Tle alts ts ark ori we the library of 4 a i {2 \ a WV YAO Dw ‘Oh 4 ae ev, Y an ss *y ¢ “Orth the compliments of EJ.du Pont de Nemours & Co.JInc. Dyestuffs Department Wilmington Delaware.U.S.A. ART-SILK. | LEATHER | | J THE DYEING OF PAPER Prepared by JOHN R. ROBERTS E. I. du Pont de Nemours & Co., Inc. Dyestuffs Department Wilmington, Delaware, U.S. A. P. 77. 1924 E. I. du Pont de Nemours Copyright 192 Introduction Chapter I. Chapter II. Chapter III. Chapter IV. Chapter V. Chapter VI. Chapter VII. CONTENTS PAGE Types of Paper if Dyeing of Paper in the Mill 13 Classes of Colors Used for Paper pay Notes on the More Im- portant Du Pont Colors for Paper Be Suggestions about Colors Best Suited for Different Grades of Paper 52, Resistance to Fading 85 Laboratory Procedure 89 Our Technical Service Index INTRODUCTION HE primary object of this book is to give in a general way information regarding the dyestuffs most generally used on paper, infor- mation which will aid in the selection and use of dyestuffs for various purposes. In it we have covered briefly the various kinds of paper made, the different processes or methods of dyeing and the laboratory pro- cedure used in testing dyestuffs and matching shades. We realize that to some a considerable part of the material will be unnecessary. Plant chemists and color men are, of course, familiar with methods and procedures used in their own mill. However, the production of most mills is confined to one general line of papers such as bonds, wrapping, container board, etc., and those working on one line may not be familiar with the processes of other lines. We hope it may be of interest to many, particularly students, beatermen, foremen and others who in time will become superintendents or managers of mills. E. I. DU PONT DE NEMOURS & Co., Inc., Dyestuffs Department, Wilmington, Delaware. CHAPTER I TYPES OF PAPER ITH the advancement in the art of paper making, the use of paper for a great va- riety of purposes has come naturally, and there has followed a specialization in the kinds of paper manufactured for these various uses. Newsprint is made almost entirely of ground wood, except for admixture of un- bleached sulfite, ranging from 10% to 25%. The machine making this class of paper is run at high speed, and the sheet is comparatively light, usually approximating a weight of 32 pounds to each 500 sheets, 24x36 inches. Some of the modern paper machines run as fast as 1000 feet a minute and make a sheet more than 175 inches wide. Newsprint, besides its principal use in newspapers, is used for cheap pad, tablet, poster and catalogue papers and some of the cheaper magazines. Boxboard is fast becoming one of the im- portant branches of the paper industry and as this branch uses waste papers largely for its basic materials, it will probably become even more important in the years to come. Board is usually made on a cylinder ma- chine, the various thicknesses being made by additional cylinders. The number of cylinders may range from three to seven, and the two outside cylinders give the outside of the sheet or linings as they are called. All kinds of 7 Newsprint Boxboard Book paper waste paper, boxes, rags, etc., go into the manu- facture of the board itself; the lining is usu- ally made of ground wood, old news, or mixed papers with a certain percentage of unbleached sulfite or Kraft. One of the oldest branches of the paper industry is the manufacturing of book and high grade printing papers. Book paper is made chiefly from rag (cot- ton and linen), sulfite and soda wood pulp, and in the cheaper grades some ground wood, all of which have been bleached except the ground wood, this being used both bleached and un- bleached. Loading materials sometimes are added to book papers to the extent of 10% to 15%, to make the paper more absorbent and more opaque. Kaolin or clay is the chief substance used. It serves to fill up the pores, thus giving a higher finish and causing the ink to be taken up rapidly. The bright surfaced papers on which some books are printed, especially when half tones have to be brought out, are known as coated papers and are the basis of an industry sepa- rate from the manufacture of paper. The principal grades of book papers are “machine finished,” and “supercalendered.” Machine finished papers receive only the finish given by the calender rolls at the dry end of the machine. This grade of paper is used largely by publishers of books and trade catalogues. Supercalendered paper is machine finished paper which has been given an additional sizing and calendering, or calendering only. 8 wae es Namie Cover papers are tough, heavy, well fin- Cover paper ished papers used for magazine, catalogue or pamphlet covers. They are made mostly of rag and bleached sulfite, although in the cheaper grades unbleached sulfite is used. Sometimes jute and rope are used in small quantities. Bond is the name given to paper that is Bond paper used for business correspondence, ledgers, and for typewriters. Bleached sulfite, rag and soda pulp are principally used in this class of paper. For the better grades, rag and bleached sulfite alone are used, while in the cheaper grades considerable quantities of soda pulp and filling materials are used. Paper used principally for personal cor- Writing paper respondence is what is meant by the term “writing paper.’ Its composition is similar to that of the various grades of bond. The linen finish on many writing papers is given by pressing the sheets against a piece of linen. Great pressure is used and the tex- ture of the linen is impressed on the paper. Wrapping papers are made from various Wrapping paper combinations of Kraft, sulfite, ground wood and sometimes waste papers. Jute and rope are also used to a small extent. For paper in which great strength and durability is required, sulfate and sulfite are used, but for cheaper wrapping papers in which strength is not paramount, ground wood is used in varying proportions. There are also on the market today, numer- ous imitations of Kraft made by coloring sul- fite pulp to the shade of Kraft. 9 Tissue paper Manila papers are very important. Such wrapping papers were originally made from pulp prepared from Manila rope, but the term is now applied to papers made from sulfite and ground wood, and colored to imitate the char- acteristic Manila shade. On account of their thinness, these papers constitute a distinct class. They include crepe, toilet, colored tissue and cigarette papers. These papers must necessarily be sup- ported on a felt in passing from one part of the machine to another and therefore, they are usually made on Harper Fourdrinier or cylin- der machines. Unbleached and bleached sulfite, rag and ground wood are used in various proportions to make tissue papers. As a good cigarette paper should be abso- lutely neutral in flavor and aroma while it is burning, pure flax or linen fiber, hemp fiber and »Yamie are usually used. Rice straw was for- Blotting paper merly considerably used, but this does not pos- sess the strength necessary to make a good cigarette. Formerly, nearly all cigarette pa- pers were made in Europe, but now a very good grade is being made on this continent. Of all the fibers used in paper manufactur- ing, cotton has the greatest capacity for ab- sorbing liquids and for this reason, by far the best blotting papers are made from rags, but they grade down all the way from pure rag to those made up with a large percentage of ground wood. Medium grade blotters usually contain a considerable quantity of soda pulp. In the manufacturing of blotting paper, care must be taken in the preparation of the 10 stock. It must be properly beaten and hard water cannot be used, as this destroys the ab- sorbing power. Alum is sometimes used in quantities not exceeding 2%. Filter paper is, in many respects, similar to blotting paper. The best filter papers consist of stock made from the best quality of cotton rags with a little wool fiber mixed in. In order to extract any mineral matter in the fiber the stock is treated with hydrochloric and hydrofluoric acids and dilute alkalies and then washed fre- quently with the purest water. Many firms in England, France, Germany and Sweden have specialized in this branch of work, but lately the industry has been entered by one or two American concerns. This is a comparatively cheap grade of paper used for wall coverings. It is usually a mixture of 85% ground wood and 15% sulfite, both being used unbleached. Old papers are sometimes used in the furnish. About 10% of clay is also added to make a suitable surface and render the sheet