Abstract: Water draining device for a paper machine or the like, in particular for a felted press of such a paper machine, including a receiving tank extending at least essentially over the machine width. The receiving tank includes a first chamber that receives arriving water and is under ambient pressure, and a second chamber that is connected to the first chamber and is under vacuum, into which the water collecting in the first chamber is aspirated and from which the water is eventually drained. A water receiving device of improved efficiency is also provided by forming a water receiving device by at least one suction channel projecting into the wedge-shaped area between the upper press roll and the dewatering belt, and extending transverse to the pulp web, which suction channel is connected to a source of reduced pressure.

Abstract: The invention relates to a method of controlling the production of filler-containing paper. Filler and retention agent are both delivered to the paper manufacturing system in such a process of paper manufacture. The amount of filler in the paper is also measured, as is also the filler concentration or the total concentration in the white water or the stock. Filler is delivered in a quantity such that the system will be buffered with filler to a generally pre-determined concentration level (control value), which is followed via measuring processes.

Abstract: In a method and an associated apparatus for discharging the whitewater from inside the loop of a continuous dewatering wire of a former, specifically a twin wire former in a paper machine the accumulating whitewater is collected by a collection tank, which is located within the loop; the collected whitewater is separated from the air, still inside the loop, by suctioning off of the area above the collection tank and the whitewater is removed from the collection tank through at least one channel that is connected to the collection tank and is located below the collection tank's water level.

Abstract: Methods for forming an absorbent fibrous composite containing absorbent material dispersed in bands through the composite and along the composite's length are disclosed. The methods generally include depositing a fibrous slurry on a foraminous support to form a web and depositing or injecting absorbent material into the web across its width to provide a web having absorbent material in bands along the composite's length. Drying the web provides a fluted absorbent composite. In one embodiment, the method is a wetlaid method and in another embodiment, the method is a foam-forming method. Preferably, the methods are twin-wire forming methods.

Abstract: A process for producing paper materials having improved wet strength. This process involves (a) preparing a suspension of unbleached or semi-bleached chemical or semichemical pulp or pulp from recycled fibers; (b) treating the pulp with a phenol-oxidizing enzyme and a mediator; and (c) de-watering the treated pulp in a paper making machine to remove process water and produce the paper material. Preferably, the paper material is heated after the completion of step (c). By the process of the invention, the wet strength of paper materials can be improved without using wet strength resins which makes the product more easily re-used. Further disclosed is a process for producing corrugated paperboard or corrugated containers.

Abstract: This invention is directed to high molecular weight water-soluble polymers comprised of zwitterionic, nonionic and cationic or anionic monomer units, and to the use of these polymers in papermaking processes.

Abstract: The invention relates to a process for controlling microbial growth in a production line for cellulosic products with the aid of gases. The invention also relates to the use of gases such as carbon dioxide, nitrogen, argon and/or non-naturally occurring mixtures thereof for controlling microbial growth. In the process an aqueous material containing water and suspended pulp fibers and/or additives therefor is treated with the gaseous inhibitor to significantly retard or inhibit the growth of microorganisms therein. An oxygen rich gas may be introduced in addition to the inhibitor of the invention.

Abstract: A method for manufacture of loaded paper or paperboard products, comprising the steps of separating at least one process stream from the papermaking process, wherein the process stream includes fines and/or filler; combining the process stream with long fibers and thickening to form a residue; treating the residue to form fiber-filler complexes; and using the fiber-filler complexes in the papermaking process to form the paper.

Abstract: The invention relates to a process for improving the drainage or dewatering of cellulosic pulp suspensions in a paper making machine, a drying machine or the like assembly. The invention also relates to a process for producing a dried cellulosic product from said pulp suspension. The drainage of said pulp suspension is improved by treating it with carbon dioxide just prior to its entering a dewatering device such as the wire section of a paper machine.

Abstract: Method for regulating a basis weight of a paper or cardboard web in the manufacturing process. The method includes determining a basis weight at an end of the manufacturing process, calculating a deviation of the determined basis weight from a predetermined target value, adjusting a concentration of a material suspension supplied to a headbox via a first control loop such that the calculated deviation is corrected, one of directly and indirectly measuring a basis weight of a resulting web in a region upstream, with regard to a web travel direction, a drying section, and supplying a signal related to the measured basis weight to a second control loop.

