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 rib construction for a draining device in a paper machine in which a loading rib is used to support and/or to load a wire or wires in a paper machine and/or to doctor water from the face of a wire or wires. The rib is loaded by pressure of a medium. Between the rib and its frame part, a pressure space is formed and defined by a flexible belt and into the loading pressure is passed into this pressure space. The flexible belt defines the pressure space so that the area of effect of the loading force is independent from the movement of the rib toward the wire(s).

Abstract: A set of ribs in a dewatering device in a paper machine which is used to support and/or to load the wire or wires in the paper machine and/or to doctor water from an inner face of a loop of the wire or wires. The set of ribs includes at least two transverse ribs placed one after the other at a distance from one another in the machine direction. The height positions of the ribs are adjustable and the ribs are interconnected in pairs by intermediate parts. The intermediate parts connect to the ribs by mechanisms of four articulated joints placed at a distance from one another in the transverse direction of the wire/wires so that the positions of the ribs in the horizontal direction remaining invariable irrespective of the height positions of the ribs in relation to one another. The intermediate parts and associated articulation mechanism are placed at a distance from one another in the vertical direction.

Abstract: A hybrid former in a paper machine including a lower-wire loop in which there is an initial single-wire portion of a forming zone. In this initial portion, there are draining elements inside the lower-wire loop and thereafter wire-guide and draining elements. The former includes an upper-wire unit in which an upper wire is guided by guide rolls and by a breast roll onto a pulp layer formed on the single-wire portion of the lower wire. In a subsequent twin-wire portion following the single-wire portion, there is a draining and forming unit which includes at least one pressure-loaded press unit and at least one draining-chamber and support unit, which units are arranged inside opposite wire loops. In the units, there are sets of ribs which are pressure-loaded against each other.

Abstract: The invention relates to a twin-wire web former for a paper machine wherein a covering wire and a carrying wire form a twin-wire forming zone between them. A method for dewatering a web is also disclosed. In the invention, water is drained out of a web running through the twin-wire zone through both of the wires. After the twin-wire zone, the web is separated from the covering wire and is transferred on the carrying wire to a pick-up point. In hybrid formers, after an initial single-wire forming zone preceding the twin-wire zone, and in gap formers, after a curved forming zone placed directly after a forming gap, there is a forming shoe provided with a ribbed deck and arranged inside one of the wire loops. This forming shoe is followed by dewatering and web forming units which include forming ribs and are placed inside both of the wire loops. At least one of the dewatering and web forming units is loaded by means of a pressure-hose arrangement.

Abstract: A twin-wire web former in a paper machine, having a single-wire initial portion, after which a twin-wire zone starts in the area of a ribbed deck of a first forming shoe placed inside one of the wire loops. After the first forming shoe, a pressure-loaded dewatering unit is arranged and which includes opposite sets of ribs and dewatering chambers. A first dewatering chamber in the dewatering unit is placed above the first forming shoe so as to remove water that drains from the area of the curved ribbed deck of the first forming shoe through its suction-deflector duct. The first dewatering chamber is followed by a second dewatering chamber, whose lower part is connected with a set of dewatering and guide ribs having gap spaces into which a drain duct of the second dewatering chamber opens. Against the set of dewatering and guide ribs, a set of loading ribs operates, which is placed inside the opposite wire loop and which operates by means of the medium pressure of loading hoses.

Abstract: A method, device, and arrangement in a paper machine for regulating the control of the transverse profile or profiles of properties of a paper web produced therein. Water is removed from the paper web under compression between two forming wires by making use of dewatering and/or forming ribs. The deflection of the dewatering and/or forming ribs in the transverse direction of the web is regulated thereby affecting the retention profile of the paper web in the cross direction. By regulating the deflection of the dewatering and/or forming ribs, the transverse fiber-orientation profile and/or the filler profile of the paper web is influenced through the control of the transverse retention profile of the web.

Abstract: The invention relates to a twin-wire web former for a paper machine wherein a covering wire and a carrying wire form a twin-wire forming zone between them. A method for dewatering a web is also disclosed. In the invention, water is drained out of a web running through the twin-wire zone through both of the wires. After the twin-wire zone, the web is separated from the covering wire and is transferred on the carrying wire to a pick-up point. In hybrid formers, after an initial single-wire forming zone preceding the twin-wire zone, and in gap formers, after a curved forming zone placed directly after a forming gap, there is a forming shoe provided with a ribbed deck and arranged inside one of the wire loops. This forming shoe is followed by dewatering and web forming units which include forming ribs and are placed inside both of the wire loops. At least one of the dewatering and web forming units is loaded by means of a pressure-hose arrangement.

Abstract: The invention relates to a twin-wire web former for a paper machine wherein a covering wire and a carrying wire form a twin-wire forming zone between them. A method for dewatering a web is also disclosed. In the invention, water is drained out of a web running through the twin-wire zone through both of the wires. After the twin-wire zone, the web is separated from the covering wire and is transferred on the carrying wire to a pick-up point. In hybrid formers, after an initial single-wire forming zone preceding the twin-wire zone, and in gap formers, after a curved forming zone placed directly after a forming gap, there is a forming shoe provided with a ribbed deck and arranged inside one of the wire loops. This forming shoe is followed by dewatering and web forming units which include forming ribs and are placed inside both of the wire loops. At least one of the dewatering and web forming units is loaded by means of a pressure-hose arrangement.

Abstract: The invention concerns a twin-wire web former in a paper machine, comprising a carrying wire and a covering wire which together form a twin-wire forming zone. In this forming zone, a forming unit is fitted, which comprises a forming board and a drainage box placed one opposite the other. In the forming board placed facing the drainage box there are a number of transverse loading ribs placed at a distance from each other. Subsequent transverse loading ribs are interconnected by intermediate parts which, together with the transverse loading ribs form ribbed shoes. These shoes can be loaded by means of loading hoses to produce a dewatering pressure in the web (W) placed between the wires. In the area of the forming unit the dewatering takes place both through the covering wire and through the carrying wire also toward the forming board through the open spaces placed between its transverse loading ribs.

Abstract: A wire loading device in a paper machine, by whose means a mechanical load is applied to the wire of the paper machine across its entire width, is disclosed. By means of this load, a pressure pulse is applied to the fiber layer or web supported by a wire or between wires. By means of the pressure pulse, the dewatering of the web is promoted, the formation of the web is improved, and/or the transverse profiles of different properties of the web are controlled, such as the transverse profiles of dewatering, filler distribution, formation, and/or retention. The loading device includes a plate-shaped spring blade, whose side is arranged as substantially parallel to the run of the wire or wires. The spring blade is adapted to drag against the inner face of a wire loop to produce a pressure pulse. The spring blade is attached, from outside its dragging area, to a frame part of the loading device.

Abstract: Method and arrangement in a machine for the manufacture of paper or board, for heating an outer face of a cylinder or roll which is in direct contact with a web to be pressed thereagainst. The cylinder or roll face is heated from outside inductively by using a magnetic field, and by which a heating effect based on eddy currents is produced in the outer layer of the roll or cylinder. A relatively thin outer layer of an electrically conductive ceramic material is used as the cylinder or roll face, in which the resistive heating effect is concentrated. The depth of penetration of the heating effect in the radial direction of the roll of cylinder to be heated is restricted to a sufficiently low depth by choosing the thickness of the ceramic outer layer and/or the electric frequency of the induction heating.