Abstract: A roll covering is particularly suitable for a roll for the treatment of a paper web, paperboard web, or any other web of fibrous material in a machine for the production and/or finishing the same. The roll covering encompasses at least one layer. The at least one layer is formed of a rubber composition that includes at least one (meth)acrylate compound and a rubber component with at least one crosslinked hydrogenated nitrile rubber. Further, the at least one layer has a recovery rate of at least 12 mm per second and/or a maximal degree of plastic deformation of 0.9%, and a maximal tan ? value of 0.16 determined in accordance with DIN 53513 at 60° C. in tension at 10 Hz, 15% static elongation, and 1% dynamic elongation.

Abstract: According to one aspect, the invention relates to a method for producing a watermark element (10) for forming a shadow watermark image in a substrate by means of dewatering of a fibrous suspension, wherein the watermark element (10) comprises a body with a relief side (12) having a relief (14) and a dewatering side (16) positioned opposite the relief side, perforations (18) being provided at least in the relief (14), a perforation (18) comprising a channel (20) with a channel inlet (21) at the relief side (12) and a channel outlet (22) at the dewatering side (16), which method includes the steps of forming perforations in a body in a mechanical manner and introducing a relief in the intended relief side, the perforations (18) being formed in such a way that the dewatering capacity, expressed as the open surface area of the channel inlet(s) per unit of surface area of the relief, is dependent on the height (h) of the channel inlet (21) with respect to the dewatering side (16), it being the case that the higher

Abstract: A method for providing a watermarking wire mesh, particularly for producing security paper and the like, comprising in sequence the following steps: associating stably at least one electrotype element at a preset region of a first working face of a watermarking wire mesh; deforming plastically at least one predefined portion of the watermarking wire mesh, which comprises at least partially the at least one electrotype element.

Abstract: [Problem] It provides a sheet forming machine which can make the thickness in the width direction of a sheet forming body be uniform, and also can obtain a sheet forming body which is integrated in stripe shapes by using different raw materials or raw materials of different colors in the width direction of one sheet forming body.

Abstract: Dewatering blades for use in papermaking machines are assembled from two or more pre-finished sub-assemblies which are in turn mounted on a base member. Each sub-assembly comprises a holder, configured to receive a plurality of segments, constructed of a wear-resistant material such as ceramic, which will be located so as to be in sliding contact with the underside of a papermaking fabric. The holders are adapted for insertion into and retention in the base member, which is subsequently affixed to the papermaking machine by known means. The construction of the sub-assemblies allows for the manufacture of a full length blade from a plurality of sub-assemblies, which dramatically reduces manufacturing cost while providing for more rapid deliveries and simplified repair of damaged blades.

Abstract: A distribution unit for adding a fiber suspension to an inlet space in a dewatering press is disclosed. The distribution unit comprises a distribution housing, which forms at least one distribution slit intended to be connected to the inlet space of the dewatering press, and at least one inlet member for adding the fiber suspension to the distribution slit. The distribution housing is provided with at least one opening to the distribution slit and a matching hatch for sealing the opening. The hatch is hinged to the distribution housing so that it is pivotable relative to the distribution housing between a first position and a second position. An inlet box is also disclosed comprising a number of the distribution units.

Abstract: Dewatering blades for use in papermaking machines are assembled from two or more pre-finished sub-assemblies which are in turn mounted on a base member. Each sub-assembly comprises a holder, configured to receive a plurality of segments, constructed of a wear-resistant material such as ceramic, which will be located so as to be in sliding contact with the underside of a papermaking fabric. The holders are adapted for insertion into and retention in the base member, which is subsequently affixed to the papermaking machine by known means. The construction of the sub-assemblies allows for the manufacture of a full length blade from a plurality of sub-assemblies, which dramatically reduces manufacturing cost while providing for more rapid deliveries and simplified repair of damaged blades.

