Abstract: A product and process of making an absorbent paper article such as paper products, towels, napkins and the like is disclosed. In the invention, one may supply a single furnish, or slurry, of cellulose fibers. Then, it is possible to separate or fractionate the slurry into at least two portions based upon fiber length in the slurry. Fines are employed in the process of manufacturing the products, and fines are specifically incorporated into an inner layer of the final paper products. Fines, short fibers, and/or fibrils are used in the process so they may contribute in a positive manner to the final paper product, rather than acting in a negative manner as a chemical “sponge” or waste material. This use of fines in the inner layers of the product reduces the manufacturing cost and waste produced in the process. A soft paper product with good strength characteristics results from the process.

Abstract: A method of processing feathers and products produced thereby. The method preferably comprises the step of reducing feathers in at least one of a refiner and a pulper. A cleaning agent is preferably added to the feather material before and/or after the reducing step. The cleaning agent will preferably be hydrogen peroxide, detergent, a surface acting surfactant, bleach, or a combination thereof. The method can also include the steps of (a) adding paper pulp to the reduced feather material and then (b) forming a product from the combined material.

Abstract: Process for manufacturing screens and screens suitable for use in wet screening fibrous paper suspensions, in which the screens include at least one screen plate having a number of sorting apertures. The process includes providing a number of fastening openings in the at least one screen plate, and inserting profiled pieces into the fastening openings. At least a portion of the profiled pieces are arranged to project beyond a screen surface.

Abstract: Process and apparatus for removing fine impurities from a fibrous suspension. The process and apparatus each provide for conveying the fibrous suspension to at least one sorting device, separating the fibrous suspension using the at least one sorting device into an accepts portion and a rejects portion, finishing at least some of the accepts portion leaving the at least one sorting device using a finishing device, separating at least some portion of the rejects portion leaving the at least one sorting device using at least one last sorting device into an accepts portion and an rejects portion, separating at least some portion of the accepts portion leaving the at least one last sorting device into an accepts portion and a rejects portion using a flotation device, and finishing at least some portion of the accepts portion leaving the flotation device using the finishing device.

Abstract: In a papermaking process, filtering of white water containing fiber material is performed by feeding the white water to a filter on a surface of which a layer of auxiliary pulp has been formed, such that the white water is filtered through the layer of auxiliary pulp and fiber material in the white water remains in the layer of auxiliary pulp. The mixture of auxiliary pulp and fiber material is removed from the filter and is fed to a fractionating screen. The screen separates the mixture into a short-fibered pulp fraction that can be returned to the papermaking process, and a long-fibered pulp fraction that is returned to the filter where it is used as auxiliary pulp to form a layer on the filter surface.

Abstract: Pressurized screen to remove contaminants from a contaminant-containing fibrous paper suspension. Pressurized screen includes a housing, a first screen element, essentially axially symmetric and rotatably mounted within housing, and a second screen element, which is essentially axially symmetric. First and second screen elements are successively arranged in suspension flow direction. At least one intake, coupled to housing, supplies suspension to housing, and at least one accepts outlet, coupled to housing, conveys a part of suspension that passes through the second screen element out of housing. At least one coarse reject outlet is located within housing to remove a part of suspension not passing through first screen element, and at least one fine reject outlet is located within housing to remove a part of suspension not passing through second screen element. First screen element includes conical shape with opening angle (&agr;) between about 10° and 170°.

Abstract: Hydrocyclone and process for removing foreign substances from a liquid to be cleaned. The hydrocyclone includes at least one inlet for the liquid to be cleaned, at least one accepted stock outlet for the cleaned liquid, and at least one reject opening for foreign substances removed from the liquid to be cleaned. The at least one reject opening includes at least one stoppage-hazard zone, and a color layer is coupled to an exterior wall of the hydrocyclone. The color layer changes appearance in accordance with different temperatures. The process includes introducing the liquid to be cleaned into a hydrocyclone through at least one inlet, discharging cleaned liquid from the hydrocyclone through at least one accepted stock outlet, and discharging the foreign substances from the hydrocyclone through at least one reject opening.

Abstract: Process for dissolving used paper including adjusting a content of solid particles of used paper to a range between about 15 and 35%, kneading the used paper with a specific work of at least about 10 kWh/t, diluting the kneaded used paper to a content of solid particles below about 6%, separating non-fibrous contaminants with wet screening, adjusting a solid material content to less than about 3%, and separating heavy particles with at least one hydrocyclone.

