Abstract: The invention relates to a method of producing a structured fibrous web of paper. The method comprises forming a fibrous web and conveying the formed fibrous web on a water receiving felt (5) to a dewatering nip. An endless belt (11) with a polyurethane surface is passed through the nip together with the fibrous web and the water receiving felt (5). After the dewatering nip, the fibrous web is conveyed by the endless belt (11) to an endless textured fabric (12) which is permeable to air and to which the web is transferred from the endless belt (11) in a transfer nip. The textured fabric (12) rans at a lower speed than the endless belt (11). After the transfer to the textured fabric (12), the fibrous web is carried by the textured fabric (12) to a drying cylinder (17). The transfer nip is formed by two rolls of which one is a suction roll within the loop of the textured fabric. The transfer nip has a length which is 5 mm-40 mm.

Abstract: Processes for making fluff pulp sheets mechanically eliminate many unwanted fiber-to-fiber bonding (fiber bundles) in the sheet. Pulp slurry is deposited on a moving bottom forming wire to form a stock web. Pulp slurry is brought into contact with a moving top forming wire. The stock web is subjected to up and down dewatering creating separately formed layers to reduce fiber-to-fiber bonding. The stock web can be subjected to strong pulsating shear forces as it is being advanced along the bottom forming wire to break fiber bundles. The pulp slurry can be deposited on the bottom forming wire utilizing a headbox with dilution control to selectively adjust the concentration of the pulp slurry. Shoe presses can be used to dewater the web after it is subjected to the pulsating shear forces.

Abstract: In an exemplary embodiment, the disclosed drying and dewatering system comprises an air knife and a vacuum slot, wherein the air knife is positioned over the vacuum slot and fibrous nonwoven material is passed under the air knife and over the vacuum slot. The embodiments of the present disclosure may be used to achieve greater water removal and more uniform binding agent distribution across the nonwoven fibrous material.

Abstract: A system and a method for dewatering an acoustical tile basemat comprising a continuously traveling wire, a device for depositing a dilute water slurry of solids including fiber and binder on the wire, a vacuum box below the wire for separating water from the solids deposited on the wire to form a basemat, a vacuum source, and a valve for cyclically connecting the vacuum source to the vacuum box at a cyclic rate that limits vacuum exposure to a length of the basemat newly arriving at the vacuum box to less than four inches per cycle.

Abstract: The fiber webs described herein may be incorporated into filter media and filter elements. The fiber webs may exhibit a high dust holding capacity. The fiber webs may also exhibit a low thickness. The fiber webs may be sufficiently flexible and/or deformable so that they may be processed to include a series of waves (also known as flutes) that extend along the cross-machine direction.

Abstract: The invention relates to a method of producing a structured fibrous web of paper. The method comprises forming a fibrous web and conveying the formed fibrous web on a water receiving felt (5) to a dewatering nip. An endless belt (11) with a polyurethane surface is passed through the nip together with the fibrous web and the water receiving felt (5). After the dewatering nip, the fibrous web is conveyed by the endless belt (11) to an endless textured fabric (12) which is permeable to air and to which the web is transferred from the endless belt (11) in a transfer nip. The textured fabric (12) rans at a lower speed than the endless belt (11). After the transfer to the textured fabric (12), the fibrous web is carried by the textured fabric (12) to a drying cylinder (17). The transfer nip is formed by two rolls of which one is a suction roll within the loop of the textured fabric. The transfer nip has a length which is 5 mm-40 mm.

Abstract: A method for forming a web of transversely extensible fibrous material includes the steps of subjecting a fluid-permeable endless conveyor belt of elastic material, of thickness increasing from its longitudinal axis to its edges, to a localized transverse stretching operation, achieved by temporarily withdrawing a longitudinal band thereof from the surface on which it naturally slides and maintaining it in contact, in this stretched condition, with at least a part of the surface of a support member; depositing a web of pliable fibrous material having a liquid content between 3% and 70% by weight against that portion of the conveyor belt of elastic material which has been transversely stretched; and with vacuum, maintaining the web of pliable fibrous material adhering to the conveyor belt of elastic material during its return to its original configuration, to cause the transverse contraction of the web and the simultaneous partial removal of liquid therefrom.

