Patent ID: 8647472

Claim:
A method of papermaking having an increased filler content, the method comprising the steps of: adding a first flocculating agent to an aqueous dispersion of filler particles in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles, adding a second flocculating agent to the dispersion after adding the first flocculating agent in an amount sufficient to initiate flocculation of the filler particles in the presence of the first flocculating agent, the second flocculating agent being of opposite charge to the first flocculant, wherein no paper stock is present during the flocculation, combining the filler particles with a paper fiber stock, treating the combination with at least one strength additive selected from the group consisting of synthetic strength additives, and forming a paper mat from the combination, the paper fiber stock comprises a plurality of fibers and water, and the initiated flocculation enhances the performance of the strength additive in the paper mat, wherein the strength additive is not starch, wherein the first flocculating agent is a copolymer of acrylamide and sodium acrylate and wherein the first and second flocculating agents have an RSV of at least 2 dL/g.