Kemira Oyj

Kemira Chemicals Oy

Kimmo Strengell

Matti Hietaniemi

Asko Karppi

Jonni Ahlgren

Jaakko Ekman

Marko Kolari

Mikko Virtanen

Anneli Lepo

Juan Cecchini

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.

Composition and method for manufacture of paper, board or the like

A method is disclosed for increasing strength properties, preferably burst strength and SCT strength, of a paper or board product. The paper or board product is manufactured from a fibrous web produced by a multilayer headbox, where an aqueous layer is formed between at least a first and a second fibre layer formed from fibrous stock suspension(s), and where feed water for the aqueous layer includes at least one cationic polymer. The method of the invention includes adding an anionic additive selected from a group comprising anionic synthetic organic polymers, anionic polysaccharides, and any of their combinations to the feed water before formation of the aqueous layer.

Method for increasing the strength properties of a paper or board product

A method for manufacture of paper, board or the like, comprising the step of dissolving a composition into aqueous solution, whereby an aqueous treatment solution is obtained for adding the obtained treatment solution to the pulp. The composition comprising a copolymer of acrylamide and at least one cationic monomer, the copolymer comprising cationic monomers at least 15 mol-%, calculated from total amount of monomers, and an ionic crosslinker agent comprising at least two carboxyl groups, wherein the equivalent ratio of carboxyl groups:cationic monomer is between 1:20 and 1:0.5.

Method for manufacture of paper, board or the like and use of the composition

The invention relates to a water-soluble polymer product in particle form, comprising amphoteric polyacrylamide, which is obtained by gel polymerisation of acrylamide together with anionic and cationic monomers. The amphoteric polyacrylamide has a mass average molecular weight MW of 1 500 000-6 000 000 g/mol, and a total ionicity of 4-15 mol-%, whereby the polymer product has a polymer content of at least 60 weight-%. The invention relates also to uses of the polymer product in paper and board making.

Polymer product in particle form and its use

The invention relates to a method for making of paper, tissue, board or the like by using recycled fiber material as a raw material. The method comprises following steps: pulping recycled paper, board or the like in a pulper and obtaining a pulp flow comprising (i) an aqueous phase and (ii) at least recycled fibers and starch having low molecular weight, which are dispersed in the aqueous phase; adding a coagulant agent to the pulp flow or to an aqueous process flow comprising starch having low molecular weight; allowing the coagulant agent to interact with the starch having low molecular weight and optionally forming aggregates; and adding at least one flocculating agent, after the addition of the coagulant agent, to any flow, which comprises interacted coagulant agent, and forming a treated flow with starch comprising agglomerate(s); retaining at least part of the said aggregates and/or the said agglomerates to the fibers or to a web, which is formed.

Method for making of paper, tissue, board or the like

The invention relates to a process for manufacturing paper, in which a filler is pretreated and suspended to form an aqueous slurry, the aqueous slurry obtained is combined with an aqueous suspension containing cellulose fibers to form a stock, the stock obtained is treated at least with a cationic retention agent and the treated stock is filtered to form paper. Retention and optical properties are improved by the filler being pre-treated with inorganic colloidal particles having an average size less than 100 nm.

Process for manufacturing of paper

The invention relates to a method for the production of paper or board, wherein retention aids are added to the stream of stock. Improved retention and more effective dewatering are achieved by adding to the stream of stock a cationic polymer solution and a suspension-form microparticle mixture composed of a swellable clay of the smectite group and a colloidal synthetic metal silicate in which the prevalent cation is magnesium.

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Espoo, Finland

Kimmo Strengell