Abstract: There is disclosed an expansion molded product, and a web and stampable sheet suitable for use in the production thereof as well as a method of producing the same. A disclosed method of producing a web, stampable sheet and expansion molded product of a stampable sheet comprises uniformly dispersing reinforcing fibers, thermoplastic resin and thermal expandable particles in an aqueous medium containing a surfactant with fine foams to prepare a foamy solution, filtering the foamy solution to form a web, heating pressing and cooling the web to form a stampable sheet, heating the stampable sheet to expand the thermal expandable particles, and shaping and cooling the stampable sheet, wherein the expanded thermal expandable particles are eccentrically located toward one-side surface of the expansion molded product of the stampable sheet by removing foams by suction during the filtering and eccentrically locating the thermal expandable particles toward one-side surface of the web.

Abstract: A method for forming a web of transversely extensible fibrous material includes the steps of subjecting a fluid-permeable endless conveyor belt of elastic material, of thickness increasing from its longitudinal axis to its edges, to a localized transverse stretching operation, achieved by temporarily withdrawing a longitudinal band thereof from the surface on which it naturally slides and maintaining it in contact, in this stretched condition, with at least a part of the surface of a support member; depositing a web of pliable fibrous material having a liquid content between 3% and 70% by weight against that portion of the conveyor belt of elastic material which has been transversely stretched; and with vacuum, maintaining the web of pliable fibrous material adhering to the conveyor belt of elastic material during its return to its original configuration, to cause the transverse contraction of the web and the simultaneous partial removal of liquid therefrom.

Abstract: A clothing for supporting a wet paper web for dewatering is provided, comprising a dewatering fabric extending in a machine direction and formed only from a woven material to have a single, substantially consistent, permeability. A pair of laterally-spaced strip portions extend along the dewatering fabric in the machine direction, with each being substantially and consistently impermeable to air and forming a substantially and consistently smooth non-water-retaining surface. The strip portions define a permeable web-carrying portion of the dewatering fabric therebetween, wherein the paper web carried thereby extends over the entire width thereof. The permeable web-carrying portion allows air to flow therethrough, exclusively of the impermeable strip portions, such that the wet paper web carried only by the permeable web-carrying portion is dewatered. The width of the permeable web-carrying portion thereby defines the width of the wet paper web dried thereon. Associated systems and methods are also provided.

Abstract: Tissue products are disclosed containing an additive composition. The additive composition, for instance, comprises an aqueous dispersion containing an alpha-olefin polymer, an ethylene-carboxylic acid copolymer, or mixtures thereof. The alpha-olefin polymer may comprise an interpolymer of ethylene and octene, while the ethylene-carboxylic acid copolymer may comprise ethylene-acrylic acid copolymer. The additive composition may also contain a dispersing agent, such as a fatty acid. The additive composition may be incorporated into the tissue web as the web is being formed. Alternatively, the additive composition may be topically applied to the web in a post processing operation. For instance, in one embodiment, the additive composition may be applied to the web as a creping adhesive during a creping operation.

Abstract: A forming section has a lower wire loop (11), which constitutes a single-wire section (T) following a breast roll (12). A first dewatering zone (Z1) has at least one stationary, first forming shoe (40) followed by a pulsating strip cover (50). The first forming shoe has leading and trailing edges and underpressure affecting through holes of the cover. The holes are openings or slots substantially in the longitudinal direction of the machine, whereby non-pulsating dewatering is applied on the stock travelling on top of the lower wire. A pulp suspension jet is fed from a headbox (30) at an impact point after the shoe leading edge. The cover is straight at least in the area between the impact point of the pulp suspension jet and the trailing edge. The impact of the pulp suspension jet on the forming wire is thus better controlled in a better way, increasing production speed.

