Manufacture of paper and paperboard

摘要

According to the present invention a process is provided 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, characterized in that the suspension is flocculated using a flocculation system comprising a siliceous material and organic microparticles which have an unswollen particle diameter of less than 750 nanometers.