the methods and appliances which have beea described. APPENDIX A. THE ADULTERATION OF SILK WITH TIN AND OF FLANNEL WITH EPSOM SALTS. Reprinted hy permission from " The Lancet " of 6th Janitary 1906. So long ago as 1899 this subject received attention in our columns, when the results of a detailed examination, carried out in The Lancet laboratory, of a large number of dress materials were published. 1 Analysis showed that what in wearing apparel may be regarded as foreign matter was frequently present in considerable quantity, and it was pointed out that many of these mineral substances, although apparently insoluble under ordinary conditions, were in most cases rendered soluble by the action of perspiration. Consequently, there was risk that poisonous substances might be brought into intimate contact with the skin under conditions favourable to their absorption. Although only insignificant traces of arsenic were discovered, zinc, aluminium, chromium, tin, magnesium, and iron were found, and, calculated upon the total w^eight of material sufficient to form a dress, it was found that the mineral matter present varied from one-tenth of an ounce to as much as nearly six ounces. Recent experiments made in The Lancet laboratory upon a number of samples of silk bought in the ordinary way at West End drapery establish- ments would seem to show that the evil in question has certainly not diminished since the former article on the subject appeared ; in fact, recent inquiries indicate that the loading and adulteration of fabrics have during the last few years become a very serious question for the community. The adulterant found in the samples of silk recently examined is stannic salt, and the quantity present in one case was nearly 36 per cent. The following is a list of some of the actual amounts discovered, from which it will be seen that although there was considerable variation in the quantities of tin present none of the samples examined was guiltless of the adulterant. The adulteration of silk has now become such an established industry " that a short statement of the process by which it is 1 The Lancet, 28th October 1899, fjp. 1186-87. 213 214 DYEING AND CLEANING. Analyses of Six Pieces of Silk. Piece. Percentage of Total Mineral Matter. Percentage of Tin calculated as Stannic Oxide (Sn02). Percentage of Real Silk Present.* 1 34-00 29-00 57-36 o oU 00 7 U 3 24-20 19-50 60-00 4 42-40 31-60 50-00 5 42-40 31-60 50-00 6 47-10 35-90 50-00 Averages. 37-40 29-60 53-84 * The percentage of real silk present is calculated from the amount of nitrogen present, 18 per cent, of which represents 100 per cent, of silk. The nitrogen therefore multiplied by 5-5 gives the real silk present. effected may prove interesting. One of the principal substances composing raw silk, and one which may be considered as the active substance in the silk, is known as sericin. This has a slightly acid reaction and a power of combining directly with metallic oxides and basic dyes, and advantage is taken of this fact to weight cheap silks to an enormous extent with tin. The method of procedure is to soak the silk for several hours in a solution of stannic chloride, after which the fabric is passed through a cold solution of carbonate of soda to set free the tin in a basic condition, so that it can combine with the sericin. A bath in neutral soap solution to make the fibre supple and to increase its affinity for more weighting material follows, and the fabric is now ready to take another turn in the tin bath. Three passages through this process will increase the weight of the silk by from 25 per cent, to 30 per cent., six by 50 per cent., seven by 75 per cent., eight by from 90 per cent, to 100 per cent, and ten by about 160 per cent. The weighting process is carried out in darkened rooms, as sunlight or any strong light renders the silk brittle during these operations. Although the strength of the fibre is greatly reduced, the appearance and lustre of the silk do not seem to be affected seriously for the time being. All goes well so long as the fabric is kept in the dark, but as soon as it is worn the light decomposes the compound of the tin and the sericin, producing oxide of tin and free acids, which rapidly destroy what is left of the fibre, so that a garment of weighted silk will tear in the wash under ordinary handling, especially under the armpits, where the effect of perspiration has been added to the other destructive agencies. As this cheap silk is used not only APPENDIX A. 215 for dressmaking jper se but as lining for other dress materials, it frequently comes in contact with the skin, and even in cases where underclothing may protect the skin from immediate contact with the silk there is always the risk that perspiration may set free the oxide of tin in a soluble form and by its absorption by the other materials bring it in direct contact with the skin, so that the wearer of such material runs considerable danger of local irritation being set up, if nothing worse. Before passing on to other materials we must call attention to a particularly obnoxious method which is in use for colouring, we cannot call it dyeing, the cheap materials used for linings and similar purposes. In this case the dye is made up into a kind of paste with some sizing material, and instead of the fabric being properly dyed this coloured size is spread