Repulping wet-strength paper

A new repulping process that uses a nonchlorinated oxidizing agent and a rewetting agent was found to be very effective in repulping wet-strength paper that was difficult to break down. The process is particularly useful in repulping unbleached paper and old corrugated containers (OCC) containing polyaminoamide-epichlorohydrin (PAE) wet-strength resins. The process involves oxidizing the wet-strength paper at a low pH with inorganic or organic peroxides followed by hydrolyzing the wet-strength paper at a high levels of PAE resins was repulped to about 95% in mill hydropulpers. This process enables papermakers to defiber unbleached paper and OCC more efficiently than commonly practiced neutral or alkaline repulping processes.