nl "■^•■OREST SERVICE ^ 3 2 15 PM V SULFITE PULPING EXPERIMENTS ON SAND PINE March 1943 No. R1429 SUN B DQks )£p"c UNITED STATES DEPARTMENT OF AGRICULTURE FOREST SERVICE FOREST PRODUCTS LABORATORY Madison, Wisconsin In Cooperation with the University of Wisconsin exfer: on sand pine By J. N. McGOVERN, Associate Technologist and .- . ... KELLER, Junior Chemist "ummary and pine (Pinus clausa) bolts with an average density of 12 pounds per cubic foot, average growth rate of $.6 rings per inch, aver- age heartwood volume of ]>&,& percent, were separated into heartwood and sapwood for sulfite pulping experiments. The sapwood had chemical charac- teristics similar to those of the whole wood of sar.i pine ' reviously received at the Forest Products Laboratory, whereas the heartwood was found to be low in lignin and cellulose contents and exceptionally high in mate- Is soluble in alcohol-benzene, ether, 1 percent sodium hydroxide, and hot water. Using moderate pulping conditions, the sapwood chips were cc °iy digested to a low bleaching pulp, but the heartwood chip "tely reduced, two-thirds of the total fibrous yield of 57 percent became screen- ing rejects. Application of a relatively low maximum tenperature and a long digestion time improved the heartwood pulping somewhat, [ Ler these favorable conditions the screening rejects amounted to two-fi: he total yield. The sapwood pulp of sand pine had a chlorine demand of only 2.9 per- cent, had much lower strength properties than sapwood pulps obtained from ir southern pines and was high in cellulose and rather high in ether tractive contents. The heartwood pulps had high chlorine demands, had Verier strength properties, were high in lignin and low in cellulose, and were exceptionally high in extra- chemical constituents of the sapwood and heartwood pulps were consistent with those of the chips before digestion. Introd.. sj Lpj Sand ; Ls a minor member of the southern yellow pine growing in orida and Alabama. A stand of sand pir.e of some HCO,000 cords, capable of supporting an annual cut of 40,000 cords on a 35~ vear rotation, grow the Ooala Natior.al Forest in north a • 1 Florida. It ha? little luml value, bu1 some outlet as sulfate and Q60< 0. R1429 - - Ruei. reported that sand pine could be readily reduced by the sulfite process to bleachable pulps in the yield range of 25 to 35 percent. This appears to be the only reference available on the sulfite pulping of this species. The possibility of making a wide variety of kraft papers includ- ing wrapping, high-grade paper, and newsprint was recently reported.— The limited investigation reported here was undertaken at the request of the Ocala National Forest to determine the feasibility of pulping sand pine by the sulfite process using commercial conditions. The experiments were conducted on separated heartwood and sapwood samples and included: (l) digestions of both the heartwood and sapwood under moderately mild pulp- ing conditions and (2) a digestion of the heartwood using a rather low maximum temperature and a long digestion time. Experimental Part Six k- foot bolts of sand pine arrived at the Forest Products Labora- tory from the Ocala National Forest on June 2k, 19^2, and were designated as shipment No. 1 667 • One badly decayed bolt was discarded. Most of the outer bark of all bolts had been knocked off during shipment. The inner bark had been penetrated with borers and beetles and serious blue stain extended to the heartwood. One-inoh discs were cut from the center of each bolt for the physical tests. After the bark had been completely removed the wood was separated into heartwood and sapwood portions and converted into 5/ < 3~i nc h chips. The two kinds of chips were sampled for chemical analyses . The digestions were made in a stainless-steel autoclave with a steam jacket. Its capacity was 1.5 cubic feet. The pulped chips were defibered in a stirrer and passed through a diaphragm screen equipped with plates having 0.012 inch slots. The digester charge was 15 «3 pounds for the sap- wood and 16. S pounds for the heartwood, both on a moisture-free basis. The acid charge was f .0 gallons. Other digestion conditions are discussed later in this paper. Results and Discussion The Wood The bolts ranged in diameter from 7 to 9 inches. The physical characteristics of this shipment were similar to those of a previous ship- ment, No. 1375 > except for a somewhat higher density, as shown in tabl^ 1. The higher density figure was within the range of densities for most southern pines . =Wells, S. D. and Rue, J. D. U.S.D.A, Bulletin 1^5 (1^27). 