Kemira Oyj

Stora Enso Oyj

Upm-Kymmene Corporation

Matti Hietaniemi

Asko Karppi

Mikko Virtanen

Rosa Carceller

Kimmo Strengell

Jaakko Ekman

Sacha Legrand

Joonas Likander

Marko Kolari

Vladimir A Grigoriev

Marco Polverari

Jyri Välimäki

Jonni Ahlgren

Anneli Lepo

Jukka Rautiainen

Kari Vanhatalo

Perttu Heiska

Elias Retulainen

Jonas Konn

Tom Lundin

Lenita Lindberg

Marcus Lillandt

Jan-Luiken Hemmes

Juan Cecchini

Erkki Hellen

Vladimir Grigoriev

Mika Suvanto

Maarit Latvanen

Elsa Olmos

Daniel Nuno Da Rita Santos

Emmi Saranpää

Joonas Hokka

Asko Koskimäki

Mari Zabihian

Josep Lluis Bisbal

Terhi Saari

Katariina Torvinen

Salla Timperi

Martina Halinen

Kristian Salminen

Janne Kataja-Aho

Daniel Nuno Santos

Erkki HELLÉN

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.

Method for on-site glyoxylation of polyacrylamide

The invention relates to a composition for use in a manufacture of paper, board or the like. The composition comprises a mixture of cationic starch having amylopectin content of at least 85%, and an amphoteric polymeric structure comprising structural units originating from non-ionic monomers, preferably (meth)acrylamide, anionic groups and cationic groups, the polymeric structure comprising cationic groups at least 0.2 mol-%.

Composition and its use for use in manufacture of paper, board or the like

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 aqueous starch.

Method for dissolving starch

A method for manufacturing a multi-layered fibrous web is disclosed, which includes at least two fibrous layers, where each layer is formed from one or more fibre stocks. The fibrous layers are combined prior to subjecting the multilayered fibrous web to wet-pressing and drying. At least one layer of the multi-layered fibrous web is formed from a fibre stock including at least 50 weight-% of a chemi-thermomechanical pulp (CTMP), a hardwood kraft pulp and/or a recycled fibre material calculated from a thick stock applied to a particular layer approach system. A first strength component and a second strength component are added to the fibre stock. The first strength component includes a cationic strength agent and the second strength component includes a synthetic amphoteric polymer composition having a net charge from &#x2212;3 to +1 meq/g (dry), at a pH of 7.

Method for manufacturing multi-layered fibrous web and multi-layered fibrous web

A method is disclosed for treating aqueous feed by dissolved gas flotation. The aqueous feed originates from industrial processing of fibrous material, where the aqueous feed includes an aqueous phase and solid particulate material suspended in the aqueous phase. The method includes bringing a flocculant in contact with the aqueous feed, flocculating suspended solid particulate material into flocs and contacting formed flocs with gas bubbles and inducing their flotation in a flotation basin. The flocculant includes a polymer composition having a charge density of at the most 1.7 meq/g dry and the polymer composition includes a cationic synthetic first polymer having a charge density at least 1.0 meq/g dry at pH 2.8, and at least one second polymer obtained by polymerization of (meth)acrylamide, the second polymer being polymerized in presence of the cationic first polymer, where the first polymer has a higher charge density than the second polymer.

Method for treating aqueous feed by dissolved gas flotation

A method for producing an aqueous copolymer solution, which comprises dissolving a copolymer of (meth)acrylamide and at least 1 mol-% cationic monomers, calculated from total amount of monomers in the dissolving water having calcium hardness of at least mg/l, expressed as Ca, and adding acid comprising monoprotic organic acid and/or mineral acid to the dissolving water and/or the aqueous solution of the copolymer in an amount sufficient to provide the aqueous solution of the copolymer with a pH of equal to or less than 4.5. The invention also relates to uses of the obtained polymer solutions in manufacturing of paper, board or the like or in treatment of sludge or water.

