METHOD OF MANUFACTURING PRINTING PAPER Russian patent published in 1998 - IPC

FIELD: pulp-and-paper industry. SUBSTANCE: kaolin is treated by carboxymethylcellulose in aqueous medium under stirring. Resulting kaolin suspension is supplemented with chlorine-containing substance and mixed with fibrous intermediate product suspension, after which paper web is formed and dried. According to invention, treatment of kaolin is conducted with stirring intensity corresponding to Reynolds number 72000-78000, and chlorine-containing substance is added at 40-50 C. The latter substance employs sodium or potassium chloride aqueous solution, amount of salt constituting 3.3 to 13.3% based on weight of dry carboxymethylcellulose. When kaolin is treated, weight ratio of kaolin, carboxymethylcellulose, and alkali metal chloride ranges from 1:0.05:0.003 to 1.66:0.11:0.007, carboxymethylcellulose being taken in amount 5.0-10.0% on weight of absolutely dry kaolin. EFFECT: improved quality of paper due to improved physico-mechanical characteristics and optimally increasing closeness of sheet. 3 cl, 2 tbl