Abstract: A twin-wire papermaking machine contains a headbox for forming a first fiber ply which is essentially downwardly dewatered at a section of a first wire. At the end of this wire section, forwardly or upstream of the inbound or on-running location of a second wire there is arranged a second headbox for forming a second fiber ply which is essentially upwardly dewatered along a subsequently arranged common path of both wires. The common path advantageously extends over an essentially water impervious, convex domed contact surface of a slide shoe and/or a jacket surface of a guide cylinder or roll. During operation, the second fiber ply is deposited upon the already extensively dewatered first fiber ply and upon passage through the common path of both wires this second fiber ply is dewatered upwardly away from the first fiber ply.

Abstract: A twin wire former of a paper making machine in which one of the wires is supported on a surface of each of a number of forming shoes longitudinally spaced along the extent of the wires. Each forming shoe has a number of longitudinally spaced grooves in the surface contacted by the one wire, each of the grooves extending in a direction at an angle to the longitudinal direction less than 90.degree., such that scraping pressure applied to the raw material liquid guided between the two wires, by the surface between the grooves is released into the grooves. This arrangement of grooves creates a pressure difference in the raw paper material liquid in a direction transverse to the longitudinal direction of the wires to produce a transverse flow of the raw paper material liquid, thereby reducing the machine-direction to cross-machine-direction ratio of the fibers of the paper being formed.

Abstract: A double sieve or twin-wire papermaking machine possesses a substantially planar section of a lower band which is equipped with a headbox. Furthermore, it contains a shoe containing a domed surface and a dewatering cylinder. Arranged after the dewatering cylinder is a deflection roll which is located at the side of both bands, typically in the form of sieves, wires or filters, which face away from the dewatering cylinder. The shoe and the dewatering cylinder are located either within the lower band or within the upper band. The first deflection roll can have arranged thereafter a second deflection roll which is located at the same side of the lower band as the dewatering cylinder.

Abstract: The disclosure concerns the wire end section of a paper making machine. The wire belt is an endless loop and the pulp suspension is supplied by one or more head boxes. The head box has an upstream and a downstream flow guide wall defining a pulp outlet opening between them. The downstream guide wall has a convexly curved slide shoe which cooperates with the passing wire belt to define a web-forming zone. At the other side of the wire belt, upstream of the outlet opening, another convexly curved wire support surface is defined for leading the wire belt into the web-forming zone. Both of the convexly curved surfaces are displaceable transversely to the direction of pulp flow from the head box. The radius of curvature of the slide shoe is greater at the outlet opening and smaller away from the outlet opening. The radius of curvature of the cooperating supporting surface on the other side of the belt is smaller than the mean radius of curvature of the slide shoe.

Abstract: A procedure for dewatering and detaching a paper web from the second former wire. The composite of first and second wire and interposed web is contacted with a first cover part of a special suction box. A roll guiding the second wire, pressing from the side of the latter deflects its run. This pressure plus centrifugal force, and the differential pressure arising from the suction box, dewater the web. The second wire is separated to follow along with the guide roll, while web and first wire are acted on by the suction box vacuum. The first wire is then contacted with a second cover part of the suction box. A twin-wire former is also disclosed, featuring within its carrying wire loop, on its twin-wire run, a rotating forming roll deflecting the composite of wires and web as it laps a given sector of said forming roll. A special suction box at the ultimate end of the wires has a bipartite cover its parts angulated against each other and preferably planar.

Abstract: A pair of enclosed explosion chamber flowboxes are combined so that the top exit slice plate of the first chamber provides the lower exit slice plate of the second chamber downstream of the first chamber so that pressurized furnishes for a two-ply web are laid one on top of the other over a very short distance.

Abstract: The wet end of a fourdrinier paper machine includes a transversely disposed roll beneath the wire. The roll is shaped and mounted for rotation at a speed which is different from the speed of the wire to create pulses of negative pressure beneath the wire for drawing liquid from the web of fibers formed thereon. Also disclosed is a fin apparatus transversely disposed beneath the wire to create a wave of positive pressure thereunder to urge the formed web off of the wire.

Abstract: A method and apparatus for continuously forming a multi-ply corrugated container board from freshly laid web plies by simultaneously forming the separate plies from aqueous slurries of fibers on corresponding foraminous fabrics, and dewatering each of them sufficiently to form a web ply capable of being handled in a papermaking machine as an integral web. All of the webs are formed on a single papermaking machine, but separately. The first web ply is laid on a traveling forming wire, such as a fourdrinier wire, and each subsequent web ply is formed in close proximity to the traveling forming wire and brought into bonding engagement seriatim with the top surface of the previously formed web ply carried on the traveling forming wire.A typical corrugated box board has three plies with the inner ply being corrugated.

Abstract: A non-laminated paper sheet product characterized by regions or islands of increased thickness, usually located in the center of the sheet for more economical use of the paper product and for conservation of wood pulp. The regions of increased thickness are formed by depositing or laying additional pulp stock onto a generally uniform thickness paper web in the web-forming area of a paper machine in either wet or dry methods of paper production. Continuous regions of increased thickness in the web can be formed by corresponding variations in the width of the web or by spraying the additional pulp onto the forming web. Islands of increased web thickness can be formed by periodically interrupting pulp stock depositing sprayheads disposed at spaced locations across the width of the forming web, with timing devices or web thickness sensors controlling the sprayheads.

