GB592548A - Process to provide with decorative designs elastic thermoplastic sheets - Google Patents

Abstract

592,548. Transferring designs ; transfers ; embossing. RADO, L. May 15, 1945, Nos. 12159/45, 35209/45, 35210/45 and 6067/46. [Class 100 (ii)] In the production of designs, which may be printed or embossed or both, on pliable, elastic sheets made from a thermoplastic substance, such as a vinyl resin, in particular polyvinyl chloride, the sheet is laid between two nohthermoplastic media of which one at least is pliable and carries a design, heat and pressure are applied whereby the. sheet becomes plastic and the design is transferred thereto or an impression of the design is embossed or both, the sheet is allowed to cool while between the two media whereby the sheet regains its elasticity, and at least the design-carrier is removed. The design may be printed in a thermoplastic ink on a carrier having a fibrous-free surface, e.g., aluminium foil glued to a paper or fabric backing, or paper impregnated with gum, glue or oil, or hydrated. At least one of the non- thermoplastic media may consist of unimpregnated paper, the surface fibres of which become permanently embedded in the vinyl sheet, the resulting misty appearance being corrected by treating the free ends of the fibres with oily substances or transparent lacquers to make the fibres transparent. A permanent backing may be provided for the vinyl sheet by applying a woven fabric to the sheet before applying the transfer ; alternatively, one of the media may form such a backing, or a fabric sheet may be placed between two vinyl sheets, the three sheets being united before or during transfer. The raised part of an embossed design may be coloured by spraying ink on to an embossed design carrier and removing surface ink. Metal foil of thickness 0.025-0.4 millimetres backed with paper weighing 40-60 grams per square millimetre, or thin paper weighing 25-30 grams per square millimetre are examples of design carriers. Temperatures of 100-120‹ Centigrade for ordinary transferring and 130-150‹ Centigrade to obtain a highly glazed surface are specified. Films made by extrusion may be immediately laid between the cover sheets and heat and pressure applied. Fig. 1 shows apparatus for carrying out the process wherein a web 1 of the vinyl product sandwiched between slightly wider carrier webs 2, 3 passes around a heated cylinder 6 under pressure from rollers 7-9, and then through a cooler 10, the webs being rewound separately on rollers 13-15. Other forms of apparatus comprise (a) a pack of vinyl sheets, Fig. 2 (not shown), interleaved with design carriers and pressed between hot plates, (b) a vinyl web and a carrier web wound together on a mandrel which is placed in an oven and rotated, Figs.' 4 and 5 (not shown), and (c) vinyl and carrier webs unwound from rollers and passed between rollers to a hot press followed by artificial cooling and rewinding, Fig. 6 (not shown). Specification 562,573 is referred to.