GB1070573A - Methods of printing or decorating the surfaces of plastic materials - Google Patents

Abstract

1,070,573. Printing processes; ornamenting. C. P. STUTCHBURY. June 1, 1964 [June 4, 1963], No. 22212/63. Headings B6C, B6G and B6J. The surface of a plastic material is printed upon or decorated by applying to the surface a solvent for the plastic, and a foil, the foil thus being bonded to the surface. The foil employed is a blocking foil used in hot-stamping presses and comprising a backing strip, a heat-release coating and a thin coating of foil. The foil may be of copper, aluminium, or gold, or a pigmented foil. In one method of printing with the foil, the parts of the surface of the plastic not required to receive foil are protected by a resist wax applied by an engraved plate. The foil is now dipped into a solvent for the plastic, or the solvent is applied to the plastic surface, or both, and the foil is applied to the plastic A roller is pressed over the foil, which adheres to the non-protected parts of the surface. The foil backing is now stripped from the plastic, and the wax removed by washing with paraffin. The removed backing strip with parts of the foil adhering thereto may be employed for printing a reverse image on a plastic surface. In another arrangement, the plastic surface is coated with foil using a solvent as before, and the foil is etched away to give the required print. The plastics may be warmed during the transfer operation. Instead of using a resist wax on the plastic, the pattern to be printed may be formed on the foil before transfer to the plastic surface. This may be done by applying a resist wax to the foil and etching with hydrochloric acid or with potassium hydroxide and methylated spirits, or the foil may be pressed on to an engraved plate to which adhesive has been applied. In the latter case, the foil is stripped off the backing at the non-pattern parts leaving the pattern in foil on the backing. The method may be employed for printing on cellulosic, acrylic and vinyl plastics, specific examples given being celluloid, " Perspex " (Registered Trade Mark) and " Cobex " (Registered Trade Mark), and may be used for. the printing of labels, business cards, watch faces and printed circuits. For printed circuits, gold foil may be employed and a second application may be necessary to obtain the desired thickness of metal. Paper, glass, " Formica " (Registered Trade Mark), or plastics such as polyethylene or polypropylene for which it is difficult to find a suitable solvent, may be coated with a plastic for which a suitable solvent is readily available, and then printed as described above. Mirrors may be produced by applying a coating of aluminium or gold foil to a plastic in the manner described above.