Compositions and colloidal particles are provided that may be used to improve a papermaking process. The compositions and colloidal particles may include a polymer and an inorganic salt. A papermaking process carried out using the presently disclosed compositions and colloidal particles may produce a paper product that has increased strength properties.

Compositions and colloidal particles are provided that may be used to improve a papermaking process. The compositions and colloidal particles may include a polymer and an inorganic salt. A papermaking process carried out using the presently disclosed compositions and colloidal particles may produce a paper product that has increased strength properties.

An aqueous prepolymer composition, which comprises a polyacrylamide base polymer comprising 10 - 40 mol-% of cationic monomers and having a weight average molecular weight Mw in the range of 120 000 - 350 000 g/mol, 0.1 - 1 weight-% of glyoxal, calculated from the total weight of the aqueous prepolymer composition, and a buffering acid for adjusting pH of the composition in the range of 2 - 4. A prepolymer composition is used in a method for producing on-site glyoxylated polyacrylamide useful in paper or board manufacturing.

A papermaking agent exhibiting an excellent freeness and paper strength effect with little increase in viscosity after long-term storage. A papermaking agent including a (meth)acrylamide polymer containing two or more starches (a1) selected from the group consisting of unmodified starch, oxidized starch, esterified starch, etherified starch, amidated starch, cationic starch, amphoteric starch and crosslinked starch, a (meth)acrylamide (a2), a polymerizable monomer having an amino group (a3), a polymerizable monomer having a carboxy group (a4) and a polymerizable monomer having a sulfonate group (a5) as essential constituent components.

A papermaking agent exhibiting an excellent freeness and paper strength effect with little increase in viscosity after long-term storage. A papermaking agent including a (meth)acrylamide polymer containing two or more starches (a1) selected from the group consisting of unmodified starch, oxidized starch, esterified starch, etherified starch, amidated starch, cationic starch, amphoteric starch and crosslinked starch, a (meth)acrylamide (a2), a polymerizable monomer having an amino group (a3), a polymerizable monomer having a carboxy group (a4) and a polymerizable monomer having a sulfonate group (a5) as essential constituent components.

The present invention provides aqueous compositions for treating fluff pulp comprising (i) one or more acrylic acid polymers containing phosphinate groups and having a weight average molecular weight of from 1,000 to 6,000 and (ii) from 5 to 50 wt. %, based on the total solids weight of the aqueous compositions, of one or more polyethylene glycols, having a formula weight of from 150 to 7,000, or, preferably, from 200 to 600. The present invention also provides individualized, intrafiber crosslinked cellulosic fibers comprising the cellulosic fiber and, in cured form, the aqueous compositions, as well as methods of making the individualized, intrafiber crosslinked cellulosic fibers.

In a method for preparing glyoxylated polyacrylamide, in which an aqueous solution of polyacrylamide is supplemented with ethanediol (glyoxal) under stirring by means of a circulation pump, the reaction is started by the addition of a base, at a basic pH value above 8, and is allowed to react under stirring and/or circulating, whereupon the reaction is stopped by the addition of an acid under stirring and/or circulating after completion of a predetermined reaction time, wherein the method is performed as a discontinuous method in which the quantitative reaction of ethanediol with an excess amount of polyacrylamide in an aqueous basic medium is controlled and/or regulated by at least one, of the following factors:

a) turbidity measurement
b) pH adaptation as a function of the temperature
c) pH adaptation as a function of the reaction time
d) drop of pH the value, or
e) current consumption of the circulation pump.

The present invention relates to a method for producing a cationic polyvinyl amine based copolymer. The present invention further relates to a cationic polyvinyl amine based copolymer and use of the copolymer in paper industry as a strength agent, a retention agent and a drainage agent.

The present invention relates to a method for producing a cationic polyvinyl amine based copolymer. The present invention further relates to a cationic polyvinyl amine based copolymer and use of the copolymer in paper industry as a strength agent, a retention agent and a drainage agent.

Methods of forming crosslinked cellulose include mixing a crosslinking agent with cellulose mat fiber fragments composed of hydrogen-bonded cellulose fibers and having a solids content of about 45-95% to form a substantially homogenous mixture of non-crosslinked, individualized cellulose fibers, drying the resulting mixture to 85-100% solids, then curing the dried mixture under conditions effective to crosslink the cellulose fibers. Some of such methods may include fragmenting a cellulose fiber mat to form the mat fragments. Systems include a mixing unit (such as a high-consistency mixer) configured to form, from the mat fragments and a crosslinking agent, a substantially homogenous mixture of non-crosslinked, individualized cellulose fibers and crosslinking agent, at ambient conditions, a drying unit to dry the substantially homogenous mixture to a consistency of 85-100%, and a curing unit and to cure the crosslinking agent to form dried and cured crosslinked cellulose fibers.