Abstract: A method for controlling a slice flow of a slurry having two or more component slurries through a headbox for a paper making machine includes, inputting a wire speed of the paper making machine; determining a jet velocity setpoint based on the wire speed; determining a header pressure setpoint for two or more headers to generate the jet velocity determined by the jet velocity setpoint, each header providing one of the two or more component slurries to the headbox; and controlling the slice flow by: generating a first speed command to a first slurry pump to generate a header pressure determined by the header pressure setpoint in a first header; and generating a second speed command to a second slurry pump to generate the header pressure determined by the header pressure setpoint in a second header.

Abstract: A valve for a vacuum drainage system includes a valve body having an interior chamber operatively connectable to a suction device and through an outlet to a vacuum source. A movable member having an aperture is secured within the chamber and movable through points between closed and open positions to adjust the open area of the aperture and the fluid flow through the outlet. The aperture is configured such that during adjustment to increase the effective operational area of the aperture, a rate of change of the effective operational area increases non-linearly in relation to a linear increase in the distance of travel, while providing advantageous and more controllable linear adjustment of the applied vacuum. The aperture can have a trilateral shape including at least one curved side, or comprise a plurality of sub-apertures, and the movable member can comprise a rotary sleeve.

Abstract: A valve for a vacuum drainage system includes a valve body having an interior chamber operatively connectable to a suction device and through an outlet to a vacuum source. A movable member having an aperture is secured within the chamber and movable through points between closed and open positions to adjust the open area of the aperture and the fluid flow through the outlet. The aperture is configured such that during adjustment to increase the effective operational area of the aperture, a rate of change of the effective operational area increases non-linearly in relation to a linear increase in the distance of travel, while providing advantageous and more controllable linear adjustment of the applied vacuum. The aperture can have a trilateral shape including at least one curved side, or comprise a plurality of sub-apertures, and the movable member can comprise a rotary sleeve.

Abstract: A forming section for a twin fabric papermaking machine, wherein after stock impingement, the two fabrics carry and sandwich the stock. A plurality of spaced apart drainage shoes, selectively provided to either or both of the fabrics, provides continuous support in the machine direction for the respective fabric in sliding contact, and each drainage shoe deflects the fabrics by a selected angle of wrap comprising an angular displacement between the leading edge and the trailing edge of the drainage shoe. At least one of the drainage shoes is secured to a drainage box and is provided with a plurality of drainage openings extending from the fabric contacting surface through to the machine side surface of the shoe. The arrangements of the invention provide improved drainage and formation of the paper web.

Abstract: A forming section for a twin fabric papermaking machine, wherein after stock impingement, the two fabrics carry and sandwich the stock. A plurality of spaced apart drainage shoes, selectively provided to either or both of the fabrics, provides continuous support in the machine direction for the respective fabric in sliding contact, and each drainage shoe deflects the fabrics by a selected angle of wrap comprising an angular displacement between the leading edge and the trailing edge of the drainage shoe. At least one of the drainage shoes is secured to a drainage box and is provided with a plurality of drainage openings extending from the fabric contacting surface through to the machine side surface of the shoe. The arrangements of the invention provide improved drainage and formation of the paper web.

Abstract: A headbox including a stock dilution profiling arrangement and associated stock delivery systems are provided, which together deliver to the forming section of a papermaking machine a uniform stock flow with more consistent basis weight and fiber orientation profiles than has previously been possible. These improvements in basis weight uniformity and fiber orientation profile provide benefits in paper sheet formation and related paper properties.

Abstract: A headbox including a stock dilution profiling arrangement and associated stock delivery systems are provided, which together deliver to the forming section of a papermaking machine a uniform stock flow with more consistent basis weight and fiber orientation profiles than has previously been possible. These improvements in basis weight uniformity and fiber orientation profile provide benefits in paper sheet formation and related paper properties.

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: 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: A cleaning apparatus is disclosed for cleaning a forming wire of a paper machine. The apparatus includes a shower which is disposed adjacent to the forming wire for applying a shower of cleaning fluid to the wire. A blow box is disposed closely adjacent to the forming wire and downstream relative to the shower. The box is connected to a source of pressurized air for blowing a jet of air through the wire for removing the cleaning fluid therefrom. A plate is disposed between the box and the wire. The plate defines a plurality of slots which are disposed obliquely to a direction of movement of the wire in order to supply a multiplicity of pressure pulses to the wire for removing contaminants therefrom.

Abstract: The headbox apparatus of this invention contributes to the production of a paper web of uniform fiber orientation by controlling the edge flow of stock into the headbox nozzle through adjustable valves positioned in edge tubes in closed loop with a fiber orientation sensor. At the same time that fiber orientation is being control through adjustable valves position in the edge tube, basis weight of the web being formed is controlled by a stock dilution systems and an adjustable slice lip, in closed loop with a basis weight profiler sensor.

Abstract: A cleaning apparatus is disclosed for cleaning a forming wire extending around a wire turning roll of a paper machine. The apparatus includes a shower which is disposed upstream relative to the turning roll for spraying a cleaning liquid onto the forming wire. A housing is disposed between the shower and the turning roll, the housing being connected to a source of pressurized air. The housing defines an opening which has a first and a second end. The housing also defines an orifice which has an upstream and a downstream end for permitting a flow therethrough of the pressurized air such that the flow of air is directed against the wire for at least partially removing the cleaning liquid therefrom. The opening cooperates with the turning roll such that the opening conforms with the turning roll for substantially sealing the opening against loss of the pressurized air so that the flow of pressurized air is directed through the orifice.

Abstract: A headbox tube bank apparatus and method of directing flow through same is disclosed for permitting the flow therethrough of stock in a papermaking machine. The apparatus includes a tube bank frame for rigidly supporting the tube bank, the frame defining a plurality of openings. A plurality of tubes cooperate with the frame such that each tube extends through and is supported by an opening. Each tube has an upstream and a downstream portion, the upstream portion defining an internal cross-machine direction section of substantially circular configuration for maximizing the velocity of the stock through the tube.

Abstract: A coater apparatus is disclosed for applying a primary flow of coating material to a moving web of paper. The apparatus includes a frame and a first and a second guide roll rotatably supported by the frame. The first and second guide rolls rotate respectively around first and second rotational axes. The second axis of rotation is disposed spaced and parallel relative to the first axis. A backing blanket extends around and is guided by the guide rolls. The blanket defines an endless loop around the guide rolls such that the web of paper is supported by the blanket during movement of the web from the first guide roll to the second guide roll. The blanket is disposed between the web and the guide rolls. A short dwell coater is disposed adjacent to the web and between the guide rolls for applying the primary flow of coating material to the web.

Abstract: A system for forming a web from a dilute, aqueous slurry of fibers wherein a thin, horizontally-extending aqueous stream of fibers is projected onto a travelling foraminous forming wire. The forming wire is disposed to travel over a forming board which has a leading lip which is deflected downwardly with respect to the oncoming jet stream. The lower surface of the jet stream is disposed substantially parallel with the surface of the travelling foraminous wire wire at the point where the stream contacts the wire to minimize turbulence at the point of initial contact of the jet stream on the wire and subsequent spouting of the fibrous stock downstream in the forming zone.