Abstract: A multi-layer web formation section has two successive wire units (300, 310) with a common wire (11). A first headbox (100) supplies fiber pulp to the first wire unit (300) forming a first partial web (W1). A second headbox (110) supplies a new fiber pulp layer to the forward end of the second wire unit (310) atop the first partial web. A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) has a first formation shoe (200b) with a curved cap (201) placed on the side of the new layer having openings (202) extending through the cap (201) with an under-pressure (P) affecting therethrough. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b) formed by fixed dewatering lists (210b), between which there are gaps (220b) and an under-pressure (Pb) affecting in these.

Abstract: Paper machine for manufacturing a fiber web of paper without through air drying (TAD) or pressing, comprising: a wet end, having a wire section with at least one forming wire, a clothing, being air and water permeable, and a dewatering unit for dewatering the fiber web; and a drying section, comprising a drying surface for the fiber web; and also a transfer roll for transferring the fiber web to the drying section, wherein the fiber web is supported by said clothing from the wire section all the way to and over the transfer roll. The clothing has a three dimensional structure for structuring the fiber web.

Abstract: A process useful for producing low density high mineral wool based acoustical panels with improved acoustical absorption properties using a water felting process is disclosed. The process includes forming a dilute slurry mixture including water, mineral wool, a thermoplastic binder and/or starch; and distributing the dilute slurry on a porous carrier to have the slurry dewatered to a base mat by gravity drainage to remove water by gravity. A vacuum is adjusted to gradually apply vacuum to the gravity dewatered base mat to further dewater the base mat without subjecting the mat to static pressure that would compress the base mat. The base mat is dried to form an acoustical ceiling product that has a low density and excellent acoustical absorption properties.

Abstract: A method of treating pulp on a porous surface of a rotating drum cylinder having a lower drum portion in a vat of pulp slurry and a radial array of filtrate conduits including: as the porous surface of the drum rotates through the vat, drawing filtrate from the slurry through the porous surface by the application of a suction to the filtrate conduits vacuum; draining the filtrate from the filtrate conduits into the filtrate chamber and to a filtrate suction conduit extending to an elevation below the vat; forming a pulp mat on the porous surface which passes filtrate and substantially blocks fibers in the pulp slurry; removing the pulp mat on the porous surface from the vat as the drum rotates; draining filtrate from the filtrate suction conduit, and before excessive gases passing through the porous surface enter the filtrate conduits, switching a fluid flow downstream of the filtrate conduits to a gas vent passage offset and below from a drum rotational axis.

Abstract: The present invention provides a cylindrical suction box assembly with a suction box having two or more suction chambers that operate at different suction pressures. A lower suction pressure suction chamber is configured to provide lower suction pressure suction and is used in conjunction with the texturing process. At least one higher suction pressure suction chamber is configured to provide higher suction pressure suction and is used in conjunction with the de-watering process of the present invention. Therefore, according to the present invention two processes that are traditionally performed on two different devices are performed on a single cylindrical suction box assembly.

Abstract: A nonwoven fibrous mat or web forming or treating system is disclosed comprising a movable, permeable wire or belt for carrying the fibrous mat or web over at least one suction tube assembly comprising a primary suction tube having a suction slot at the top of the primary suction tube and an exit tube communicating with the primary suction tube mounted beneath the permeable belt to have the suction slot on or close to the bottom surface of the movable belt. The suction slot is at least 3.6 meters long and up to more than 5.3 meters long, and the exit tube of the suction tube assembly communicates with the primary suction tube through an opening in the primary suction tube, the opening being generally centered around a centerline of the suction slot. This primary suction tube assembly provides a more uniform suction distribution along the suction slot and reduces fouling of the suction slot compared with previous suction tube assemblies.

Abstract: A process and a device for dewatering a fiber web 3, especially a paper web, using vacuum. The vacuum seen by a given unit are of the web is pulsed between a maximum value V and a minimum value. At least one suction box 7 is provided with perforations beneath the running web where the vacuum is applied with a pulsating effect on the web.