Abstract: A process and apparatus for the preparation of improved cellulose pulps is provided, in which defibered pulp is screened for removal of shives, and fibers with low bonding ability are removed in hydrocyclones, and rejects from the hydrocyclones are treated in refiner. In the process a specific combination of characteristics for the hydrocyclones and the volumetric flow is used in order to prepare pulps which give products of improved qualities, such as higher tensile strength, tear strength, light-scattering, surface smoothness, and especially low shive content.

Abstract: The invention concerns a method for producing a paper web. According to the method a stock is produced from the fibrous raw material and the stock is formed to a web which is dried on a paper machine. According to the invention the stock is formed from a mechanical pulp prepared from wood material of the Populus family and from bleached chemical spruce pulp, whereby the amount of the mechanical pulp is 20 to 70 weight-% and the amount of the bleached chemical softwood pulp is 80 to 30 weight-% of the dry matter of the stock. It is preferred to use an aspen pulp, over 70% of the fiber fractions of which comprise fiber fractions +100, +200 and −200, and the proportion of the −200 fraction is 45% or less. A coated fine paper can be produced from the paper web whose properties are better than those of a traditional fine paper having the corresponding bulk and grammage, on the same capacity level the paper produced by the invention will give a yield gain of up to more than 20%.

Abstract: A pulper device includes a vessel in which an annular flow can be generated. The flow acts upon a liquid-sold mixture located inside the vessel and effects a pulping of the same. The device also comprises a screening device for separating coarse materials from the suspension, whereby the screening device has the shape of a truncated cone. The truncated cone is provided with holes on the lateral surface thereof and can be mounted on the base of the vessel in such a way that the truncated cone points upward with the small circular surface thereof, and the lateral surface lies in an approximately tangential manner to the toroidal flow. The screening device is subdivided into different segments and these segments can be individually mounted from the external side of the vessel.

Abstract: Paper and absorbent products having reduced pitch content and enhanced properties, including increased tensile index, tear index, burst index, Scott Bond, smoothness, and stiffness. Further, pulps of the invention, although having slightly reduced brightness, are more responsive to bleach chemicals thereby permitting the use of less chemicals to achieve a specific brightness. The products are produced by a process that includes extracting wood particulates with a solvent for naturally-occurring volatile organic compounds and pitch. The extracted wood particulates are then pulped and formed into paper and absorbent products with enhanced properties. Due to the extraction of volatile organic compounds, the pulping and paperforming stages of the process are substantially free of emissions of volatile organic compounds that occur naturally in wood. Moreover, the extraction of pitch reduces or eliminates pitch fouling of equipment and permits the production of paper products of enhanced qualities.

Abstract: A screen device for separating fiber suspensions comprises a screen (40) defining a central chamber (36), and a rotor (15) in the central chamber having a first (21) and a second (27) rotor portion, respectively, provided with first (43) and second (41) pulsation elements, respectively, for pulsating the suspension close to the screen along a first (11) an a second (9) axial screen portion, respectively, of the screen. The first rotor portion (21) and the first axial screen portion (11) define a first screen chamber (39) and the second rotor portion (27) and the second axial screen portion (9) define a second screen chamber (37). Distribution means (22, 28) are provided for dividing the incoming fiber suspension into two part streams having the same axial directions in relation to the rotor and for distributing the two part streams to the first and second screen chambers (39, 37), respectively.

Abstract: Processes are disclosed for processing low consistency newsprint pulp including refining the pulp in a first refiner to a consistency of greater than 2%, screening the processed pulp with a slotted screen basket with a slot width of from 0.05 to 0.15 mm, with the withdrawal of the primary reject portion being greater than 50%, withdrawing the accept portion for further processing, dewatering the reject portion to provide a high consistency pulp, refining the high consistency pulp in a second refiner, screening the processed high width consistency pulp with a slotted screen basket having a slot of less than 0.15 mm, and combining the two accept portions for the further processing steps.

Abstract: Pressure type screening apparatus for screening papermakers' stock and method of use is disclosed. Screen (20) has an inlet screening surface (23) and an outlet surface (unlabled). Pressure transducers (not shown) vary the fluid pressure on the inlet surface of the screen (23) from a maximum to a minimum, and also vary the fluid pressure on the outlet surface of the screen (20) from a minimum to a maximum at a repetitive cyclic rate. The amplitude of such pressures is such that flow reversal occurs through the screen (20) and any fiber mat that tends to form on the inlet surface (23) is disrupted or fluidized.