Abstract: A non-woven web of fibrous material is produced using a moving foraminous element in the practice of the foam process. A first foam slurry of air, water, fibers and a surfactant is generated and centrifugally pumped into contact with the moving foraminous element. Substantially fiber-free foam is withdrawn from the foraminous element while forming a non-woven web of fibrous material on the foraminous element, and at least a part of the substantially fiber-free foam is used in the generation of the first foam slurry. Recycling is also typically practiced using a centrifugal pump, and the centrifugal pumps are preferably degassing pumps which remove some of the gas from the foam. By practicing the invention it is possible to produce fibrous webs using the foam process that are more than two meters wide, and at a forming speed of more than about 100 m/min (e.g. about 200-500 m/min).

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: Chemical additives can be adsorbed on cellulosic papermaking fibers at high levels with a minimal amount of unadsorbed chemical additives present in the papermaking process water. A method includes treating a fiber slurry with an excess of the chemical additive, allowing sufficient residence time for adsorption to occur, filtering the slurry to remove unadsorbed chemical additives, and redispersing the filtered pulp with fresh water. Filtrate from the thickening process contains unadsorbed chemical additive and it is not sent forward in the process with the chemically treated fibers. The method can be employed to make improved paper products.

Abstract: Device and process for controlling or regulating a basis weight of a web in a web manufacturing process of a web producing machine. The device includes a first control circuit, adapted to adjust the basis weight, that includes at least one adjustable device for influencing the basis weight and at least one basis weight sensor. A second control circuit having at least one sensor for detecting a concentration of incoming backwater is also provided. The process includes measuring the basis weight of the material web, adjusting the basis weight of the web with a first control device having at least one device for influencing the basis weight, detecting a retention change in a second control circuit, and counteracting the retention change by influencing a concentration of a stock suspension placed one of onto a wire and between wires.

Abstract: Apparatus and process for guiding portions of backwater produced or stored at different levels of a machine. The apparatus includes an upper backwater chamber arranged to receive first backwater, a lower backwater chamber arranged below the upper backwater chamber and to receive at least a portion of the first backwater from the upper backwater chamber. A plurality of hydraulic lines are arranged to couple the upper backwater chamber to the lower backwater chamber, and inlet openings of the plurality of hydraulic lines are arranged inside the upper backwater chamber and are arranged at different geodetic heights relative to one another. The process includes collecting first backwater in an upper backwater chamber, and guiding the first backwater from the upper backwater chamber to a lower backwater chamber through inlet openings to a plurality of hydraulic lines. The inlet openings are arranged at different geodetic heights relative to one another.

Abstract: An arrangement for handling white water from a paper machine comprises a white water channel having an inlet end for receiving white water from a paper machine and an opposite outlet end defining a main outlet through which the white water is discharged into a container. A channel bottom slopes downward and an additional outlet is provided between the main outlet and the inlet end, the bottom having a first bottom portion that leads away from the inlet end up to the additional outlet and a second bottom portion that leads away from the additional outlet toward the main outlet. The first and second bottom portions are so arranged in relation to each other that each of the bottom portions slopes downward in the flow direction at an angle of inclination that exceeds a critical angle of inclination that avoids sedimentation on the bottom.

Abstract: Apparatus and process for producing foam formed fibrous web in which the furnish is made up by mixing a thin water slurry of fibers at a consistency in the range of from about 0.5 to about 7 weight percent fibers with sufficient aqueous foam containing a surfactant and having an air content in the range of from about 55 to about 80 percent by volume to form a foamed fiber furnish containing from about 0.1 to about 3 weight percent fibers which is supplied directly to the forming felt or wire of a twin wire papermaking machine, adding makeup surfactant and discarding excess aqueous foam from the process as required to maintain the desired volume of foamed liquid therein.

Abstract: Backwater cycle of and process for circulating water in a paper machine having a wet zone. The backwater cycle includes at least one application device arranged to apply a composition containing at least one of pigment and filler onto a fiber web in the wet zone, a first backwater cycle that supplies a stock inlet with backwater removed from the production process upstream, relative to a web travel direction, of the at least one application device, and a second backwater cycle that accepts a remainder of the backwater. The process includes extracting backwater from the fiber web, and feeding backwater, which is not charged with the at least one of pigments and fillers, to a stock inlet.