opaque. Hangings must be well sized so that they will not break when the paste is applied. Care must be taken also to see that the moisture content is right because if the paper is over dried it will be brittle. Oatmeal wall papers receive their name from the oatmeal appearance which the sur- face has, due to the addition of wood flour. The stock consists usually of old newspapers, ground wood, and unbleached sulfite. There are two classes of oatmeal paper, duplex and oatmeal pulp. The former is really 11 Filter paper Hangings Oatmeal wall paper Building and roofing paper Glassine and greaseproof paper two sheets, one the lining or back sheet and the other a thin colored sheet which contains the wood flour. The latter is a single sheet throughout which the wood flour is uniformly distributed. . These are made from very coarse and cheap materials such as low grade rags, gunny sacks, coarse jute, wastes, sulfite screening, etc. Cheapness and bulkiness are the prin- cipal requirements. For the making of these papers the stock is beaten a long time until what is known as “hydration” takes place, that is, the fiber takes up water chemically and becomes transparent. Unbleached or bleached sulfite is usually used. 12 si | Pe P thin coating of the size. It is obvious that the dyestuffs have a better chance to adhere to the fibers before they receive this coating. In the mill the color is “built up” in the beater by starting with quantities of color that will be sure to produce a shade on the light side of the sample. Small hand samples are made from the stock in the beater, dried out, and compared with the sample to be matched. Additions of color are made until, in the judg- ment of the color man, or beater engineer, the finished paper will be a match for the sample. It sometimes happens that too much color is added to the first beater. In this event the excess color must be held out of the second beater and the two dropped into the chest to- gether. It is always advisable to withhold some of the color from the third beater; then, if the color comes too deep on the machine, it can be quickly remedied by ‘“doctoring” the third beater and dropping it immediately into the chest. The color usually is deeper in the finished paper than in the hand sample. This varies with the finish put on the sheet and the type of colors used. Basic and direct colors in light shades show the least change, while acid colors in heavy shades will show a difference up to 10% to 20%. Supercalendering or water- finishing a sheet will also deepen the shade to about an equal extent. Good judgment as to what may be expected on the machine from a beater hand sample can only be obtained by experience. In running standard colors which have been made before, the usual procedure is to color the first beater with the formula used at 15 Matching shades Color is usually deeper on finished paper Prevention of mottled effects Causes of mottling the time of the last run. A hand sample is made from the beater and if the shade is not right, the necessary colors are added. If off- shade or too deep the second beater is colored with such amounts of colors that the mixture of the two beaters will give the desired shade. Different “blows” of the same kind of stock, and different lots of bleached stock, vary considerably in color, and it is impossible to produce a uniform shade without changing the formula from time to time. Mottling of the fibers in paper dyeing is one of the banes of the paper maker, but with a little thought and the following of a few sim- ple rules, much of this can be avoided. Some aniline dyestuffs have much more affinity for vegetable fibers than others, and it is this property which causes the mottled effect. It is not particularly objectionable in the cheaper wrapping and water finished pa- pers, but it is not permissible in the higher grade papers, such as bonds, writing, book, and cover papers. In general, mottling is caused by adding the dyestuff in a hot concentrated solution to the beater in such a manner as to color a smaller number of fibers immediately, or it may be caused by adding the dyestuff to a mixed fur- nish in which the colors will “fix” on one of the stocks much more quickly than on the other. The direct and basic dyestuffs, with the possible exception of Pontamine Yellow CH, Du Pont Auramine, and Du Pont Rhodamine B and a few others, generally cause mottled fibers in the sheet, if precautions are not taken when 16 ae are 4 Ven’ an ol or a ie rr 7 _ adding them to the beater. On the other hand, acid colors do not have any decided affinity for the fibers and they can be added to the beater under any and all conditions without mottling the sheets in the slightest. To avoid a mottled effect when coloring a straight furnish, unbleached sulfite for ex- ample, the best plan is to add the color in a cold and very weak solution. Making the ad- dition slowly will also help, giving the color a chance to be more evenly distributed through the stock. 2 Methylene Blue, Methyl Violet, Victoria Green, and the Basic Browns, are particularly troublesome in this respect, being usually very concentrated colors. Generally speaking, dyestuffs, basics in particular, have less affinity for bleached stock than for unbleached. If the dyestuff is added to a mixture of these materials, it would natur- ally go on the unbleached fibers more quickly, coloring them more deeply than the bleached fibers. In mixed furnishes of these materials, it is always best to furnish the bleached stock first, and then to add the dyestuffs. After these are thoroughly mixed, the unbleached stock may be added. In this manner, the bleached stock has an opportunity to take up some of the color before the unbleached fibers begin absorbing it. Ground wood is usually mixed in a furnish with unbleached sulfite. The majority of the direct and basic colors will go onto the un- bleached sulfite much more quickly than onto the ground wood, and when using this material in furnish, it is advisable, when practical, to put the ground wood in first, then the color, 17 Use cold, dilute solutions of dyes In mixed stock furnish the bleached stock first Dyeing of mottled papers and after mixing thoroughly, the unbleached sulfite. If the ground wood should become more deeply colored than the rest, it would not show noticeably in the sheet, as its fibers are usually fine and short. In furnishes in which clay is used the color may be mixed with the clay and water before adding to the beater, thus reducing its tendency to mottle the fibers. } Mottled papers are used principally for cover paper, fine stationery, blotting papers, and sometimes for wall papers. The fibers are made in many colors. Sometimes two or three different colored fibers are mixed together, the effect being most beautiful. Basic colors may be used for dyeing vege- table mottling fibers, but they are not ordi- narily recommended for fine papers because of their poor fastness. When they are used, twice as much tannic acid as dyestuff, by weight, should be added to the beater as this increases their resistance to light and helps to overcome their tendency to bleed. As a rule the mottling fibers are un- bleached sulfite or cotton rags.* Hither may be * Because of its long curling fibers wool is often used as a mottling fiber and in such cases the wool may be dyed with acid colors. As a rule the dyeing of this material should be done in some container other than a beater because it is necessary to add sulfuric acid to the dyebath. The following formula may be used for this work: 10 to 20% Glauber’s salt 4% sulfuric acid or with 10% bisulfite of soda and the required quantity of dyestuff Enter the wool fibers and dye for 1 hour at a boil- ing temperature. Finally add sulfate of alumina to fix the dyestuff as well as possible. The fibers should then be washed thoroughly, especially if they are to be used soon after dyeing. 