GB388050A - Improvements in or relating to the coating of glass and other objects with varnish-films - Google Patents

Abstract

388,050. Coating surfaces. WADE, M. C., 6, Broadlands. Road, and SHARPE, W. S., 12, New Court, Carey Street, both in London, (Representatives of WADE, H.).- (Bonniksen, C. W.; Wald Hotel, Post Unterach, Mondsee, Austria.) Aug. 13, 1931, No. 22921. [Class 95.] Varnish films are dried by treating the wet film with a liquid which is immisible with the varnish but absorbs the solvent from the varnish solution. The varnish solution may be a solution of a cellulose ester, for example celluloid in acetone. The treating liquid may be a vegetable oil such as castor oil, oil of cloves or oil of peppermint or petrol, benzene, toluene, alcohol or water. The solvent may be separated from the used treating liquid by fractional evaporation and the purified liquids may be used cyclically. Contained gases such as air may be removed from the varnish solution and treating liquid before use. The celluloid layer from which the camphor has been removed by the treating liquid may be treated in a bath containing a plasticizer such as diethyl phthalate. A film 13 of varnish solution falls from a slot 12 in a hopper 11 on to a sheet of glass 15 fed by rollers 16, 17, the rate of feed of the glass sheet being slightly greater than the rate of fall of the solution. Excess solution is received by a roller 14 from which it is removed by a doctor 20 and collected for re-use. The coated sheets are lowered by a conveyer 18 at a slight angle into a bath 19 through which the treating liquid circulates at a temperature of about 35‹ C. After emerging from the bath 19, the sheet preferably passes into a second bath of treating liquid at about 80‹ C. to remove the final traces of solvent and thence into a steam heated oven, after which excess treating liquid is' removed by rubber covered squeegee rollers. Specifications 293,214, [Class 95, Paints &c.], and 387,721, [Group VIII], are referred to.