Abstract: Compositions of aluminum chlorohydrate and high molecular weight branched epichlorohydrin amine condensate polymers are applied to waste liquids, such as pulp and paper mill effluents having a lignin content, to reduce true color. The branched epichlorohydrin amine condensate polymer is branched using branching agents which result in a molecular weight greater than about 300,000 and permit solubility. When applied to waste liquids, the high molecular weight branched epichlorohydrin amine condensate polymer and aluminum chlorohydrate react with the lignin components in the waste liquid to form an insoluble agglomerate thus reducing the true color of the waste liquid. The resulting agglomerate, including the colored lignin, may be filtered from the waste liquid.

Abstract: A method for eliminating detrimental substances in a process liquid. The process liquid has a first pH and, in addition to said detrimental substances, comprises metal ions and suspended material. Carbon dioxide is added to the process liquid in order to bring the process liquid to a second pH, lower than the first pH. Thereby, the metal ions comprise hydroxide builders, wherein the carbon dioxide (CO2) is added in an amount which causes the second pH to be between 8 and 6.5, so that the carbon dioxide primarily forms bicarbonate ions (HCO3−) having a pH-buffering effect and the metal ions primarily form metal hydroxides. Thereafter, the detrimental substances coagulate or agglomerate with the metal hydroxides and are adhered to the suspended material so that they become inactive. The method is advantageously used in connection with pulp and/or paper making processes.

Abstract: The present invention relates to a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, and to the use of a thus obtained pigment slurry for the preparation of a coating compound for the paper industry or in the paper stock for papermaking. An essential element of the invention is a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, characterized in that the residual water sludges containing the fillers and coating pigments are subjected to mixing and then milling together with fresh pigments or fresh fillers in the form of powders, fresh-pigment containing slurries and/or fresh-filler containing slurries to yield a pigment slurry.

Abstract: A nonwoven web of fibrous material is made by the foam process using a manifold of a particular construction. The manifold has a casing with first and second opposite ends including an inlet for a foam-fiber-surfactant slurry at the first end, and optionally a valved outlet at the second end. A center section of the manifold casing has a (e.g. rectangular) cross-section that becomes smaller moving from an inlet toward the outlet. First and second substantially closed side walls, a porous front wall having an effective length, and a back wall opposite the front wall, are provided for the center section, the walls planar or curved. Any suitable structures are provided for introducing a second (e.g. substantially fiber-free, or a fiber-foam slurry) foam into the center section through the back wall.

Abstract: Process and device for the mixing of suspensions with possibly different natures and/or compositions in the stable section of a paper machine. In the process, a suspension, particularly of the backwater of the paper machine, is piped in a mixing tube with the main flow direction in the longitudinal direction of the tube, and additional suspensions, with possibly different solid content, are injected. In the device, a mixing device and piping carry the suspension in the stable section of a paper or cardboard machine and blend suspensions with a higher solid content into a first suspension with little or no solid content. The mixing device and piping include a tube, at least one inlet for the first suspension, a plurality of feeds for the higher solid content suspensions to be admixed, and one outlet for the blended suspension, with a new solid content, arranged downstream from a bend in the tube.

Abstract: In a method and an associated apparatus for discharging the whitewater from inside the loop of a continuous dewatering wire of a former, specifically a twin wire former in a paper machine the accumulating whitewater is collected by a collection tank, which is located within the loop; the collected whitewater is separated from the air, still inside the loop, by suctioning off of the area above the collection tank and the whitewater is removed from the collection tank through at least one channel that is connected to the collection tank and is located below the collection tank's water level.

Abstract: Chemical additives can be adsorbed on cellulosic papermaking fibers at high levels with a minimal amount of unadsorbed chemical additives present in the papermaking process water. A method includes treating a fiber slurry with an excess of the chemical additive, allowing sufficient residence time for adsorption to occur, filtering the slurry to remove unadsorbed chemical additives, and redispersing the filtered pulp with fresh water. Filtrate from the thickening process contains unadsorbed chemical additive and it is not sent forward in the process with the chemically treated fibers. The method can be employed to make improved paper products.

