Abstract: Suction box for a machine producing a web containing cellulose fibers, said suction box being placed inside a rotating suction roll (2) provided with a perforated jacket (1), said suction box (3) comprising a suction chamber (4) having a suction inlet (6) placed against the interior surface (5) of the suction roll and a suction connection (7) for creating a negative pressure in the suction chamber and sucking water through the perforations (8) in the suction roll into the suction chamber. The suction inlet (6) is provided with ribs (10) laid in a direction transverse to the direction of rotation (9) of the suction roll (2) and forming suction slits (11) in the longitudinal direction of the suction roll near the interior surface (5) of the suction roll.

Abstract: A papermaking apparatus such as a Fourdrinier table which includes a long blade and a trail blade. In the first aspect of the invention, the long blade includes an upper undulated surface with vents passing from the upper undulated surface to the lower surface of the long blade which is at substantially atmospheric pressure. In the second aspect of the invention, the trail blade includes an elevator-type device for adjusting the vertical position of the trail blade. In a third aspect of the invention, a single elevator is used to adjust the angle of the blade, the blade is provided as a modular or multiple-piece design, mounting buttons are used to engage slots of T-shaped cross section in the blade and/or ceramic inserts are included at wear points.

Abstract: A paper machine roll, in particular for a soft calender or supercalender, which includes a metal frame, roll ends, and shafts. The frame is coated with a polymer coating over at least a middle area or central region thereof while lateral regions may optionally remain uncoated. In order to equalize a difference in temperature between the roll ends and the optionally non-coated lateral regions of the metal frame, on one hand, and the coated central region area of the roll, on the other hand, an arrangement for equalizing the difference in temperature is provided by heating the roll ends and the optionally non-coated lateral regions of the metal frame.

Abstract: Shoe press for treating a material web that may include a press shoe to be pressed against an opposing element, e.g., a counter roll, with a fluid permeable press jacket and a felt belt being positionable between the press shoe and the opposing element, and a plurality of support elements including cylinder devices and pistons supported on a carrier. The press shoe may have a concave-shaped press face forming a nip with the opposing element such that the nip has a predetermined longitudinal span. The press shoe may be movable on the plurality of support elements, and the pistons of the plurality of support elements may carry the press shoe to permit a tilting movement of the press shoe both in a web travel direction and lateral to the web travel direction. A stop may support the press shoe in the web travel direction and may absorb horizontal forces acting on the press shoe.

Abstract: A papermaking apparatus such as a Fourdrinier table which includes a long blade and a trail blade. In the first aspect of the invention, the long blade includes an upper undulated surface with vents passing from the upper undulated surface to the lower surface of the long blade which is at substantially atmospheric pressure. In the second aspect of the invention, the trail blade includes an elevator-type device for adjusting the vertical position of the trail blade. The first and second aspects may be used independently or simultaneously.

Abstract: A cleaning apparatus is disclosed for cleaning and removing contaminants from a forming wire of a paper machine. The apparatus includes a shower which is disposed adjacent to the wire for supplying a cleaning fluid onto one side of the forming wire. A leading blade is disposed downstream relative to the shower. The leading blade contacts the wire on the one side of the wire and extends in a cross-machine direction across the wire. A trailing blade is disposed downstream relative to the leading blade. The arrangement being such that the leading blade and the trailing blade defined therebetween a cross-machine directional slot. The slot is connected to a source of pressurized air so that the pressurized air flows through the slot and through the wire for removing the cleaning fluid and the contaminants from the wire. Furthermore, the trailing blade and the wire define therebetween a wedge shaped gap which converges in a direction from the slot and away from the leading blade.

Abstract: Press device for treating a material web that may includes an impermeable press element having a press face, an opposing element, and a nip formed between the press element and the opposing element. The press device may also include a felt belt that guides the material web through the nip and that is positioned between the material web and the opposing element. The material web may be separated from the press element after leaving the nip because the press element may further include at least one of grooves and holes formed in the press face that close in the nip due to pressing forces to form a smooth surface, and that open after leaving the nip.