Abstract: A hybrid system for processing papermaking fibers includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.

Abstract: A process for producing new corrugated containerboard from old corrugated container (OCC) without using expensive virgin UKP includes three new steps. These steps are separating corrugated medium from OCC before pulping linerboard, removing micro-fibrils from defibered linerboard furnish, and minimizing the loss of long fibers through reject streams of fine screens.

Abstract: Cylindrical screen, particularly for paper pulp, of the type comprising at least one filtering element (10) positioned between two flanges (1, 2) by means of a number of bars (3). The filtering element is composed by wires (10) placed side by side and held by rings (11). This filtering element is rigid in the axial direction and is placed upstream from the above mentioned bars (3), in relation to the direction of flow of the pulp. The filtering element is held against the bars (3) through the rings (11) that are in contact with the bars without being attached to them, so as to maintain its shape by withstanding the pressure exerted by the pulp.

Abstract: the present invention provides a method for pre-processing and processing straw pulp and forming a byproduct suitable for animal consumption. The present invention also provides a paper product comprising straw pulp. According to the present invention, straw pulp is formed by steam exploding straw chips in the presence of either no caustic or a small amount of caustic.

Abstract: Dense, tramp material, is efficiently separated in a comminuted cellulosic fibrous material feed system, for example in a chemical cellulose digester feed system, in a simple but effective matter. By merely utilizing a generally vertical conduit and a slurry flow within it (which may be augmented by high speed liquid introduction), that is caused to turn in a radiused path, centrifugal force allows separation of the tramp material into a cavity beneath the radius transition without requiring any mechanical element to engage the slurry. Appropriate purges, baffles, and discharge mechanisms may be provided. Alternatively, a tramp material separator may be built into an otherwise conventional metering screw in a digester feed system, or one or more centrifugal separators can be provided downstream of the slurry pump in a chip slurry transport system or digester feed system.

Abstract: A discontinuous lignocellulose fiber is described for use as a reinforcing filler for thermoplastic composite compositions. The fiber filler includes a significant percentage by weight of long, “hair-like” fibers. Specifically, at least about 20 percent by weight of the fiber filler is discontinuous lignocellulose fiber with a fiber length greater than about 15 millimeters and a fiber diameter less than about 0.5 millimeters. A moldable thermoplastic composite composition including the discontinuous lignocellulose fiber comprises about 20 to about 50 percent by weight of the fiber filler and about 50 to about 80 percent by weight thermoplastic. The discontinuous lignocellulose fiber filler yields thermoplastic composite compositions having improved physical properties over basic thermoplastic. The improved physical properties can be achieved without the use of coupling agents, although coupling agents may be used to further enhance the composite properties.

Abstract: A method of processing recycled waste paper includes pulping waste paper in a first drum pulper. White fibers are separated from the waste paper in a first screen drum. The white fibers are then processed by screening, cleaning, deinking and bleaching. The remaining waste paper is pulped within a second drum pulper. The brown fibers are separated from the waste paper in a second screen drum. The brown fibers are processed by screening, cleaning and bleaching.

Abstract: A pressure screening apparatus for screening a stock suspension and screen clearer for a pressure screening apparatus.

Abstract: A method for treating diverse pulp and paper products to produce a homogenous cellulosic feedstock comprises the steps of feeding diverse pulp and paper products into a vessel, introducing steam into the vessel while agitating the products, purging the gases from the vessel while agitating the products, sealing the vessel so that the vessel is pressure tight, saturating the products with steam at sufficient temperature and pressure to expand molecular structure of the products, while agitating the products, depressurizing the vessel to further enhance the molecular expansion of the products, and discharging the processed products. Alternatively, the method can be performed without purging the gases, if the temperature in the range of about 287° F. to about 312° F., and the pressure is in the range of about 40 to 65 psig.

Abstract: Process and apparatus for removing fine impurities from a fibrous suspension. The process and apparatus each provide for conveying the fibrous suspension to at least one sorting device, separating the fibrous suspension using the at least one sorting device into an accepts portion and a rejects portion, finishing at least some of the accepts portion leaving the at least one sorting device using a finishing device, separating at least some portion of the rejects portion leaving the at least one sorting device using at least one last sorting device into an accepts portion and an rejects portion, separating at least some portion of the accepts portion leaving the at least one last sorting device into an accepts portion and a rejects portion using a flotation device, and finishing at least some portion of the accepts portion leaving the flotation device using the finishing device.

