A strength additive system for manufacturing paper, board, tissue or the like includes preferably as separate components, a cationic strength agent, such as a cationic polymer with aldehyde functional groups, and an anionic copolymer obtained by polymerization of a reaction mixture including (meth)acrylamide and anionic monomers, the standard viscosity of the obtained copolymer being in a range of 1.5-5.0 mPas. A method for manufacturing of a paper, board, tissue or the like is further disclosed.

The invention relates to an aqueous composition comprising (a) polymers having primary amino groups and/or amidine groups to a combined content for these groups of ≧1.5 meq/g of polymer, and (b) 0.01 to 50 mol % of 1,4-cyclohexanedione (b) based on the combined amount of primary amino groups and amidine groups of the polymers,
wherein the pH of the aqueous composition is ≦6,
and further to its use as strength enhancer and to a method of producing paper and board, employment of the aqueous composition and also the paper and board thus obtained.

Methods for producing paper or cardboard are provided that comprise the steps (A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created, wherein the final polymer A is obtainable by radical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; and hydrolysing the starting polymer V in order to obtain the final polymer A, (B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.

Methods for producing paper or cardboard are provided that comprise the steps (A) adding a final polymer A to a first aqueous fibrous material suspension, whereby a second aqueous fibrous material suspension containing final polymer A is created, wherein the final polymer A is obtainable by radical polymerisation of the monomers (i), (ii), (iii), (iv), and (v) as described herein in the amounts provided herein; and hydrolysing the starting polymer V in order to obtain the final polymer A, (B) dewatering the second aqueous fibrous material suspension containing final polymer A on a water-permeable substrate to form a wet paper structure, (C) dewatering the wet paper structure, whereby the paper or the cardboard is formed.

A dry strength composition for manufacture of paper, board or the like is disclosed. The dry strength composition includes, as a mixture, at least one anionically derivatized polysaccharide, and cationic starch having an amylopectin content ≥80 weight-%. The anionically derivatized polysaccharide and the cationic starch provide the composition with a charge density in a range of 0.1-1.5 meq/g, when measured at pH 2.8, and −0.1-−3 meq/g, preferably −0.3-−2.5 meq/g, more preferably −0.5-−2.0 meq/g, when measured as an aqueous solution, at pH 7.0. Further disclosed are a use of the composition and a method for manufacturing paper, board or the like.

A dry strength composition for manufacture of paper, board or the like is disclosed. The dry strength composition includes, as a mixture, at least one anionically derivatized polysaccharide, and cationic starch having an amylopectin content ≥80 weight-%. The anionically derivatized polysaccharide and the cationic starch provide the composition with a charge density in a range of 0.1-1.5 meq/g, when measured at pH 2.8, and −0.1-−3 meq/g, preferably −0.3-−2.5 meq/g, more preferably −0.5-−2.0 meq/g, when measured as an aqueous solution, at pH 7.0. Further disclosed are a use of the composition and a method for manufacturing paper, board or the like.

Embodiments of the present invention relate to a method of making a paper comprising the steps of: a) providing a cationic wet strength resin comprising a polyamidoamine epihalohydrin, a condensation copolymer of epihalohydrin and amine, or combination thereof; b) providing an anionic polymer; c) co-mixing the cationic wet strength resin and the anionic polymer to provide a composition comprising polyelectrolyte complexes; d) providing an aqueous pulp slurry, draining the aqueous pulp slurry on a screen to form a wet fiber web, and drying the wet fiber web to obtain the paper, wherein said co-mixed composition is introduced to the aqueous pulp slurry or on the formed wet fiber web. Embodiments of the present invention further relates to a paper wet strength composition, its use in paper making and a paper obtainable therefrom.

Embodiments of the present invention relate to a method of making a paper comprising the steps of: a) providing a cationic wet strength resin comprising a polyamidoamine epihalohydrin, a condensation copolymer of epihalohydrin and amine, or combination thereof; b) providing an anionic polymer; c) co-mixing the cationic wet strength resin and the anionic polymer to provide a composition comprising polyelectrolyte complexes; d) providing an aqueous pulp slurry, draining the aqueous pulp slurry on a screen to form a wet fiber web, and drying the wet fiber web to obtain the paper, wherein said co-mixed composition is introduced to the aqueous pulp slurry or on the formed wet fiber web. Embodiments of the present invention further relates to a paper wet strength composition, its use in paper making and a paper obtainable therefrom.

The present invention relates to an enhanced process for the production of cellulose pulps with increased quality and applicability of said pulps, especially their physical resistance properties and degree of resistance to drainage, through an enzymatic treatment step comprised in the production process of said cellulose pulp, concomitantly with the polymer dosage based on carbohydrates.

The present invention relates to an enhanced process for the production of cellulose pulps with increased quality and applicability of said pulps, especially their physical resistance properties and degree of resistance to drainage, through an enzymatic treatment step comprised in the production process of said cellulose pulp, concomitantly with the polymer dosage based on carbohydrates.