Abstract:
In manufacturing a moving web, such as a tissue sheet, the web is transported at very high speeds, often in an unsupported manner, which can result in unstable operations regarding handling and winding of the web. This is particularly true in the region between the creping blade and the reel for a lightweight, low modulus tissue sheet that is characteristic of a high-quality, soft tissue basesheet. To provide an improved means of controlling the tissue web during manufacture and to improve the manufacturing rate, an apparatus and method of stabilizing the moving web that incorporates a creping blade foil, one or more aerodynamic sheet stabilizing foils, and a roll foil in a specific relationship to each other is disclosed. This method has been shown to improve the stability of a moving tissue web, allow for a higher rate of operation, and enable the production of softer tissue basesheets.
Abstract:
A system and method effectively threading the moist tail of a web through a pulp dryer. A tail threading belt in a closed loop passes the tail of the web through the dryer, and the most tail of the web is transferred from a support wire in the press section of a pulp machine to the tail threading belt. Transfer may be effected using a suction roll with a suction sector and a blower sector, or by using a suction chamber having a perforated escort belt which cooperates with it to engage the tail section on the wire and fully support it during transfer to the threading belt. The threading belt may be folded over to contain the tail web inside it while it passes through the dryer.
Abstract:
A 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. The web is transferred on this transfer surface as a closed draw onto the drying wire or equivalent in the dryer section following after the press section.
Abstract:
Process for guiding a web from one treatment station to another in a web manufacturing or treatment process. The process includes guiding the web with at least one pneumatic support device and controlling air pressure in the at least one pneumatic support device via a microprocessor. The air pressure is related to at least one quality factor of the web.
Abstract:
A web support foil positioned adjacent to a Yankee dryer above a creping doctor. The foil supports the web as it leaves the dryer. Mounted to the top of the foil is an adjustable air deflector which is positioned tangent to the Yankee dryer. The air deflector blocks air moving along the web. A slotted opening draws air from a leading-edge pocket collecting fibers which are broken loose during the creping action. The web is held against the bottom side of the foil by one or more air jets which are directed over the bottom surface on the foil. The jets of air function as coanda air jets and prevent the web from sticking to the bottom surface of the foil while creating a Bernoulli effect which holds the web against the bottom of the foil.
Abstract:
A single tier dryer system has dryer rolls with a reversing roll positioned between each pair to transfer and wrap the dryer felt and paper web against the next dryer roll. A vacuum box is positioned between the dryer rolls and over the reversing roll to hold the web on the dryer felt by vacuum. Threading of a tail from the web is accomplished by blowing the web tail off a first dryer roll's surface with a jet of air positioned adjacent to the position on the dryer roll where the dryer felt leaves the dryer roll's surface. The vacuum box is divided by a baffle to isolate a portion of the vacuum box near the front of the dryer rolls, and a damper is positioned within the reversing roll to increase the vacuum in the isolated portion of the vacuum box to facilitate threading of the tail.
Abstract:
A novel sheet transfer stabilizer is provided for transferring a fibrous wet sheet from a press section to a dryer section of a paper-making machine by way of a felt. The sheet transfer stabilizer includes a composite Venturi box which is disposed between a felt roll of the press section and a first dryer. The Venturi box includes three side-by-side Venturis, an inlet Venturi, an outlet Venturi, and a main Venturi. Such Venturi boxes are used to create and maintain a vacuum in the felt/web system.
Abstract:
A strip severing device for a feed strip to be threaded in a machine for producing or processing a paper web. The device has a swingably mounted guide plate for the guiding of the feed strip selectively toward or away from a web separating device. The separating device has a support element which can be rotated. It carries at least one flexible or flexibly supported separating element which swings out from a position of rest into an operating position in which it severs the feed strip coming from the guide plate.
Abstract:
A machine or making a fiber web such as paper with the fiber web having a running direction in the machine, the machine including a dryer section which removes moisture from the fiber web and a laser cutter assembly disposed adjacent the fiber web that generates a laser beam for cutting the fiber web. The laser cutter assembly includes a conduit that the laser beam passes through. The conduit includes a fluid inlet for receiving a fluid extinguishant such as carbon dioxide gas. A heat sink is used to prevent the laser through the conduit when the fluid extinguishant is absent in the conduit. The fluid extinguishant emitting from an outlet of the conduit inhibits generation of a flame caused by the cutting of the fiber web by the laser beam.
Abstract:
An apparatus for stabilizing a low-strength sheet having a width and a top surface and moving in a first direction at a rate sufficient to entrain air. The apparatus includes an airfoil adapted to extend along the top surface of the sheet. The airfoil, in turn, includes: a bottom surface adapted to extend along a portion of the top surface of the sheet; a first surface extending a first distance from the bottom surface at a first juncture; a second surface extending a second distance from the bottom surface at a second juncture; and a top surface extending from the first surface at a third juncture to the second surface at a fourth juncture. The first distance in general is less than the second distance. In addition, the apparatus is oriented in a manner such that the portion of the apparatus which first encounters the entrained air is the first surface of the airfoil, and the first and bottom surfaces of the airfoil form an acute angle such that the first surface directs a substantial portion of the entrained air away from the sheet. The apparatus may include a forebody, a passageway, and/or a deflector.