Abstract: A device and process for aerating dispersions, particularly for flotation of pulp suspensions, in a de-inking process. The process includes at least two stages, where each stage has a separate liquid circulating system which sucks in the gas or air and mixes it with the liquid. The device has at least two flotation cells, with each of the cells having a separate injector and a separate circulation system including a pump.

Abstract: The present invention relates to a method for recycling of old corrugated container (OCC) using flotation and kneading treatment and more particularly, to a method for recycling of OCC, wherein OCC is treated withflotation and kneading, treatment, and thereby removing fines and ink spot in the waste pulp and improving the strength and drainage property. As a result, it can be recycled similar to the expensive virgin unbleached kraft pulp.

Abstract: A hydrocyclone and a process for discharging impurities from a suspension containing paper fibers using a hydrocyclone having a radially inner area. The hydrocyclone includes an inflow for introducing the suspension to be purified, an accepted stock outflow for discharging the purified suspension, a separating part, a reject discharge device for discharging impurities of the suspension, at least one element for adding a diluting liquid at an addition point which is located in a radially inner area of the hydrocyclone, wherein the at least one element has at least one aperture opening axially and opposite to a discharge direction of the impurities. The process includes adding a diluting liquid into the suspension in the radially inner area of the hydrocyclone, wherein the diluting liquid is added in a flow direction opposite to an axial discharge direction of the impurities.

Abstract: A discontinuous lignocellulose fiber is described for use as a reinforcing filler for thermoplastic composite compositions. The fiber filler includes a significant percentage by weight of long, “hair-like” fibers. Specifically, at least about 20 percent by weight of the fiber filler is discontinuous lignocellulose fiber with a fiber length greater than about 15 millimeters and a fiber diameter less than about 0.5 millimeters. A moldable thermoplastic composite composition including the discontinuous lignocellulose fiber comprises about 20 to about 50 percent by weight of the fiber filler and about 50 to about 80 percent by weight thermoplastic. The discontinuous lignocellulose fiber filler yields thermoplastic composite compositions having improved physical properties over basic thermoplastic. The improved physical properties can be achieved without the use of coupling agents, although coupling agents may be used to further enhance the composite properties.

Abstract: Apparatus for removing fine impurities from a fibrous suspension comprises a dissolution device, a pre-purification device, a wet straining device, and at least one flotation device. The wet straining device comprises at least two sorting devices present in sequence, each sorting device having a wire for separating the fibrous suspension into an “accepts” portion and a “rejects” portion. The flotation device is adapted to purify the “accepts” portion of at least one sorting device, and further separates the fibrous suspension into an “accepts” portion and a “rejects” portion. The process for removing fine impurities from a fibrous suspension comprises the steps of subjecting the fibrous suspension to a dissolution process, subjecting the fibrous suspension to a pre-purification process, purifying the fibrous suspension in a wet straining process, and purifying “accepts” portions from the wet straining process by a flotation process.

Abstract: Process and apparatus for separating compressed material containing paper fibers where the apparatus includes at least three hammer rollers arranged essentially in a same plane and each hammer roller includes rotatable hammers. The process includes rotating the rotatable hammers, transporting the material over the at least three hammer rollers in a transport direction essentially parallel to the plane and transverse to the axes of the rollers, breaking up the material into fine material and non-fine material, and separating the fine material from the non-fine material by allowing the fine material to pass through gaps formed between the hammer rollers. The apparatus includes a machine frame and a plurality of rotors arranged next to one another in the machine frame. Axes of the driven rotors are arranged to lie in at least one plane, and the rotors are positioned to form free gaps between the driven rotors.

Abstract: Process for dissolving used paper including adjusting a content of solid particles of used paper to a range between about 15 and 35%, kneading the used paper with a specific work of at least about 10 kWh/t, diluting the kneaded used paper to a content of solid particles below about 6%, separating non-fibrous contaminants with wet screening, adjusting a solid material content to less than about 3%, and separating heavy particles with at least one hydrocyclone.

Abstract: Cellulosic fines and cellulosic fibers are separated from a suspension containing the fines, the fibers and hydrophobic materials by screening the suspension to remove the fibers, and then subjecting the resultant filtrate to dispersed air flotation in the presence of calcium and generally a separation aid to form an upper Reject fraction in which the hydrophobic material is concentrated and a lower Accept fraction in which the cellulosic fines are concentrated.

