| abstract |
FIELD: paper-and-pulp industry. n SUBSTANCE: pulp for manufacturing mainly box-destination cardboard contains sulfite cellulose, wood-pulp, and secondary fiber. Sulfite cellulose is, more particularly, bisulfite cellulose bleached to 84-86% and having rigidity 30-35 Kappa units, tear resistance 430-460 mN, and punching resistance 430-460 mN. Such bisulfite cellulose is obtained by pulping mixture of softwood and foliferous wood at pH of cooking liquor 1.6-2.3, SO 2 concentration 6.0-6.5%, and temperature 145-152°C. Wood-pulp is the one subjected to chemical, thermal, and mechanical treatment and characterized by whiteness 72-75%. Secondary fiber is ground paper waste with specified degree of grinding, optionally in the form of blend of differently ground marks. n EFFECT: improved strength characteristics and reduced manufacturing expenses. n 4 cl, 1 tbl, 4 ex |