﻿94 



RICHMOND. 



A maximum temperature of 150° was reached in one hour and maintained for 

 three hours — a total of four hours for the entire cook. 



The yield was as follows: Rope fiber, 66.5 per cent; jute fiber, 56 per cent. 



The chief features of the sulphite pulps made from Manila and jute stock are 

 the light, gray color to be obtained direct from the washing engine. 



ABACA WASTE SULPHITE DIGESTIONS. 



Baled waste from hand-stripped Manila hemp from Albay Province 

 was thoroughly hand sorted and dusted to free it from coarse husks and 

 sand; at least 50 per cent of the original weight of the waste being 

 removed by this treatment. It was then cut to a suitable fineness (about 

 4 to 5 inch lengths) and closely packed into the digester, strong pressure 

 being used to hold the charge submerged in a small volume of liquor. 

 Four to five times its weight of liquor proved sufficient to pulp the 

 material under the conditions of the respective experiments outlined 

 below. 



Table No. 10. — Sulphite digestion of abaca waste. 



Exper- 

 iment 

 No. 



Composition of the liquor. 



Duration of digestion. 



Maximum 

 tempera- 

 ture 

 carried. 



Yield of un- 

 bleached 

 pulp. 



Total 



so 2 . 



Combined 



so 2 . 



Available 

 S0 2 . 



Time to 

 reach max- 

 imum tem- 

 perature. 



Total 

 time. 



1 



2 



3« 



4 



5* 



Per cent. 

 3.57 

 3.34 

 3.40 

 3.6 

 3.55 



Per cent. 

 1.76 

 1.30 

 1.50 

 1.2 

 1.36 



Per cent. 

 1.81 



2.04 

 1.90 

 2.40 

 2.18 



Hours. 



2 

 2 

 li 



2 



1 



Hours. 

 7 

 5 

 6 

 5 

 4 



°C. 

 150- 



140-145 

 145 

 150 

 140 



Per cent. 



48.9 



47 



48.75 



50.76 



59.2 



• The charges for experiments 3 and 5 consisted of 8 pounds of hemp waste and 1 pound of 

 jute bagging. 



Remarks. — An ordinary bisulphite of lime and magnesia liquor, such 

 as is generally used in the manufacture of sulphite wood pulp, is ap- 

 plicable to this material. 



The state of subdivision and the extremely porous nature of the waste, 

 allows of the heating of the boiler to the maximum temperature it is 

 desired to maintain in the shortest possible time, without danger of 

 burning the pulp. 



Three to four hours' digestion at temperatures ranging between 140° 

 and 150° C. will produce a strong, gray-colored stock which washes and 

 beats readily by the usual methods, but these conditions of time and 

 temperature do not dissolve all of the chaff and cellular matter present, 

 and the result is a rather poor appearance when the pulps are molded 

 into boards or sheets. The cellular matter remaining in the pulps is 

 nonfibrous and has no felting power, but it does possess a cementing 

 nature which adds to the strength of paper made from such half-stuff 

 and I do not think that it will be necessary to attempt to remove all of 

 the nonfibrous portions from hemp waste for the production of colored 