Abstract: Apparatus is disclosed for screening fiber suspensions including a housing, an annular screen disposed within the housing, a rotor disposed within the annular screen for rotating relative to the annular screen, pulsation wings disposed between the outer surface of the rotor and the annular screen for relative rotation with the rotor, an inlet for the fiber suspension to feed the fiber suspension to one end of the screening zone, an accept outlet for a portion of the fiber suspension which passes through the annular screen, a reject outlet for a portion of the fiber suspension which does not pass through the annular screen, and a dilution liquid nozzle for supplying a dilution liquid to the screening zone between the rotor and the annular screen, the dilution liquid nozzle disposed proximate to the reject outlet and directing the dilution liquid into the screening zone along the outer surface of the rotor.

Abstract: The invention comprises, in one form thereof, a method of removing wax from recycled cellulosic fiber. The cellulosic fiber is pulped in a pulper to a suspension with a consistency of less than about 10% by weight. The suspension is then screened to remove coarse and fine contaminants. The screened suspension is diluted to a consistency of less than about 3% by weight. The wax is removed from the diluted suspension using a froth flotation device. The suspension is then washed and/or thickened.

Abstract: A screen apparatus of the invention is provided with a tank for receiving a papermaking material; a screen situated inside the tank for dividing the tank into a first chamber and a second chamber to separate a foreign substance from the papermaking material; a first supply passage for supplying the papermaking material into the tank; a second supply passage for supplying the papermaking material into the tank; a stirring member disposed between an inner wall of the tank and the screen to stir the papermaking material introduced in the first chamber; a screened papermaking material discharge passage communicating with the second chamber for discharging a screened papermaking material outside the tank; and a foreign substance discharge passage communicating with the first chamber for discharging a foreign substance outside the tank.

Abstract: The process targets the removal of interfering materials from an aqueous fibrous material suspension, especially if this is produced from recycled paper. Thereby interfering materials, such as printing ink particles, small synthetic particles, or sticky contamination, are eliminated by flotation in a particularly advantageous manner. In accordance with the invention, the combination of low-intensity and high-intensity flotation is undertaken, whereby the low-intensity flotation generally works in the gravitational field and the high-intensity flotation in a centrifugal field.

Abstract: This invention relates to a process for recovering raw materials from a stream of residual or collected material (R) which comprises a plurality of different materials and which arises during the manufacture of paper (P) in a paper mill (1) and/or in a material processing installation (2) and/or in a paper machine (3) and which is discharged therefrom, wherein the stream of residual or collected material (R) is fed to an installation (4) for separating at least one fiber fraction contained in the stream of residual or collected material (R) via a screening operation and for separating an ash fraction (A) comprising black particles.

Abstract: A casing has a pulp slurry inlet, a reject outlet and an accept stock outlet and accommodates a rotor. The rotor has a hollow cylinder with scraper blades at its outer periphery. A screen plate is disposed outside of the scraper blades to provide between them a passage facing to the screen plate. The hollow cylinder is formed with pulp slurry outlets. Rotation of the hollow cylinder causes the pulp slurry to be circulated outside and inside of the hollow cylinder, so that separation of the pulp slurry into accept stock and reject is repeatedly carried out by the screen plate.

Abstract: An alkaline cellulose pulp pulping process treats soap and fiber-containing liquids to separate fibers from the liquids prior to further treatment of the liquids (e.g. by evaporation and combustion, or by cooking to produce tall oil). Black liquor containing soap, and/or washer filtrate containing soap, are fed to one or more soap separating tanks, and then the soap fraction from the top of the tanks is fed to a pressure screen where fiber separation takes place (preferably at a temperature of at least 70.degree. C.). Black liquor may be added to the soap fraction to dilute it, and preferably simultaneously raise its temperature. The pressure screen has a screen surface with holes of 0.4 mm diameter or less, or slots with a width of 0.2 mm or less.

Abstract: A screen apparatus is formed of a tank for receiving a papermaking material, a cylindrical first screen for partitioning the tank into a first chamber and a second chamber, an annular second screen disposed in the first chamber, and a rotating member disposed in the first chamber. The first screen has a closed end at one side, an open end at the other side, and a plurality of first openings in a circumferential portion thereof. The annular second screen has second openings in a plate portion and a large opening at the center thereof. The annular second screen is disposed adjacent to the first screen at the side of the closed end, and the rotating member faces the large opening of the second screen and the closed end of the first screen. Also, the rotating member includes first agitating members facing the second screen, and second agitating members facing the second screen.

