Patent ID: 6228217
Filing Date: 2001-05-08
Classification: D21H

Abstract:
A process for preparing an aqueous papermaking suspension containing pulp fibers and a polyelectrolyte complex, comprising:a) providing an aqueous suspension comprised of pulp fibers and surface active carboxyl compounds;b) adding to the aqueous suspension a water-soluble cationic polymer and a water-soluble anionic polymer that are reactable in the aqueous suspension to form the polyelectrolyte complex, and a compound containing a multivalent cation having at least a +3 charge; andc) forming the polyelectrolyte complex;wherein said compound containing a multivalent cation is added at a level such as to provide an amount of cation equivalent on a molar basis to the amount of aluminum present in alum added at a level of from about 1.5% to about 6% based on the dry weight of pulp fibers.