over the surface by rollers. When dry it has a perfect appearance, and the fraud is not distinguished until the fabric is brought in contact with moisture, either in the wash or through perspiration, when the dye practicdly leaves the fabric. Although it is true that the majority of the dyes derived from aniline and what are known generally as coal-tar colours are very much faster to light than they used to be, the lack of fastness to soap and water, which many of the materials at present in use exhibit, is a source of serious complaint from laundrymen and those who have to handle' them. A suit of flannelette pyjamas, upon which we recently made some experiments, was of a very pleasant blue shade when purchased, but in two washings the colour was completely re- moved. Instances of this kind might be multiplied almost indefinitely from other instances which have come under our own experience, or have been brought to our notice by laundrymen from whom we have made inquiries. The loading of fabrics intended for wearing apparel is by no means confined to silk, and is such a serious factor in the manu- facture of the cheaper varieties of flannel, amongst which we may include blankets, that in sorting the various articles which come into the laundry, before going through the cleansing process a laundryman has to be very careful to pick out any new goods of this description and to wash them separately, otherwise the large amount of loading material which they contain might interfere so seriously with the washing process as to necessitate a second washing of a whole batch of goads. This is even more true of the cotton bands, etc., attached to the woollen materials, which usually receive separate treatment. This weighting of material is so serious in almost every department, that it is quite a revelation to see the quantity of loading material, largely china clay, which is washed out of cheap table linen and similar goods, 216 DYEING AND CLEANING. and to observe what a very little of the apparently stout fabric appears to be left after contact with water for a few minutes. We must recall also that in our previous investigation into the amount of mineral matter in dress fabrics we discovered consider- able proportions of Epsom salts and zinc compounds in flannel. It would be bad enough if the sophistication of fabrics were confined to loading them, but unfortunately this is not the case. The modern manufacturer in many instances adulterates the fibre of his fabric first and loads it afterwards. Silk is adulterated with artificial silk made from cellulose, flannel and woollen material with cotton, linen with cotton, whilst " mercerised " cotton is employed in many ways. Some of these mixtures of fibres are quite legitimate, but a good many are not, and amongst the most serious of which the community has to complain at the present time is the adulteration of linen with cotton. The substitution of cotton for linen has become so serious that the Irish flax spinners have been compelled to take action in self-defence, and prosecutions of retailers have occurred in most of our principal towns. They form very interesting reading, for they show that a certain section of the retail trade has become so lost to a sense of right and wrong that it is seriously claiming that the passing-ofl" of cotton goods for linen is a trade custom and therefore justifiable. The common practice seems to be to sell cotton shirts or collars or fronts made of one-ply linen and two-ply cotton, or in other proportion according to the nature of the garment. In many cases these were actually sold as " all linen " and so described on the invoice. In a recent prosecution at Bradford the manager of a firm seriously contended that the word linen " was the trade term for linen-fronted goods, and that it did not necessarily imply that in their trade the goods so described were all flax. In reply to a question from the stipendiary magistrate the witness admitted that he had not a single all-linen collar in his place — not one that he would guarantee to be pure linen. A defendant at another court remarked that he did not believe that anyone present was wearing an all-linen collar ; he felt quite sure that the prosecuting inspector's collar was cotton ; and so on. Now, w^hatever may be the hygienic difference between cotton and linen, there is a large difference in the cost and in the wearing capabilities. Cotton fabrics disintegrate comparatively readily, the fibre being much shorter than linen^ whereas linen has a long and very strong fibre. The consequence is that cotton fabrics contribute rapidly to the formation of that fluff" which is the bugbear of the modern housewife. The table linen not so very long ago consisted wholly of linen ; nowadays a large pro- APPENDIX A. 217 portion of it consists of a cotton warp and a linen weft, and sometimes it is entirely of cotton. In the wash the difference soon becomes apparent ; an appreciable amount of fibre becomes separated from the surface of the cotton fabric, and although a certain amount is removed in the rinsings yet a large proportion remains clinging to the materials when dry. In use this soon becomes separated and adds appreciably to the dust and dirt of the living-room. In some of those loosely woven tablecloths, which are sent out felted together with size, starch, and china clay, so that they