Strength improvement of dry-formed paper by spraying of dry strength agent and hot pressing

摘要

This study was conducted to find a way of improving the strength of dry-formed paper made from mixed hardwood bleached kraft pulp. Cationic polyacrylamide (C-PAM) and oxidized starch solutions were sprayed to improve dry strength of dry formed paper. The effects of pressing pressure, pressing time and temperature on tensile strength and bulk when these two strength agents are applied were investigated. Application of hot pressing improved tensile strength and decreased the bulk reduction. Tensile strength of dry formed paper increased, reached a maximum and decreased with pressing time when no strength agent was applied. Spraying treatment of dry strength agents, C-PAM and oxidized starch, improved the tensile strength. Cationic PAM performed better for tensile improvement than oxidized starch.