The invention relates to a method for separating particulates out of filtrates of a paper, cardboard, paperboard or pulp production plant and for reapplying the separated particulates to a surface of paper, cardboard or paperboard, comprising at least the following steps: a) separating the particulates out of the filtrates at a size of less than 1200 pm, b) coagulating the separated particulates of same, c) as applicable, mixing the separated particulates with further particulates from a paper, paperboard or pulp production, and/or microfibrillated cellulose (MFC), d) forming an aqueous suspension from the particulates, e) as applicable, adding to the suspension further additives for the surface treatment of paper or paperboard, selected from native and oxidatively degraded starch or calcium carbonate, f) homogenously applying the formed suspension to a paper or paperboard surface in a quantity between 0.5 and 30 g/m.sup.2, in particular 4 and 15 g/m.sup.2, and g) drying the paper or paperboard.

The invention relates to a method for treating biomass (1). In a step (S10) of the method, the biomass (1) and an amount of water (2) is fed into a first reactor unit (10) such that the biomass (1) is impregnated using the amount of water (2) while the biomass (1) is transferred through the first reactor unit (10) by a conveyor means (11). In another step (S20), the impregnated biomass (22) is transferred from the first reactor unit (10) to a separation unit (20) in which at least a part (21) of the amount of water (2) used for impregnation can be separated from the impregnated biomass (22). In another step (S30), the impregnated biomass (22) is transferred from the separation unit (20) into a second reactor unit (30) in which the impregnated biomass (22) is subjected to a predetermined pressure (S30). The invention further relates to the use of the method for treating non-wood material as well as to a device for treating biomass (1).

The present invention relates to a method for manufacturing an intermediate product that can be stored and transported and efficiently converted into microfibrillated cellulose with limited energy input at the time of conversion. More specifically, the invention involves the use of dewatered carboxymethylcellulose or carboxylated cellulose fiber having a low degree of substitution and a high amount of additives.

Methods of fractionating lignocellulosic biomass using hydrotropic sulfonic acids are provided. Also provided are methods of forming lignin particles, furans, sugars, and/or lignocellulosic micro- and nanofibrils from the liquid and solid fractions produced by fractionation process. The fractionation can be carried out at low temperatures with short reaction times.

Provided is a processing device which includes a fluffing section for fluffing fibers contained in a sheet-like material, the fibers being at least near a surface of the sheet-like material, and a particle supplying section for supplying particles having Mohs hardness of 2 to 5 to the fluffed fibers. In addition, in such processing device, the particle supplying section preferably has an ejecting portion for ejecting the particles.

Methods of fractionating lignocellulosic biomass using hydrotropic sulfonic acids are provided. Also provided are methods of forming lignin particles, furans, sugars, and/or lignocellulosic micro- and nanofibrils from the liquid and solid fractions produced by fractionation process. The fractionation can be carried out at low temperatures with short reaction times.

A method (10, 110) for cleaning fibers from a contaminated article is disclosed. The method (10, 110) can include providing a contaminated article comprising contaminates and at least one of fibers and filaments. The method (10, 110) can further include adding a plurality of magnetic particles (18, 118) to a first solution and pulping (20, 120) the contaminated article to separate the at least one of fibers and filaments from the contaminated article to provide dissociated pulped fibers. The method (10, 110) can further include applying a magnetic field (22, 122) to the suspension including the dissociated pulped fibers and removing (26, 126) at least some of the plurality of magnetic particles and at least some of the contaminates from the suspension. The dissociated pulped fibers can be dried (34, 134) to provide clean fibers.

A fiber processing system includes a fiber processing unit having an inlet, accepts outlet, and solid discharge outlet and configured to remove solid contaminants from a fiber-containing stream to produce an accepts stream exiting the accepts outlet and a solid discharge stream exiting the solid discharge outlet. The fiber processing system includes an optical system having an imaging device and image processing system. The imaging device is configured to capture images of the solid discharge stream at or downstream of the solid discharge outlet, and the image processing system is configured to determine relative fiber content, a relative generation rate, types of materials in, or combinations thereof of the solid discharge stream from the captured images. The fiber content, generation rate, and/or types of materials of the solid discharge stream are used to control operation of the fiber processing system or other upstream pulp processing equipment.