look thick and solid, the fluff is so serious that if a laundryman happens by misfortune to wash one in a batch with other table linen it will contaminate the whole, and the unfortunate customer who uses good table linen is horrified to think that the laundryman is destroying her expensive fabrics in the most ruthless manner. The wholesale adulteration of linen has become so serious that a large linen shop in the West End of London is, or was a short time since, placarded with notices to the effect that on account of the difficulty of distinguishing between cotton and linen the assistants were forbidden to give any kind of warranty. This notice is akin to the announcement by which many publicans evade the Sale of Food and Drugs Act — namely, by stating that spirits are sold as ''diluted." To take the case of flannels and woollens again : these are frequently adulterated with cotton and loaded, although in a different manner from cotton, but even amongst the numerous goods that are sold as natural wool and guaranteed unshrinkable many are found to which this term can only be applied in derision. On account of the construction of the fibre, woollen goods if not washed with great care are always liable to shrinkage, but unless they have been very badly treated this shrinkage should not be great if the fabric is properly shrunk in a soap liquor before the garments are made up. A large number of the garments now sold through the retail hosiers and linendrapers are not properly shrunk, even in the case of some which are largely advertised and are supposed to bear a high name for quality, the result being that the shrinkage is excessive. The wool fibre is covered with a number of serrations, and these have a tendency to interlock and to pull the fabric closer and closer together, especially if during the washing process the fabric is subjected to serious changes of temperature, such as removing from hot water into cold, which causes the fibres to move. It has been discovered, however, that treatment of the fibre with hydrochloric acid will cause such an alteration in these barblets that the fibres have no longer a tendency to interlock, although they are not seriously affected in any other respect, and a large 218 DYEING AND CLEANING. quantity of woollen underclothing which, to use the trade term, has been " kymoed " is now on the market. Shrinkage is not confined to woollen goods, as cotton goods will sometimes shrink along the warp when being washed for the first time. In the modern power loom the fibres are often severely stretched in the direction of the warp, and the fabric takes the first opportunity of recovering itself when moistened. On the other hand, we have been shown some samples of chintz which have been causing a veritable panic amongst the furnishing houses and dyers and cleaners. An ordinary width of this when wetted stretches two inches. The effect of this upon a suit of chintz furniture covering and the feelings of the housewife when she gets it home can readily be imagined. Yet another very important difference between the old and the new style of fabric is in the length and strength of the fibres employed. The short staple wool, for instance, which is now largely woven into our garments, would have been discarded not many years ago and employed only for making felt, being regarded as too short to weave into satisfactory yarn. In cotton and linen, again, especially the latter, there is nothing like the care employed in selecting the fibres that there used to be, with the consequence that they break much more frequently in the weaving, apart from possessing much less intrinsic strength. Here again there is no time to knot the broken ends properly together, but they are given a twist which secures them for the time being. As soon as the size is washed out of the goods when they go to the laundry many of these broken ends develop into holes, and we have had a large number of tablecloths submitted to us for examination in which these holes could be traced in various stages of progress. Examination with an ordinary magnifying glass was quite sufficient to show what was wrong with the fabric. Bleaching, again, is conducted in a hurry and the methods employed are much more drastic than they used to be, with the natural result of a seriously weakened fibre. From the instances which we have given above it will be seen that the trade in fabrics is in as bad a condition now as regards adulteration as was the trade in food and drugs when The Lancet first stepped into the arena in 1850 to combat the demon of adulteration, and the question arises. What remedies can we propose? The only weapon that the public at present possesses is the Merchandise Marks Act, which penalises a trader for applying a false description to his goods. As applied to the drapery and hosiery trade, however, and regarded from the ordinary purchaser's point of view, this Act suffers from the defect that not only can a coach-and-four be driven through it APPENDIX A. 219 but two motor-cars as well. Except where cotton is wrongly described as linen it is practically impossible to apply the Act to cases of deception in the sale of fabrics. The trader is much too wily to be caught in such a very loosely woven net as the Merchandise Marks Act. He simply applies some adjective to the word describing the material — he calls it " Chinese