GB1316744A - Moulding - Google Patents

Abstract

1316744 Moulding plastic material M A E RHIANDO 10 July 1970 [10 April 1969] 18509/69 18510/69 and 18511/69 Divided out of 1316744 Heading B5A Granular material is fed into a mould and a foraminous layer is applied to the material, a binder being applied to the material before or after the application of the layer, the material and layer being then compressed and the binder set or cured. In Fig. 1 an endless conveyor belt 10 comprises mould cavities 48, Fig. 3, and channels 52 for the collection of excess granular material and binder. Granular material is supplied to the belt from a dispenser 22 and a thermosetting plastics binder is then fed to the material in the mould cavities from a dispenser 23. A foraminous layer, constituting a reinforcing mesh 30, is applied to the belt surface by a dispenser 24 and a film 32 of plastics material is laid on the mesh by a dispenser 25. The belt assembly is then compressed between platens 34, 38 and the binder cured to provide a number of moulded articles attached to the mesh from which the film 32 may be removed. The positions of the dispensers 22, 23 may be reversed. In the embodiment of Fig. 2 the mould belt is associated with the upper platen 34 of a press, and after being supplied with granular material from a dispenser 22 and covered by a reinforcing mesh 30 the mould cavities are inverted as they move around the platen and engage a film of plastics material coated with thermosetting binder supported on a conveyer 36. The assembly is then compressed between platens. The granular material feed hopper may include a doctor blade controlling the quantity of material on the mould part of the conveyer belt; further doctor blades 78, Fig. 3, deflect excess material to the outer channels 52. Examples of granular materials include aluminium silicate, kaolin, bauxite, silicon carbide, marble, quartz, granite, sand, ceramic, glass, spheres of plastics material, mica and aluminium. The reinforcing mesh may comprise woven or non-woven materials and may include rayon, glass, cotton, asbestos, metal, hessian, jute or nylon. Amongst articles which may be thus moulded are tiles, traffic markings such as arrows, lines, cats eyes and anti-skid road surfaces.