Patent ID: 8454796
Filing Date: 2013-06-04
Classification: D21H

Abstract:
1. A process of making filled paper comprising the steps of: providing a thick stock cellulosic suspension that contains mechanical pulp and filler; diluting the thick stock cellulosic suspension to form a thin stock suspension, wherein the filler is present in the thin stock suspension in an amount of at least 10% by weight based on a dry weight of the thin stock suspension; flocculating the thin stock suspension by adding a polymeric retention/drainage system; draining the thin stock suspension on a screen to form a sheet; and then drying the sheet, thereby making paper, wherein the polymeric retention/drainage system comprises, i) a water-soluble branched anionic polymer; and ii) a water-soluble cationic or amphoteric polymer; wherein the anionic polymer is present in the thick stock or thin stock suspension prior to the addition of the cationic or amphoteric polymer.