silk," " Cathay silk," " Carthaginian silk," anything but " silk " — and is safe. Similarly with flannel, it rarely appears in the linen- draper's window without some patriotic adjective — it is Welsh flannel, Scotch flannel, Irish flannel, but very rarely flaimel ; certainly not "pure flannel." However desirable it might be in theory to compel manufacturers and retailers to apply correct descriptions to their goods, it would hardly be practicable to compel them to placard their windows with such announcements as "Tin silks: all the rage," "Epsom-salted flannels," "China clay table linen," and so forth, however accurate such descriptions might be. It is equally impracticable to expect customers to demand a warranty with every yard of material which they buy, because, in the first place, they would not ask for it, and in the second place they would not get the warranty if they did. Not long since we asked for a written guarantee at a certain wool-shop that the underclothing which we were about to purchase, although warranted in the firm's advertisements not to shrink, would not do so in reality, but were refused on the ground that the firm did not know what laundry we were going to send it to. And this brings us to another very serious matter — namely, that the sophisticators of fabrics — manufacturers, wholesalers, and retailers together — are endeavouring to pass the responsibility for their Diisdeeds on to the unfortunate laundryman or dyer and cleaner, who, in nine cases out of ten, is in no way to blame. The bad- wearing qualities of the table linen, which goes into holes on the first wash, the raw edges on the collars, the thinness of the blankets, and so forth, are attributed to the laundryman's chemicals and machinery, instead of to the fraudulent methods employed in the manufacture and sale of the goods. Ladies compare the wearing qualities of the linen that their mothers used to buy with that which they purchase themselves, and put the blame on the laundries for the bad qualities of the latter. Good linen, for example, will wear well even in the modern laundry, and in proof of this we were shown a handkerchief not long ago which had gone regularly through the wash for almost a generation, including many years' washing in a modern steam laundry, and which appeared to be little the worse. Such things can hardly be bought nowadays, even if a purchaser is willing to pay a high price. To take the case of the tinned silk again, 220 DYEING AND CLEANING. which we have recently analysed : the silk blouse which appeared so charming when new crumbles almost at once in the sun, the tin is converted into oxide, which is removed as powder in the wash, the acid attacks the fibre and causes it to go into holes as soon as it reaches the hands of the laundryman or dyer and cleaner, and when its once proud possessor receives back the rag which was once a blouse, her wrath is expended, not upon the draper who sold it, but upon the unfortunate dyer and cleaner to whom was intrusted the impossible task of rendering it equal to new. In distributing the blame we must not place the whole of it upon the shoulders of the manufacturers and retailers, bad as they are, but must mete out a considerable share to the fair sex who in their desire to obtain showy materials at a cheap rate give direct encouragement to these objectionable practices. Every year the cry goes forth for something cheaper than last year that will look as well, and the draper is only too ready to meet the demand and to encourage it. Nevertheless, it must be borne in mind that the sophistications are so skilfully conducted that they would deceive all but the expert, and the housewife with a limited purse can hardly be severely blamed if she buys at cheap prices goods which look all right. The real and most serious blame must be laid at the door of the manufacturer and retailer, and the only way that we can see open at the moment to save the unfortunate customer from their devices is to educate her as rapidly as possible concerning the practices which are in vogue. This is certainly a large undertaking, but, so far as we can see, it is the only way to grapple with the difficulties in the absence of some drastic legislative measure. One practice that we should certainly like to see prohibited at the earliest moment is the loading of fabrics of any kind with mineral matter — we do not include the mordants which may be necessary to fix the dyes on the material. This practice of loading goods with china clay and other materials was designed in the .first instance to swindle the unsuspecting Hindoo who buys his cotton cloth by weight instead of by length, and the practice has now spread to the greater part of the goods on the home market. Such loading, whether it be carried out in cotton, linen, or silk, serves no good purpose what- ever ; it is simply a fraud, and is quite unjustifiable. Moreover, we are still of the opinion stated in our previous article, that in addition to the actual danger to health caused by the presence of the irritant mineral poisons in dress fabrics, the presence of mineral substances generally tends to nullify the important pro- perties of clothing of keeping the body warm and protecting it from the cold, and, above all, of allowing the free passage of air from within and without." APPENDIX B. Acetic Acid. Acetic acid (both