METHOD FOR PREPARING A PAPER PULP FROM FIBROUS NON-WOODY LIGNOCELLULOSE PLANT MATERIAL.

摘要

WE CLAIM (1) A method of preparing a paper pulp from a fibrous non-woody lignocellulose plant material having fibers and pith therein, comprising the sequential steps of wetting said plant material with a wetting substance selected from the group consisting essentially of aqueous liquid, such as fresh water, white water, black liquor as herein described and mixtures thereof, so as to form an aqueous plant material slurry thereof wet depithing said plant material by subjecting said aqueous plant material slurry to a shredding operation so as to detach substantially all of the pith from the fibers in said plant material and produce a slurry of released pith and fibers , diluting said slurry of released pith and fibers with an aqueous liquid such as fresh water, white water, black liquor as herein described or mixtures thereof separating the pith from the fibers in said slurry of released pith and fibers so as to obtain a resultant fiber slurry , partially dewatering said resultant fiber slurry , impregnating the fibers in said resultant fiber slurry with an aqueous solution of an alkaline hydroxide by adding said aqueous solution of an alkaline hydroxide to said resultant fiber slurry so as to produce a mixture of impregnated fibers and aqueous solution of an alkaline hydroxide and causing chemical digestion of said impregnated fibers by subjecting said mixture to a temperature in the range of about 330 to 380F and steam pressure in the range of about 100 to 150 psig