18 used but the latter are, perhaps, the better as the direct colors have a little better affinity for rag than wood fibers and they are generally used because they do not “bleed” or wash out and color the rest of the paper as do basic or acid dyestuffs. In dyeing the fibers they are usually put, with as little water as possible, into the beater which should be supplied with a steam pipe for heating. The dyestuff which has previously been dissolved in hot water is then added and after circulating for a while 6% to 10% of common salt or double the quantity of Glau- ber’s salt is added in solution. The beater is then heated almost to the boiling point and kept at this temperature for about a half hour, after which it is allowed to cool. Two percent of alum is then added to fix the dyestuff more thoroughly, an addition which, it should be re- membered, changes the shade of a great many of the direct colors. The beater of dyed fibers should then be washed for a while with a drum washer and then dropped into the drainers to drain. It is always best to allow the fibers to drain thor- oughly before using as this helps to prevent bleeding. In making the mottled papers the fibers are added in the percentages desired, usually from 1% to 5%, after the stock to which they are to be added has been beaten and the roll raised. This is done so that the fibers will be as long as possible and show up well. The background or the main component of the paper is usually bleached sulfite, rag, or a combination of the two, depending on whether 19 Dyeing the fibers The background may be dyed or left uncolored For tissues and other light weight papers Acid colors are recommended Pontamine Black EX for deep shades the sheet is blotting, writing, cover, etc., and may either be dyed or be made natural color. If the background is to be dyed it should be colored first and the fibers thrown in after the size and alum have been added so that no color will be taken up by the fibers. DIPPING PROCESS Some light weight papers, particularly tis- sues, are colored by the dipping process, in which the sheet is run over a felt or rubber roll, the lower portion of which turns in a color solution. The sheet is then run between squeeze rolls to get rid of the excess color and then over the dryers. When tissue paper is to be creped it is run over a steel roll against which is fitted a steel doctor blade that wrinkles or crepes the paper before it is dried and then it is run over the dryers. Acid colors are always recommended for dipping as they work better than the other types. The brighter shades are sometimes ob- tained with some of the basic dyes such as Methylene Blue, Methyl Violet, Crystal Violet, Rhodamine and Auramine. In making crepe tissue an alkaline adhesive is sometimes used in the color solution to make the sheet cling to the steel roll, and thus assist in the crepeing. This adhesive usually has an effect on the basic dyes and prevents their use for this work. With the exception of Pontamine Black EX, the direct colors are not used to any extent. This direct black finds large use for the produc- tion of deep blacks on dipped tissues. 20 CALENDER COLORING Some of the heavier papers and boards are For heavier papers colored by the calender-coloring process. This 2"¢ >o2tds process puts a thin film or stain, of color on either one or both sides of the sheet and is more economical than beater dyeing, the two sides being alike or dissimilar. One or more color boxes are arranged on the calenders so that one or more rolls are cov- ered with a film of color solution. The pressure of the calender rolls limits the quantity of color that is carried through to such an extent that the sheet is practically dry by the time it leaves the calender stack. Acid colors are usually recommended as in Acid dyes usually the dipping process, but basic and direct colors '°ommende4 of particularly good solubility may be used. To produce a given shade the solution must be much more concentrated than in the dipping process, and the color which requires a large amount of water for solution or one that pre- cipitates easily will give trouble. The basic colors most commonly used for this work are DuPont Auramine, Du Pont Rhodamine B, Du Pont Safranine T Extra and Du Pont Methylene Blue ZX. Of the direct colors Du Pont Brilliant Paper Yellow Concen- trated and Pontamine Black EX are the most commonly used. COATED PAPERS In a coating mill the color is applied to the Ingredients of the finished sheet of paper in a solution of casein, ©°?0"® ™*'re mixed with clay and sometimes wax, starch and satin white. The casein is first cut with approximately 10% to 15% of its weight of 21 Brushes smooth out the ccating Dyestuffs used borax. Soda ash is sometimes added as a pre- servative for the casein, and ammonia is some- times used to make the coating more water- proof. The satin white, clay, or other con- stituents, and the color are added to the casein, the whole forming a very thin paste. The sheet is run through this paste after which it is run under a series of brushes ranging from coarse to fine. These brushes vibrate back and forth smoothing out the coat- ing, the last set of fine brushes leaving a thin uniform film of the paste on the sheet. The sheet is conducted through hot air lofts to dry it, and finished in the calenders. Acid colors of good solubility are recom- mended for this work, although certain basic dyestuffs such as Du Pont Methylene Blue ZX and Du Pont Auramine are sometimes used. A few of the direct colors, particularly Ponta- mine Yellow SXP and SXG are also suitable for this work. The coating mixture is alkaline, and it is therefore necessary to use colors not too sen- sitive to alkali. 22 ii = = : CHAPTER III CLASSES OF COLORS USED FOR PAPER N the dyeing of paper four classes of dye- stuffs are used. BASIC COLORS The basic dyestuffs appear on the market in the form of salts, such as hydrochloride, oxa- late, or double zinc salts of certain color bases. These are the most important for the paper trade because of their great brilliancy and tinc- torial power. However, they are seldom used in very high grade papers except in small quantities to brighten the shade. Their fast- ness to light is very poor, the paper fading almost to the color of the stock in one or two hours of exposure to direct sunlight. As the classes of paper on which these colors are used are usually not of a permanent nature, this fact is not particularly objectionable. All basic colors can be dissolved together, but should not be mixed or dissolved with acid or substantive colors, as they would thereby be precipitated as color lakes and would not only be wasted, but the precipitate would be apt to produce spots in the finished paper. Basic dyes are very sensitive to hard wa- ter, containing bicarbonate of lime, or magne- sium or any free alkali which tends to precipi- tate the free color base. Solutions of basic dyes, with the exception of Auramine, Chrysoi- dine and Basic Brown, may be boiled, but they 23 Basic colors are very brilliant Basic dyes cannot be mixed with acid or direct colors Basic dyes are sensitive to hard water Acid colors dye evenly Acid colors give better results if dissolved before adding to the beater can all be dissolved at a temperature around 160° F., which is preferable. When dissolving mixtures. of dyestuffs, and especially basic colors, care should be taken that all of the com- ponent colors are completely dissolved to avoid variations in shade. It is better to strain the solution through a fine sieve to insure removal of undissolved material. ACID COLORS Acid colors appear on the market in the form of salts of the color acids. Their tinctorial power generally is poorer than that of the basic dyes, but because of their brightness and even dyeing, they are widely used. They require size and alum to hold them on the fiber. Experience has shown that raising the proportion of size increases the strength of the color more than adding a larger quantity of alum. Metallic salts, such as lead acetate, calcium chloride, aluminum chloride, — aluminum acetate, when used in quantities of 1% or more, all tend to increase the strength of this class of color. Acid colors can be mixed with the substan- tive colors without the precipitation of a color lake, as occurs with basic dyes. This class of colors is, in mill practice, usually added to the beater in the dry form. Better results will be obtained if the dyestuffs are dissolvéd. Acid dyes are not very sensitive to heat and can be dissolved at a temperature a little below the boil. They are not particularly sensitive to cal- cium or magnesium bicarbonate and sulfate in _ water, except when the calcium or magnesium salts of the color acid are insoluble. 