the dilute acid, 30 to 40 per cent., and glacial acetic acid) is tested by titration with normal caustic soda solution, using phenolphtbalei'n as indicator. The specific gravity of acetic acid is shown in the following table {Roscoe) : — Specific Gravity at 15°. Acetic Acid, per cent. Specific Gravity at 15°. Acetic Acid, per cent. 1-0007 1 1-0746 75 1 -0067 5 1-0748 80 1-0142 10 1-0739 85 1-0214 15 1-0713 90 1-0284 20 1-0705 91 1-0350 25 1-0696 92 1-0412 30 1-0680 93 1 -0470 35 1-0674 94 1-0523 40 1-0660 95 1-0571 45 1-0644 96 1-0615 50 1-0625 97 1-0653 55 1-0604 98 1-0685 60 1-0580 99 1-0712 65 1-0553 100 1-0733 70 Table of Percentages of Hydrochloric Acid. Specific Gravity. Degree Baume. Degree Twaddell. Percentage HCl. Specific Gravity. Degree Baume. Degree Twaddell. Percentage HCl. 1-000 0-0 0 0-016 1-105 13-6 21 20-97 1-005 0-7 1 0-15 1-110 14-2 22 21-92 1-010 1-4 2 2-14 1-115 14-9 23 22-86 1-015 2-1 3 3-12 1-120 15-4 24 23-82 1-020 2-7 4 4-13 1-1-25 16-0 25 24-78 1-025 3-4 5 5-15 1-130 16-5 26 25-75 1-030 4-1 6 6-15 1-135 17-1 27 26-70 1-035 4-7 7 7-15 1-140 17-7 28 27*66 1-040 5-4 8 8'16 1-145 18-3 29 28-61 1-045 6-0 9 9-16 1-150 18-8 30 29-57 1-050 6-7 10 10-17 1-155 19-3 31 30-55 1-055 7-4 11 11-18 1-160 19-8 32 31-52 1-060 8-0 12 12-19 1-165 20-3 33 32-49 1-065 8-7 13 13-19 1-170 20-9 34 33-46 1-070 9-4 14 14-17 1-175 21-4 35 34-42 1-075 10-0 15 15-16 1-180 22-0 36 35-39 1-080 10-6 16 16-15 1-185 22-5 37 36-31 1-085 11-2 17 17-13 1-190 23 0 38 37-23 1-090 11-9 18 18-11 1-195 23-5 39 38-16 1-095 12-4 19 19-06 1-200 24 0 40 39-11 1-100 13-0 20 20-01 221 222 DYEING AND CLEANING. Table of Percentages of Nitric Acid at 15°. Specific Gravity. Degree Baume. Degree Twaddell. Percentage HNO3. Specific Gravity. Degree Baume. Degree Twaddell. Percentage HNO3. 1*000 Q 0 0*10 1*265 30*2 00 1'005 0*7 \ 1 '00 1 *270 30*6 f^i 0^ 1*010 1*4 2 ± U\J 31*1 00 1*015 2*1 3 2*80 1 *280 31 "5 44*41 1*020 9*7 4 ^•70 0 1 \j 1*285 32*0 0/ 4^•^ ft 40 lo 1*025 3*4 5 1*290 32 '4 00 4«J 1*030 4*1 5*50 1*295 32 '8 ^.Q 4fi'79 1 '035 4-7 7 6*38 1*300 33*3 D\J 47 '40 4/ 4y 1*040 5*4 8 7*26 1*305 33*7 Ul 48 -9^ 40 ZO 1*045 6*0 9 8*13 1*310 34*2 4»7 U/ 1*050 6*7 10 8*99 1*315 34 '6 63 4Q«80 1*055 7*4 11 9*84 1*320 35 *0 64 o\J 1 J. 1*060 8*0 12 i\j 00 1*325 35*4 01 00 1*065 8-7 13 11*51 1*330 35 '8 00 Pi9«^7 t>Z 0/ 1*070 9*4 14 12*33 1*335 36 '2 fi7 00 zz 1 *075 10*0 15 13*15 1*340 36*6 68 1 "080 10*6 1 6 13*95 1*345 37*0 fiQ uy 54 -09 04 «70 1*085 11*2 17 14*74 1*350 70 55 -70 1*090 11*9 18 15*53 1 '355 37*8 71 / J. 1 "095 12*4 19 16*32 1*360 38*2 79 57-57 1*100 13*0 20 17*1 1 1*365 38*6 7.^ 58*48 1*105 13*6 21 17*89 1 *370 39*0 74 59*39 1*110 14*2 22 18*67 1 *375 39*4 75 60 '30 1*115 14*9 23 19*45 1*380 39*8 7fi 61 *27 1*120 15*4 24 20*23 1*385 40*1 77 62*24 1*125 16*0 25 21*00 1 -390 40*5 78 63*23 1*130 16*5 26 21 '77 1*395 40*8 7Q 64*25 1*135 17-1 27 22*54 1*400 41 *2 80 65*30 1*140 17 '7 28 23*31 1*405 41 *6 81 1 •145 18*3 29 24*08 1 '410 42*0 82 1*150 18*8 30 24*84 1*415 42*3 83 68*63 1 *155 19*3 31 25*60 1 '420 4.9-7 84 69*80 1*160 19*8 32 26*36 1 *425 43*1 85 70*98 1*165 20*3 33 27*12 1 '430 43*4 86 79'17 1 *170 20*9 34 27*88 1*435 43*8 87 73 '39 1*175 21*4 35 28*63 1 *440 44*1 88 74*68 1*180 22 *0 36 29 *38 1*445 44*4 89 75*98 1*185 22*5 ^7 30*13 1 *450 44*8 90 77-98 / / zo 1 '190 23*0 38 30*88 1*455 45*1 91 1 *195 23*5 oy 31*62 1*460 45*4 92 7Q«Q8 1*200 24*0 32*36 1*465 45*8 93 81*42 1*205 24*5 41 33*09 1 *470 46*1 94 82 *90 1*210 25*0 42 33*82 1*475 46*4 95 84*45 1*215 25*5 43 34*55 1*480 46*8 96 86*05 1*220 26*0 44 35*28 1*485 47*1 97 87-70 1*225 26*4 45 36*03 1*490 47*4 98 89*60 1 *230 26*9 46 36*78 1*495 47*8 .. 99 91*60 1*235 27*4 47 37*53 1*500 48*1 100 94*09 1*240 27*9 48 38**29 1-505 48*4 101 96*39 1*245 28*4 49 39*05 1*510 48*7 102 98*10 1*250 28*8 50 39*82 1*515 49*0 103 99*07 1*255 29*3 51 40*58 1*520 49*4 104 99*67 1*260 29*7 52 41*34 APPENDIX B. 223 Table of Percentage of Sulphuric Acid {Lunge and Isler). Specific Gravity . 15° at ~. 4 Degree Baume. Percentage H2SO4. Specific Grravity . 15° at i^. Degree Baume. Percentage H2SO4. 1-000 0 0-09 1-560 51-8 65-08 1-010 1-4 1-57 1-570 52-4 65-90 1-020 2-7 3-03 1-580 53-0 66-71 1-030 4-1 4-49 1 -590 53-6 67-59 1-040 5-4 5-96 1-600 54-1 68-51 1-050 6-7 7-37 1-610 54-7 69-43 1-060 8-0 8-77 1-620 55-2 70-32 1-070 9-4 10-19 1-630 55-8 71-16 . 1-080 10-6 11-60 1-640 56-3 71-99 1-090 11-9 12-99 1-650 56-9 72-82 1-100 13-0 14-35 1-660 57-4 73-64 1-110 14-2 15-71 1-670 57-9 74-51 1-120 15-4 17-01 1-680 58-4 75-42 1-130 16-5 18-31 1-690 58-9 76-30 1-140 17-7 19-61 1-700 59-5 77-17 1-150 18-8 20-91 1-710 60-0 78-04 1-160 19-8 22-19 1-720 60-4 78-92 1-170 20-9 23-47 1-730 60-9 79-80 1-180 22-0 24-76 1-740 61-4 80-68 1-190 23-0 26-04 1-750 61-8 81 -56 1-200 24-0 27-32 1-760 62-3 82-44 1-210 •25-0 28-58 1-770 62-8 83-32 1-220 26-0 29-84 1-780 63-2 84-50 1-230 26-9 31-11 1-790 63-7 85-70 1 -240 27-9 32-28 1-800 64-2 86-90 1-250 28-8 33-43 1-810 64-6 88-30 1-260 29-7 34-57 1-820 65-0 90-05 1-270 30-6 35-71 1-821 90-20 1-280 31-5 36-87 1-822 65-1 90-40 1-290 32-4 38-03 1-823 90-60 1-300 33-3 39-19 1-8-24 65-2 90-80 1-310 34-2 40-35 1-825 91 -00 1-320 35-0 41-50 1-826 65-3 91-25 1-330 35-8 42-66 1-8-27 91-50 1-340 36-6 43-74 1 -828 65-4 91-70 1-350 37-4 44-82 1-829 91-90 1-360 38-2 45-88 1-830 92-10 1-370 39-0 46-94 1-831 65-5 92-30 1-380 39-8 48-00 1-832 92-52 1-390 40-5 