Abstract: A method of treating chemical pulp for the manufacture of microfibrillated cellulose includes the following steps: a) providing a hemicellulose containing pulp, b) refining the pulp in at least one step and treating the pulp with one or more wood degrading enzymes at a relatively low enzyme dosage, and c) homogenizing the pulp thus providing the microfibrillated cellulose. A microfibrillated cellulose obtainable by the method is also provided. The microfibrillated cellulose can be used in food products, paper products, composite materials, coatings or in rheology modifiers (e.g. drilling muds).

Abstract: Device for measuring the two-dimensional velocity of a moving paper web having opposed first and second surfaces, wherein comprising: at least one light source directed at said first surface and arranged to transmit light through said paper web; at least one image capturing device directed at said second surface, and arranged to receive said transmitted light and produce a two-dimensional image of a section of said paper web; a control unit, arranged to control said at least one light source and at least one image capturing device, and to receive two-dimensional images from said at least one image capturing device, and comprising computation means arranged to compute the velocity component of said paper web in the machine direction and/or the cross direction by calculating the cross correlation of two two-dimensional images.

Abstract: Device for measuring the two-dimensional velocity of a moving paper web having opposed first and second surfaces, wherein comprising: at least one light source directed at said first surface and arranged to transmit light through said paper web; at least one image capturing device directed at said second surface, and arranged to receive said transmitted light and produce a two-dimensional image of a section of said paper web; a control unit, arranged to control said at least one light source and at least one image capturing device, and to receive two-dimensional images from said at least one image capturing device, and comprising computation means arranged to compute the velocity component of said paper web in the machine direction and/or the cross direction by calculating the cross correlation of two two-dimensional images.

Abstract: A reinforcement element, comprises at least one sensor fiber adapted for strain measurements based on stimulated Brillouin scattering within said sensor fiber.

Abstract: A method for treatment of chemical pulp for the manufacturing of microfibrillated cellulose includes the following steps: a) providing a hemicellulose containing pulp, b) refining the pulp in at least one step and treating the pulp with one or more wood degrading enzymes at a relatively low enzyme dosage, and c) homogenizing the pulp thus providing the microfibrillated cellulose. According to a second aspect of the invention a microfibrillated cellulose obtainable by the method according to the first aspect is provided. According to a third aspect of the invention, use of the microfibrillated cellulose according to the second aspect in food products, paper products, composite materials, coatings or in rheology modifiers (e.g. drilling muds) is provided.

Abstract: The present invention provides a method for extracting polymeric pentose, preferably xylan, from a polymeric pentose containing liquid/slurry, preferably black liquor, comprising the following steps: a) providing a polymeric pentose containing liquid/slurry; b) concentrating the polymeric pentose by membrane separation of a said polymeric pentose containing liquid/slurry; and c) adding alcohol to the concentrate obtained in step b) and subsequently acidifying said concentrate obtained in step b) for precipitating polymeric pentose whereby a polymeric pentose product, or an intermediate polymeric pentose product, is obtained. In this above way polymeric pentose, e.g. xylan, is separated whereby the use of methanol (less lignin must be kept in solution) and acid (less acid which buffers the pH-decrease) become much lower.

Abstract: In a method of forming a layered fibrous web, the method includes the steps of leading at least two different fiber suspensions through a head box (10), separating the fiber suspensions from each other by a blade device (18, 180), supplying the fiber suspensions to a web forming device (24) and forming a water layer having a transversely uniform flow at an outlet at the end of the blade device (18, 180), such that the water layer constitutes an extension of the blade device and thereby prevents mixing of the fiber suspensions. The blade device (18, 180) can be freely movable in a substantially vertical direction in order to permit an equalization of pressure between the fiber suspension layers separated by the blade device and thereby reducing wake effects downstream the edge of the blade device. A paper machine for carrying out the method is also disclosed.

Abstract: In a process of treating wood chips for reduction of the concentration of undesirable inorganic elements prior to cooking in a production line for chemical pulp, the wood chips, having entrapped air, are treated with an aqueous leaching liquor at elevated temperature and pressure, followed by draining at atmospheric pressure or below atmospheric pressure, the pressures being controlled to yield a moisture content in the wood chips as low as possible for adequate leaching result and behavior of the chips in a subsequent digester. The aqueous leaching liquor is e.g. pulp mill process water with a low content of undesirable inorganic components, such as bleach plant spent liquor or condensate. The aqueous leaching liquor drained from the treated wood chips may be purified and recycled back to the process.

Abstract: Method of determining a surface illuminated by incident light. First the intensity (I1(x,y)) of light reflected from the surface is recorded in a first image of the surface. After this, the intensity (I2(x,y)) of light reflected from the surface is recorded in a second image of the surface, taken at a different angle of illumination. Only the diffusely reflected light is recorded. The difference between the recorded intensities of the first and the second images is determined to obtain a representation that emphasizes variations in gradient of the surface. This representation is further processed by signal-adapted integration to a topographic description, that is, a height function of the surface.