24 To increase the fastness to light and to obtain deeper and more brilliant shades, pulp is sometimes dyed with a bottom of acid colors and topped with a basic dye. This color lake produced from acid and basic colors makes a fuller dyeing than can be obtained by acid colors alone, and is sometimes cheaper, and in addi- tion is much faster to light than if made from basic dyes only. Acid colors have a tendency on bleached sulfite to remain on the surface of the sheet, and often, where excessive heat is used, the color will dry on the surface in spots. DIRECT COLORS The substantive or direct cotton dyes are salts of color acids which do not require acid (or in the paper industry, alum) to develop their tinctorial power. They dye cellulose di- rectly without the addition of any mordant or fixing agent. They are used largely to dye un- sized blottings, and the colored fibers used in mottled blotting, cover, envelope, and similar papers. As a class, substantive colors have lower tinctorial power than acid or basic colors, but those that find application in the paper indus- try, are in most cases, faster to light and other deteriorating influences. Most substantive colors are sensitive to hard water, some of the color being precipitated in the form of insoluble lime or magnesium salts. These colors are best dyed with the addi- tion of common salt in order to exhaust them more fully. In very deep shades, it is advan- tageous to heat the stock to about 140° F. In general, paper mills do not follow this proced- 25 Topping with basic dyes Used largely for un- sized blottings and for mottling fibers Direct colors give colorless backwaters Strength shown depends on length of beating Soda ash brightens the shade Ponsol colors are used as pigments ure even though it would save some of the waste of color in the backwaters. In general, substantive colors give almost colorless backwaters. In heavy shades, when there is a tendency to bleed, a small amount of alum will clear up the backwaters of a majority of the direct colors, although in most cases, the shade is reddened. | It might be well to state here that the strength shown by these colors depends to a considerable extent on the beating, and this accounts for the variance between laboratory dyeings and mill runs in color strengths. In general, it might be stated that about 60% to 80% as much color will be required in the mill as in the laboratory to produce the same shade. This applies principally to the medium and deeper shades, the difference in laboratory samples and mill runs in tints and light shades being much less. Soda ash tends to brighten nearly all of the direct colors, and it will often be found ad- vantageous to use this in small amounts where it will not appreciably affect the sizing quali- ties. PONSOL COLORS The Ponsol colors or the vat colors of the anthracene series, in so far as paper dyeing is concerned, are used in the form of insoluble pigments. They appear on the market in the form of pastes or powders, and are used only in the tinting of high grade papers. They are fast to acid and alkali and may be considered, from the paper maker’s point of view, as abso- lutely sunproof. 26 HELIOPONT COLORS Of late years, there have appeared substi- tutes for the vat colors mentioned above. These are sold by the Du Pont Company under the name of Heliopont colors. They are not so fast to alkali or light as the Ponsol colors, but are far superior to any other aniline colors in fastness to light. They appear on the market in the form of pastes and powders, the latter being very distinctly preferable because they are easier to handle in the mill and give more uniform shades. The Heliopont colors are added to the beater in the dry powder, though they may be mixed with water into a thin paste and meas- ured by the cup, pint, or quart. PIGMENTS Pigments used in the coloring of paper pulp are of two types: colored insoluble inor- ganic compounds, such as Prussian Blue, lead chromate, Ultramarine, etc., or, insoluble or- ganic compounds which are true dyestuffs, such as the Ponsol and Heliopont colors. These latter dyes are discussed under the aniline dyes. On the border line between insoluble pigments and soluble aniline dyestuffs may be considered such products as Soluble Prussian Blue. True pigments differ from dyestuffs in that there is no direct coloring or absorption by the paper stock in the beater, but merely a me- chanical entanglement of the insoluble colored body. The depth of the coloration of the paper, therefore, depends largely on the degree of sizing, the character of the stock, (slow stock retaining larger amounts of the pigment than 27 Heliopont colors are faster to light and alkali than other aniline colors Prussian Blue, lead chromate, etc. Pigments differ from dyes Earth pigments Pigments are low in tinctorial power a free stock), and also on the type and opera- tion of the paper machine. Strong suction, either at the suction box or by the suction roll, tends to produce a two-sided effect on the paper, the top side being more strongly tinted or col- ored than the wire side. With strong suction, or with a free stock, there is a tendency to lose a higher percentage of pigment in the back- water, the pigment behaving exactly like clay or other loading material. Pigments, if used in large amounts, have a decided weakening action on the paper, acting in this way also like ordinary loading material. The earth pigments, such as ochre and Turkey umber, should be tested for grit. Grit, if present in any appreciable quantity, is very apt to cause pinholes in the sheet, thus causing frequent breaking of the paper while it is going over the machine. It also has an abrasive ac- tion on the felts, wires and calender rolls, tend- ing to wear them out quickly. Pigments, as a rule, are very low in tinc- torial power. The following comparisons ob- tained by laboratory trials, will give some idea of the tinctorial strength of a few of them in comparison with aniline dyestuffs. 400 parts of Turkey umber were matched with 100 parts of a fast aniline dye mixture, or with 18 parts of a cheaper and less permanent basic dye mix- ture. 400 parts of red oxide were replaced with 84.4 parts of a fast aniline dye mixture, or with 34.6 parts of a cheaper basic aniline dye mixture. 400 parts of French ochre could be replaced with 8 parts of an aniline dye mixture, while 48 parts of chrome paste were replaced with 1 part Du Pont Auramine Concentrated. The low tinctorial power and other drawbacks 28 have, gradually, to a large extent, caused their - gubstitution by aniline dyes. Certain of the pigments, such as red oxide, for example, are characterized by great per- manence and resistance to light and chemicals. The inorganic pigments used as colors to tint or color paper stock in the beater are of very minor importance in comparison with the aniline colors and the individual pigments will receive only a brief consideration. This yellow pigment usually appears on the market in the form of the paste, but the mill may color the stock by adding a solution of lead acetate (sugar of lead) to the beater and, after a short time, when the lead acetate is thor- oughly mixed with the fiber, precipitating it in place by means of a solution of sodium or po- tassium bichromate. By this latter method it is difficult to hold the shade of each individual beater uniform, as the temperature, concentra- tion and alkalinity of the water tend to vary the shade. Heat and especially alkali change the bright lemon shade to an orange cast. Canary paste is darkened by hydrogen sulfide or by any sulfates that may be left in the stock. Yellow ochres and siennas are natural sili- cates, the ochres containing hydrated oxide of iron, the siennas containing manganese oxide. The color varies from yellow to brown, the tinctorial power being very low. | Umbers are complex natural silicates of a brown shade containing a higher percentage of manganese oxide than is found in the siennas. 