Abstract: Apparatus and process for producing foam formed fibrous web in which the furnish is made up by mixing a thin water slurry of fibers at a consistency in the range of from about 0.5 to about 7 weight percent fibers with sufficient aqueous foam containing a surfactant and having an air content in the range of from about 55 to about 80 percent by volume to form a foamed fiber furnish containing from about 0.1 to about 3 weight percent fibers which is supplied directly to the forming felt or wire of a twin wire papermaking machine, adding makeup surfactant and discarding excess aqueous foam from the process as required to maintain the desired volume of foamed liquid therein.

Abstract: A method of treating solid containing material derived from effluent or sludge from a plant for de-inking paper, the material containing calcium in the form of one or more insoluble calcium compounds, the method including the steps of treating the material with an acid to cause dissolution of the calcium thereby forming a calcium ion-containing solution in which insoluble solids are suspended, separating the solution from the insoluble solids and incinerating the separated solids. The solution containing calcium ions may be treated by adding one or more reagents to form a calcium compound precipitate, eg calcium carbonate. The particulate solids produced following the incineration step and following the precipitate formation may be employed as pigments or fillers in paper making or paper coating.

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: Apparatus and process for producing foam formed fibrous web in which the furnish is made up by mixing a thin water slurry of fibers at a consistency in the range of from about 0.5 to about 7 weight percent fibers with sufficient aqueous foam containing a surfactant and having an air content in the range of from about 55 to about 80 percent by volume to form a foamed fiber furnish containing from about 0.1 to about 3 weight percent fibers which is supplied directly to the forming felt or wire of a twin wire papermaking machine, adding makeup surfactant and discarding excess aqueous foam from the process as required to maintain the desired volume of foamed liquid therein.

Abstract: The invention relates to a method of recovering energy in a forming section of a papermaking or boardmaking machine, wherein stock from a headbox is fed into a forming zone of a forming section, said forming zone including at least one looped forming fabric curving along a convex surface of a support member, and water is drained from the stock through said at least one forming fabric in the forming zone to form a paper or board web, the water passing through said at least one fabric being thrown out from the forming zone and possessing kinetic energy, characterized by placing a movable component in the water thrown out from the forming zone, so as to cause the water to move the component, and thereby recovering part of the kinetic energy. The invention also relates to an arrangement in a papermaking or boardmaking machine.

Abstract: A sample collecting device takes samples from the white water drained from the web through the wire in the wire part, at a number of points in the cross direction of the web. An analyzer analyses the samples and forms a retention profile for controlling the paper machine. The device for measurement and regulation of the retention profile comprises means for measurement of the retention profile across the web width from different points of width of the web. The headbox comprises ducts passing to different points of width of the headbox to pass a flow of liquid containing a retention agent in the headbox into connection with the stock flow to regulate the retention profile across the web width. The ducts have valves which are regulated on the basis of the retention profile data for regulating the retention agent into duct flow.

Abstract: An arrangement for handling white water from a paper machine comprises a white water channel having an inlet end for receiving white water from a paper machine and an opposite outlet end defining a main outlet through which the white water is discharged into a container. A channel bottom slopes downward and an additional outlet is provided between the main outlet and the inlet end, the bottom having a first bottom portion that leads away from the inlet end up to the additional outlet and a second bottom portion that leads away from the additional outlet toward the main outlet. The first and second bottom portions are so arranged in relation to each other that each of the bottom portions slopes downward in the flow direction at an angle of inclination that exceeds a critical angle of inclination that avoids sedimentation on the bottom.

Abstract: The invention relates to a method and equipment for controlling properties of paper, in which method the effect of the flow of retention agent (Fra) and the stock flow (Fts) on the basis weight of the paper (BW) is modelled. The fulfilled modelling is used to adjust the basis weight of the paper (BW) by controlling simultaneously the flow of retention agent (Fra) and the stock flow (Fts).

Abstract: The invention relates to a method and equipment for controlling properties of paper, which method comprises modelling the effect of the flow of retention agent (Fra) both on the amount of filler in the white water and on the paper ash content (ASH), and the effect of the flow of filler (Ffi) both on the paper ash content (ASH) and on the amount of filler in the white water. The fulfilled modelling is used to adjust the amount of filler in the white water and the paper ash content (ASH) by controlling simultaneously the flow of retention agent (Fra) and the flow of filler (Ffi).