Abstract: An apparatus for drying a fibre web of paper or paperboard is provided. The apparatus includes an adjustable heated press nip including at least one pressure device. The pressure device includes a roll, supporting one side of the web and at least two pressure shoes opposite the device and acting on the other side of the web. Each of the pressure shoes include means for providing an individual pressure respectively on the web. At least one intermediate conduit is arranged in-between the pressure shoes. The intermediate conduit includes means forming an additional individual pressure zone on the web.

Abstract: A method and apparatus for obtaining a basis on which the gloss quality of a sample surface of a sample, such as a paper sheet, can be determined by illuminating the sample surface and registering the intensity of the reflected light.

Abstract: A process and apparatus for manufacturing wood chips as raw material in the production of mechanical pulp in order to reduce energy consumption. The process includes irreversibly deforming a plurality of fibers of at least one piece of wood in a direction perpendicular to the longitudinal axis of the fibers. The wood fibers include summerwood fibers. The irreversible deformation is accomplished through mechanical treatment. The apparatus used includes one or several tools arranged so that the forces created during the process act in a direction substantially perpendicular to the longitudinal axis of the fibers so as to irreversibly deform the fibers across the grain.

Abstract: A method of determining the filler content of paper, wherein the paper stock is examined prior to delivering the stock to the de-watering section of the paper machine, and wherein the volume concentration of particles in the stock that have a size which is greater than the characteristic size of the filler is determined at varying mechanical working of the pulp, and the amount of filler retained in the paper is predicted from the result of at least two such determinations.

Abstract: The invention relates to a method of determining the concentration of sulfide and optionally also of polysulfide in liquors and solutions of smelt deriving from the sulfate process. According to the method, the concentrations are determined by measuring the light absorption of the liquor or the solution in the ultra-violet range. According to one preferred embodiment, the method is applied to determine the degree of reduction in sulfate liquor and smelt derived from burning liquor, wherein the concentrations of sulfate, thiosulfate and optionally sulfite and/or carbonate are determined by measuring the light absorption of the liquor or the solution in the infrared range, whereafter the degree of reduction is calculated from the measuring data obtained.

Abstract: An arrangement for measuring mechanical properties of foil material (10), preferably paper. The arrangement includes a material excitation unit (12) and a material sensing detection unit (14). The two units are connected electrically to a common arithmetical unit (18). This unit is intended to register and convert electrical signals deriving from the two first mentioned units (12, 14) in a manner to produce final signals which represent the material properties to be measured. The excitation unit (12) includes a laser which, through electromagnetic radiation, is intended to generate in the gaseous atmosphere surrounding the material local transient gas-pressure pulses within variable surface zones which are well-defined geometrically, without the excitation unit coming into contact with the material. These gas pressure pulses cause the material (10) to stretch locally in the boundary regions of the zones, such stretching of the material being necessary to the measuring process.

Abstract: A method for measuring the flexibility of fibers, particularly cellulose fibres, in a flowing suspension. The fibre form of a large number of fibres is registered at two different pictures of suspension flow. A predefined fibre form is calculated for each flow picture, and a relationship, for example the quotient between two measurements of mean fibre form is determined and utilized to define fibre flexibility. The invention also relates to an arrangement for carrying out the inventive method, wherein the arrangement includes a flow-through container (20) through which the suspension flows, a transparent window (26) mounted in the container wall, a CCD-type camera (30) which functions to photograph fibres passing the window, a picture analysis unit (34) coupled to the camera (30), and a data processing unit (36) for processing information obtained from the picture analysis unit (34).

Abstract: The present invention relates to a method and to an apparatus for detecting the presence of bark and for determining the barking degree of wood or chips. Accordingly, the apparatus includes a light source (12) which directs a concentrated light beam (14) onto the measurement object (16), for instance a log which is moved continuously in a transport chute (20). The shape and/or size of the light image obtained on the log (16) at the point (18) on which the light beam (14) impinges on the log is detected with the aid of a camera (10), preferably a CCD-camera. The shape and/or size of the light image is mutually different for wood and bark. The detection values obtained by the CCD-camera (10) are evaluated in a processing means.

Abstract: Method of reducing the energy consumption at the refining/beating of cellulose-containing material by the addition of alkali to the material for neutralizing acid groups bonded to the fibre wall. According to the invention, the pH-value in the pulp suspension is measured at the refiner outlet, the alkali is added in an amount depending on the measured pH value for neutralization without excess in the beating zone or immediately before the material enters the same, in an amount of 0.05-9 kg/ton, preferably 0.5-5 kg/ton, suitably 1-4 kg/ton, calculated as NaOH.

Abstract: Variations in the properties of a continuously running web are measured by reciprocating the scanning device across the web. The movement of the scanning device is so time controlled that this movement is out of phase with the variation in the paper properties in the machine direction of the web.

Abstract: The present invention relates to a process for obtaining retention of the manufacture of paper, whereby one adds a cationic, high polymer polysaccharide at the preparation of a stock of paper pulp; that one adds an anionic aluminium compound, or a combination of an aluminium salt and an alkali or an acid to the formation in situ of such an anionic aluminium compound immediately prior to the head box, whereby pH immediately prior to the head box is kept at pH 7 to 8.