A product includes a microfibrillated cellulose composition, a starch derivative, and an anionic cellulose derivative, as a combined preparation for simultaneous or separate use. The anionic cellulose derivative has a number average molecular weight comprised between 300000 g/mol and 800000 g/mol, and a degree of substitution comprised between 0.3 and 0.65. Additionally, a paper sheet includes the product as an additive to increase the initial wet web strength and/or dry tensile strength of the paper sheet.

A softener composition for use in the manufacture of paper includes a softener and an acidic material, wherein the softener composition has a relative acidity (RA) value of more than 0.05.

A relatively inexpensive papermaking agent having a high concentration and a high molecular weight that exhibits an excellent freeness and paper strength effect obtained using starches which are biomass materials. A papermaking agent which is a (meth)acrylamide polymer containing starches (a1), 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, wherein the ratio between the amount of the component (a1) used in terms of non-volatile content weight and a total amount of the components (a2) to (a5) used is [(a1)/{(a2)+(a3)+(a4)+(a5)}]=5/95 to 45/55, and wherein the (meth)acrylamide polymer has a non-volatile content concentration of 22 to 35 weight %, and a weight average molecular weight of 1,500,000 to 7,000,000.

A paper-strengthening agent comprising an amphoteric (meth)acrylamide polymer and an amphoteric (meth)acrylamide polymer, wherein each of constituent monomers of the amphoteric (meth)acrylamide polymer and the amphoteric (meth)acrylamide polymer comprises (meth)acrylamide, a cationic unsaturated monomer, an anionic unsaturated monomer, and a crosslinkable unsaturated monomer, and has a specific weight-average molecular weight, and wherein each viscosity of the paper-strengthening agent, the polymer, and the polymer satisfies a specific relationship.

The present invention relates to a complex of polymers and to the use thereof in a method of making paper, cardboard or the like. This complex of polymers is obtained by polymerizing water-soluble monomers: in the presence of a host polymer that comprises vinylamine functions and of a non-polymeric transfer agent, and in the absence of a branching or crosslinking agent of the ethylenic polyfunctional type. It is obtained as from a mass ratio of anionic monomer to water that is greater than 0.035.

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.

Disclosed is method for on-site glyoxylation of polyacrylamide in a paper or board mill, where a discontinuous batch glyoxylation reaction of aqueous reaction mixture is performed in reactor vessel having driven agitator to form aqueous polymer composition comprising glyoxylated polyacrylamide. The method comprises forming or obtaining the aqueous reaction mixture comprising polyacrylamide base polymer and glyoxal, determining alkali consumption of the mixture, and adding to the mixture, based on determined alkali consumption, pre-determined amount of alkali for adjusting pH to 8-10. The temperature is optionally adjusted to 15-40° C. and the on-site glyoxylation reaction of polyacrylamide base polymer is allowed to proceed. Viscosity of the mixture and/or a variable related to the viscosity is measured, acid is added to the mixture for lowering pH to <8, when a predetermined end viscosity value is attained, and the aqueous polymer composition comprising glyoxylated polyacrylamide is removed from the reaction vessel.

A method of reducing contaminants in a pulp or papermaking process includes the steps of: providing a lignocellulosic pulp comprising lignocellulosic fibers and at least one hydrophobic contaminant; providing a cationic polymer; providing a cleaning blend comprising a vegetable oil alkyl ester and at least one surfactant; and applying the cationic polymer and the cleaning blend to the lignocellulosic pulp to reduce a content of the at least one hydrophobic contaminant in the pulp or papermaking process.

A method is provided for generating aldehyde-functionalized polymers such as GPAM, wherein progress of the aldehyde-functionalized polymer formation is monitored by measuring viscosity using an online viscometer. A method is also provided for enhancing paper strength, said method comprising generating an aldehyde-functionalized polymer, such as GPAM, according to the present disclosure, and combining said aldehyde-functionalized polymer with a fiber slurry or applying it to a paper sheet.

The invention relates to a composition and method for manufacture of paper, board, tissue or the like. The composition comprises an amphoteric polymer component, which has a weight average molecular weight of at least 600 000 g/mol, preferably at least 1 000 000 g/mol, more preferably at least 2 000 000 g/mol, and at least one synthetic cationic polymer component, which is a copolymer of a polyamidoamine and has a weight average molecular weight ≤550 000 g/mol, preferably ≤500 000 g/mol, more preferably ≤400 000 g/mol and dispersity index more than 15, preferably more than 20, more preferably more than 25.