Patent ID: 6168686
Filing Date: 2001-01-02
Classification: D21H

Abstract:
A process to improve the drainage rate and retention of fines during papermaking with a mechanical pulp-based furnish substantially free of fillers in a papermaking process substantially free of silica and/or bentonite while maintaining sheet formation properties comprising the steps of: A. adding to an aqueous paper furnish containing pulp, sequentially or in combination: (i) from about 1 to about 50 lbs/ton of a cationic or amphoteric starch; and (ii) either about 0.1 to about 10 lbs/ton of a cationic organic polyelectrolyte or from about 2.5 to about 10 lbs/ton of a cationic inorganic polyelectrolyte; and thereafter B. adding to said aqueous paper furnish containing pulp and said cationic or amphoteric starch and said cationic polyelectrolyte, from about 0.25 to about 0.75 lbs/ton of a high molecular weight anionic acrylamide copolymer, wherein the molecular weight of said anionic acrylamide copolymer is greater than about 10,000,000; wherein in said process no fillers are added to the mechanical pulp-based furnish.