GB1335399A - Fibrous web formation - Google Patents

Abstract

1335399 Paper-making apparatus M C BEST (Beloit Corp) 29 Oct 1970 51486/70 Heading D2A In a paper-making machine a headbox 11 feeds stock between wires F1, F2 which extend round breast rolls 12, 13 and then converge and extend in a sharply curved path round a guide 14 whereby water is removed from the stock by centrifugal force. The wires then pass over suction boxes 15 and the formed web is thereafter transferred by a suction couch roll 16 to a felt PF. The rolls 12, 13 may be solid or perforated and the guide 14 is a perforated roll. A saveall S is provided and the wires are driven by means M1, M2 and are tensioned at T1, T2. In a second embodiment, Fig. 2 (not shown), the guide roll 14 is replaced by a stationary guide the tail end of which diverges from the wires by at least 5‹ and which has a curved leading edge. The surface of the guide has a hard coating of tungsten carbide, titanium carbide or a ceramiccrystalline refractory metal oxide, e.g. aluminium oxide, and is highly polished. In a third embodiment, Fig. 3 (not shown), the wires extend round a stationary guide then round two guide rollers where the web is further dewatered by centrifugal force and thereafter over the suction boxes. In a fourth embodiment, Fig. 4 (not shown), the construction is similar to that of the embodiment shown in Fig. 1 but the wires have an increased wrap round the roll 14 and then extend upwardly. The roll 14 may be solid. In a fifth embodiment, Fig. 5 (not shown) the construction is similar to that of the embodiment shown in Fig. 1 but additional stationary guide elements engaging the outside of the wires are disposed in opposed staggered positions between the breast rolls 12, 13 and the roll 14. Each of these guide elements has a curved leading edge and deflects the wires by at least 5‹, and its surface is of hard material. In a sixth embodiment, Fig. 6 (not shown), which is similar to that shown in Fig. 5 the additional guide elements are rollers.