This invention relates to a method for manufacturing a sheet of paper or cardboard, according to which, before forming said sheet, at least one N-vinylformamide polymer that is partially hydrolyzed in the form of an inverse emulsion is added, at one or more injection points, to a fibrous suspension in the presence of an anti-gelling agent, and having a cationic regain between 30 and 150%, the inverse emulsion having a weight ratio of partially hydrolyzed N-vinylformamide polymer to anti-gelling agent in the range between 1,000,000/5000 and 1,000,000/50,000.

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 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.

The present invention relates to a gas barrier film for a paper or paperboard based packaging material, said gas barrier film comprising: a microfibrillated cellulose layer (MFC layer), at least one surface of which has been metallized; and a polymer dispersion coating layer disposed on at least one surface of the MFC layer. The present invention further relates to a paper or paperboard based packaging material, containers and carton blanks comprising the gas barrier film, and to a method for manufacturing the gas barrier film.

The present invention relates to a method for preparing loaded paper pulp for use in the manufacture of paper or paper board. At least one process stream containing a plurality of unrefined pulp fibers and at least one process stream of at least one filler are combined in a refiner to form a loaded paper pulp composition having a plurality of surface enhanced pulp fibers that are loaded with particles of the at least one filler.

The present invention relates to a method for preparing loaded paper pulp for use in the manufacture of paper or paper board. At least one process stream containing a plurality of unrefined pulp fibers and at least one process stream of at least one filler are combined in a refiner to form a loaded paper pulp composition having a plurality of surface enhanced pulp fibers that are loaded with particles of the at least one filler.

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.

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.

This invention relates to an additive based on (co)polymers resulting from the reaction between at least one dialdehyde compound and at least one complex (co)polymer obtained by polymerization of water-soluble monomers in the presence of at least one host (co)polymer comprising vinylamine functions.

The present invention relates to a method and an arrangement for dissolving starch. Specifically, the present invention relates to a method for dissolving starch by introducing mechanical force to at least partially gelatinized agueous starch.