49-06 1-833 65-6 92-75 1-400 41-2 50-11 1-834 93-05 1-410 42-0 51-15 1-835 65-7 93-43 1-420 42-7 52-15 1-836 93-80 1-430 43-4 53-11 1-837 94-20 1-440 441 54-07 1-838 65-8 94-60 1-450 44-8 55-03 1-839 95-00 1-460 45-4 55-97 1-840 65-9 95-60 1-470 46-1 56-90 1-8405 95-95 1 4oU 4o-o 57-83 1 -8410 y/ uu 1-490 47-4 58-74 1-8415 97-70 1-500 48-1 59-70 1-8410 98-20 1-510 48-7 60-65 1-8405 98-70 1-520 49-4 61-59 1-8400 99-20 1-530 50 0 62-53 1-8395 99-45 1-540 50-6 63-43 1-8890 99-70 1-550 51-2 64-26 1-8385 99-95 224 DYEING AND CLEANING. Table of Percentage of Aqueous Ammonia Solution AT 15° {Lunge and Wiernick). The numbers given in the third column are corrections to be applied for the interval of temperature 13° to 17°. Jf, for example, the specific gravity has been found to be 0*900 at 13°, the value at 15° is found by subtracting 2 x 0*00057 =0-001 from this number (0*900). One obtains the value 0*899, and therefore the per- centage of ammonia is J per cent, higher. Specitic Gravity. Percentage NH3. Correction for + 1°. Specific Gravity. Percentage NH3. Correction for ± 1°. 1-000 0*00 0*00018 0-940 15-63 0*00039 ' 0-998 0-45 0-00018 0*938 16*22 0*00040 0*996 0*91 0-00019 0-936 16-82 0-00041 0*994 1*37 0*00019 0-934 17-42 0-00041 0-992 1*84 0-00020 0-932 18-03 0*00042 0*990 2-31 0*00020 0-930 18-64 0*00042 0*988 2-80 0-00021 0*928 19-25 0*00043 0*986 3-30 0*00022 0*926 19*87 0*00044 0*984 3-80 0*00022 0*924 20*49 0-00045 0*982 4*30 0*00022 0*922 21-12 0*00046 0-980 4*80 0*00023 0-920 21*75 0*00047 0-978 5-30 0*00023 0*918 22-39 0*00048 0-976 5-80 0-000-24 0*916 23-03 0*00049 0-974 6*30 0*00024 0-914 23*68 0-00050 0-972 6-80 0*00025 0-912 24*33 0*00051 0-970 7-31 0-00025 0*910 24-99 0-00052 0-968 7-82 0-00026 0-908 25*65 0-00053 0*966 8-33 0-00026 0*906 26*31 0*00054 0*964 8-84 0-00027 0-904 26*98 0-00055 0*962 9-35 0-00028 0-902 27-65 0*00056 0-960 9-91 0*00029 0*900 •28-33 0*00057 0*958 10*47 0-00030 0*898 29-01 0-00058 0*956 11*03 0*00031 0*896 29-69 0-00059 0-954 11-60 0*00032 0-894 20-37 0*00060 0-952 12-17 0*00033 0*892 31-05 0*00060 0*950 12*74 0*00034 0*890 31-75 0*00061 0-948 13*31 1 0*00035 0-888 32*50 0-00062 0-946 13*88 1 0-00036 0-886 33*25 0*00063 0-944 14-46 0*00037 0-884 34-10 0*00064 0-942 15*04 1 0*00038 0-882 34*95 0*00065 APPENDIX B. 225 Specific Gravity of Solutions of Sodium Carbonate at 15° {Lunge). opecinc Gravity. Q 1 1 1T~^ P JJcXlllllt/. Lycgl ceo Percentao;e by Weight. Na^OOs. NasCOa + lOAq. 1 -007 1 1-4 U 0/ 1 OU/ 1-014 2 2-8 1 ± oo o Jo/ 1-022 3 4-4 9 'HQ i) DO/ 1 029 4 5-8 1-036 5 7-2 ] -045 6 9-0 A -90 1-052 7 10-4 1-060 8 12-0 t> / i 1-067 9 13-4 6-37 17*180 1-075 10 15-0 7-12 19-203 1-083 11 16-6 7-88 21-252 1-091 12 18-2 8-62 23-248 1-100 13 20-0 9-43 25-432 1-108 14 21-6 10-19 27-482 1-116 15 23-2 10-95 29-532 1-125 16 25-0 11-81 31-851 1-134 17 26-8 12-61 34-009 1-142 18 28-4 13-16 35-493 1-152 19 30-4 14-24 38-405 Specific Gravity of Solutions of Common Salt at 15° {Gerladi), Specific Gravity. Percentage NaCl. Specific Gravity. Percentage NaCl. Specific Gravity. Percentage NaCl. 1-00725 1 1-07335 10 1-14315 19 1-01450 2 1-08097 11 1-15107 20 1-02174 3 1-08859 12 1-15931 21 1-02899 4 1-09622 13 1-16755 22 1-03624 5 1 -10384 14 1-17580 23 1-04366 6 1-11146 15 1-18404 24 1 -05108 7 1-11938 16 1-192-28 25 1-05851 8 1-12730 17 1-20098 26 1-06593 9 1-13523 18 1-20433 26-395 Specific Gravity of Solutions of Sodium Sulphate (Glauber's Salt) at 19° (Schiff). Specific Gravity. Percentage Na2SO4 + 10Aq. Percentage Na2S04. Specific Gravity. Percentage Na2SO4 + 10Aq. Percentage Na2S04. 1-0040 1 0-441 1-0642 16 7-056^ 1-0079 2 0-881 1-0683 17 7-497 1-0118 3 1-3-23 1 -0725 18 7-938 1-0158 4 1-764 1-0766 19 8-379 1-0198 5 2-205 1-0807 20 8-820 1-0238 6 2-645 1-0849 21 9-261 1-0278 7 3-087 1-0890 22 9-702 1-0318 8 3-528 1-0931 23 10143 1-0358 9 3-969 1-0973 24 10-584 1-0398 10 4-410 1-1015 25 11 025 1-0439 11 4-851 1-1057 26 11-466 1 -0479 12 5-292 1-1100 27 11-907 1-0520 13 5-373 1-1142 28 12-348 1 -0560 14 6-174 1-1184 29 12-789 1-0601 15 6-615 1 -1226 30 13-230 15 226 DYEING AND CLEANING. Comparative Hydrometer Scale Sp. Gr., Twaddell and Baume, AT 12-5'' C. TwaddelL Baume. Specific Gravity. Twaddell. Baume. Specific Gravity. U u I'OOO 54 30-6 1*270 1 07 1*005 55 31*1 1-275 2 1'4 I'OlO 56 31*5 1 -280 3 2-1 1-015 57 32*0 1 -285 4 27 1*020 58 32*4 1 *290 5 3-4 1-025 59 32*8 1*295 Q 41 1*030 60 33-3 1*300 7 47 1*035 61 33*7 1*305 8 5-4 1*040 62 34*2 1*310 9 6-0 1*045 63 34*6 1-315 10 67 1*050 64 35-0 1*320 11 7-4 1*055 65 35-4 1*325 12 8-0 1-060 66 35*8 1 -330 13 87 1-065 67 36-2 1-335 14 9-4 1-070 68 36*6 1*340 15 10-0 1*075 69 37*0 1*345 16 10-6 1*080 70 37-4 1*350 17 11-2 1*085 71 37*8 1*355 18 11-9 1-090 72 38*2 1-360 19 12-4 1-095 73 38*6 1 -365 20 13-0 1*100 74 39*0 1-370 21 13'6 1*105 75 39*4 1-375 22 14-2 1*110 76 39-8 1-380 23 14'9 1 -115 77 40*1 1*385 24 15-4 1*120 78 40*5 1-390 25 16-0 1-125 79 40*8 1-395 26 16-5 1*130 80 41*2 1-400 27 17*1 1-135 81 41-6 1-405 28 177 1*140 82 42*0 1*410 29 18-3 1-L45 83 42-3 1*415 30 18-8 1-150 84 42*7 1*420 31 19*3 1-155 85 43*1 1*425 32 19'8 1-160 86 43*4 1-430 33 20-3 1*165 87 43-8 1-435 34 20*9 1*170 88 44*1 1*440 35 21*4 1*175 89 44-4 1*445 36 22-0 1*180 90 44*8 1-450 37 22*5 1-185 91 45-1 1-455 38 23 0 1'190 92 45-4 1*460 39 23-5 1-195 93 45*8 1*465 40 24-0 1-200 94 46*1 1*470 41 24*5 1-205 95 46*4 1*475 42 25-0 1-210 96 46-8 1*480 43 