Patent ID: 6454902
Filing Date: 2002-09-24
Classification: D21H

Abstract:
A process for making paper or paper board comprising forming a cellulosic suspension, flocculating the suspension, draining the suspension on a screen to form a sheet and then drying the sheet, wherein the cellulosic suspension is flocculated by the addition of a water soluble cationic synthetic polymer of intrinsic viscosity of at least 4 dl/g, wherein the flocculated cellulosic suspension is subjected to mechanical shearing and then reflocculated by a subsequent addition of a reflocculating system, and in which the reflocculating system comprisesi) a siliceous material and ii) a water soluble anionic polymer of intrinsic viscosity at least 4 dl/g, and in which the siliceous material (i) and water soluble anionic polymer (ii) are added to the cellulosic suspension subsequent to the centriscreen and wherein the cationic polymer is added to a thin stock stream of the cellulosic suspension.