Abstract:
Method of determining mechanical properties in the thickness direction of a sheet material (4), by supporting the sheet material (4) on a surface (5); advancing a body (1) having an impacting surface (6, 9) facing the sheet material into engagement with the sheet material (4) supported by said surface (5); sensing and registering the position, velocity or acceleration of the impacting surface (6, 9) of the advancing body (1) as a function of time during the movement of the body (1) in relation to the displacement sensor (3); and analysing said function to obtain the mechanical properties. The present invention also relates to an apparatus for carrying out said method and a use of a body (1) and a sensor (3) in a method or in an apparatus, for determining mechanical properties of a sheet material (4).
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:
Procédé de mesure de la flexibilité de fibres, notamment de fibres de cellulose, dans un flux de suspension. On photographie la conformation fibreuse d'un grand nombre de fibres à deux endroits différents du flux de suspension. On calcule la conformation fibreuse prédéfinie pour chaque image de flux, et on établit un rapport, par exemple le quotient ente les deux mesures de forme fibreuse moyenne, qui servira ensuite à déterminer la flexibilité des fibres. L'invention concerne aussi un appareil permettant de réaliser le procédé de l'invention, comprenant un récipient de circulation (20) à travers lequel passe la suspension, une fenêtre transparente (26) montée dans la paroi du récipient, une caméra de type CCD (30) qui photographie les fibres passant derrière la fenêtre, une unité d'analyse des photos (34) couplée à la caméra (30), et une unité de traitement des données (36) qui traite les informations obtenues grâce à l'unité d'analyse des photos (34).
Abstract:
The present invention relates to a method for utilizing a wood hydrolysate obtained from a hydrothermal treatment of a wood material method comprises the steps of providing a wood material, treating the wood material by means of an aqueous hydrothermal treatment so that a wood hydrolysate and a wood residue is formed. The wood hydrolysate comprises oligo- and polysaccharides as the main component of dry matter. The method further comprises the steps of; separating the wood hydrolysate into at least a first and a second fraction and using at least one of the at least first and second fractions for production of an intermediate or end product. Such end product may be e.g. a film, coating, package or a gel. The present invention also relates to a polymer product such as a film, a coating or a gel and its applications. The present invention provides for biodegradable and renewable polymer products and a method which utilizes and extracts a very high product value from a process.
Abstract:
Dewatering arrangement adapted to use in a twin-wire dewatering section of a stock processing machine, comprising a single-ply head box (4) for supplying stock through a nozzle (8) with an inlet (11 ) fed by a tube bank (6) with tubes (7) of non-circular cross- section, a closed loop first wire (2) adapted to receive the stock from the head box (4) on its upper surface and with pressure pulse generating blades (5) mounted inside the loop, a closed loop second wire (3) adapted to be fed on top of the first wire (2), and with pressure pulse generating blades (13) mounted inside the loop, thereby pressing the stock between itself and the first wire (2). The inlet height of the headbox nozzle (8), defined as the total tube bank height minus the total upstream thickness of eventual nozzle vanes (14), is at least 150 mm. By using a larger height of the headbox nozzle it is possible to lessen the risk of formation damages and also to use a higher slice opening, without formation disturbances. This in turn also gives better potential for paper strength and formation. The arrangement is suitable to both paper and paper board machines.
Abstract:
Dewatering arrangement adapted to use in a twin-wire dewatering section of a stock processing machine, comprising a single-ply head box (4) for supplying stock through a nozzle (8) with an inlet (11 ) fed by a tube bank (6) with tubes (7) of non-circular cross- section, a closed loop first wire (2) adapted to receive the stock from the head box (4) on its upper surface and with pressure pulse generating blades (5) mounted inside the loop, a closed loop second wire (3) adapted to be fed on top of the first wire (2), and with pressure pulse generating blades (13) mounted inside the loop, thereby pressing the stock between itself and the first wire (2). The inlet height of the headbox nozzle (8), defined as the total tube bank height minus the total upstream thickness of eventual nozzle vanes (14), is at least 150 mm. By using a larger height of the headbox nozzle it is possible to lessen the risk of formation damages and also to use a higher slice opening, without formation disturbances. This in turn also gives better potential for paper strength and formation. The arrangement is suitable to both paper and paper board machines.
Abstract:
The present invention provides a method for the modification of lignocellulosic materials. Cellulose fibres are treated with an aqueous electrolyte-containing solution of an amphoteric cellulose derivative for at least 5 minutes at a temperature of at least 50 °C. The pH during the treatment is approximately 1.5-4.5 or higher than 11; or the concentration of the electrolyte is approximately 0.0001-0.05 M if the electrolyte has monovalent cations, or approximately 0.0002-0.1 M if the electrolyte has divalent cations. Further the invention relates to products obtainable by the above mentioned method and uses of said products for manufacturing paper with a high wet strength and rayon fibres.
Abstract:
A method to predict and/or control the strength properties of a foil-like material in relation to machinery and processes for manufacturing this material. The measurements are performed locally on the foil-like material and with a high spatial resolution - from 20 mm and less - to obtain a mean value and variation regarding at least one local mechanical property of the foil-like material, whereby the strength value or control signal worked out from the measurement results obtained is used to achieve the strength prediction and/or the process and quality control desired.
Abstract:
Process for the manufacturing of wood chips as raw material in the production of mechanical pulp in order to reduce the energy consumption in the production of pulp, characterized in that the wood fibres, including the summerwood fibres, are irreversibly deformed across the grain, i.e. in a direction perpendicular to the longitudinal axis of the fibres. Preferably this is done through mechanical treatment with one or several tools, arranged so that the forces created in the treatment act in a direction substantially perpendicular to the longitudinal axis of the fibres.
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. The detection unit (14) senses this stretching of the material, without coming into contact with the material, by detectingtransient changes in these material zones.