A method for manufacture of paper or board, in which method an inverted solution of cationic polymer is added to the fiber suspension for providing retention enhancement without over-flocculating fiber stock and destruction sheet formation and/or improving drainage and enhancing or at least maintaining strength of paper or board, An inverted solution has a bulk viscosity of 50-150 mPas at 0.2 weight-% cationic polymer concentration and inverted solution comprises cationic polymer obtained by reverse phase emulsion polymerization of a monomer blend comprising non-ionic monomers, 15-50 mol-% cationic monomers, an optionally at most 50 ppm of a crosslinking agent, and a chain transfer agent, and the obtained reverse phase emulsion of cationic polymer is inverted into an aqueous solution.

The present invention relates to a process for obtaining cellulose or a mixture containing at least cellulose and at least lignocellulose from at least one substrate that is at least to some extent amenable to fermentation comprising at least the steps of (1) to (3) and optionally (4), namely conversion of the substrate via addition of at least one inorganic base into an aqueous mixture with pH≥8.5 (step 1), ultrasound treatment of the aqueous mixture obtained after step (1) (step 2), separation of the aqueous mixture obtained after step (2) into a liquid aqueous phase and a disperse mixture containing, cellulose or a mixture containing at least cellulose and at least lignocellulose (step 3) and optionally purification of the disperse mixture obtained after step (3) containing cellulose or of the mixture containing at least cellulose and at least lignocellulose (step 4), where step (1) and step (2) of the process respectively are carried out at a temperature <100° C. and Where the ultrasound treatment in step (2) takes place in one or more treatment phases, where the duration of a treatment phase is in the range from 0.2 to 60 seconds and each treatment phase is carried out with a sonotrode frequency in the range from 14 to 22 kHz.

A water-dispersible composite structure, which comprises one or more layers, and a method of producing the same. At least a part of the layers is formed by a fibrous web or sheet containing 50-90 parts by weight of wood fibers and 10-90 parts by weight of annual or perennial plant fibers and/or 10-50 parts by weight of synthetic short-cut fibers, and 0.1-20% by weight of a binder, calculated from the weight of the fibers, and at least a part of the binder being a water-soluble polymer and another part a water dispersible binder, and the fibrous sheet or web being produced by wet forming. By means of the invention, the fibers of the composite structure can be recovered and recycled by equipment conventionally used in the paper and paperboard industry.

Disclosed is a method and system for recycling waste paper that employs mechanical force to reduce the waste paper to its constituent fibers. The disclosed method does not require the addition of chemicals or heat to the pulping process, but instead uses impact and frictional forces to break the waste paper down into fiber. The disclosed method also requires very little water, thus reducing the need for complicated water purification systems.

A sheet manufacturing apparatus including an accumulating unit that causes a defibrated product to accumulate in a dry manner and forms a web, a moisture adding unit that adds moisture from a side of one surface of the formed web such that a moisture content of the web is equal to or more than 12 mass % and equal to or less than 40 mass %, and a heating unit that heats the web to which moisture is added. The heating unit has a first portion that comes in contact with the one surface of the web and a second portion that comes in contact with another surface of the web, and the heating unit heats the web in a state of a surface temperature of the first portion being higher than a surface temperature of the second portion.

A recycled cellulose pulp composition is provided which comprises recycled cellulosic fibers and cellulose ester staple fibers. The recycled cellulose pulp containing co-refined re-cycled cellulose fibers and cellulose ester staple fibers can be added to a hydropulper and fed back through a refiner to make wet laid products.

A fiber processing device includes a drum having a plurality of openings on an outer peripheral surface, sieving a raw material containing fibers, and configured to rotate about a rotation axis, a housing that supports the drum, a guide portion (convex portion) provided on an outer peripheral surface of the drum; and a restriction portion (bearing) that restricts movement of the drum in a direction of the rotation axis by contacting the convex portion. At least one of the restriction portion and the guide portion is configured to rotate about an axis (rotation axis) orthogonal to the rotation axis.

The present invention is related to a deinking primer composition for deinking of a substrate, wherein said deinking primer composition comprises a binder component that has a polymeric backbone with pendent hydroxy or carboxy groups that have been esterified or acetalised or ketalised to such an extent that the binder component has an acid value of 0-50 mg KOH/g or a hydroxyl value of 0-600 mg KOH/g, preferably 0-400 mg KOH/g, so that a primer layer prepared from said deinking primer composition is dissolvable in an alkaline aqueous medium.

A process including providing a paper substrate; disposing a water soluble precoat composition onto all or a portion of the paper substrate to provide a treated paper; applying an image onto the treated paper using a toner or an aqueous ink to provide an imaged paper; wherein the water soluble precoat composition forms a temporary barrier between the toner or aqueous ink and the paper substrate; and wherein, during a paper pulping process, the water soluble precoat composition dissolves thereby releasing the toner or aqueous ink from the paper substrate.

In a defibrating apparatus, when a region, of a discharge path, including a discharge unit is a downstream discharge path, a region, of the discharge path, other than the downstream discharge path is an upstream discharge path, a region, of a screen, constituting the downstream discharge path is a downstream discharge screen, a region, of the screen, constituting the upstream discharge path is an upstream discharge screen, and a through-hole that causes a defibrating chamber to be in communication with the discharge path is a communication hole, the communication hole is provided on the screen such that the air is less likely to pass through the downstream screen than the upstream screen.