GB739801A - Improvements relating to the production of decorated articles from thermosetting synthetic resins - Google Patents

Abstract

739,801. Moulding decorated articles from thermosetting synthetic resin. HAYWARD, L. H. March 4, 1952 [March 13, 1951], No. 6087/51. Class 87 (2). [Also in Group VIII] A design in printing inks or other media is applied to one surface of a piece of absorbent paper, the design-bearing surface is bonded under pressure to a backing of thin sheet material to form a thin composite wafer, and the wafer, impregnated with a thermosetting synthetic resin, is applied to the surface of an article of thermosetting synthetic resin that is being compressionmoulded, whereby the wafer is embedded in the article. As described, the paper and backing are impregnated separately and then bonded together. Either the design-bearing paper or the backing may be next to the article. Figs. 3 and 5 show a motor-car-horn button E being made in a twopart mould D; D<2>, from thermosetting powder E<1>. In the mould part D<2> is a recess D<1> in.which is located a wafer comprising a sheet A of paper impregnated with a varnish made from thermosetting resin and having a design B printed or otherwise applied to it, and a backing C comprising one, two or three layers of paper similarly impregnated. In making the wafer the impregnated sheets are dried (as by heat which at least partly cures the resin) and then united by pressure, the surface of the backing being roughened as by sandblasting to improve bonding. As shown, the wafer is put in the recess, then the powder is put in the mould and pressure and heat are applied to effect the moulding in one step, but in a modified procedure an initial compression may be applied to the powder in the mould to shape it into a coherent tacky mass, then the mould is opened, the wafer is put into the recess, the mould is closed, and curing completed. In Fig. 3 the backing may be opaque, e.g. of white lithoponeloaded paper or coloured paper, but where the backing is on the outside, Fig. 4 (not shown), it must not be pigmented and is rendered transparent during the moulding. The resin used for impregnating the design-bearing sheet A may be melamine-formaldehyde, that for the backing urea-formaldehyde, and that for the article urea- or phenol-formaldehyde. The sheet A may be degreased as described in Specification 732,774. The wafer may be placed in the recess by hand or by means of the mechanical carriers described in Specification 739,802. If the mechanical carriers are used the recess may be omitted from the mould, in which case the wafer is embedded flush with the surface of the article. Instead of being applied to the mould, the wafer may be applied to the initially shaped article. The wafers may be prepared individually, or cut out from a large composite sheet. Specification 706,179 also is referred to.