초록 ▼

Producing polymer dispersions for use in papermaking with a relatively high content of a solubilized polymeric material which serves in the presence of paper filler as binder and dissolves only with difficulty, by continuously passing an aqueous suspension of the particulate binder through a treatme

Producing polymer dispersions for use in papermaking with a relatively high content of a solubilized polymeric material which serves in the presence of paper filler as binder and dissolves only with difficulty, by continuously passing an aqueous suspension of the particulate binder through a treatment zone (2,3,4) in at least part of which it is subjected to shear, the rate of flow and degree of shear being such that the residence time in the zone allows optimum swelling of the binder and the resulting solution of polymeric binder is visually homogeneous. Flocculant and filler are preferably also incorporated to provide a continuous supply of preflocculated filler for a papermaking furnish. Typical materials are cold water soluble starch as binder, polyacrylamide as flocculant and chalk whiting as filler.

대표청구항 ▼

In a method of supplying filler to a papermaking furnish which comprises the steps of forming preflocculated filler and then adding it to papermaking furnish, the improvement which comprises forming the preflocculated filler by continuously forming a suspension of polymeric binder in particulate for

In a method of supplying filler to a papermaking furnish which comprises the steps of forming preflocculated filler and then adding it to papermaking furnish, the improvement which comprises forming the preflocculated filler by continuously forming a suspension of polymeric binder in particulate form in water in which the concentration of the binder solids in the suspension is at least 0.5 percent by weight, said binder being a starch-based polymer; continuously passing the formed suspension through a zone wherein the suspended particulate polymeric binder is allowed to swell in the water and is subjected to shear; regulating the rate of continuous flow of the resulting dispersion through the zone, and the degree of shear applied, so that the residence time of the dispersed polymeric binder in the zone is at least sufficient for optimum swelling of said polymeric binder in the water and the resulting solution of polymeric binder in the water is visually homogeneous; continuously passing said solution to the papermaking furnish; and introducing filler into the water sufficiently in advance of contact of said solution with the papermaking furnish such that said filler is preflocculated prior to contact thereof with the papermaking furnish.