Wet Strength Paper Repulping: Effect of Process Variables

The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables such as repulping time, pulp stock concentration, soaking time, temperature, and reactant concentration in the repulping stage were examined using a Plackett- Burman design. The repulping time was the most crucial and influential process variable affecting repulping characteristics and formation related properties. The other repulping process variables having a significant effect on pulp yield were soaking temperature and pulp stock concentration, whereas for formation index and feature-size, pulp stock concentration, soaking temperature and time were important variables. The formation index was increased by an increase in repulping time, pulp stock concentration and soaking time whereas the feature-size was decreased by an increase in repulping time, soaking temperature and pulp stock concentration. The formation index and the rejects were more sensitive to changes in process variables than the feature-size.