PROCESSING METHOD OF CELLULOSE-CONTAINING WASTES Russian patent published in 2019 - IPC D21C5/02 

FIELD: pulp industry.

SUBSTANCE: invention relates to preparation of pulp from cellulose-containing wastes, in particular from waste paper for production of paper and cardboard. At insignificant humidification of cellulose materials there is reduction of cutting effect at dry grinding, due to which number of fractions of fine fibers is reduced, which increases mechanical strength of produced cellulose material. Besides, mechanical properties of cardboard are increased due to separation of flow into long-fiber fraction and fraction of fine fibers. This provides the possibility of using the proposed method for production of large-capacity high-strength multilayer types of cardboard, including a multilayer test liner or white liner. Set task is achieved due to that in the method of processing cellulose-containing, comprising grinding in air with further removal of ground wastes through the chamber with vacuum, dispersing the ground wastes in an aqueous medium, adding auxiliary components, by grinding, characterized in that milling cellulose-containing wastes in air is carried out at moisture content of 10 to 20 % in two steps, namely, coarse grinding of cellulose-containing wastes and fine dispersion into fibers, after which dry fibers are separated into short and long-fiber fractions, wherein dispersion and grinding in water medium of long-fiber fraction is carried out directly at stages of wet preparation of mass, which is supplied to molding of lower layer of cardboard, and fraction of fine fibers is dispersed at stages of wet preparation, and then supplied to molding of upper layer of cardboard.

EFFECT: increased mechanical properties of cardboard (resistance to expansion, breaking length, breaking strength, modulus of elasticity) due to grinding of cellulose-containing wastes in air medium at low humidity (from 10 % to 20 %).

1 cl, 1 dwg, 1 tbl