METHOD OF PREPARING PULP FROM WASTE PAPER FOR MANUFACTURING PAPER AND CARDBOARD Russian patent published in 2000 - IPC

FIELD: paper-and-pulp industry. SUBSTANCE: invention, in particular, relates to technology of processing hard-to-repulp old paper banknotes and, more specifically, to preparing waste paper pulp for grinding required for manufacture of paper and cardboard. Waste paper is first repulped for 25-60 min at 30-60 C on hydropulper in presence of oxidant, preferably hydrogen peroxide, and then subjected to enzymatic treatment at pH 4.0-6.5 with enzyme complex from mutant Geotrichum candidum 3C-106 based on cellulases and hemicellulases containing at least 2 galactinases, 3 arabinases, 5 endo-1,4-beta-xylanases, 4 beta- xylodases, 4 beta-glucosidases, 2 alpha-galactosidases, and 2 beta- galactosidases in amounts ranging between 0.005 and 0.100% based on the weight of absolutely dry waste paper. EFFECT: enhanced process efficiency due to accelerated grinding of pulp, improved environmental characteristics of pulp due to removal of resins and reduced adhesion of fibers to resins.. 4 cl, 3 ex