Abstract: A multi-layer web formation section has at least two successive wire units (300, 310). First and second headboxes (100, 110) supply pulp suspension jets to the forward end of the first wire unit (300) and the second wire unit respectively to form a first partial web (W1) and a second partial web (W2) which are joined at a joint (N1) between the second wire unit (310) and a bottom wire (11). A first non-pulsating dewatering zone (Z1b) in the forward end of a two-wire stretch of the second wire unit (310) is formed by a fixed formation shoe (200b) having a curved cap (201) placed against one side, having openings with an under-pressure applied. A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b), formed by fixed dewatering lists (210b) in the cross machine direction with gaps (220b) therebetween with an under-pressure (Pb) applied.

Abstract: A method and a device are for compacting a web of endless fabric including a nonwoven. According to the method and device, the web of endless fabric is subjected to the following treatment steps: a) impinging the web of endless fabric with a pressurized liquid; b) sucking off liquid; c) squeezing off liquid; and d) drying the web of endless fabric.

Abstract: A method of dewatering a fibrous web in a paper machine including the steps of carrying the fibrous web on a side of a first fabric; contacting the fibrous web with a side of a second fabric, the fibrous web being between the first fabric and the second fabric; and passing air successively through the first fabric, the fibrous web and the second fabric.

Abstract: A web is formed between two wire loops (13, 14), in a wire section of a paper or board machine, in connection with which dewatering elements (12, 17, 15, 28) are placed and in which water is drained from a stock suspension from between the two wires (13, 14). In the region of a twin-wire zone, a suction roll (15) is placed within one wire loop and a suction box (16) having a curved surface is situated in opposed relationship with the suction roll (15) on the wire loop. After the suction box (16), the web is guided, due to the effect of a vacuum of the suction roll (15), forwards on the surface of the wire loop of the suction roll (15).

Abstract: The invention relates to a method of draining a fiber pulp suspension, where the fiber pulp suspension is applied to a convergent dewatering space arranged between two wires travelling in the same direction. In the dewatering space, water and powdery substance are removed from the fiber pulp suspension through the wires. Pressure pulses are generated in the fiber pulp suspension along the length of the dewatering space with pressure pulse elements that are on opposite sides of the wires relative to the fiber pulp suspension and in contact with or at a distance from the wires. The invention also relates to an apparatus according to the method.

Abstract: A process and apparatus for removing water from a mechanical pulp, chemical pulp or paper sheet, carried between top and bottom wires running through a dewatering machine having a first dewatering zone. The apparatus includes at least one suction box positioned downstream of the first dewatering zone. The process includes generating an air current in at least one of the wires downstream of the first dewatering zone with the suction box. The air current removes water from the wire and directs it into an inner chamber of the suction box. The invention also refers to a device for implementing the process.

Abstract: Apparatus for treating a fibrous web that includes at least one supporting surface arranged to support a surface of the fibrous web, and at least one sealing device positionable adjacent a surface of the web opposite the surface of the web supported by the at least one supporting surface. The at least one sealing device includes a sealing element and a holder structured and arranged to hold and to enable lateral sliding movement of the at least one sealing device cross-wise to a web travel direction.

Abstract: A pulp moulding process including the steps of pulp stock, forming wet products by means of forming die (7), transferring the wet products from the forming die by means of a heated transferring die-and-heated pressing tool arrangement (13)(14) for in-mould pressing and drying of the wet product, and delivering the dried products to a down line facility (18). The invention encompasses a pulp moulding system, a pulp moulding apparatus, and a pulp moulded product made by such a process, system and/or apparatus.

Abstract: The invention relates to a roll for a paper or board machine comprising axle journals on whose support the roll is arranged to revolve, end flanges with which the axle journals are connected, and a mantle which is connected with the end flanges. The mantle is provided with a number of openings extending through the mantle and/or recesses formed into the outer surface of the mantle, which openings and/or recesses form a regular pattern. Solid connecting portions in the outer surface of the mantle around said openings and/or recesses are opened so that, from each opening and/or recess, there is a connection, provided in the form of a groove or an additional recess extending into the outer surface of the roll mantle, with at least each of the openings and/or recesses adjacent to it.

