Recycled Pulp in Wet-Strength Grades Using Neutral/Alkaline-Curing Resins, 1991 Papermakers Conference Proceedings
This paper compares wet- and dry-strength effects of neutral-curing wet-strength resins in representative virgin and recycled pulps, both bleached and "higher-yield" (unbleached and CTMP blends). Although the papers from recycled pulps generally had less dry strength than those from comparable virgin pulps, their wet-strength response (as % wet/dry tensile) was generally good. The higher-yield pulps as a group, including CTMP blends, were more responsive than the bleached pulps. Combinations of resin with carboxymethylcellulose restored dry strength in recycled stock more in bleached than in higher-yield pulps. In some bleached stock, epoxide-type resins outperformed azetidinium type resins. In hypochlorite repulping of wet-strength broke, more strength is lost unavoidably in drying and redispersing the paper than from chemical degradation of the fibers.
Recycled Pulp in Wet-Strength Grades Using Neutral/Alkaline-Curing Resins, 1991 Papermakers Conferen