GB1144665A - Couching apparatus for a paper-making machine - Google Patents

Abstract

1,144,665. Couching paper web. J. M. VOITH G.m.b.H. 28 March, 1966 [27 March, 1965], No. 13516/66. Heading D2A. A paper web is couched from a wire, which is entrained about at least a part of a hollow cylinder which is peripherally grooved and has perforations in the groove or grooves of the cylinder, by a roll resting against the cylinder which has a suction box inside, air passing from the inside of the cylinder, through the perforations, along the groove or grooves, and back through the perforations into the suction box so that water is removed from the perforations before the web is couched. The cylinder may be a forming cylinder disposed in a vat and may have a wire screen supported on a wire strand helically wound in shallow indentations on the grooved cylinder, and possibly have a suction region in the forming zone formed by a further suction box or by. a wall extending from the inside wall of the cylinder down into the white water therein. Alternatively the paper web is formed on a wire travelling upwardly to the hollow cylinder. In the above embodiments there may be a plurality of forming and couching stations through which a single felt passes. Alternatively the cylinder and roll may be used in a Fourdrinier machine. The cylinder may be grooved circumferentially, or helically with a single- or multi-start and in one or both directions.