Manufacture of paper and paperboard

摘要

A process of making paper or paper board comprising forming a cellulosic suspension, flocculating the suspension, mechanically shearing the suspension and optionally reflocculating the suspension, draining the suspension on a screen to form a sheet and then drying the sheet,wherein the suspension is flocculated or reflocculated by introducing a water-soluble polymer of intrinsic viscosity above 3 dl/g into the suspension, characterized in that the water soluble polymer exhibits a rheological oscillation value of tan delta at 0.005 Hz of above 1.1. The process has the advantage of improving retention.