March, 1909.] 



229 



FIBRES. 



'' LALANG," {I MP ERA TA ARUNDI- 

 NACEA, Cyrill) AS A PAPER-MAKING 

 MATERIAL. 



By G. Stewart Remington. 

 One of our correspondents sent a sam - 

 ple of lalang grass recently to England, 

 and ha,s received the following report, 

 also samples of paper made from lalang 

 grass entirely and half lalang and half 

 cotton :— 



Certificate of Analysis. 

 This is to certify that the above sam- 

 ple has been carefully examined with 

 the following results : — 



This grass was forwarded to "The 

 Aynsome Technical Laboratories " for 

 investigation, that its commercial use 

 as a source of pulp for paper-making 

 might be ascertained. 



The object of the present report is to 

 draw attention to the importance and 

 value of this grass as a pulp-pioducing 

 material, and to indicate its chief char- 

 acteristics and economic value. 



The sample was a pale buff colour, 

 lustrous in appearance and of fair 

 strength, of the order of Graminea^. 



The chemical examination furnished 

 the following results, the percentages 

 other than that of moisture being ex- 

 pressed on the dry material :— 

 " Moisture ... ... 13 21 



Ash ... ... 4-14 



Loss on L. Hydrolysis ... 10*70 

 Loss on B. Hydrolysis ... 46 65 

 Loss on Mercerisation ... 31*62 

 Loss on Acid Purification ... 0"95 

 Gain on Nitration ... 21*19 



Cellulose ... ... 47-41 



Length of Ultimate Fibre ... 1*20 m.m. 



The ultimate fibre obtained from this 

 grass is very similar in most respects to 

 Esparto; the yield of bleached fibre being 

 about the same. This is a favourable 

 indication inasmuch as "Esparto" is 

 one of the best known and most useful 

 sources of supply to the trade. The 

 fibres as seen under the microscope 

 are short, smooth, cylindrical, fairly 

 uniform in diameter, gradually taper- 

 ing to rounded extremities ; they also 

 occur together in little bundles. The 

 pulp will be found to contain a number 

 of small cuticular cells which do not 

 however shew in the finished paper. 

 The fibres are stained a pale yellow with 

 iodine solution, which fades more 

 radidly than is usual with coloured 

 pulps, 



The results obtained from the chemi- 

 cal analysis show the grass is capable 

 of yielding a good quality of cellulose, 

 suitable in every way for the manu- 

 facture of paper. Although the grass 

 is very susceptible to the action of 

 dilute alkalis, the final product is ex- 

 ceptionally pure and readily resolved. 



From observations noted during this 

 preliminaiw examination the following 

 scheme was adopted for the production 

 of the pulp on a large scale. 



Process. 



The available grass in its natural con- 

 dition weighing 400 grams (14*1 oz.) was 

 in a clean state, and required little treat- 

 ment beyond cutting; iuto small pieces 

 ready for boiling. It is usually neces- 

 sary on a large scale to pass the material 

 through some type of cleaner to re- 

 move dirt and adventitious matter. The 

 grass was then thoroughly wetted and 

 soaked until it became soft and pliable. 

 It was placed in a boiler of the spherical 

 type, covered with water and digested 

 with caustic soda corresponding to 15 % 

 on the grass treated for a period of ten 

 hours under a pressure which was kept 

 constant at four atmospheres ; an even 

 temperature about 135° C. being main- 

 tained. 



Owing to the quantity of material at 

 our disposal being somewhat limited, 

 it was only possible to conduct one 

 experiment, consequently a good margin 

 in the use of caustic and a degree of 

 general treatment was allowed. 



The pulp obtained after washing was 

 of good uniform quality and colour. 

 The yield agreed very closely and was 

 only slightly higher than the prelimi- 

 nary chemical analysis shewn, which in- 

 dicates complete reaction in the digester. 



The pulp was carefully beaten for 

 about an hour and at the same time 

 bleached, chloride of lime being used for 

 the purpose ; 10 parts of dry powder 

 being used for 100 parts of pulp. 



The stuff was taken from the beater 

 and well washed, and subsequently a 

 small quantity of loading was gradually 

 added and the whole again beaten for 

 half-an-hour. At this stage of the oper- 

 ation the rosin size was introduced and 

 the decomposition of the soda resinate 

 completed with the calculated quantity 

 of alum. The amount of size used cor- 

 responded to 4 % on the dry pulp present, 

 the total time occupied in preparation 

 of the pulp for running on the machine 

 being two hours. 