25*5 1*215 97 47*1 1*485 44 26-0 1-220 98 47-4 1-490 45 26*4 1-225 99 47*8 1-495 46 26-9 1*230 100 48-1 1*500 47 27-4 1 -235 101 48-4 1*505 48 27-9 1*240 102 487 1-510 49 23-4 1-245 103 49*0 1-515 50 28-8 1*250 104 49*4 1-5*20 51 29-3 1*255 105 49*7 1*525 52 297 1*260 106 50-0 1*530 53 30-2 1*265 To convert degrees Tw. into sp. gr., multiply by 5, add 1000, and divide by 1000. APPENDIX B. 227 Comparison of Temperature Degrees. C = Celsius or Centigrade ; F = Fahrenheit. c. F. C. F. C. F. C. F. -17 + 1*4 + 13 + 55-4 + 43 + 109-4 + 72 + 161*6 - 16 3*2 14 57*2 44 111*2 73 163-4 -15 5-0 15 59-0 45 113-0 74 165*2 -14 6*8 16 60-8 46 114*8 75 167-0 -13 8 '6 17 62-6 47 116*6 76 168-8 -12 10-4 18 64-4 48 118-4 77 170-6 -11 12*2 19 66-2 49 120*2 78 172-4 -10 14-0 20 68-0 50 122*0 79 174-2 -9 15*8 21 69-8 51 123-8 80 176-0 -8 17-6 22 71-6 52 125-6 81 177*8 _7 19'4 23 73-4 53 127-4 82 179*6 -6 21-2 24 75*2 54 129*2 83 181*4 -5 23-0 25 77-0 55 131*0 84 183*2 _4 24*8 26 78-8 56 132*8 85 185-0 -3 26-6 27 80-6 57 134-6 86 186-8 -2 28-4 28 82-4 58 136*4 87 188-6 _1 30-2 29 84-2 59 138-2 88 190-4 *0 32-0 30 86 0 60 140-0 89 192-2 + 1 33*8 31 87-8 61 141-8 90 194*0 2 35-6 32 89-6 62 143-6 91 195-8 Q O ^7 -A o/ 4 9^ oo Q1 -A DO ly/ 0 39-2 34 93-2 64 147-2 93 199-4 t 41-0 35 95-0 65 149-0 94 201*2 6 42-8 36 96-8 66 150*8 95 203*0 7 44-6 37 98-6 67 152*6 96 204*8 8 46-4 38 100-5 68 154-4 97 206*6 9 48-2 39 102-2 69 156-2 98 208*6 10 50-0 40 104-0 70 158-0 99 210-2 11 51-8 41 105-8 71 159*8 100 212-Ot 12 53-6 42 107-6 ■'^ Freezing-point. . f Boiling-point. Rules for Converting Temperatures from one Scale to Another. (a) To convert Centigrade into Fahrenheit degrees. Multiply the degrees by 9, divide the result by 5, and add 32. For example, 36° C. into F. 36° X 9 = 324; 324 -+5 = 64-8; 64-8 + 32 = 96-8° F. In the case of temperatures below the freezing-point, 0° of the Centigrade scale, the rule is to multiply by 9, divide the result by 5, take the difference between the number so obtained and 32 ; if it be the larger number add the sign - to the result ; if 228 DYEIKG AND CLEANING. the smaller, add the sign + . The following examples illustrate these rules : (1) -8° C. to F., and (2) - 40° C. to F. (1) 8x9-72; 72^5 = 14-4; 32-14-4- +17-6° F. (2) 40x 9 = 360; 360-^5 = 72; 72- 32= - 40° F. (b) To convert Fahrenheit degrees into Centigrade degrees. Subtract 32, multiply the result by 5, and divide this result by 9. Thus, convert 82° F. into C. degrees. 82-42 = 40 ; 40x 5 = 200; 200^9 = 22-2° C. When the temperatures are between 32° and 0° F., take the difference between 32 and the degree and proceed as before, adding a - sign to the result. For example, reduce 26° F. to C. degrees : 32- 24 = 8; 8x5 = 40; 40-^9 = 4-4= - 4-4° C. If below 0° F. add 32 to this degree and proceed as before, adding a - sign to these results. For example, reduce - 18° F. to C. degrees : 18 + 32 = 50; 50x 5 = 250; 250-^9 = 26•6= - 26*6° C. APPENDIX C. NOMENCLATURE OF STABLE HYDROSULPHITES. The various trade names given by the makers to the different stable hydrosulphites at present on the market do not give any definite indication of the chemical composition of these bodies ; these particulars are given in the following table (Schmid, Bull. Ind. Mulhouse^ through J.S.D.C.), Name. Maker. Composition. Employment. 1 . Rongalite C . . . 2. Hydrosulphite NF cone, . 3. Hyraldite C Extra . B.A.S.F. M.L.B. C. ^ Sulphoxylate of soda- y formaldehyde ) NaHS02+CH20+2H20 Discharges on dyed cottons. 4. Rongalite CW . 5. Hydrosulphite NFW cone. 6. Hyraldite CW Extra B.A.S F. 1 M.L.B. C. ^ The same product as 1, >• 2, and 3, but with an ) addition of zinc oxide Discharges on wools. 7. E-ongalite C simple . 8. Hydrosulphite NF . 9. Hyraldite A . . . B.A.S.F. M.L.B. C. •\ The double compound of 1 sulphoxylate of soda- 1 formaldehyde and bi- V sulphite of soda-form- 1 aldehyde [ NaHSOa + CH2O + 2H2O] + J [NaHS03+CH20+H20] cotton. 10. Rongalite CW simple 11. Hydrosulphite NFW 12. Hyraldite W . B.A.S.F. M.L.B. ! ) The same product as 7, 8, ^ and 9, but containing an ) addition of zinc oxide Discharges on wool. 13. Rongalite Special 14. Hydrosulphite NF Special cone 15. Hyraldite Special B.A.S.F. M.L.B. C. ) The same as 1, 2 and 3, ( but with an addition of r a catalytic agent, such ) as Induline Scarlet Discharges on cotton. 16. Decroline .... 17. Hydrosulphite AZ . 18. Hyraldite Z . . . B.A.S.F. M.L.B. C. \ The basic sulphoxylate of zinc-formaldehyde, in- Y soluble in water, but soluble in acetic acid j (Zn0H)HS02+CH20 Stripping colours. 19. Hydrosulphite eonc. B.A.S.F. powder . B.A.S.F. Hydrosulphite of soda j free from water V For the setting of vats with Indigo, the Indanthrenes, etc., and for bl e a c h i n g certain ani- mal and vege- table p r 0 - ducts. 