Abstract: The present invention relates to a method for treating a pulp suspension in which the suspension is rotated in a rotationally symmetrical, rapidly rotating and permeable screen basket so that the suspension is subjected to the influence of a centrifugal force and dewatered at the same time as the suspension is conveyed by a rotating screw along the inner wall of the screen basket. The invention is characterized in that the suspension is caused to rotate by means which are arranged at the entrance to the screen basket, and in that the outer edges of the said screw bear against or are immediately adjacent to the screen basket and rotate at a higher speed than does the screen basket so that the screw scrapes the inner wall of the screen basket.

Abstract: A method and apparatus for decontaminating a liquid suspension comprising a decontaminating cell. The decontaminating cell has an upper light contaminate collection hood and/or a lower heavy contaminate collection trough. A method and apparatus are provided for decontaminating a liquid suspension by infusing the suspension with a gas, mechanically agitating the suspension, or providing chemical additives thereto. The liquid suspension is then directed to the decontaminating cell under a pressure head sufficient to purge the contaminates therefrom.

Abstract: A wastepaper treatment method and system which combines the pulping and sorting in a pulping drum (10) with a following wet-strength processing, performed with high mechanical intensity, e.g., in a pulper (20). With the easily pulping paper materials being separated already from the drum (10) in a fines fraction (3), particular advantages result in terms of quality and economy.

Abstract: A method and apparatus for controlling a multi-step screening apparatus (1) controls other accept, reject and dilution flows in relation to the flow measured in the accept channel (7a) of the first screening step (3a). Thus a simpler control unit (9) can be used and accept of higher quality can be obtained than before. The apparatus has a control unit (9) aranged to measure the flows of all accept, reject and dilution water channels (7a-7c, 5a, 5b, 11a, 11b) and to adjust the flow of the other channels on the basis of the flow of the accept channel of the first step.

Abstract: Disclosed is a process for fractionating cellulosic fibers that is effective to result in cellulosic fibers that exhibit desired properties such as fiber length and fiber coarseness values. The fractionating process is quite efficient and has been found to produce cellulosic fibers that are more homogeneous in their properties as compared to the starting mixture of cellulosic fibers. Also disclosed is a handsheet prepared from the fractionated cellulosic fibers for use in disposable absorbent products.

Abstract: A method of papermaking having zero liquid discharge. A pulp slurry is produced from recycled cellulosic material and the slurry contains suspended cellulosic fiber material, solid contaminants and dissolved water soluble solids. The pulp slurry is subjected to a cleaning operation to produce a first flow stream containing the cellulosic fiber material and dissolved solids and a second flow stream containing dissolved solids along with solid contaminants. The first flow stream is washed with water to remove a substantial portion of the dissolved solids and provide a washed pulp which is used in a papermaking machine to produce a paper sheet. The second flow stream from the cleaning operation is compacted to produce a solid residue that can be landfilled and a liquid residue containing dissolved solids that can be recycled to the pulp cleaning operation.

Abstract: Disclosed is a process for upgrading paper-grade wood pulp to dissolving grade pulp which is suitable for use in the preparation of viscose rayon, cellulose ethers and cellulose esters such as cellulose acetate. The process utilizes a sequence of caustic extraction, xylanase treatment and caustic extraction to remove most of the xylan, which may be recovered for use in the production of xylose, xylitol, and furans.

Abstract: A paper-making screen apparatus for separating foreign matters from paper-making raw materials is formed of a screen having a first annular end plate located at an end; a second annular end plate located at the other end thereof, having a plurality of openings for male screws; a plurality of interval keeping members secured to the first and second end plates to keep an interval therebetween, and having female screws on the side facing the second end plate; a plurality of male screws engaging the female screws; and a plurality of rod-shaped members connected to the first and second end plates, and annularly arranged parallel to each other at certain intervals.

Abstract: A sieve for sorting fiber suspensions, symmetrical in relation to an axis, with an inflow side for the fiber suspension to be sorted and an opposite outflow side. This sieve is useful for pressure sorting machines having a rotor that may be rotated around the axis of the sieve and that is provided with profiled elements around the inflow side of the sieve in order to generate positive and negative pressure pulses in the fiber suspension that is to be sorted. The inflow side of the sieve has grooves approximately parallel to the axis of the sieve that follow each other in the circumferential direction of the sieve. A through-channel opens into each groove. The grooves are delimited by a front and a rear side wall, seen in the direction of rotation of the profiled elements.