Method for preventing web rewetting
AssigneeSulzer Bros. (U.K.) Limited
InventorEberhard Wassermann
Life of this patent
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AssigneeSulzer Bros. (U.K.) Limited
InventorEberhard Wassermann
Estimating the term…
A method for preventing web rewetting in a paper making machine of the type comprising a forming cylinder with an apertured or perforated periphery, with or without a foraminous belt wrapped around the cylinder, on which cylinder there is formed, during rotation of the cylinder, a paper web by a pressure slice to which paper slurry or stock is supplied, the paper web remaining on the periphery of the cylinder or belt over a major portion thereof, while water is drawn from the web by means of one or more suction boxes located within the cylinder and extending from the pressure slice to a transfer zone where the web is transferred from the cylinder or belt onto a felt or wire cloth for subsequent processing. In the remainder of the paper making machine there is provided a suction box extending over an arc from said web transfer zone to the area of said pressure slice to prevent rewetting of the withdrawn web.
In a method of making paper using a paper making machine comprising a forming medium having a perforated surface, a pressure slice adjacent said surface, and a transfer zone from which a formed web is withdrawn, and wherein the withdrawn web is exposed to water thrown out from a length of said forming medium extending between said transfer zone and said pressure slice in a direction of movement of said medium, comprising the steps of moving said medium, supplying paper stock material from said pressure slice to said medium in a forming zone during movement of said medium, producing suction at said medium at the transfer zone thereof, withdrawing the formed web from said medium at the transfer zone, water from said moving medium tending to impinge on said withdrawn web, the additional step of producing suction at said medium along substantially the entire length of said medium extending between the transfer zone and the pressure slice in the direction of movement of said medium so as to prevent rewetting of said withdrawn web.
Dependencies are inferred from the claim text.