Kemira Oyj

Jennifer Riser

Yuping Luo

Junhua Chen

Zheng Dang

Ronald Robinson

Jaakko Hiltunen

Timo Valkealaakso

Barbara Lukasik

Kirsi Terava

Andrew Pencek

A method for preparation of a starch-promoted alkyl ketene dimer (AKD) sizing emulsion is provided. The inventive method comprises adding a sizing promoter comprising high-charge cationic starch and polyaluminum chloride (PAC) to a stabilized AKD emulsion and further wherein addition of said sizing promoter comprising high-charge cationic starch and PAC is effected at ambient temperature, after emulsification, stabilization, and homogenization of said stabilized AKD emulsion; and prior to addition of the starch-promoted AKD sizing emulsion to papermaking furnish, pulp, or fiber stock.

High cationic starch as a promoter in AKD sizing emulsions

The present invention provides a novel method and composition for enhancing the efficiency of starch adsorption (i.e., starch trapping) from starch-containing furnishes comprising high content of recycled fibers for use in paper making processes such as pulp, paper, or board production. A novel polymer coagulation system is disclosed in which two quick inversion cationic emulsion polymers (starch trapping polymers A and B) are co-mixed at optimal blend ratios to meet specific recycled fiber and process water requirements for different recycled fiber plants and added to furnishes prior to formation of paper or board in a paper machine. Co-mixed solutions of starch trapping polymers A and B provide synergistic enhancements in (i) starch trapping efficiency and (ii) starch retention in the produced paper or board over equivalent dosage levels of singly administered polymer A, polymer B, or conventional starch trapping products, without over-flocculation or formation of stickies.

Starch fixation and retention in recycled fiber systems

A method for manufacture of paper or board, in which method an inverted solution of cationic polymer is added to the fiber suspension for providing retention enhancement without over-flocculating fiber stock and destruction sheet formation and/or improving drainage and enhancing or at least maintaining strength of paper or board, An inverted solution has a bulk viscosity of 50-150 mPas at 0.2 weight-% cationic polymer concentration and inverted solution comprises cationic polymer obtained by reverse phase emulsion polymerization of a monomer blend comprising non-ionic monomers, 15-50 mol-% cationic monomers, an optionally at most 50 ppm of a crosslinking agent, and a chain transfer agent, and the obtained reverse phase emulsion of cationic polymer is inverted into an aqueous solution.

Method for manufacture of paper or board and paper or board obtained by the method

A surface treatment composition is disclosed including anionic polyacrylamide, which has a weight average molecular weight, MW, in the range of 100 000-2 000 000 g/mol, and free glyoxal. Further disclosed is a use of the surface treatment composition, a method for producing paper, board or the like and a paper product.

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Marietta, GA, United States of America

Jennifer Riser