Abstract: A roll and blade gap former for a paper machine having first and second wires guided in a respective loop and defining a twin-wire forming zone, a forming gap in which the first and second wires converge before the twin-wire zone, a headbox including a slice channel having a slice opening through which a stock suspension jet is fed into the forming gap to form a web between the wires, and drainage and forming elements arranged in the twin-wire zone for removing water from the web. To provide an improvement in the control of the Z-direction properties of the web, the former includes turbulence generating vanes arranged in the slice channel in the headbox to cause turbulence in the stock suspension jet upon its discharge from the slice opening into the forming gap and a first forming roll arranged in the twin-wire zone and which constitutes the first drainage and forming elements in the twin-wire zone after the forming gap.

Abstract: Breast box for a papermaking machine. The breast box includes devices in order to add, across the width thereof, localized and dosed material dilution liquids, and located within the breast box is a guiding device having a plurality of channels located immediately downstream of the supply and distribution apparatus, with the guiding device including a multiplicity of inserts in which the channels are located and on whose outer surfaces hollow chambers are formed, wherein the hollow chambers can be filled with the material dilution liquid, the latter then flowing from these hollow chambers into open recesses in the distribution device, with the recesses being directed upstream to the suspension stream existing in the distribution apparatus during the operation thereof.

Abstract: A method and apparatus is disclosed for controlling the flow of stock mixture through an enclosed head box chamber, such as in a paper-making machine, and onto a forming surface thereof. A plurality of plates are arranged in the chamber to extend transversely across the chamber, with the top edges of the plates and the inner wall of the chamber defining therebetween an opening through which the stock mixture flows. The plates are selectively moved toward and away from the inner wall to vary the configuration of the opening and, thus, control the flow of stock mixture through the openings such that selective movement of selected plates controls the cross-sectional flow profile across the width of the chamber and, correspondingly, controls the cross-sectional flow across the width of the outlet from the chamber and onto the surface forming the sheet material.

Abstract: A method and device for removing water from a paper or board web and for passing the web as a closed draw from a forming wire or transfer wire of the web former to the press section and through one or more dewatering press nips in the press section. The web that runs on the forming wire or transfer wire is made to adhere in a transfer and pre-press zone to an outside face of a transfer belt which is substantially non-water-receiving. After this pre-press zone, the web is separated substantially immediately from the wire and passed on support of the transfer belt onto the next press fabric in the press section and/or into the next press nip. In the pre-press zone or zones, a substantial amount of water is removed out of the web substantially in one direction only, and, at the same time, the web is made to adhere reliably to the outside face of the transfer belt.

Abstract: A gap former, consisting of a double sieve former 3 which is made up by an inner sieve 4 and an outer sieve 5, is in the initial stage of the process wrapped around a roller press 8 with a diameter of at least 800 mm. After the sieves have traveled such that a given segment of the sieves is no longer in contact with the roller press, the segment enters between a number of contour brackets 10 and 11 at which time the segment is moving rather steeply downward. During this stage an upper layer 6 of paper or cardboard which has been compressed is deposited onto a lower layer 7 that is already resting on the primary longitudinal sieve 2.

Abstract: A method of de-inking wastepaper by pulping the paper in the presence of an enzyme is disclosed. The enzyme dislodges the ink particles from the paper fibers. The preferred enzymes are the acid resistant carbohydrases. The de-inking medium is an aqueous solution of the enzyme, preferably maintained at a pH less than about 7 and at a temperature between about 20.degree. C. and about 60.degree. C. No conventional chemical de-inking agents are required. The dislodged ink particles may be removed by any conventional method, such as flotation or washing.

Abstract: Proposed is a method for the dewatering of a material layer (S) of paper fibers in a double-screen former, where the sheet weight (oven dried sheet weight (otro)) is more than 100 g/m.sup.2 and/or the screen circulates with a speed of at least 100 m/min. In accordance with the invention the two screens are guided at two guide surfaces (5 and 7) which, for example, belong to open forming cylinders. In this arrangement forming cylinders of this kind are so dimensioned and positioned that no dewatering elements which contact one of the screens are present between the run-out line (11) of the screens (2, 3) from the first guide surface and the run-in line (12) at the second guide surface.