Abstract: Paper pulp insulation of uniform weight per unit length is formed simultaneously on each of a plurality of advancing electrical conductors (21--21) by the use of a dual zone headbox (23) which cooperates with a forming cylinder (24). In one zone of the headbox, the average velocity of a pulpous mixture flowing in a channel (54) is controlled by a first velocity control member (58) after which the pulpous mixture is split into a plurality of streams to form a pulp ribbon (29) below each of the conductors on the periphery of the forming cylinder. In the other zone, the pulpous mixture is passed through a channel (57) prior to being split into individual streams that are deposited as ribbons (31--31) above the conductors. The average velocity of the pulpous mixture in the channel (57) in the other zone is controlled by a second velocity control member (66) having a plurality of discrete individually adjustable sections which are aligned with the streams.

Abstract: A twin-wire web forming section in a paper machine includes a lower endless carrying wire which laps a forming roll and an upper endless covering wire which laps at least a part of the portion of the lower carrying wire which laps the forming roll. First and second substantially straight runs of the carrying wire are defined prior and subsequent to the forming roll, respectively, in the direction of travel of the lower endless carrying wire, the first straight run comprising the initial single-wire portion of a web-forming zone. An open-surfaced forming board is operatively associated with the initial single-wire portion. A headbox is disposed at the forward end of the initial single-wire portion, the longitudinal axis of which is substantially aligned with the direction of movement of the initial single-wire portion.

Abstract: The invention relates to a paper machine of the kind having a continuous inner wire cloth and a continuous outer wire cloth which are passed together around a deflecting component, located within the inner wire cloth, for effecting extraction of water through the outer wire cloth, said machine also having a water extraction box located within the inner wire cloth in front of the deflecting component, and a breast (delivery) box, an upper lip of which lies adjacent the inner wire cloth in the vicinity of the water extraction box and defines, with a support surface provided by the water extraction box, a preliminary water extraction zone in which water can be extracted through the inner wire cloth into the water extraction box.

Abstract: A papermaking machine is shown with an inner traveling screen and an outer traveling screen which are led towards each other to form a generally layered arrangement therebetween during a region of their joint travel and, in such region, the inner and outer screens are caused to pass over a portion of a water extracting or dewatering roller; a water collection apparatus situated outside of the roller serves to collect water centrifuged from the screens passing over the roller; and a preliminary water extraction zone preceeds the roller and such zone extends over a portion of, for example, a generally horizontal section of the inner screen.

Abstract: Paper pulp insulation of uniform weight per unit length is formed simultaneously on each of a plurality of advancing electrical conductors (21--21) by the use of a dual zone headbox (23) which cooperates with a forming cylinder (24). In one zone of the headbox, the average velocity of a pulpous mixture flowing in a channel (54) is controlled by a first velocity control member (58) after which the pulpous mixture is split into a plurality of streams to form a pulp ribbon (29) below each of the conductors on the periphery of the forming cylinder. In the other zone, the pulpous mixture is passed through a channel (57) prior to being split into individual streams that are deposited as ribbons (31--31) above the conductors. The average velocity of the pulpous mixture in the channel (57) in the other zone is controlled by a second velocity control member (66) having a plurality of discrete individually adjustable sections which are aligned with the streams.

Abstract: A double filter papermaking machine comprising two filters guided over a dewatering cylinder. A first one of the filters contains a linear section or path located in front of the cylinder. A domed dewatering or slide shoe, shorter than such linear section, is arranged ahead of the cylinder. The second filter is equipped with an adjustable guide roll, by means of which it is possible to regulate the contact location of the second filter at the first filter, and specifically, between a location disposed at the starting region of the shoe and a location arranged after the shoe at the dewatering cylinder. A regulation device or regulator can be provided which contains a feeler for sensing the position of the water line at the dewatering cylinder.

Abstract: A two-wire papermaking system for the formation of paper from paper slurry includes a first section where the slurry is maintained under pressure in a condition of minimum pond height under the guidance of a looped lower (bottom) web carrying wire having a single run over a progressive series of independently controlled dewatering boxes immediately prior to passage from the headbox through the adjacent slice and a second section comprising two wires (the said web carrying wire and a looped top or covering wire) facing each other (and between which the forming web is enclosed) and guided conjointlyover a dewatering roll to follow a downwardly curved path while secondary dewatering ensues through the top wire due to centrifugal forces before passage over a suction transfer roll where a first transfer from the bottom (forming) wire to the top wire ensues preparatory to passage over a vacuum transfer box for a second transfer from the top wire to a wet web saturator fabric or a through dryer fabric for delivery o

Abstract: The auxiliary roll of the separating system is located downstream of the main roll and is spaced from the main roll at a distance less than 0.25 times the diameter of the auxiliary roll and greater than the combined thickness of the two wires and paper web therebetween, e.g. a distance of 10 millimeters. A separating wall is located between the main roll and main wire on the upstream side to block the entry of air between the main wire and main roll. The spacing of the two rolls ensures a positive separation of the paper web on the main wire.

Abstract: Structure for facilitating separation of a web and wire in a paper machine. Steam is supplied to the wire at the separating location where the web and wire separate from each other at a side of the wire opposite from the side where the web forms so as to facilitate separation of the web and wire from each other. Steam is supplied from the interior of a container which has a foraminous wall directly engaging the wire so that through the pores of the foraminous wall the steam will discharge to be conducted to the wire. The structure is particularly suitable in connection with twin-wire formers as well as in connection with the manufacture of tissue paper.