Patent ID: 8038846

Claim:
A process for making paper or paperboard, comprising: forming a cellulosic suspension; passing the cellulosic suspension through one ore more shear stages; draining the cellulosic suspension on a screen to form a sheet; and drying the sheet; wherein the cellulosic suspension is flocculated before draining by adding a flocculation system comprising greater than or equal to 0.01 percent by weight of: an organic micropolymer in an inorganic salt solution, and an inorganic siliceous material; wherein the organic micropolymer and the inorganic siliceous material are added after one of the shear stages; wherein the organic micropolymer and the inorganic siliceous material are added simultaneously or sequentially; wherein the flocculation system further comprises an organic water-soluble flocculant material comprising a substantially linear synthetic cationic, non-ionic, or anionic polymer, having molecular weight greater than or equal to 500,000 atomic mass units, that is added to the cellulosic suspension before the shear stage in an amount such that flocs are formed; wherein the flocs are broken by the shearing to form microflocs that resist further degradation by the shearing, and that carry sufficient anionic or cationic charge to interact with the siliceous material and the organic micropolymer to give better retention than that which is obtained when adding the flocculation system after the last point of high shear without first adding the flocculant material to the cellulosic suspension; wherein percent by weight is based on the total weight of the dry cellulosic suspension wherein the organic micropolymer is an organic water soluble, anionic or cationic, water-in-water or dispersion micropolymer composition.