Abstract: A doctor assembly is disclosed for use in a paper-making machine. The doctor assembly includes a doctor blade holder into which a doctor blade may be inserted and the doctor blade holder includes a pressure plate, pressure adjustment system, a support tray, and a bracket in accordance with an embodiment. The pressure plate is for supporting and aligning the doctor blade in a cross machine direction for application to a machine roll. The pressure adjustment system is for adjusting the pressure applied to the machine roll by the doctor blade, said pressure adjustment means including at least one fluid reservoir having a wall that contacts the pressure plate. The support tray for supporting the at least one fluid reservoir, and the support tray includes at least one bracket alignment feature. The bracket is attached to the support tray for pivotal attachment to the pressure plate.

Abstract: Methods for dewatering a fiber suspension in a twin-wire press, having a lower wire and an upper wire, and a first and a second dewatering table, which supports the wires such that a dewatering space is defined by the wires, are disclosed. The wires transport the fiber suspension under compression of the wires by the dewatering tables, such that the fiber suspension is dewatered and forms a fiber web between the wires. A separate pressing force is applied against one of the wires, such that this wire presses the formed fiber web via the second wire against one of the dewatering tables and further dewaters the fiber web. The separate pressing force is adjusted such that a desired dryness of the fiber web leaving the dewatering tables is achieved. A twin-wire press is also disclosed.

Abstract: A method and apparatus for transferring a vibrational force to the wire of a papermaking machine in order to re-align the fibers of the web forming on the wire or to clean press section felts. In some embodiments, the apparatus is a vibrational device including at least one vibration-inducing mechanism, a vibrational head coupled to the vibration-inducing mechanism for vibrating the wire, and a dampening mechanism coupled between the vibrational head and the vibration-inducing mechanism.

Abstract: A method and apparatus for transferring a vibrational force to the wire of a papermaking machine in order to re-align the fibers of the web forming on the wire or to clean press section felts. In one preferred embodiment, the apparatus is a vibrational device including a vibrational device frame, at least one vibration-inducing mechanism coupled to the vibrational device frame, and a vibrational head coupled to the vibration-inducing mechanism for vibrating the wire.

Abstract: A method and apparatus for beginning the formation of a paper web on a traveling forming wire, or between a pair of converging forming wires, includes a headbox on a papermaking machine for projecting a stock stream onto the forming wire, or between the forming wires over the porous face surface of a forming shoe. The forming wire or wires are looped to travel in a continuous path, and within at least one of the looped forming wires is the forming shoe, which is porous by way of grooves or openings over at least a portion of its face surface. The grooves are in the surface of the forming shoe which engages the inner surface of the looped forming wire to define a portion of the path of travel of the forming wire adjacent the headbox from which the stock stream is projected onto, or between, the forming wire(s). The grooves extend in the surface facing the forming wire from a point downstream of the leading edge in the nose portion of the face surface of forming shoe in the direction of forming wire travel.

Abstract: An adjustable blade apparatus including an operative surface which cooperates with a forming wire of a forming section. The apparatus includes a stationary support which extends in a cross machine direction relative to the forming wire. The support defines a guide rail having a front and a back end. The front end is disposed at a different elevation relative to the back end. The arrangement is such that the guide rail slopes in a cross machine direction. A blade defines the operative surface and the blade cooperates with the guide rail such that the blade is adjustably supported by the support. The arrangement is such that relative cross machine directional movement between the guide rail and the blade adjust the elevation of the operative surface relative to the wire.

Abstract: A web former for a paper machine having a lower-wire loop which forms an initial single-wire part of a dewatering zone. The former also includes a top-wire unit which includes an upper wire which forms a twin-wire dewatering zone together with the lower wire. The former also includes a first forming roll in a direction of web travel that is provided with an open hollow face and is fitted inside the upper-wire loop. The twin-wire forming zone begins in conjunction with the first forming roll. There is a forming shoe inside the lower-wire loop which is provided with a curved deck that guides the lower-wire loop. The former includes a second forming roll fitted inside the upper wire loop and situated after the forming shoe. A device for collecting water is provided in the former and operates without any external suction source, with dewatering being based upon kinetic energy of water that is being removed and/or upon gravity.

Abstract: The device comprises a head box with a nozzle for applying a pulp suspension on a wire located below the nozzle. A pressure plate is located after the nozzle over the pulp suspension. The pressure plate comprises a concave formed portion, against which the pulp suspension is sprayed, and a subsequent convex formed portion. The fiber web is formed in a forming zone where dewatering is effected in that the convex portion of the pressure plate and an unsupported portion of the wire are pressed against each other.