Abstract: A process and apparatus for removing water from a mechanical pulp, chemical pulp or paper sheet, carried between top and bottom wires running through a dewatering machine having a first dewatering zone. The apparatus includes at least one suction box positioned downstream of the first dewatering zone. The process includes generating an air current in at least one of the wires downstream of the first dewatering zone with the suction box. The air current removes water from the wire and directs it into an inner chamber of the suction box. The invention also refers to a device for implementing the process.

Abstract: Suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs.

Abstract: This invention relates to an improvement in coatings particularly suited for the preparation of paper products having an ink jet coating applied thereto and to the resulting paper products. The improvement in ink jet coatings resides in the incorporation of a primary amine functional polyvinyl alcohol (PVOH/PVNH2) as a polymeric binder. One form of an amine functional polyvinyl alcohol is produced by the hydrolysis of a copolymer of vinyl acetate and N-vinylformamide or vinyl acetate and allyl amine. Another is the polyvinyl butyral derivative of polyvinyl alcohol which typically is formed by the reaction of a 4-amino alkyl aldehyde dialkyl acetal, such as 4-aminobutyraldehyde dimethyl acetal with polyvinyl alcohol.

Abstract: Method for forming a continuous web on a forming fabric includes providing a pressurized chamber, processing the forming fabric through the pressurized chamber, and distributing a pressurized flow of a slurry having a first composition in the pressurized chamber across the width of the forming fabric to form the continuous web.

Abstract: A method and arrangement for preventing rewetting of a web in a paper machine. In the method, a web supported by a wire is passed by at least two vacuum boxes/chambers after the last suction roll or equivalent in a web former such that, in the running direction of the web, by means of a first vacuum box/chamber and by means of a second vacuum box/chamber the transport of moisture from the wire back into the web is prevented. In the arrangement at least two vacuum boxes/chambers are arranged after the last suction roll or equivalent in a web former, and the web and wire are arranged to be dewatered by means of a first vacuum box/chamber and the transport of moisture from wire back into the web is prevented by means of a second vacuum box/chamber, the vacuum generated in first vacuum box/chamber being higher than the vacuum generated in the second vacuum box/chamber.

Abstract: A suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs. A method in a suction box in a paper machine, wherein a vacuum is formed in a vacuum chamber of the suction box and, during formation of the vacuum, the deck and/or the ribs is/are pressed against the wire.

Abstract: Suction box in a paper machine including a vacuum chamber, a deck or a number of substantially U-section holders open toward a wire and ribs arranged in the deck or the holders so that they can be loaded against the wire. At least in a running situation, the deck of the suction box is curved or the ribs are arranged to provide a curve run of the wire so that the wire tension of the curved run over the deck or ribs serves to lower a normal force which is produced by the vacuum present in the suction box and which is effective between the wire and the deck or ribs.

Abstract: A wet section (10) of a paper or cardboard machine and a process for the manufacture of a fibrous material web are suggested. The wet section (10) exhibits a double-screen segment (US), in which two screens (16, 18) are guided about parallel to one another and into which a fibrous material suspension (27) is introduced. The double-screen segment (US) is looped around a roll (22). The means (30, 32, 38) for the immobilization of the fibrous material suspension in the double-screen segment (US) are provided on the roll (22), for the formation of the fibrous material web. Moreover, the wet section exhibits means (32, 34, 36; 34, 36, 66) for further draining of the fibrous material web.

Abstract: Suction device and process for at least one of conditioning and drainage of an endless felt. The device includes a housing having at least one vacuum chamber, and a plurality of suction slits located on a suction surface of the housing that is adapted to face the endless felt. The plurality of suction slits are oriented to extend at least one of in and obliquely to a travel direction of the endless felt. The process includes guiding the endless belt over a suction surface of a vacuum chamber, and suctioning a surface of the endless belt with a plurality of suction slits located in the suction surface of the vacuum chamber. The plurality of suction slits extend in a direction that is at least one of in and oblique to a belt travel direction.

