OTHER USES OF THE MAIZE CROP 



797 



That good paper can be made from corn [maize] stalks chap. 

 was proven long ago. The Government's present experiments xvn - 

 which are being carried out by the Forest Service and the 

 Bureau of Plant Industry in co-operation, are merely to obtain 

 authentic data on this subject, and to determine if possible just 

 what is necessary to make the manufacture of paper pulp from 

 corn stalks a commercial success. The corn stalks thus far 

 experimented with have been those grown locally during the 

 season of 1907, but there is no reason to suppose that the 

 material grown in the Corn-belt would not yield fully as good 

 a product. 



" The stalks are received in the laboratory in bundles, which 

 are opened out and shaken to remove loose dirt. They are 

 then cut into short pieces and washed to remove as much field 

 dirt as possible, and are then ready to put into the digester 

 tor cooking. Before the regular cooking process is commenced 

 the stalks in the digester are extracted several times with water 

 and live steam under 10 to 25 pounds pressure. This removes 

 much soluble material, containing most of the nutritious matter 

 originally present in the stalks, and after partial evaporation 

 of the extract it could probably be used as cattle food. After 

 the extraction with water is completed, the caustic soda is 

 added to the material in the digester and the regular cooking 

 process is proceeded with. The ' cooks ' made have varied 

 from several hours at 95 pounds steam pressure down to one 

 and a half hours at 1 10 pounds, and the caustic soda used has 

 been from 10 to 25 per cent of the bone-dry stalks removed. 

 It is found that the best results are obtained by using about 

 15 to 10 per cent of caustic soda and cooking about two hours 

 after a pressure of 1 10 pounds is reached. 



" After the ' cook ' is completed the fibre is blown out of 

 the digester into a vat with a false bottom which allows the 

 waste liquors to drain away. The material is washed in this 

 vat with hot water until the waste liquors, which are very dark 

 brown, are removed, and it then goes to a specially constructed 

 screen which separates the pith cells from the long fibre. This 

 process is necessary as the pith cells tend to make the paper 

 harder than is desired for many grades. The fibre, after 

 separation of the pith, is found to be long and strong and 

 could be used for nearly any grade of white paper as it is 

 ' found to bleach easily with 7 to 12 per cent of bleach. It 

 could also be employed in the unbleached state for wrapping 

 paper, and with the addition of ground wood for the production 