229 INDEX. Acetic acid, Specific gravity of, 221. Acid dyestuffs, 128. Ammonia, Specific gravity of, 224. Animal fibres, 11. Artificial silk, 7. ,, dyeing, 163. Barbe system, 58. ,, Distillation for, 74. Soap for, 51 . Basic dyestuffs, 128. Beer stains, Removal of, 79. Benzene, 29. absorbed by fibres, 52. Non-inflammable, 33. , , solubility in water, 7 1 . Benzine, 24. American, 25. ,, Analysis of, 25. ,, Artificial light with, 100. Borneo, 25. drying-room, 101. ,, Germicidal power of, 28. ,, leakage, 103. , , machinery, Earthing of , 1 0 1 . , , Purification and recovery of, 66. „ by distillation, 68. ,, by settlement, 67. ,, *' spontaneous " fires, 102. ,, Sumatra, 25. Benzol, 29. , , Analysis of, 30. ,, Composition of, 29. ,, Toxic properties of, 31. Blanket cleaning, 114. ,, finishing, 212. Bleaching, 110. Blinds (see window blinds). Blood stains. Removal of, 78. Body ironer, 185. Bolts, Steam, 189. Bust finisher, 189. Calender, Downham, 203. Carbon tetrachloride, 31. ., ., Advantages of, 23. Carding machine, 212. Cellulose acetates, 8. Chardonnet silk, 7. Chenille, Finishing, 210. China grass, 10. Chintz cleaning, 118. ,, glazing, 204. Chip dyeing, 180. Cofl'ee stains. Removal of, 79. Colouring matters. Classification of, 126, 130. Colour stains, Removal of, 80. Cone, 186. Construction of premises, 99. Cotton, 2. , , Acids on, 4. Alkalies on, 5. bleaching, 113. Chemical composition of, 4. ,, dyeing, 142, 156. ,, fibre, length of staple, 8. ,, Mercerisation of, 6. ,, Nitric acid on, 5. Organic acids on, 5. Oxidising agents on, 7. ,, plant, Species of, 3. Reducing agents on, 7. ,, Sulphuric acid on, 4. Cretonne cleaning, 118. ,, finishing, 207. Curtain cleaning, 115. ,, finishing, 196. ,, frames, 196. Cylinder, 210. Cylindrical cleaning machines, 39. Decoudun, 198. 230 INDEX. 231 Decroline, 136, 229. Developed dyes, 129. Direct dyes, 127. Distillation, 68. Dry cleaning, 23. definition, 23. ,, ,, general arrangement, 48. ., ,, History of, 24. ,, ., Hydro -ex tractors for, 45. ,, ,, machines, Construc- tion of, 41. Method of, 51. ,, preliminary examina- tion, 33. ,, ,, Soap for, 51. ,, ,, Sorting for, 34. Dry Dyeing, 166. Dust wheel, 35. Dyed cotton, After-treatment of, 156. Dyeing, 123. Acids for, 129. ,, Appliances for, 124. assistants, 129. ,, ,, Preparation of goods for, 132. ,, ,, Selection of pro- cess, 138. Dyes, Equalising power of, 143. ,, Fastness to ironing of, 145. ,, light of, 144. , , , , J , perspiration of, 145. ,, ,, ,5 rubbing of, 145. ,, ,, washing of, 146. ,, Selection of, 143. ,, Solubility of, 143. EASTMAN-KEbTON machine, 189. Enamel stains, Removal of, 78. Fancy cleaning, 110. Feather cleaning, 175. ,, curling, 179. ,, dyeing, 175. Feculose, 164. Finishing, 182. furnishings, 193. ., wearing apparel, 182. Flax plant, 9. Formic acid, 131. Fruit stains. Removal of, 79. Furs, Cleaning of, 54. Glanzstoff, 8. Glauber's salt. Specific gravity of, 225. Glazing, 201. Glove brushing machine, 56. ,, cleaning, 54. ,, ,, by hand, 55. ,, by machine, 56. ,, ,, Uval machine for, 57.. ,, polishing machine, 57. Gofiering, 198. Goods, Marking of, 21. Reception of, 21. Grass stains, Removal of, 80. Grease stains, Removal of, 78. Half-wool dyeing, 138, 146. Hat cleaning, 179. ,, dyeing, 180. Hemp, 10. Hill & Holttum machine, 193. Holderness clips, 187. Home Ofiice memorandum (1906), 89'. ,, Report (1896), 85. Hydrochloric acid. Specific gravitv of, 221. Hydro-extractors, 45, 122. Hydrogen peroxide. 111. Hydrometer tables, 226. Hydrosulphite, 136, 229. Hydrosulphites, Stable, 136, 229. Hyraldite, 136, 229. Ink stains. Removal of, 79. Iron stains, Removal of, 79. Irons, Crown, 207. ,, for finishing, 183. Jute, 10. ,, dyeing, 163. Knollman apparatus, 188. "Lancet " reprint, 213. Licence, Form of, 92. Light, Fastness to, 144. Linen, 9. ,, bleaching, 113. ,, dyeing, 142, 155. ,, Properties of, 9. London County Council Report (1890),. 94. ., ,, Warning, 99. MoiiD ANT dyes, 128. Nitric acid, Specific gravity of. 222. Nonex fittings, 47, 103. INDEX. Non-liability, 21. Oil stains, Removal of, 78. Paint stains, Removal of, 78. Petroleum Act, 1871, 81 ; 1879, 84 ; 1881, 84. Pile fabrics, Finishing, 207. Pitch stains. Removal of, 78. Pressing machine, 193. Pyroxylin, 5. Ramie, 10. dyeing, 163. Regulations and precautions, 81. Rhea, 10. Rinsing tank, 45. Rongalite, 136, 229. Salt, Electrolysis of, 113. ,, Specific gravity of, 225. Saponine, 51. Satin chip dyeing, 181. Scott system, 63. Separator, Description of, 70. Serge finishing, 210. Shale spirit, Scotch, 25. Silk, 15. Acids on, 16. ,, Alkalies on, 18. ,, Artificial, 7. ,, bleaching. 111. ,, dyeing, 142, 158. ,, fibre, Structure of, 15. frame, 208. Physical properties of, 16. Spun, 15. ,, weighting, 213. ,, and cotton dyeing, 142, 161. ,, and wool dyeing, 142. Silks, Wild, 18. Skin rugs. Cleaning, 172. Dyeing, 173. Soap, 108. Sodium carbonate. Specific gravitv of, 225. ^ ,, peroxide, 112. sul})hate. Specific gravity of, 225. Spotting, 74. Sprays, 187. Stain removal, 74. Standing baths, 148. Steaming table, 185. Straw bleaching, 180. dyeing, 180. Stripping agents. Oxidising, 134. ,, Reducing, 135. ), processes, 133. Substantive dyes, 127. Sulphuric acid. Specific gravity of. Sunflower machine, 38. Tables, Specific gravity, 221. Tar stains. Removal of, 78. Tea stains. Removal of, 79. Tetrapol, 109. Textile fibres, 1. Titanous chloride, 137. Tumbler machines, 36. Tussore silk, 18. ,, Chemical properties of, 19. Vacuum distillation, 71. Vanduara silk, 1, 7. Vat dyes, 128. Vegetable fibres, 2. Viscose silk, 8. Viyella, 1. Water absorbed by fibres, 52. brushing, 75. Wax stains. Removal of, 78. Well tumbler, 38. Wet cleaning, 106. Window blind cleaning, 119. finishing, 196. glazing, 201. Wine stains, Removal of. 79. Wool, 11. Acids on, 13. Alkalies on, 14. bleaching. 111. Chemical properties of, 13. Chlorine on, 14. ,, dyeing, 141, 155. Physical properties of, 12. ,, and silk dyeing, 160. ,, silkandcottondyeing, 141,153. PRINTED BY NEILL AND CO., LTD.. T'DINBURGH.