GB838392A - Process and apparatus for use in the application of coatings or coverings of plastic material - Google Patents

Abstract

<PICT:0838392/III/1> A protective coating of a hardened synthetic resin is provided on the surface of a pellicle, board or like article by traversing the surface below two closely-spaced liquid curtains which form two superposed layers thereon; one of the curtains comprises one or more of the organic compounds from which the resin is produced, and the other contains a complementary organic compound or compounds which react with those contained in the first curtain to form the hardened synthetic resin. The curtains may contain respectively the diglycidyl ether component of an epoxy resin and a hardener therefor, e.g. an amine; a polyester and a polyisocyanate; an intermediate condensate for a urea-formaldehyde resin and an acid accelerator; or a partially polymerized polyester resin and a hardener therefor, e.g. an organic peroxide, in one curtain and a partially polymerized polyester resin and an accelerator, e.g. cobalt naphthenate, in the other. In the last case the components can be dissolved in a polymerizable vinyl monomer, e.g. styrene; the polyester resin may be one derived from an alpha-beta unsaturated di-carboxylic acid, e.g. maleic, and a polyhydric alcohol, e.g. glycol. The curtains may be applied by passing the articles to be coated beneath two troughs having slots from which curtains issue. In the form shown, the articles slide under their own weight on a working surface 12 which is provided with round glass tubes 14 which are interrupted beneath the two troughs 13 to allow excess coating material to be received in collecting tanks. Alternatively, horizontal conveyer belts can be used. The apparatus can be fitted with heating means.