Abstract: A multilayer papermaker's press felt fabric comprising in combination a woven first fabric layer, typically a double layer fabric, has a cross machine direction pin seam. A second fabric layer is located on the paper side face of the first fabric layer, and a layer of needled batt is applied to the paper side face of the second layer binding the layers together. A flap comprising a short length of the second fabric layer with attached batt overlays the pin seam area in the first layer. The second layer comprises a plurality of relatively narrow strips, which are located with a lateral edge at a first cant angle of from more than 1.degree. to less than 20.degree. to the machine direction. A third layer, similar to the second layer, can be included on the machine side of the first layer; the strip widths, the cant angles, and the direction of the cant angle relative to the machine direction for each of the two strips need not be the same. The fabric is assembled using a spiral winding technique.

Abstract: In a twin wire former a headbox injects stock onto a forming wire with which a second forming wire is brought into gradual engagement. A forming shoe directs the two wires along a path of increasing curvature, above which water is drained by adjustable auto slices. The two wires with the web therebetween then follow an oscillating S-shaped path between seven S-rolls and are directed upwardly through three individually loaded press rolls with increasing pressure to about four hundred and fifty pounds per linear inch at the last wet press. Drainage pans collect water from the upper surface of the twin wires and water thrown off the upper press rolls. The press rolls are individually pneumatically pivotable to increase nip pressure, and collectively pivotable to open all the nips. Next a high pressure dry nip can increase the fiber content of the web to thirty-five percent fiber.

Abstract: A papermaking vacuum apparatus having a web-facing surface adapted to support a papermaking belt and comprising a head, a body and at least one vacuum slot disposed in the head and defining an aperture on the web-facing surface. The vacuum slot is in fluid communication with the web-facing surface and extends from the web-facing surface to the body which is in further fluid communication with a vacuum source. The web-facing surface comprises a leading surface and a trailing surface. The leading surface has a transitional area juxtaposed with the aperture created by the vacuum slot. This transitional area has a predetermined Z-directional spacing from the papermaking belt, which Z-spacing continuously and gradually increases in the machine direction whereby the amount of vacuum pressure applied through the vacuum slot to the paper web gradually increases as the paper web travels in the machine direction over the slot.

Abstract: The invention relates to a press for the dewatering of fiber material webs with two press elements, the pressing surfaces of which can be pressed towards one another while forming a press gap, with the fiber material web being guided through the press gap together with at least one dewatering band extending between the fiber material web and in each case one of the press elements. Each dewatering band is separated at the press gap outlet from the fiber material web and is guided at at least one side of the fiber material web in a section following the press gap over a predeterminable angular region of the respectively associated press element. A short suction zone can be variably designed in all embodiments so that a reverse moistening of the fiber material web through the dewatering band after departing from the press gap is at least partly prevented and a guide roll for the fiber material web following the press gap can be arranged as close as possible to the press gap.

Abstract: A resin-impregnated endless belt for a long nip press or calender of the shoe type has a base fabric in the form of a multilayer braided structure wherein each of the constituent layers are connected to those adjacent thereto by at least one interlocking yarn to inhibit interlayer delamination. The base fabric is in the form of an endless loop, at least the inner surface of which is coated with a polymeric resin material, such as polyurethane. The polymeric resin material impregnates the structure of the base fabric, rendering it impermeable to oil and water.

Abstract: A twin-wire gap former in a paper machine in which an outer wire and an inner wire are guided by guide rolls and by web forming members. The wires form a twin-wire zone which starts from a forming gap into which a slice part of a headbox feeds a stock suspension jet. The forming gap is followed by a curved portion of the twin-wire zone which is guided by a first forming roll placed inside the loop of one of the wires. The forming-gap arrangement includes two opposite tip plates which define a slice channel between them. The lip plates extend deep into the forming gap so that the free ends of the lip plates are placed in direct vicinity of the forming wires or in contact with the wires. On the curve sector of the twin-wire zone, which starts after the forming gap and which is guided by the first forming roll, inside the loop of one of the wires, a water drainage box is provided, at which box the edges of the sides that are placed against the inner face to the wire are substantially sealed.