Abstract: There is provided a deinking process carried out using white water according to which an excellent whiteness and an excellent areal ratio of residual ink fines can be secured while maintaining a proper pulp yield. In the deinking process comprising a flotation step wherein use is made of treatment water containing white water, at least part of the flotation step is effected in the presence of at least one compound selected from the group consisting of cationic compounds, amine compounds, acid salts of amine compounds, and ampholytic compounds.

Abstract: A method and apparatus for recovery of surfactant from a foamable liquid aqueous solution thereof wherein foamable liquid containing surfactant is sparged with air or gas forming foam enriched in surfactant and residual liquid depleted in surfactant, foam enriched in surfactant is separated from residual liquid and resolved into foamable liquid enriched in surfactant by separation of gas or air therefrom.

Abstract: The invention relates to a method of recovering energy in a forming section of a papermaking or boardmaking machine, wherein stock from a headbox is fed into a forming zone of a forming section, said forming zone including at least one looped forming fabric curving along a convex surface of a support member, and water is drained from the stock through said at least one forming fabric in the forming zone to form a paper or board web, the water passing through said at least one fabric being thrown out from the forming zone and possessing kinetic energy, characterized by placing a movable component in the water thrown out from the forming zone, so as to cause the water to move the component, and thereby recovering part of the kinetic energy. The invention also relates to an arrangement in a papermaking or boardmaking machine.

Abstract: Mixing and recirculation cycling system and method, for use in the stable section of a paper or cardboard machine. The system includes a dilution water-regulated headbox, a backwater tank having a backwater inlet and at least one stock suspension inlet adapted to provide for the mixing of stock suspensions with the backwater. Also provided is a mixing tank operatively connected to the backwater tank, at least one backwater inlet operatively connected between the backwater tank and the headbox, and a pressure-increasing device operatively connected between the mixing tank and the backwater tank.

Abstract: Water draining device for a paper machine or the like, in particular for a felted press of such a paper machine, including a receiving tank extending at least essentially over the machine width. The receiving tank includes a first chamber that receives arriving water and is under ambient pressure, and a second chamber that is connected to the first chamber and is under vacuum, into which the water collecting in the first chamber is aspirated and from which the water is eventually drained. A water receiving device of improved efficiency is also provided by forming a water receiving device by at least one suction channel projecting into the wedge-shaped area between the upper press roll and the dewatering belt, and extending transverse to the pulp web, which suction channel is connected to a source of reduced pressure.

Abstract: A process arrangement for the short circulation in a paper or board machine including stock chests for component stocks, metering pumps for component stocks, cleaning devices, pumps, a headbox and a wire section as well as a system of pipes connecting these elements, together with regulation devices. After the metering pumps, the component stock flows are passed into a closed mixing volume in which the component stocks are mixed and diluted with a first dilution water flow. From this closed mixing volume, the stock is passed in a closed space by a first feed pump of the main line of the process through a screen and a centrifugal cleaner to the suction side of a second feed pump of the main line, where a second dilution water flow is passed to the stock. The second feed pump feeds the stock through a machine screen to the inlet header in the headbox.

Abstract: Regulation method in a paper machine for controlling the variation of the basis weight of a paper web in the machine direction in which the basis weight profile of the web is measured by means of a measurement device and a basis weight regulation system receives a signal of the measurement of the basis weight from the measurement device and generates a regulation signal for controlling the flow of thick stock passed into a short circulation circuit in the paper machine by a basis weight valve and/or a regulation pump. The variation of the basis weight in the machine direction in the paper machine is controlled, besides by the short circulation circuit of regulation, also by a substantially faster second circuit of regulation which comprises one or more actuators for controlling the flow rate of the dilution water flow in the dilution profiling system of the headbox and/or the consistency of the dilution water flow across the entire width of the paper web.

Abstract: A nonwoven web of fibrous material is made by the foam process using a manifold of a particular construction. The manifold has a casing with first and second opposite ends including an inlet for a foam-fiber-surfactant slurry at the first end, and optionally a valved outlet at the second end. A center section of the manifold casing has a (e.g. rectangular) cross-section that becomes smaller moving from an inlet toward the outlet. First and second substantially closed side walls, a porous front wall having an effective length, and a back wall opposite the front wall, are provided for the center section, the walls planar or curved. Any suitable structures are provided for introducing a second (e.g. substantially fiber-free, or a fiber-foam slurry) foam into the center section through the back wall.