Abstract: In the present invention, in a process in which a fiber suspension supplied in a flat layer manner is subjected to natural dehydration, pressure dehydration, or suction dehydration, while circulating a cylindrical suction cylinder, and thereby, dehydration slowly proceeds and a paper web is formed, and this paper web is moved to an endless felt by means of a suction couch roll to produce paper, a tapered suction roll sleeve 6, the outer peripheral surface of which is cylindrical and the inner peripheral surface of which has an inclination identical to that of the outer circumference of the tapered suction roll cell 5 is attached and detached, and thereby, it becomes easy to conduct the attachment and detachment of various types of wires wound on tapered suction roll sleeve 6.

Abstract: A suction breast roll former has a support surface with a plurality of apertures formed therein that are operatively connected to a vacuum source. A headbox has a flexible roof extending downstream from a slice opening and disposed adjacent to a support surface of the suction breast roll. The headbox permits the flexible roof to bend over a range of movement relative to the support surface to match the shape of a drainage curve suiting current operating conditions. A method of forming a paper web includes the steps of supplying an aqueous suspension of papermaking fibers to a forming zone created between the suction breast roll and the headbox. The headbox includes a slice body and an apron that define a slice opening therebetween and also has a flexible roof extending from the slice opening and spaced from the support surface to define a forming zone therebetween. A forming fabric is passed through the forming zone to receive the aqueous suspension of papermaking fibers.

Abstract: A method and device for dewatering a paper or board web and passing the web as a closed draw from a lower wire of a web forming section, in which the web is formed between the lower wire and an upper wire, to the press section and through one or more dewatering press nips in the press section. The web is separated from the upper wire on a first suction zone or block of the suction roll, after which the web is affixed to the lower wire over a second suction zone or block of the suction roll. The web is then affixed, in a pre-press and transfer nip formed by the suction roll and a smooth-faced roll, onto the outer face of a substantially non-watering-receiving transfer belt, the web being passed on support of this belt into the first press nip. In the press nip, water is pressed out of the web into a water-receiving press felt.

Abstract: Improved method of removing water from a wet web of paper includes the steps of (a) passing the web and its supporting fabric above and in sliding contact with a surface of a meniscus separator unit having a plurality of spaced cells in contact with the inner surface of the fabric; (b) applying a small vacuum to an internal space of each cell to extract water from the web using the tension meniscus of water while preventing air from passing through the web; and (c) permitting air from the atmosphere only to be applied to the inner surface of the fabric by each cell and thence into the fabric to replace water removed from the fabric in step (b) thereby enhancing the removal of water from the web and from the fabric, the atmospheric air passing along and through the interstices between the inner and outer surfaces of the fabric to the internal space of each cell.

Abstract: An apparatus and method for molding articles from a fibrous slurry. The apparatus comprises a forming die manufactured from a water insoluble, porous, relatively rigid and easily shaped material having molding surface shaped to the contour of the article to be molded, a vacuum vessel for receiving the forming die, and an opening through the vacuum vessel for communicating with a vacuum means for applying suction through the forming die to draw the slurry against the molding surfaces to form a fiber layer having the configuration of the article to be molded.

Abstract: The invention relates to a method for preventing rewetting of a web in a former. Water is removed from the web (W) by means of dewatering members. The web (W) is formed by forming members and forming rolls on support of a wire loop/loops. The wire loop/loops (10) is/are guided by alignment, guide and/or suction rolls (11, 12). The web (W) supported by a wire (10) is passed by at least two vacuum boxes/chambers (16, 17) after the last suction roll (11). At least two vacuum boxes/chambers (16, 17) are fitted after the last suction roll (11). The web (W) and the wire (10) are arranged to be dewatered by means of a first vacuum box/chamber (16). The transport of moisture from the wire (10) back into the web (W) is prevented by means of a second vacuum box/chamber (17), and a vacuum (P.sub.1) in the first vacuum box/chamber (16) is higher than a vacuum (P.sub.2) in the second vacuum box/chamber (17).

