Fourdrinier for removal of water from wet fibre suspension - has impermeable film fused to support structure with passages for liq. and gas to pass through

摘要

The structure of a sieve (6) esp. a fourdriner for the drying section of a papermaking machine, has a cladding (2) for the woven or grid support structure (1) which is impermeable to liq. and/or has a closed pore structure. The cladding (2) has passages (5) through it to allow liq. and gas to pass through. The support structure (1) is pref. a woven sieve material of mono- or multi-filaments, or the filaments are in spiral coils, or it is a flat material. The cladding (2) is a film (3), fused into place at least at one outer surface (10) of the support structure (1), esp. with passages (5) through it. One surface (7) of the film (3) is fused to the surface (10) of the support structure (1), and the other surface (4) of the film (3) is flat. The film (3) is of a polymer material, such as polyurethane, acrylate or the like, and can be formed from a bulking agent which fills the support structure (1). The passages (5) are formed after the film (3) is polymerised, through perforations, slits, etc. The smooth and flat surface (4) of the film (3) in contact with the paper web, is treated to allow further reactions through electron or laser or UV beams or a high frequency process. The woven support structure can be provided by only a single yarn or filament system. ADVANTAGE - The fourdrinier is easily produced and gives an effective action in the removal of water from the wet fibre suspension and pulp, for conversion into paper.