GB831906A - Method of manufacturing panels and panel so produced - Google Patents

Abstract

Decorative panels, which are resistant to heat, are produced by a method which comprises applying to a carrier base sheet one or more layers of a pigmented synthetic resin varnish, to form a pattern, design or solid colour thereon, baking said layer or layers and thereafter hot-pressing the said coated carrier base sheet to a protective sheet impregnated with a thermosetting synthetic resin, which protective sheet is transparent and is, by such hot-pressing operation, strongly adhered to the carrier base sheet. The pigmented synthetic resin varnish is a pigmented solution of both a polyester resin and an aminoplast, e.g. a urea formaldehyde resin, and preferably includes a melamine-formaldehyde resin. The polyester resin is a condensation product of a dicarboxylic acid such as phthalic acid and a polyhydric alcohol such as glycerol, i.e. an alkyd resin. The base sheet may be a plate formed of bonded wood fibres, wood splinters, asbestos fibres, glass fibres or natural fibrous cellulose bonded as pulpboard. The pigmented synthetic resin varnish may be applied by spraying, rolling on, or screen printing, and more than one coat may be applied. It is then baked, e.g. in convection furnaces, by infra-red radiation or by electric high-frequency energy. Each coat may be roughened by grinding before the application of the next. A design may be produced by moving over the surface two or more spray guns spraying different colours in the desired pattern. The pigmented synthetic resin varnish may contain in addition to pigments, fillers such as powdered mica, silica gel, pumice powder, silica or that known as "Asbestine" (Registered Trade Mark) to form a rough surface. If the base material is sufficiently thick, panels according to the invention may be used as table tops without reinforcement, being equipped only with a frame and the necessary legs. Specification 684,085 is referred to.