29 Chrome Yellow or Canary Paste Ochres and Siennas Umbers Sap Brown At one time Sap Brown was used in large quantities on all grades of paper. With the advent of aniline colors, which are much easier to handle, the use of this product was discon- tinued by a large percentage of the mills and at the present time only limited quantities are used. For cheap wrappings it has been sub- stituted with combinations of basic colors such as Chrysoidine, Methyl Violet and Victoria Green. On higher grade papers, where fast- ness is essential, the same shade may be ob- tained with direct or acid combinations. Sap Brown is used in the paper mill as a dyestuff rather than a pigment. It is low in tinctorial power, difficultly soluble, sensitive to hard water, and is difficult to apply so as to obtain uniform shades. Lamp Black, The various kinds of lamp or carbon Paris Black blacks produced as soot by the incomplete com- bustion of various oily organic compounds are used to some extent for the production of black or gray papers. Lamp black has a tendency to streak and speck the paper and rub badly and is a decided nuisance in the beater room, as due to its fine state of division and low specific gravity, it is apt, through careless handling, to get into the air and later settle in the form of soot. In order to avoid this nuisance it is a good plan to weigh the requisite amount of lamp black into a paper bag and to throw bag and all directly in front of the roll so that it is incorporated at once with the pulp. Uniform results in shade regardless of the length of time of beating are practically unobtainable. Mixtures of basic dyes are gradually replacing lamp black, while for higher grades of paper, 30 direct blacks, shaded by direct yellow, or other shading colors are used. Red oxide, an oxide of iron, is used to some Red Oxide extent for the coloring of cheap roofing, red _ rosin-sized papers, and a few other products. The various kinds of red oxide, while very per- manent and unaffected by alkali, have the gen- eral drawback of other pigments. Various Prussian blues, both as pigments and in soluble form, being fast to light, are used extensively in tinting and coloring paper. They are very sensitive to alkali, a great draw- back to their use in oatmeal wall paper and hanging papers, as freshly plastered walls or alkaline glues affect the color. These have a tendency, however, to produce two-sided effects. A pigment green made by coloring stock in the beater with chrome yellow and Prussian blue is occasionally used, but the results are not nearly as satisfactory as those which may be obtained with aniline colors. Ultramarine, a double silicate of sodium and aluminum containing some sodium sulfide, is used for tinting the higher grades of white paper, but its use is decidedly limited by its sensitiveness to acids and alum. 31 Prussian Blue Ultramarine CHAPTER IV NOTES ON THE MORE IMPORTANT DU PONT COLORS FOR PAPER BASIC COLORS CaaS u PONT Auramine O is a basic dyestuff of O Extra, and high tinctorial strength suitable for the Concentrated coloring of the cheaper grades of paper, where no special fastness to light is required, such as the cheaper colored hangings, poster, wrapping (both sulfite and Kraft), tissue, board, glassine, etc. It is also suitable for calender coloring and dipping as well as for coating purposes. Owing to its brightness and also its cheapness as com- pared with acid yellows of similar shade, it is used in large quantities in the production of lemon and canary yellow on all grades of bond. It is used for topping various acid oranges, and for shading the basic browns, blues and greens in the production of the various Kraft brown shades of wrapping paper. It is probably the most extensively used dyestuff in shading or brightening sulfate or Kraft papers. This dyestuff in solution is very sensitive to heat and should not be dissolved at a tem- perature above 160° F. Du Pont Auramine is offered to the trade in three concentrations; Du Pont Auramine O being 60%, and Du Pont Auramine Extra, 80% of the strength of the concentrated brand. 32 _ Chrysoidine is placed on the market in both red and yellow shades, both shades being used extensively in wrapping paper, usually in ~ combination with Auramine, Victoria Green, Methyl Violet, etc., for the production of brown shades. In a majority of cases the yellower brand is desired because of its brightness. The largest use for Chrysoidine is in the manufacture of fiber container boards and other grades of boxboards. The combination of Du Pont Chrysoidine GN and Du Pont Basic Brown BR will produce the brightest shades of brown possible, while the duller shades are produced with Du Pont Chrysoidine R in combination with Du Pont Basic Brown G or GX. Chrysoi- dine also competes with the acid oranges in the manufacture of leather-board. Du Pont Basic Browns BR and GX, two brands representing the red and yellow shades of Basic Browns, serve as a basis, in combina- tion with other basic dyes, for the various Kraft, brown and chocolate shades on Kraft, sulfite and other cheap wrapping papers. The BR brand is the most commonly used as it is brighter and gives a more desirable shade. Like Du Pont Chrysoidine, the Du Pont Basic Browns are extensively used for leather-boards and boxboards, also in many of the basic mix- tures commonly known as Kraft browns. Du Pont Rhodamine B is a very bright bluish red, mainly used for tinting and in con- junction with tinting blues, for shading whites. It has the advantage of working equally well on all kinds of stock. Du Pont Rhodamine is also 33 Du Pont Chrysoidines R and GN Du Pont Basic Browns BR and GX Du Pont Rhodamine B and B Extra Du Pont Paper Blue R Concentrated and Du Pont Methyl Violet NE Du Pont News Blue B Concentrated and BN suitable for dyeing by the dipping process and for use on coated papers. This product is offered in two strengths, Du Pont Rhodamine B Extra being five times the strength of Du Pont Rhodamine B. The stronger brand is seldom used in the paper trade because when used on tints, very slight errors in the amount of color used will throw off the shade. Du Pont Paper Blue R Concentrated and Du Pont Methyl Violet NE are suitable for the production of all violet shades. For the produc- tion of deep blues, these violets are used for topping direct colors. In combination with basic greens, they produce a series of deep blues, but these change to a reddish shade un- der artificial light. By using a combination of Du Pont Methylene Blue ZX, and a little basic violet, this can be avoided. Du Pont Paper Blue R Concentrated alone is used extensively for tinting newsprint paper, being the brightest product for this use, but both basic violets are used considerably, the shades being thrown over to the red or blue side when necessary by the addition of Du Pont Methylene Blue or Du Pont Rhodamine. Du Pont Methyl Violet NE in combination with Du Pont Victoria Green Small Crystals and DuPont Chrysoidine GN is universally used for producing deep blacks and browns. These basic violets are suitable for calen- der coloring, dipping and for coating. Du Pont News Blue B Concentrated and BN are dyestuffs manufactured especially for 34 the tinting of cheap papers such as news, cheap book, etc. Alone or shaded to the red with Du Pont Rhodamine B or other pinks they pro- duce clear bright shades. Du Pont Methylene Blue ZX is used for the production of clear blue shades, which are but little affected by artificial light, and in conjunc- tion with Du Pont Crystal Violet Powder, Du Pont Paper Blue R Concentrated, or Du Pont Methyl Violet NE and Du Pont Rhodamine B, for tinting whites. It can also be used for calender coloring and coating. The various properties of Du Pont Victoria Green Small Crystals make its use advantage- ous on sized or non-sized wood pulp and for coating, calender work and dipping. It is used extensively for the production of various shades of green; with Du Pont Auramine, bright yel- lowish green shades are made, with Du Pont Chrysoidine GN or the Du Pont Basic Browns, olive green shades. For deep blues a very economical combination can be made with Du Pont Methyl Violet NE or Du Pont Paper Blue R Concentrated. Du Pont Victoria Blue BX is the brightest of the basic blues and is used whenever a bril- liant shade of blue, which does not need to be fast to light, is desired. It is especially recommended for brilliant blue shades on wrapping, tissue and other cheap papers. Alone or shaded with the Du Pont Basic Violets or Du Pont Victoria Green Small 35 Du Pont Methylene Blue ZX Du Pont Victoria Green Small Crystals Du Pont Victoria Blue BX and B Concentrated Du Pont Fuchsine Powder Concentrated Du Pont Safranine T Extra Crystals, it is used in the production of all bright blue shades varying from violet to green. When dissolving this color, as it is quite sensitive to hard water or alkali, it is advisable - to add a small amount of acetic acid. If used in a concentrated solution, there is danger of mottling the sulfite stock in the ground wood and sulfite furnish. Du Pont Fuchsine Powder Concentrated is widely used for magenta shades. In combina- tion with DuPont Orange RO or Du Pont Orange II Concentrated, it produces deep reds. Cheap black combinations can be made with mixtures of Du Pont Fuchsine Powder Concen- trated, Du Pont Victoria Green Small Crystals and Du Pont Basic Browns. At the present time DuPont Fuchsine Powder Concentrated finds considerable application in the tinting of cheap grades of white paper, and is used some- what in calender coloring cheap boxboards. The largest prewar consumption was for the manufacture of wrapping paper. This product is not quite as soluble as many other basic colors and care must always be exercised in a mill to see that the solutions are not