14 CROP PLANTS FOR PAPER MAKING. 



COTTOX STALKS. 



Cotton stalks tested in coo})eration with the Forest Service of this 

 Department were among the first crop wastes reduced to pulp. The 

 aggregate quantity of these stalks produced in the United States is 

 large. Those who have given attention to the matter estimate it at 

 10,000,000 tons. The yield per acre of stalks is much lower than that 

 of any of the raw plant materials thus far discussed, and probably 

 does not exceed 1,000 pounds. Cornstalks will average more than 

 twice this quantity; rice straw, four times as much; and broom 

 corn, six times this total. Numerous inventors have been attracted to 

 cotton stalks by the large quantity grown, and much has been claimed 

 for paper said to be made from them. At the present time no paper 

 mill is using the material. 



In the experiments thus far conducted by this Department cotton 

 stalks have been found to require harsh chemical treatment, using 

 about 30 per cent of caustic soda, which is 5 per cent more than poplar 

 wood requires. They required from six to nine hours, with steam 

 pressures of from 90 to 110 pounds, for cooking. The jdeld of fiber 

 ranged from 35 to 43 per cent in various tests, but the fiber was found 

 to be short and inferior in strength. With this yield and the low 

 production of 1,000 pounds per acre it would require 5 acres of stalks 

 to make a single ton of pulp. Difficulties were also encountered in 

 connection with bleaching. The dark outer bark proved very refrac- 

 tory, necessitating the use of a large quantity of bleaching powder. 

 All samples of paper made from this material which the writer has 

 examined contain so much unbleached material as to render them 

 unsuitable for anything except wrapping purposes. It is possible 

 that methods may be devised which will produce a pulp sufficiently 

 white and a fiber sufficiently strong to make cotton stalks a promising 

 material, but the results obtained to date are not encouraging. 



BAGASSE. 



Bagasse is the refuse of the sugar cane after the juice has been 

 expressed. It is susceptible to the treatment given to the stalks of 

 corn and broom corn and some of the other materials that have been 

 discussed. When treated by the caustic-soda process in the ordinary 

 manner the yield of pulp has been comparatively low. The indi- 

 vidual fibers, while rather short, are slender, so that a moderately 

 strong sheet of paper can be produced. The pulp bleaches easily, 

 especially if it has first been extracted by the method described for 

 cornstalks. A large percentage of pith is present, which, in practice, 

 would have to be dealt with as in the case of corn. Several small 

 plants have been built with a view to making various forms of pulp- 

 board and the rougher grades of paper from bagasse, but so far as 



SS-The paper upon which this page is printed was made from hroom-corn 

 sialics and poplar wood. Sec page 3. 

 [Cir. 82] 