Abstract: A two-wire former of a papermaking making machine has the following characteristics: (1) two continuous, loop-shaped wires (1, 2) form together an inlet gap for the paper pulp suspension; (2) a sheet forming zone has a section in which both wires are guided parallel to each other; (3) a plurality of guide rollers are arranged inside and outside both wire loops; (4) a roller (3, 4) associated to each wire loop deflects the associated wire at the beginning of the parallel section; (5) at least one of both inlet rollers (3, 4) has a circumferential area that forms no closed surface (forming roller). According to the invention, (6) both wires runs on the paper pulp-bearing section in a substantially horizontal direction; (7) the top wire is separated from the bottom wire by a separating suction box (8) with a curved surface; (8) the dewatering element (7.1) that follows the forming roller on the same side of the wire is provided with elastically suspended dewatering strips (7.3).

Abstract: A process and device for increasing the gloss and/or smoothness of a web of material are described, whereby a web of material (5) is passed through a roller gap where it is exposed to pressure. A steam dispensing device (7) is provided upstream of the roller gap relative to the direction of travel (9) of the web of material (5). The increase in gloss and/or smoothness is to be accomplished without consuming much energy. To do so, the steam is condensed on the web of material and the web of material (5) is guided through the roller gap before the increase in moisture content of the surface due to the steam treatment has dropped below a predetermined value. The predetermined moisture content is in the range of 12% to 25%.

Abstract: A method and device for cutting a paper web (9) in a twin wire former (1) is described, said web being formed between two forming fabrics (4, 5) while wrapping a section of a forming roll (3), and the web cutting being carried out with the aid of jet cutters (10, 11) discharging jets of pressure medium so that a paper web of final width is obtained and, when applicable, a tail in the web. The jet cutters (10, 11) are arranged at the forming roll (3) so that the web cutting is carried out in the web at a point where the recently formed paper web (9) and the forming fabrics (4, 5) together wrap said section of the forming roll (3) in a sandwich structure.

Abstract: A paper or board machine and a method for passing a paper or board web from a forming section to a press section in a paper or board machine wherein the web is carried on a first wire in the forming section or transferred to a first wire from a forming wire of the forming section. The web that runs on the first 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. The pre-press zone includes an extended nip defined by an extended-nip roll and a smooth-faced press roll, the extended-nip roll having a hose mantle and a press shoe arranged in a loop of the hose mantle. 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.

Abstract: The invention relates to a roll press including at least three rolls forming several press nips for the treatment of a web of material. One press roll comprises a very flexible roll shell which is rotatable around a fixed support and is mounted on the support by at least one support element which has a concave support surface for defining a wide press nip with a cylindrical backing roll. The backing roll forms an additional press nip with at least one not sag-controlled roll. To obtain as uniform as possible a press nip between the backing roll and at least one additional roll which is without sag control, the circumference of the roll shell of the backing roll decreases axially towards its ends, i.e., that roll may be crowned.

Abstract: A press roll intended, together with a press shoe, to cooperate with a counter roll to form a press with long nip for paper or board machines, said press roll comprising two end walls, a jacket, the edge portions of which are secured by an elastic clamping ring to peripheral parts of the end walls, a form-stable clamping ring being screwed to the inner side of the end-wall part to clamp the outwardly expandable elastic clamping ring so that the edge portion of the jacket is clamped firmly against a counter-support member. According to the invention each end wall includes guide means to provide a guided engagement relationship between the form-stable clamping ring and the end-wall part.