concentrated, in order to avoid having any of the color settle out in the mixing tank. Du Pont Safranine T Extra is one of the brightest of the basic reds and is used wherever a brilliant, cheap red, of no great fastness to light, is desired. It may be used on unsized paper as well as sized, this property being of particular interest to the blotting trade. When used with all rag stock, no alum is required for retention. When mixed with Du Pont Aura- 36 mine and Du Pont Rhodamine B, beater scarlets of excellent brilliancy are obtained. Its prin- cipal use is for the production of bright pink and red shades on wrapping and medium grade papers. This color is one of the most widely used in the paper trade. When used in a mill, care must be taken to avoid mottling, particularly on mixed furnishes, as it has decided affinity for sulfite. ACID COLORS The acid colors are extensively used in tinting and coloring the higher grades of writ- ing, book, hanging, cover, fiber and wrapping papers, roofing and leather-board, and in the dipping of tissues and the calender coloring of board. Du Pont Metanil Yellow Concentrated is used extensively as a calender color for produc- ing the yellow shades of fiber container board, and for coating and dipping. It is suitable for producing goldenrod shades where extreme fastness is not essential. All brands of Metanil Yellow are sensitive to acid and care must be exercised to prevent the use of an excess of alum. On this account it often makes a bad impression in a mill and many concerns are opposed to its use. It is also somewhat sensitive to the heat of the dryers. However, because of its relatively low price its consumption is very large, and it finds extensive use in the production of yellow and buff shades of container board and boxboards, Du Pont Metanil Yellow Concentrated Du Pont Tartrazine O Du Pont Orange II Concentrated Du Pont Orange RO It is also used in considerable amounts for shading Kraft wrapping. Du Pont Tartrazine O has little affinity for the fiber and cannot be used as a beater color. It is, however, one of the best acid yellows ob- tainable for calender coloring, dipping and coat- ing. It is bright canary yellow which is ex- tremely fast to light, being so superior to most other soluble aniline yellows that it is in a class by itself. Du Pont Orange II Concentrated produces bright orange shades on practically all grades of stock. In combination with Du Pont Bril- liant Crocein FL,-.it produces brilliant scarlets; shaded with DuPont Victoria Green Small Crystals, olive greens. Like other acid colors it requires size and alum to hold it on the fiber. It is used considerably in the production of leather-board and finds wide application in the manufacture of building and roofing papers, be- sides being suitable for beater dyeing, coating, calender coloring and dipping. Du Pont Orange RO is much redder and brighter, and also stronger, than Du Pont Orange II Concentrated. It has better affinity for the fiber and gives clearer backwaters in heavy shades. Its principal advantage is that it is non-foaming. Even when used in large quantities it causes very little foam and there- fore gives much less trouble than the other acid oranges which always foam in the screen, head- box, and on the wire. Du Pont Orange RO is somewhat faster to light than Du Pont Orange II Concentrated, and is used extensively for all grades of sized papers. In combination with the acid or direct yellows any shade of orange may be produced. With Du Pont Brilliant Crocein FL or Du Pont Safranine T Extra, it produces brilliant scar- lets and oxbloods. It is very soluble and is especially suitable for calender coloring, dip- ping and coating. Du Pont Phloxine B, Du Pont Erythrosine B and Du Pont Rose Bengal are used for bright pinks on sized papers, especially on stock free from ground wood. They are not especially fast to light but the fastness and also the blue- ness of the shade may be increased by the addi- tion of lead acetate. They are also most suit- able for dipping and coating, Du Pont Phloxine B being used extensively for this work as it pro- duces a brilliant shade unobtainable with other dyestuffs. Pontacyl Fast Red AS is especially adapted for use on unbleached fibers, for which it has a greater affinity than the majority of acid dye- stuffs. On account of its dullness, its use in higher grade papers is limited. Its reasonable price, however, causes it to be used consider- ably in the production of acid mixtures. Pontacyl Fast Red AS is suitable for use in the duller shades of pink to full reds on wrapping and other cheap papers. Alone, or shaded to the yellow with Du Pont Orange RO or Du Pont Orange II Concentrated, it is used as a substitute for red oxide in building papers. It is sensitive to alum, an excess tending to throw it yellower and duller.’ 39 Du Pont Phloxine B, Du Pont Erythrosine B and Du Pont Rose Bengal Pontacyl Fast Red AS Pontacyl Rose P Pontacyl Ruby PL Concentrated Du Pont Brilliant Crocein FL Pontacyl Blue R Pontacyl Rose P produces brilliant bluish pinks, possessing good fastness to light. It is especially useful as a shading red for the tint- ing blues. Pontacyl Ruby PL Concentrated is a bluish pink, the distinguishing characteristic of which is excellent fastness to light. This makes it especially valuable for the production of pinks on bonds, writing and other high grade papers, and as a shading pink for the various tinting blues on the same classes. It has very good affinity for the fibers and gives practically clear backwaters. Du Pont Brilliant Crocein FL has several characteristics which place it above all other colors of its type. It is extremely fast to light, being several times faster than the ordinary Crocein Scarlet. It has very good affinity for the fibers and gives clear backwaters, even in heavy shades. No trouble is experienced by foaming in the beaters or on the machine as is usually the case with other acid scarlets. Du Pont Brilliant Crocein FL is used in the production of pink bonds, writing, wall, cover and other papers where extreme fastness is desired. By shading it with Du Pont Brilliant Paper Yellow Concentrated, extremely fast to light salmon shades are produced. By using it in combination with DuPont Orange RO, brilliant, full scarlets may be obtained. - Pontacyl Blue R works well as a beater color producing clear, bright blues of moderate fastness to light.. It is used for tinting whites, 40 but its principal use is in calender coloring and the dipping of tissues. Alone and in combina- tion with Pontacyl Green B or Pontacyl Light Green SF Yellowish or Pontacyl Violet 4BL a wide variety of brilliant blue shades may be obtained. Du Pont Soluble Blues R and 8R are red- dish shades of blue which are used extensively for tinting whites on all grades of paper from newsprint to bond. Their fastness to light is very good. Pontacyl Fast Blue R is very fast to light and dyes evenly on sized papers of all grades of stock. It is a very good tinting white for all grades of paper where some degree of fastness to light is essential. The solubility is good so that it works well as a calender color or for dipping tissue or for coating. Pontacyl Fast Blue R is a very economical color to use for all purposes. Pontacyl Green B has fairly good at for the fibers, is fairly fast to light and is suit- able for producing light greens on bond and other medium grade papers where moderate fastness is desired. It is used either alone or in combination with other colors for dipping tissues and for calender coloring. With Pontacyl Violet 4BL or Pontacyl Blue R, it produces a wide variety of brilliant shades. Pontacyl Green SON cannot be used to ad- vantage as a beater color, as it has little affinity 41 Du Pont Soluble Blues R and 3R Pontacyl Fast Blue R Pontacyl Green B Pontacyl Green SON Pontacyl Light Green SF Yellowish Pontacyl Blue Black SX Du Pont Nigrosines WSB Powder and WSJ Powder for the fibers, but its good solubility makes it very suitable for calender coloring, dipping and coating. It is bluer in shade than the other acid greens. : Pontacyl Light Green SF Yellowish is the yellowest of the acid greens and is used to some extent for the production of light green bonds and writings. Its principal use is for calender coloring, dipping of tissue and coating. Pontacyl Blue Black SX has the advantage of dyeing equally well on various stocks and is used for producing uniform light and deep steel blues, both in the beater and on the calenders. These blues can be shaded to bluish black by using Du Pont Soluble Blue R and topping with Du Pont Methyl Violet