GB1257301A - - Google Patents

Abstract

1,257,301. Moulding sheets and panels. M. A. E. RHIANDO. 16 Dec., 1968 [15 Sept., 1967], No. 42191/67. Heading B5A. [Also in Division B2]- Sheets or panels having a granular coating for use as constructional or decorative elements in the building industry are produced by applying a layer of a settable binding material to a moulding surface and causing an excess of granular material to flow across the surface of the surface in such manner that the weight of excess granules causes some of the granules to become embedded in the binding material to form a coherent coating. The flow of granular material across the surface may be produced by tilting the moulding surface alternately in opposite directions relatively to the horizontal or by rocking the moulding surface backwards and forwards. The granules may consist of ceramic granules which have been pigment coated and fired, particles of glass, enamel, or granite chippings, marble or other mineral aggregate which may be coated with a glaze or a resin such as polyurethane, melamine or polyesters. As shown in Figs. 3 and 4 base member 26 is formed with a well 54 lying below the level of granular material receiving troughs 32, 34 which well receives a female mould 50, the surface 52 of which has been sprayed with a binding material. Preferably before being sprayed with the binder the surface 52 is provided with a release layer to which the binder will not adhere, e.g. a polytetrafluoroethylene coating or a thermoplastic polypropylene. The well 54 may be sufficiently deep to accommodate moulds 50 of different depths, the mould being packed from below to bring its peripheral surface in the same plane as the base of the troughs 32, 34 so that granules passing across the mould surface will not meet any obstruction. When the mould 50 is in correct position in the well 54, the base member 26 is rocked about the shaft 24 so that the trough 32 is tilted to an upper position and excess granules flow across the mould surface and are collected in trough 34 in its lower position. The reverse flow of granules takes place with reverse tilting of the base 26. The mould 50 is then passed through a spray booth 46 where a coating of binding material seals- and waterproofs the granular coating. When the coating of binding material has hardened beyond the tack point, the mould 50 is removed and placed in a press 56 having a correspondingly shaped male mould 58. The granular layer is then covered with a mat of glass fibres above which is applied a polyester resin including a catalyst and hardener. The press is then operated so that the two moulds come together and distribute the resin over the mould surfaces and forces the fibre mat to the shape of the granule coating covering the mould surface. When the laminate is sufficiently cured, the moulds are separated.