METHOD OF MANUFACTURING PAPER PULP Russian patent published in 1999 - IPC

FIELD: pulp-and-paper industry. SUBSTANCE: invention relates to production of printer's paper using modified aluminum sulfate (coagulant) and water-soluble synthetic polymers and copolymers as flocculants. Water-fibrous dispersion of cellulose fiber is prepared, which is supplemented and glued with colophony glue. Paper pulp is then neutralized with aluminum sulfate (coagulant) preliminarily combined with cationic polyelectrolyte to pH 6.0-6.5. pH value is adjusted to 7-8 and precipitation with coagulant and flocculant is performed. As flocculant, following substances are utilized: polysulfone-pyrrolidinium chloride, MW 2500-3000; copolymer of methacrylamide with methacrylic acid ammonium salt, MW 10000-100000; piperylene-methacrylic acid copolymer, MW 10000; and piperylene- acrylonitrile copolymer, MW 10000. EFFECT: enhanced efficiency of paper production, increased degree of paper pulp and kaolin retention, improved physico-chemical characteristics of paper, and reduced specific consumption of wood. 2 cl, 1 tbl, 5 ex