NE, and when shaded with Du Pont Orange RO and Du Pont Metanil Yellow, it will produce full black shades which have the advantage of not showing any bronzy effects. It is a very satisfactory product for calender coloring, coating and dipping. Du Pont Nigrosines WSB Powder and WSJ Powder are both used extensively for the pro- duction of grays on all grades of paper ranging from chip board to high grade bonds. They have the advantage of producing very uniform dyeings even in light tints, which makes them valuable colors for shading purposes. They are also suitable for calender work, coating and dipping, and may be considered the fastest to light of any of the blacks used on paper. WSB is the blue shade and WSJ the jet shade. DIRECT OR SUBSTANTIVE COLORS _ The direct or substantive colors are used for dyeing the higher grade wall papers, espe- cially oatmeal papers, for writing, book, cover, blotting and parchment papers, vulcanized fibers, etc. They are especially well suited for dyeing blotting papers and mottling fibers. The use of direct colors gives, in most cases, a per- fectly clear backwater. This is especially true if a small amount of alum, any amount over 4 lbs. per 1000 lbs. of stock, is used. : Pontamine Yellow SXP is one of the most extensively used direct yellows for coloring both sized and unsized papers, such as blotting, bond, wrapping, oatmeal and other wall papers. Alone or in combination with other suitable colors it produces all shades of buff to deep goldenrod. Combined with Pontamine Green BX or GX, any shade of moss green blotting may be obtained. - Pontamine Yellow SXP is very suitable for coating papers and competes with French ochre for this work, giving a brighter and more uniform shade. Pontamine Yellow SXG possesses about the same properties as Pontamine Yellow SXP, but is decidedly greener in shade. It is suitable for use in shades where the SXP brand is too red, its principal use being for shades ranging from India tints to the greener goldenrods on medium to high grade papers. Pontamine Yellow SXG has good solubility and is suitable for use on coated papers. 43 Pontamine Yellow SXP Pontamine Yellow SXG Pontamine Yellow SXR Pontamine Yellow CH and CH Concentrated Du Pont Brilliant Paper Yel- low Concentrated Pontamine Fast Yellow 4GL Pontamine Yellow SXR is similar in prop- erties to Pontamine Yellow SXG and SXP, the shade being redder than that of the latter. Itis suitable for the redder shades of buff and goldenrod. 3 Pontamine Yellow CH is greener in shade than Pontamine Yellow SXP, is much faster to light, and is extremely fast to alkali. For this reason it is used extensively for the color- ing of soap wrappers. It also finds consider- able use in the production of India tints, canary and buff shades on bond and other high grade papers. Du Pont Brilliant Paper Yellow Concen- trated is a very bright direct yellow of excep- tionally good tinctorial power for its class. Itis one of the fastest to light of the aniline yellows, and finds wide use in the production of bonds, cover papers, blotting and other papers where its sensitiveness to alkali will not interfere. Alkali turns it a bright red, but an excess of alum will often tend to overcome this feature. Du Pont Brilliant Paper Yellow Concen- trated has one advantage over all the other aniline yellows. It gives much less two-sided effect and for this reason its use is becoming more and more extensive in mills where the machines are equipped with suction couch rolls. Pontamine Fast Yellow 4GL is the greenest in shade of the direct yellows and is also very fast to light. It is suitable for the production of canary shades on bonds, blottings, and other sized and unsized papers. | 44 A Pontamine Blue BBF and BBF Concen- trated are two strengths of a direct blue some- what dull in shade but used quite extensively in dyeing unsized as well as sized papers. 74 parts of the OOS te aba ia brand equal 100 parts of the single strength. | fe ptsscsses ep pi: Ptieas to light and is one of the most economical direct blues to use. It finds extensive use in the oatmeal wall paper trade and also in wrapping and other papers where some degree of fastness is de- sired. 4% ‘ " t % od Ae 73 f . 4 Pontamine Blue AX is a direct blue of a red shade, used for blues on sized and non-sized papers; for dyeing stock to be used for mottled or granite papers; and in conjunction with Pontamine Black EX for the production of the deepest black blues for all grades of paper. Itis fairly fast to light and this fastness may be de- cidedly increased by the addition of copper sulfate. Pontamine Sky Blue 5BX is used for the production of mottled fibers for granite papers and for light blue shades on bond and other high grade papers. 50 parts of the 5BX Con- centrated brand equal 100 parts of the 5BX. Pontamine Sky Blue 6BX, the greenest and brightest of the direct blues, finds extensive use in the production of fast to light blue shades on all grades of paper. Alone, or shaded with Pontamine Blue AX and treated with copper sulfate, various shades of blue, which are ex- 45 Pontamine Blue BBF and BBF Concentrated Pontamine Blue AX Pontamine Sky Blue 5BX and 5BX Concentrated Pontamine Sky Blue 6BX Du Pont Purpurine 4B Concentrated Pontamine Scarlet B and Pontamine Fast Scarlets 4BS and 8BS Pontamine Fast Red 8BL tremely fast to light, may be produced. It is used extensively for the production of colored fibers for granite papers. . Du Pont Purpurine 4B Concentrated is used extensively for the production of deep red shades on both unsized and sized papers such as blotting, wrapping, tissue, cover, etc. Vulcanized fiber mills use it extensively in the production of red shades and to brighten shades in which red oxide is used. It is one of the best colors obtainable for dyeing fibers for mottled or granite papers. . Du Pont Purpurine 4B Concentrated is very sensitive to acid and alum, and it is neces- sary to add about 1% soda ash to the beater to develop the full color and obtain even dye- ings. Pontamine Scarlet B and Pontamine Fast Scarlets 4BS and 8BS are direct scarlets which are suitable for the production of a wide range of reds from pink to scarlet on both sized and unsized papers. They possess good fastness to light and good solubility. The distinguishing characteristics of Pont- amine Fast Red 8BL are high tinctorial power and extreme fastness to light. It is stronger than any of the other direct reds or scarlets and is much superior in fastness to light. It is sur- passed in this respect by only one dyestuff, Du Pont Brilliant Crocein FL, the latter being an acid color. Pontamine Fast Red 8BL is bright bluish red in shade and is suitable for the production 46 of pink to red shades on all grades of paper, both sized and unsized, where fastness is essen- tial. Pontamine Fast Orange S works well on both sized and unsized paper, producing brilliant orange shades of good fastness to light. It is suitable for use on blotting, bond, cover and wall papers. Pontamine Red 12B Concentrated pos- sesses very good fastness to light and acid and is fairly fast to alkali. The shade is thrown slightly yellower by alum but is not dulled as are most of the direct colors. It is bright pink in shade and is suitable for use on blotting, cover, wall, bond and other high grade papers. Pontamine Greens GX and BX are the yellow and blue shades of a direct green par- ticularly suited for sized or non-sized papers and for dyeing cellulose fibers for mottled papers. They possess fairly good fastness to light. Both are widely used for the production of green blotting and cover papers and for color- ing vulcanized fibers. Pontamine Brown R is very fast to light and is very suitable for use on both sized and unsized papers such as blottings, cover, etc. Pontamine Brown D38GP is much yellower in shade than Pontamine Brown R, is very fast to light, but is somewhat sensitive to acid and 47 Pontamine Fast Orange S Pontamine Red 12B Concentrated Pontamine Greens GX and BX Pontamine Brown R Pontamine Brown D3GP Pontamine Diazo Black BH Concentrated Pontamine Blacks EX and EBN dulled by alum. The addition of soda ash will brighten the shade and make it yellower. It is very suitable for the production of tan and brown blottings and for brown cover and wall papers where good fastness is desired. Pontamine Diazo Black BH Concentrated is well suited for coloring both sized and unsized papers and finds considerable use in the manu- facture of deep blue shades of blotting and cover papers. Pontamine Blacks EX and EBN are, per- haps, the most widely used direct colors. Their fastness to light is very good and they are very suitable for the production of black shades on all grades of stock from cheap pattern to high — grade blottings and cover. By using a base of 20 to 30 lbs. and shading with such basic colors as Du Pont Chrysoidine GN, Du Pont Methyl Violet NE, and Du Pont Victoria Green Small Crystals, any shade of black may be produced very economically. These colors are also used extensively in the production of black vulcan- ized and insulating fiber, especially the latter, as fiber for this purpose contains no free carbon such as lamp black. These colors are of excellent solubility and find wide use in the dipping of plain and crepe tissue and in coating. THE HELIOPONT COLORS These have been mentioned elsewhere but they are of sufficient importance to warrant a more detailed description and a more precise outline of the method of application. 