Abstract: A web-forming section and method in a paper machine. The web-forming section includes a lower wire loop having an initial lower wire run constituting an initial single-wire dewatering zone of the web-forming section in which the web is dewatered through the lower wire, and an upper wire loop having a joint run with a subsequent run of the lower wire to form a two-wire dewatering zone of the web-forming section within which dewatering takes place substantially through the upper wire. A first open faced forming roll is situated within the upper wire loop so that the two-wire dewatering zone begins and curves upwardly in the region of the first forming roll. A forming shoe within the lower wire loop has a curved deck whose center of curvature is situated on the side of the lower wire loop and further guides the joint run of the upper and lower wires in the two-wire dewatering zone.

Abstract: In a papermaking machine, a drainage interrupting mask of a certain width is disposed between a continuously moving endless Fourdrinier wire and respective suction box therebelow for interrupting web formation through the said certain width and along the length of the forming web and providing a dividing of the web with that portion of the web outboard of the mask being recycled for subsequent reuse as pulp slurry while the remainder of the forming web continues forwardly for the usual papermaking functions.

Abstract: An apparatus for affecting a web drained on a wire, comprising a lower wire which runs as an endless loop; disposed transverse members which supporting the lower wire, disposed at a distance from each other; an upper wire which runs as an endless loop and presses the web formed on the lower wire in the area between the supporting members. Inside the upper wire loop there is disposed a dewatering shoe which is in contact with the upper wire, and a roll which together with the dewatering shoe form a flow channel for leading upwards the water pressed out.

Abstract: An improvement in a web-forming section of a paper machine intended as a modernization of a fourdrinier-wire part by which an improved formation of the web and an adjustable dewatering thereof by which better retention and desired distribution of fillers and fines is achieved.

Abstract: A wire section in a paper machine includes an upper wire unit which is compact and easily exchangeable, if required, the construction of the wire section being such that old, single-wire planar wire machines can be converted to twin-wire machines. The paper machine wire section includes a lower wire having an initial single-wire run in which dewatering of a web takes place, and at least one upper wire unit following the initial single-wire run which defines a twin-wire dewatering zone with an adjacent run of the lower wire and in which dewatering of the web takes place through both the lower and upper wires. The twin wire dewatering zone is further defined by a curved, solid-cover forming shoe situated within the upper wire loop and wherein the forming shoe is preceded by a curved dewatering zone where dewatering is mainly through the upper wire.

Abstract: An improved hydrofoil for use in a paper forming apparatus, such as a fourdrinier, is provided with a nip on both the trailing edge and leading edge. The nip on the trailing edge is provided in a standard manner for desired drainage, while the nip in the leading edge of the foil is provided to "pump" water back into the paper material to break up wire side flocs.

Abstract: Apparatus for controlling the position and location of a stationary device extending across the transverse dimension of a web in a paper machine for acting on the web during operation of the paper machine and by which the distance of the device from the web and/or its angular position is adjusted. The control apparatus is provided at both transverse ends of the frame of the stationary device and comprises a slide member assembly including a first slide member which supports the frame portion of the stationary device, a second slide member supported on the frame of the paper machine and an intermediate slide member situated between the first and second slide members and slidably engaging the same at respective engaging pairs of sliding surfaces thereof. The intermediate slide member and one of the first and second slide members have opposed engaging curved sliding surfaces, the center axis of such curvature substantially coinciding with a straight line defining the tip edge of the stationary device.

Abstract: A twin wire papermaking machine which has a multichambered suction dewatering device located over the forming wires downstream from the forming roll. The dewatering device deflects the forming wires into a concave path to aid in formation and dewatering.

Abstract: By imposing pressure pulses on mobile fibers in suspension in paper making stock slurry in the primary drainage area of the forming zone of a roll former substantially uniform distribution of the fibers is effected in forming of the paper web. A device for effecting the pressure pulses is located adjacent to the primary drainage area and may comprise a pressure pulse producing element of selected shape to control the length of the pressure pulse for the particular character of paper making fiber stock slurry involved in the paper web being formed.