Method and apparatus for forming metal surface coatings

1,137,823. Coating with metals. INSTITUT NATIONAL DU VERRE. Jan. 3, 1966 [Feb. 8, 1965; Oct. 11, 1965], No. 135/66. Heading C7F. Sheets of e.g. glass, ceramic, metal and plastics are coated with metal by flowing films of liquid composition into the sheets, and allowing the liquids to react to form the metal coating. Glass sheets 13 are fed under tanks 3 which deliver films 15 from slots 5. Guides 23, Fig. 2, maintain a constant width of film and thus help to keep a constant thickness. The metal coating 21 is washed by water sprays 19. The liquids may be (g. /1) (a) silver nitrate 10 to 35, caustic soda to 10 to 30, mercuric nitrate or cyanide 0À015 to 0À050, and ammonia 30 to 100 ml. (b) glucose 5 to 22. A further example is described of a copper plating solution, and the copper may be plated on the silver surface. Surface active agents e. g. methyl and carboxymethyl cellulose may be added. The conveyer for moving the sheets may have a high speed section for the coating operation and a low speed section for washing and drying. Alternatively the sheets can be stationary and the tanks movable. Each liquid composition may be split into parts and deposited separately.