2 -Bray, M. W. and Martin, J. S. South. Pulp L Paper Jour., June 19^2. Mimeo. No. Rllj-29 -2- The chemical composition of the sapwood from shipment No. 1 667 , given in table 2, showed good agreement with that of the v/hcle wood from shipment No. 1375> although shipment No. 1375 appeared to be ur Ly low •. osans and ether extractive material. The heartwood from No. 1 667 difJ rreatly from its own sapwood or the whole wood of the previous shipment. It was low in lignin and alpha and total cellulose contents and high in material extracted by alcohol-benzene, ether, 1 percent sodi hydroxide, and hot water. The high caustic solubility valup indicated the presence of decay but none was detected visually. pulpinp Experiments Because the physical and chemical character! ties of previous sh! - ments of sand pine were similar to those of northern jack pine ( J banks ianr.a ), pulping conditions known to be fairly satisfactory for jack pin« were used for the first experiments. The application of these r.od- °rately mild conditions to the sand pine sapwood resulted in complete pulp- - and a very low bleaching pulp. This is shown by digestion No. : II- Ln table 3- Th° screening rejects of approximately 1 percent ire -.— blly due to the presence of a small proportion of heartwood. Qie sapwood pulp, which was slightly overcooked, had very poor strength properties. I much weaker than sulfite pulps from other southern pints. It was high in both total cellulose and alpha cellulose content. A higher content °the r soluble material than desirable for satisfactory paper making ? present. It does not appear from these results that the sapwood, even if it can be readily obtained free from heartwood, is a promising mater for sulfite pulping under standard commercial conditions. This dee? net preclude the possibility that more suitable pulping conditions sai be developed to improve the qualities of the sapwood pulp. The heartwood, when digested under the conditions or the s r - wood, was not successfully pulped, as shown by the data for No. -??-Y in table 3« The bisulfite in the cooking liquor was exhausted about 2 hours sooner than in the sapwood digestion, indicating the pr°~ence of the bi- sulfite-destroying components that are typical of pine heartwor:. exhaustion of the bisulfite and consequently the shortened pulping t caused incomplete pulping and gave evidence of an extremal; Fr stc ' material. Approximately two-thirds of the total fibre the form of screenings. The screened heartwood pulp was high extractives and low in total and alpha cellulose (table k). [1 . ore, d a high bleach requirement as shown by the chlorine require!) table j. It was very weak from a 2.0 5.9 12.2 77.1 2S.6 —Average for 5 bolts, none containing decay, 2 —Oven-dry weight and green volume. Table 2. -- Chemical analyses of the sapwood and hr •• rood o: : Shipment I667 -.Sapwood : Heartwood Shipment 1375 ole wood Lignin. Cellulose : Total Alpha, Pentosans : Total In cellulose, Solubility in: Alcohol benzene :.er 1 percent sodium hydroxide Hot wate r Ash, 26. S" 6O.5 46.6 11.4 10. g • 1.9 9.2 2.4 • 3 24.0 4S.0 35.6 ] . ' • 14.0 25.O 7.0 .2 27.2 61.0 42.9 6.9 2.2 2.5 Mimeo. No. R1429 Chlorine requirement Percent ON K\ NO • • • CVJ NO CVI rH rH r leld Soreenlnge Percent ON J* 10 O ^ ON f\ rH 1 | J, 6 • • i o i alal no no kn 1 h ihlol i UTN. UN rH 1 Ol ol a i i. w rr\ un *» a ia • O w 1 O l*\ M & H *» iXl H rH H a i 1 B I i

• i ol irN r*N .* IHBl Cooking Time to max. temp. Houre 8 8 10 1 • O, 1 .1 NO NO c> ■ K E i o r*N fN r<\ 1 jt III rH rH t-\ ■atlon Time at 110° C. Houre OOO CVI CU CJ Peneti Time to 110° C. Koura in in rH rH CJ -ng .d Comb. Per- cent 1-35 1-35 1.36 Al O 1 rH 1 a) 1 a) cvi 1 1 1 uo 1 t. 1 ocn 1 a 1 H IP. 1 a 1 *> 1 1 C 1 a 1 a IB 10 1 >» it. n it. 1 a 1 a ip. no r«- +»| •*- K\ rl c • • . al no no r*- ol ^t rH ITN ON NO NO no r»- r^- — — Kind Sap- wood Heart- wood Heart- wood Digestion Number X x X rH O 0i 10 • «0 *) l*N l»> l*\ o c rH a «<.o 3 p. r^ I 01 a 1 <-> o 1 o « o -I u +» a t, a a 6 *» tea a as PHJI f 01 cmcjI l. c a. v O.I o| t. E hi a P.I0I o I I4JI J- rH t. 6 NO NO * • r-< B a-. U a. X C p t. D Bfl f a. w O * X £ O a) to a rrOG O x+» UNIVERSITY OF FLORIDA ii ii mil mi iim mi mi ii mil in 3 1262 08925 4485