Abstract: The press section of a papermaking machine has two conventional presses followed by two or three presses including one heated Extended Nip press thereby allowing control of the two-sidedness of the web by balancing the temperature and pressure of the Extended Nip Press with the pressure and temperature of the additional presses to form a one-sided sheet. The use of smooth high temperature press felts can aid in the reduction of two-sidedness of the formed web. The dryer section may alternatively add a fifth press utilizing the first dryer roll as the backing roll, two Extended Nip presses, a heated Extended Nip press followed by a heated conventional press, or a heated Extended Nip press in the third pressing position followed by a conventional heated press utilizing the first dryer as the backing roll.

Abstract: A press blanket in a pressing device intended for extracting water from a web in the press nip of a papermaking machine comprises an elastomeric matrix, in which the outer area, facing the web, is subjected to a thermal treatment in order to increase the wear-resistance. Although the elastomeric matrix thus consists of the same material throughout, the outer area, which is subjected to greater stresses, therefore exhibits increased wear-resistance. The press blanket is made in a single operation, by casting a hot-casting elastomeric matrix onto a cylindrical casting mold, while at the same time reinforcing threads are wound into the material. The press blanket is selectively thermally treated in order to achieve increased wear-resistance at the outer surface facing the web to a depth below the depth of grooves or bores on this outer surface.

Abstract: A press section for a paper machine employing at least two press nips placed one after the other. Of these nips, at least the first nip is an extended nip or an extended roll nip. The last nip in the press section is placed on a level higher than the preceding nip. The first nip and/or, when more than two nips are employed, the nip that immediately precedes the last nip is/are provided with two press fabrics that receive water. The paper web is transferred on the lower fabric of the two press fabrics onto an upper fabric of the last nip. On the lower face of the upper fabric, the web is transferred into the last nip. After the web transfer point, the upper fabric of the last nip has a relatively short upwardly inclined run. After this, the upper fabric is turned and guided by the lower roll of the last nip over a considerable sector thereof. The last nip is placed after, or at the vicinity of, the uppermost point of the lower roll that forms the last nip.

Abstract: A former section provided with a twin-wire zone in a paper machine including a carrying wire and a covering wire which form the twin-wire zone therebetween them, and web-forming and draining members arranged in the twin-wire zone. In an initial part of the twin-wire zone, a stationary unit of forming ribs is arranged inside a loop of one of the wires and includes transverse forming ribs extending across the entire width of the wires and placed at a distance from one another to define gaps therebetween. A loading unit is placed opposite to these forming ribs inside the loop of the opposite wire and includes spring blades which are loaded against that wire. The dragging and loading areas of these spring blades are placed substantially in the middle areas of the gaps between the forming ribs in the stationary unit of forming ribs to prevent crushing of the web between the forming ribs in the stationary unit of forming ribs.

Abstract: A press section in a paper machine including a first press nip formed between an upper roll and a lower roll whereby a paper web to be dewatered is passed through the first press nip on support of two press felts. The press section includes at least a second and a third press nip formed in connection with a smooth-faced center roil. A press felt is passed through the second and third press nips formed in connection with the center roll. The lower roll in the first nip is a metal-mantle lower roll which has a diameter substantially larger than the diameter of the upper roll in the first nip.

Abstract: This invention provides an integrated system for recovering fibers from mixed grades of waste paper and simultaneously cleaning (deinking) waste fibers. The system comprises a mild alkaline pulping process with oxygen and hydrogen peroxide followed by rapid decompression of fibers and then by hot washing.

Abstract: A method and apparatus for treating a fiber paper web in a press device wherein the web is guided through a press nip form between a press roll and a backing element in the form of a backing roll, and wherein the press roll includes a surrounding roll jacket comprised of plastic and a stationary cross head axially traversing the roll jacket. Preserving the roll jacket by cooling the roll jacket at least areawise in the axial direction of the roll jacket which increases the abrasion resistance of the roll jacket. Various devices for cooling the roll jacket include spraying coolant at the outer surface of the roll jacket, spraying coolant at the surface of a felt belt which then engages the roll jacket in a press nip, blowing air into the outlet end of the press nip between the roll jacket and the felt belt and/or blowing air into the space surrounding the outer surface of the roll jacket, e.g., the interior of the loop of the felt belt or the interior of a liquid collecting pan surrounding the roll jacket.