48 Heliopont Blues R, M, G and 4G represent Heliopont green. The R brand is for the red or pinkish white, the M brand is very similar in shade to Ponsol Blue RP Triple Powder, but somewhat brighter and is the most suitable color for a _ neutral shade of white. The G and 4G are for the greener shades of white, and are also used in the production of light blues on bonds and similar papers. These colors may be thrown into the beater in the dry powder, or made into a thin paste with water, taking care that the mixture is stirred thoroughly before any is measured into the beater. As they have the properties of pig- ments it is well to give them as much time as possible in the beater to develop the full strength. Weak alkalies have no effect on them and they are fast to acid. In this respect, they have the advantage over Ultramarine, which is sensitive to acid to such an extent that the color “goes back” in stock which lies in the chest for any length of time. The Heliopont Blues are not approached in fastness to light by any of the soluble aniline blues and are surpassed by only one other type, the Ponsol colors. In the selection of a tinting blue it is ad- visable, in fact necessary, to use one which re- quires a small amount of a shading pink or red. The color of the stock changes from day to day and it is usually necessary to vary the amount of red in order to control the shade. The brightest, fastest, and most satisfactory whites are produced by using a blue which requires a minimum amount of shading red. If a green 49 four shades ranging from the red to the very ee R, M, G d4G Ponsol Blue RP Triple Powder Ponsol Blue 3GP Triple Powder shade of blue were used with a large amount of red to produce a pinkish white, the shade would be duller and less light resistant than it would be if a redder shade of blue were used. As a shading red to use in conjunction with the Heliopont Blues, we recommend Pontacyl Ruby PL Concentrated. This is a bright pink acid dyestuff of excellent fastness to light and is very satisfactory for this work. PONSOL COLORS This group far surpasses any other type of dyestuffs in properties. All of its members are fast to both acid and alkali, extremely fast to chlorine, not being affected by any chlorine © which might be left in poorly washed stock. And, in addition, inasmuch as they withstand sunlight indefinitely they may be called abso- lutely fast to light. Ponsol Blue RP Triple Powder has many advantages over any of the other tinting blues. As a paper color it may be called absolutely fast to light as it will resist direct sunlight in- definitely. Ponsol Blue RP Triple Powder is very suit- able for the tinting of whites and the produc- tion of light blue shades on high grade papers and specialties. Ponsol Blue 3GP Triple Powder is greener in shade than the RP Triple Powder brand, but possesses the same properties. It is suitable for shading the latter product to the green and for the production of blue tints on high grade papers. 50 Ponsol Yellow GP Double Powder possesses Ponsol Yellow GP the fastness properties typical of the group. It Povble Powder is suitable for the production of India tints and buff shades on high grade papers and specialites. 51 CHAPTER V A FEW SUGGESTIONS ABOUT COLORS BEST SUITED FOR DIFFERENT GRADES OF PAPER N this chapter we are recommending the most suitable colors for use on the various grades of paper and showing dyeings of cur- rent and special shades on some of the most generally used furnishes. nee grade 1. Colors particularly recommended for writing papers, 5 ae peoena high grade writing papers, bonds and book book papers papers: Du Pont Brilliant Paper Yellow Con- centrated Pontamine Fast Yellow 4GL Pontamine Yellows SXP and SXG s Pontamine Yellow CH and CH Con- - centrated Du Pont Orange RO Pontamine Fast Orange S$ Du Pont Brilliant Crocein FL Pontacyl Ruby PL Concentrated Pontacyl Rose P Pontamine Fast Red 8BL Ponsol Blue RP Triple Powder Heliopont Blues R, M, G and 4G Pontamine Sky Blues 5BX and 6BX Du Pont Soluble Blue R Pontacyl Green B Pontamine Brown D3GP Pontamine Black EX Du Pont Nigrosines WSB Powder and WSJ Powder The following samples were dyed on a fur- nish of 1000 lbs. Bleached Sulfite 20 lbs. Size 25 Ibs. Alum 52 4 ozs. 8 ozs. 5 ozs. 10 ozs. 5 ozs. 10 ozs. Ponsol Blue RP Triple Powder Ponsol Blue RP Triple Powder Heliopont Blue G Heliopont Blue G Heliopont Blue M Heliopont Blue M 5 ozs. Heliopont Blue R 10 ozs. Heliopont Blue R . . ‘” d 3 ozs. Pontamine Fast Red SBI, : 4 lbre aedieon a ne Gop en 22 Colors for blotting 03.66.05 sn oe Geb in wea cee 73 DONG ss Ske es oe oe 0b oi dide ay, kane 52 DOOK © esata o's) ails vo. k's b oie le lel bia sce pig eee 52 boxboard \\.%.i% 6 sa +0 else sie le 9 lsat alle eee ane 77 COVED! Saw eV i ebiele Sis lel ncbewna toe ek nan 59, 63 Kral io os ieee, 6 0b vibe sue bn 64 steam proof spool papers ...:... «sues meena wall-oatmeal (02.06 osecidie's o 5 wince Sate tenn 59, 63 WEIN ke ico vin eis's oe na tis som 6 sal 0e ate Cover Papers Cescription. 2.56. os vv» «0 0.0 op pe Ale ain pee 9 COloTS FOR sie aca sa cdverecee sa » 55/01 gee ve 59, 63 dyeings: Of 2 bsc5 ek nvcg ys + 0s Wolsey ee 60-63 Dipping Process description) -visies «+ ane eye ele .e(o oon © 5 aetna 20 colors \fLOTiaas srs. eee Pri rs 20 cae Be ase DIRECT COLORS Du Pont Brilliant Paper Yellow Concentrated... 44 Du Pont Purpurine 4B Concentrated ........... 46 mrrnn re PisOk Tudeh ab xia eee ake ba cheb be ee 48 Be SMIIIING IDO IGEN dc bck es oth ar bebe wesaur 48 MeeuSRISEESERT PLE AL Pela aoe & 6 1erN vot wo vo as ae ee we 45 Pontamine Blue BBF and BBF Concentrated... 45 monmtnmine. Brown DSGP oes Oo oa oe ew Caw eee 47 Bree IEE CELDT Fur i Wc as a pew ele oc ceed ees 47 Pontamine Diazo Black BH Concentrated ...... 48 emernne- Fast Orange SS vale .t sek co db aeines 47 Meremreneties oaGt ICU SEALE yoy eas ecw wea ne eawe 46 Pontamine Fast Scarlet 4BS ............ 0.008. 46 Pontamine Fast Scarlet 8BS ............ecc00. 46 Pontamine Fast Yellow 4GL .......... 0. ccaeee 44 Meme CaTCeOn EN. cw ec cc ee lee ee Cas AT MUP ESOT AT a cab ewadline de AT Pontamine Red 12B Concentrated ............. AT MU NICLO CSPICL. Es 5 oy beeen shee wie e's wie 46 Pontamine Sky Blue 5BX and 5BX Concentrated 45 Semramune pky GING GBX 2... ee lee et bee 45 Pontamine Yellow CH and CH Concentrated.... 44 SenInTETeN SY CLIOW Tar oc le es kk cic twee kews 43 MEPATIO SY GLNW SA eg o's a o's cheese civ aiacle ees 43 MEEITIES TY GUIOW. SG Elsa cb ce eis veces ewtens 44 Dyeing of Paper in the Mill a SLED A ep el 13 IIR TFG ls hcg a a ag signet y o.3 eie cin srs aw at alll TER ee ie gah a caliny «, 6) 6: 0! 0 «ale poe lee 21 Golan ——Method Of AddING «1.6... sc. cere e cece wes 13 TOE A a Siu nig pin sipis o.s'+'s aie « Sie. 20 EM UOTIAMORS ec ciel ds basal sltidia ec ese eee. 15 NRNIBUREN iyi nic ol hea dl x)'w tle vis’ wiv'a'sisis eee se te 18 pigments—method of adding .................. 14 prevention of mottled effects .............6.6.- 16 RESIS a cy dig baled cielsiec secs ye veaeb us 85 Re Sg oy ys Sate eG Che cies See e cv accees 11 EEE ADOT: iu salx a Geeiv Wed acd 6 9 a see a0 Ws 10 ERE ena Cha nae lip A ian ah ay 4 piaie'a s s.0/0 wintade'e 76 MS LL gy Teva tive so by didn eG. 4 be 8 vee gree 31 Rees tS Utila lis ¢cly's\sleditias «sien e sees 29 Wall Papers TIMER SIS chicas ste sie pile aa ale d's 's\e da oa 11 RM etn et ee se are wile ava’ 59, 63 Writing Papers id ca aih'a bine bin ond. ose 4 6310's yee 9 eu yas pa pieth ond cela ape eee 9 8 52, 59 dyeings (see Bond Papers, dyeings) Wrapping Papers ORE KG 8 ills les lero nese. 4 0 9i4 «4 .0°e 00 9 NIN (06a d5s)e sTgNhin'g's 6 vidi Sensis 4 ps ee 0's 64 CME Hello gai i i lp ga a ea 65-73 te SPECIO( Ue: Wal af 20 ) 47> THE GETTY CENTER LIBRARY —