Patent ID: 8888957

Claim:
A process for producing paper providing improved drainage and retention which comprises: (i) providing an aqueous suspension comprising cellulosic fibers, (ii) adding to the suspension after all points of high shear a drainage and retention aid comprising: a. a cationic starch having a degree of cationic substitution (DS C ) from 0.01 to 0.5, and a charge density of from about 0.05 to about 6.0 meq/g; b. an inorganic polymer P1 being a cationic polyaluminium chloride having a charge density in the range of from 2.5 to 10.0 meq/g; and c. a polymer P2 being an anionic polymer selected from anionic silica-based polymers comprising anionic silica-based particles having an average particle size in the range of from about 1 to about 10 nm; and (iii) dewatering the obtained suspension to form paper.