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: A non-woven web of cellulosic synthetic fibrous material is produced using a twin wire former. The former may have a closed first end and closed first and second sides, and a second end provided by first and second moving foraminous elements. An interior structure between the sides and second end may have at least first and second different length pluralities of conduits extending from the former first end toward the second end, and defining by themselves, or with wall elements, the interior volume into a first volume and a second volume on opposite sides thereof. A first fiber/foam slurry is introduced into the first volume and a second fiber/foam slurry in the second volume, and suction box assemblies are provided on the opposite sides of the foraminous elements from the interior volume for withdrawing foam from the slurries to forming a non-woven web on the foraminous elements.

Abstract: Process for cleaning or maintaining the cleanliness of a low-consistency branch of a stock density-regulated headbox system including a constant part of a paper or cardboard machine having at least one high-consistency branch and one low-consistency branch, possibly sectioned. The final concentration output by the headbox onto a wire or between two wires is determined by a mixing ratio of high-concentration and low-concentration suspension flows. The process includes supplying the low-consistency branch with an increased content of solid particles. Headbox system including a constant part of a paper or cardboard machine, having a stock density regulation that is sectioned across the machine width by variably mixing a high-consistency suspension and a low-consistency suspension, with a high-consistency branch and a low-consistency branch. The headbox system includes at least one supply to the low-consistency branch for introducing solid particle contents into the suspension flow.

Abstract: The present invention relates to a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, and to the use of a thus obtained pigment slurry for the preparation of a coating compound for the paper industry or in the paper stock for papermaking. An essential element of the invention is a process for recycling fillers and coating pigments from the preparation of paper, paperboard and cardboard found in the residual water sludges from coating plant waste waters, deinking plants, internal water treatment plants or separators, characterized in that the residual water sludges containing the fillers and coating pigments are subjected to mixing and then milling together with fresh pigments or fresh fillers in the form of powders, fresh-pigment containing slurries and/or fresh-filler containing slurries to yield a pigment slurry.

Abstract: Raw materials useable in the manufacture of paper, cardboard and carton are recovered from waste sludge. After precipitation of the coarse particles, the sludge is centrifuged to remove black particles and then divided by fractional screening into its fiber, filler, pigment and agglomerate components. The agglomerate component is shear-treated and again fractionated, while the fibers, fillers and pigments, following further treatment if necessary, are fed to their points of reuse.

Abstract: Process and device for the mixing of suspensions with possibly different natures and/or compositions in the stable section of a paper machine. In the process, a suspension, particularly of the backwater of the paper machine, is piped in a mixing tube with the main flow direction in the longitudinal direction of the tube, and additional suspensions, with possibly different solid content, are injected. In the device, a mixing device and piping carry the suspension in the stable section of a paper or cardboard machine and blend suspensions with a higher solid content into a first suspension with little or no solid content. The mixing device and piping include a tube, at least one inlet for the first suspension, a plurality of feeds for the higher solid content suspensions to be admixed, and one outlet for the blended suspension, with a new solid content, arranged downstream from a bend in the tube.

Abstract: A method in a paper machine for arrangement of water circulation therefor and arrangement of a water circulation system in a paper machine. In view of full or partial closing of the water circulations in a paper machine, the wash water flows from the fabrics and from other devices in the paper machine as well as the water drained from the paper web to be produced are recovered selectively based on the place of origin thereof in the paper machine. At least a part of the recovered different water flows are cleaned, and the cleaned water flows are recirculated to applications of reuse suitable in view of their washing potential in the papermaking process.

Abstract: Wastewaters and circulation waters in papermaking, in deinking and in pulp bleaching are treated by adsorption of water-soluble anionic compounds and compounds dispersed in water from the wastewaters and circulation waters over finely divided adsorbents which consist of insoluble, only slightly swellable polymers which contain polymerized vinylamine units, and these polymers are used as adsorbents for treating water circulations in papermaking and for treating paper machine wastewaters and wastewaters from the deinking process and from pulp bleaching.