The invention relates to a method for treating starch in pulp, paper and board making processes, in which processes recycled fibre material is used as raw material wherein the recycled fibre material is pulped in a pulper and obtaining a pulp flow comprising an aqueous phase and at least recycled fibres and starch dispersed in the aqueous phase. The method comprising the following steps: adding amylase enzyme inhibitor and/or at least one biocide to pulp flow or to an aqueous process flow comprising starch for preventing starch degradation, andadding an amphoteric polymer obtained by copolymerisation of (meth)acrylamide with cationic and anionic monomers to pulp flow or to an aqueous process flow comprising starch for binding starch to the fibres.

The invention relates to a method for treating starch in pulp, paper and board making processes, in which processes recycled fibre material is used as raw material wherein the recycled fibre material is pulped in a pulper and obtaining a pulp flow comprising an aqueous phase and at least recycled fibres and starch dispersed in the aqueous phase. The method comprising the following steps: adding amylase enzyme inhibitor and/or at least one biocide to pulp flow or to an aqueous process flow comprising starch for preventing starch degradation, andadding an amphoteric polymer obtained by copolymerisation of (meth)acrylamide with cationic and anionic monomers to pulp flow or to an aqueous process flow comprising starch for binding starch to the fibres.

To provide a new inorganic particle composite fiber including a large amount of adhering inorganic particles, An inorganic particle composite fiber includes: fiber; and inorganic particles fixed to the fiber, the fiber being thread-like in shape, the inorganic particles being fixed to the fiber via an ionic polymer.

To provide a new inorganic particle composite fiber including a large amount of adhering inorganic particles, An inorganic particle composite fiber includes: fiber; and inorganic particles fixed to the fiber, the fiber being thread-like in shape, the inorganic particles being fixed to the fiber via an ionic polymer.

The present invention relates to a copolymer comprising at least one hydrophilic monomer; at least one hydrophobic monomer and at least 10% by weight of methyl styrene, particularly suitable to be used as detackifying agent for reducing negative effects caused by natural pitch and/or adhesive contaminants in both pulping and papermaking operations.

The present invention relates to a copolymer comprising at least one hydrophilic monomer; at least one hydrophobic monomer and at least 10% by weight of methyl styrene, particularly suitable to be used as detackifying agent for reducing negative effects caused by natural pitch and/or adhesive contaminants in both pulping and papermaking operations.

The invention relates to a chemical treatment system for manufacture of paper, board or the like and to a method employing it. The system comprises a first component, which is a glyoxylated polyacrylamide having a net cationic charge density and obtained by glyoxylation of a cationic polyacrylamide base polymer having a weight average molecular weight MW in a range of 30 000-500 000 g/mol. The system further comprises a second component, which comprises a mixture of at least a high-amylopectin starch, and an anionic first polymer, which has a weight average molecular weight MW>200 000 g/mol. The second component has a net cationic charge density in a range from 0.05 meq/g to 0.9 meq/g, when measured at pH 2.8, and a net anionic charge density in a range from ?2 meq/g to ?0.1 meq/g, when measured at pH 7.

The invention relates to a chemical treatment system for manufacture of paper, board or the like and to a method employing it. The system comprises a first component, which is a glyoxylated polyacrylamide having a net cationic charge density and obtained by glyoxylation of a cationic polyacrylamide base polymer having a weight average molecular weight MW in a range of 30 000-500 000 g/mol. The system further comprises a second component, which comprises a mixture of at least a high-amylopectin starch, and an anionic first polymer, which has a weight average molecular weight MW>200 000 g/mol. The second component has a net cationic charge density in a range from 0.05 meq/g to 0.9 meq/g, when measured at pH 2.8, and a net anionic charge density in a range from ?2 meq/g to ?0.1 meq/g, when measured at pH 7.

The invention relates to an aqueous dry strength composition suitable for use in manufacture of paper, board or the like. The composition includes a mixture of a synthetic polymer component, which is a copolymer of acrylamide and at least one anionic monomer, and a cationic starch component. The polymer component has an anionicity of 1-60 mol-%. The synthetic polymer component and cationic starch component provide the composition with a charge density in the range of 0.05-1 meq/g, when measured at pH 2.8, and 0.2-3 meq/g, when measured at pH 7.0. The invention also relates to a method for making of paper, board or the like, where the dry strength composition is diluted with water, and the solution of the dry strength composition is added to the fibre stock before or after the addition of a cationic strength agent.

The invention relates to an aqueous dry strength composition suitable for use in manufacture of paper, board or the like. The composition includes a mixture of a synthetic polymer component, which is a copolymer of acrylamide and at least one anionic monomer, and a cationic starch component. The polymer component has an anionicity of 1-60 mol-%. The synthetic polymer component and cationic starch component provide the composition with a charge density in the range of 0.05-1 meq/g, when measured at pH 2.8, and 0.2-3 meq/g, when measured at pH 7.0. The invention also relates to a method for making of paper, board or the like, where the dry strength composition is diluted with water, and the solution of the dry strength composition is added to the fibre stock before or after the addition of a cationic strength agent.