Abstract: A unique method of producing a reinforced moulded sheet having one continuously planar face and having a plurality of ribs or thickened areas which provide a corresponding plurality of prominences directed outwardly of the other face, said prominences having predetermined shapes, locations and dimensions to serve as reinforced areas for said sheet. And a series of new or improved composite hollow moulded panels, each comprised of at least two co-extensive elements, each of said panels being reinforced and improved by the provision of at least one of said reinforced moulded sheets as an external element of said at least two co-extensive elements, the ribs or thickened areas of said reinforced sheet being glued internally of said hollow panel to the adjacent co-extensive element thereof.

Abstract: A twin-wire former of a paper machine, for high speed paper machines whose web running speed is of an order of from about 1600 m/min to about 2500 m/min. The former includes a carrying wire guided in a loop and a covering wire guided in a loop to define a twin-wire zone and an inlet or forming gap between the wires. A pulp suspension layer or a pulp suspension jet is fed into the inlet or forming gap through a discharge duct of a headbox. The former also includes, as a combination, a first forming-suction roll arranged proximate the forming gap in a loop of one of the wires and a second forming-suction roll arranged inside the loop of the wire opposite to the wire inside whose loop the first forming roll is arranged. The forming-suction rolls have suction zones over which the twin-wire zone is curved on certain sectors. In the suction zones, the vacuum levels are arranged adjustable independently from one another, and possibly relative to one another, so as to minimize the unequalsidedness of the web.

Abstract: A drainage device and method which provides for drainage from paper or pulp stock on a fabric in a sheet or mat making machine which includes a primary blade and trail blade with a gap therebetween for drainage wherein the size of the gap controls drainage and the primary blade is so configured so as to force a portion of the drained liquid through the fabric to create paper stock activity and disbursement while minimizing turbulence and maintaining laminar flow in the machine direction along with providing reinforcement of CD shear.

Abstract: In a method for forming a sheet from a fiber-water suspension, the fiber-water suspension is supplied on a traveling bottom wire at a first zone thereof to dewater the fiber-water suspension. Subsequently, the suspension is introduced between the bottom wire at a second zone and a top wire, and dewatering is effected. The sheet is further caused to travel around a sheet-forming roll while keeping the sheet in contact therewith by the bottom wire at a third zone thereof, and reformation of the sheet is carried out. Finally, the sheet on the bottom wire is caused to travel up to a fourth zone thereof to effect a further dewatering with a fourth dewatering device disposed adjacent to the bottom wire at the fourth zone thereof, whereby a final stage of sheet formation is carried out. An apparatus for carrying out the above method is also disclosed.

Abstract: A prepress for a paper web in a paper machine including a load shoe which is pressed against a backing element, preferably a vacuum roll, by a load pressure generating by a medium, preferably liquid, which at the same time acts as a lubrication medium in the prepress. The load shoe is in direct engagement with a water permeable wire upon which the paper web is supported.

Abstract: A wire part of a machine for the production of continuous fibrous material webs, especially a papermaking machine, includes two continuous wire belts which together form a twin-wire zone. At least one supporting element having a supporting surface is disposed in the region of the twin-wire zone. At least a part of the supporting surface provides a supporting region which supports a first wire belt on its inner surface and a second wire belt on its outer surface. At least one formation box is provided and is disposed in the supporting region. The formation box is designed in such a way that, in the region of the inner surface of the second wire belt in the formation box, pressure values can be adjusted from a reduced pressure to an excess pressure acting on the inner surface of the second wire belt. The formation box extends in the direction of movement of the wire part over at least a part of the supporting region.

Abstract: A disc filter used in the pulp and paper industry meets modern requirements by axially dividing the tank and shaft (with the flow channels) into at least two separate and distinct portions, so that the treatment of pulp in several different stages using the same disc filter is possible.