Method for producing polymer solutions

The invention relates to a water-soluble polymer composition obtained by polymerizing in an aqueous polymerisation medium, which comprises degraded starch, at least following monomers: acrylamide and/or methacrylamide, and &#x3e;2 mol-% of at least one unsaturated mono- or dicarboxylic acid(s) or salts thereof. The polymer composition has an anionic net charge at pH 7 and a dry solids content of &#x3e;5 weight-%. The invention relates also to the use of the polymer composition for surface sizing of paper, board or the like as well as to a surface size composition comprising it.

Polymer composition, its use and a surface size

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2,500,000-18,000,000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

Use of a polymer product for deposit formation control in manufacture of paper or board

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 &#x2265;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 &#x2212;0.1-&#x2212;3 meq/g, preferably &#x2212;0.3-&#x2212;2.5 meq/g, more preferably &#x2212;0.5-&#x2212;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.

Dry strength composition, its use and method for making of paper, board or the like

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

Method for manufacturing a multi-layered paperboard, multi-layered paperboard and composition for use in multi-layered paperboard manufacturing

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 cationic glyoxylated polyacrylamide polymer composition having improved storage stability for use in manufacture of paper, board or the like, which aqueous composition includes a glyoxylated polyacrylamide polymer having a cationic charge density in a range of 0.8-1.8 meq/g of dry polymer in dry content of 5-15% and a buffering acid. The aqueous composition has pH in a range of 2.2-4.0 and a viscosity of less than 80 mPas measured at 25&#xb0; C. by using a Brookfield viscometer after 30 days storage at 35&#xb0; C. or after 60 days storage at 23&#xb0; C.

Glyoxylated polyacrylamide polymer composition, its use and method for increasing the strength properties of paper, board or the like

A method is disclosed for dewatering of sludge from a pulp, paper or board making process, such as deinking sludge, including obtaining of an aqueous sludge including an aqueous phase and a fibre material suspended in the aqueous phase. The sludge is subjected to a pre-thickening step, where a first part of the aqueous phase is removed from the sludge and to a pressing step, where a second part of the aqueous phase is removed from the sludge, thereby obtaining a dry pressed sludge. Before or at the pre-thickening step a polymer composition having a charge density of at the most 1.7 meq/g, preferably at most 1.5 meq/g, more preferably at most 1.1 meq/g, is added to the sludge.

Method for dewatering of sludge from a pulp, paper or board making process

The present invention relates to a method for providing a pretreated filler composition for use in paper and board manufacturing including the steps of: a) providing a filler comprising precipitated calcium carbonate, said filler being in the form of a slurry comprising no additives; b) providing at least one polymer selected from polyvinylamine or polyacrylic amide, said polymer having a charge density of an absolute value of at most 4 meq/g determined at pH 7; c) combining said at least one polymer of step b) with the filler of step a); d) providing a slurry of nanofibrillar cellulose; e) combining said nanofibrillar cellulose slurry with the formed combination of step c) and forming a pretreated filler composition comprising aggregates. Further it also relates to a pretreated filler composition prepared therefrom, and its use in stocks, paper and paper board.

Method for providing a pretreated filler composition and its use in paper and board manufacturing

A polymer composition includes a first host polymer, which is a copolymer of (meth)acrylamide and at least one cationic first monomer, and a second polymer, which is a copolymer of (meth)acrylamide and at least one cationic second monomer. The second polymer is polymerised in presence of the first host polymer, and the first host polymer has a higher cationicity than the second polymer, the difference in cationicity of the first host polymer and the second polymer being at least 3 mol-%, at least 5 mol-%, more preferably at least 7 mol-%. The polymer composition has a standard viscosity of &#x3e;2.0 mPas, measured at 0.1 weight-% solids content in an aqueous NaCl solution (1 M), at 25&#xb0; C., using Brookfield VII T viscometer with UL adapter. The invention relates also to uses of said polymer composition.

Polymer composition and its uses

Growing community of inventors

Espoo, Finland

Matti Hietaniemi