Abstract: Apparatus is disclosed for dewatering pulp suspensions including a pair of cylindrical rotatable liquid-premeable press rolls forming a nip therebetween, so that the material suspension can pass between the nip to be dewatered and to form a material web, a pair of doctor blades disposed below the nip, each associated with one of the press rolls for removing the material web therefrom, and a sealed casing enclosing at least the upper portion of the pair of press rolls, the sealed casing including an inlet for the material suspension, and the pair of doctor blades being coupled together so that they are movable relative to the nip in order to alter the distance between the pair of doctor blades and the nip when the size of the nip is adjusted.

Abstract: A blanket passes over a concave shoe which is urged against a backing roll to form a press nip. The ends of the blanket are attached to circular heads. The transition from the nip-imposed cardioid shaped to the circular shape maintained by the heads results in a region of the blanket subject to fatigue. The heads are mounted on journals for motion between inboard stops and outboard stops which are spaced apart approximately 4 inches in the cross machine direction. Positioning of the heads on the journals is controlled by four hydraulic pistons mounted between the support beam and each head. Multiple hydraulic systems are controlled to extend the life of the blanket by alternating between holding the back head fixed and letting the front head float and fixing the front head and letting the back head float.

Abstract: A paper making machine for the production of a fiber material web includes a drying cylinder, first and second bearing assemblies, a fixed rigid support, a fixed structure and a flexible device. The drying cylinder has two longitudinal ends, a longitudinal axis and at least one fluid passage for receiving heated fluid. Each bearing assembly is attached to and rotatably carries a respective longitudinal end of the drying cylinder. The fixed rigid support substantially immovably supports the second bearing assembly. The flexible device allows for longitudinal thermal expansion of the drying cylinder in a direction substantially parallel to the longitudinal axis of the drying cylinder. The flexible device carries the first bearing assembly and interconnects the first bearing assembly to the fixed structure.

Abstract: An extended nip press having a concave shoe which is supported on a hydraulic actuator which urges the shoe against a backing roll. A pair of opposed profile control hydraulic actuators apply a pure couple about the load support line formed by a bearing pin which transmits the support load from the hydraulic actuator to the shoe. A leading hydraulic actuator is positioned in front of the load support line and pulls down on the shoe. A trailing hydraulic actuator is positioned behind the load support line and pushes up on the shoe. The leading hydraulic actuator and trailing hydraulic actuator are equally spaced from the load support line and have equal hydraulic actuator area and are connected to the same hydraulic reservoir. Thus the hydraulic actuators exactly balance each other out except for the couple or torque which they apply about the load support line.

Abstract: A press section is provided for a papermaking machine having an Extended Nip press before a conventional press section such as a Beloit Corporation Tri-Nip or Twinver press. A Beloit Corporation Extended Nip.RTM. press or similar type press, preferably of the closed blanket type, is installed before a conventional two or three nip press and thus reduces the problem of the web sticking to the center roll in the conventional press. The use of an Extended Nip press in front of a conventional pressing section can also increase the bulk of the web being formed. The pressing section of this invention is particularly useful for pressing webs formed of 100 percent tropical hardwood fibers which contain resinous particles which can cause problems in sticking to the center roll.

Abstract: An arrangement and method for transferring a paper web in high-speed paper machines having a press section arranged between a web former and a dryer section. In the press section, there is one or more press nip zones dewatering the web, at least the last one of which is an extended nip through which at least two press fabrics that receive water are passed. The web is passed between the press fabrics through the last extended-nip zone so that the draining of water out of the web takes place through both faces of the web. After the last extended-nip zone, the web follows one of the fabrics passing through the last extended-nip zone by the effect of a difference in pressure avoiding rewetting of the web. The fabric carrying the web is passed through a gently loaded transfer nip zone in which the web is transferred onto a transfer surface more adhesive than the face of the fabric.

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 has a textured clothing interposed between the web-facing surface of the vacuum apparatus and a backside of the papermaking belt. The textured clothing creates leakage between the backside of the papermaking belt and the web-facing surface of the vacuum apparatus and effectively eliminates the vacuum seal between these two surfaces.