| 摘要 |
<p>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 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 reflocculating system comprises (v) a siliceous material and (vi) a water soluble anionic polymer of intrinsic viscosity at least 4 dl/g, wherein the siliceous material and water soluble anionic polymer are added to the suspension simultaneously or by addition of the siliceous material before or after addition of the water soluble anionic polymer, the siliceous material (i) and water soluble anionic polymer (ii) are added to the cellulosic suspension subsequent to the centriscreen and the cationic polymer is added to thin stock stream of the cellulosic suspension.</p> |
