Patent GB-817293-A (GB)
Title: Improvements in or relating to compound sheet materials
IPC: D06N3/02
Filed: 1956-07-23
Abstract: 817,293. Laminates and laminating. DANDRIDGE, G. F. J., and NEEDS Ltd. July 22, 1957 [July 23, 1956], No. 22717/56. Class 140. [Also in Group XV] An ornamental laminate comprises a sheet of slightly porous material coated with a fibrous fabric laid between two thin films of cellulose acetate forced into the material and fabric by pressure after being temporarily softened by means of a solvent. As shown, the board or backing B is passed between pairs of rollers 10, 11, the lower rollers being preferably steel-faced and the upper ones covered with hard rubber. A film of cellulose acetate A descends from a supply drum 12 and is pressed against the first roller 11 by an idler roller 13, e.g. of wood, and into the nip of the rollers where it is pressed on to the backing B. The surfaces of the film and backing which are to come into contact are sprayed with acetone from a perforated pipe 14 extending parallel to the rollers; a metal shield 15 protects the film from the effects of acetone vapour before it reaches the spray. The first set of rollers forces the cellulose acetate into the wetted surface of the backing. At the entrance to the second set of rollers the backing is covered by a cotton fabric F drawn from a supply drum 16 and a second film of cellulose acetate A from drum 17. The adjacent surfaces of the fabric and second film are sprayed with acetone from another perforated pipe 18, the descending film being protected from the effects of vapour by a shield 19. The assembly then passes between the second set of rollers, under the pressure of which the cotton fabric F becomes impregnated by the cellulose acetate, the two films being bonded together to form a substantially integral mass with the fabric F and backing B. The rollers may be driven, e.g. by an electric motor 20, driving one of the rollers by a belt 21, the other rollers being connected therewith by chains, belts or gearing. The perforated pipes 14, 18 may be replaced by multiple spray guns arranged to traverse the sheets. The backing may consist of plasterboard, building board made from wood waste, plywood, cork or the like. The cellulose acetate sheet is preferably about 0.003 inch thick. The fabric may have a decorative surface which remains visible on the side covered only by a thin film of cellulose acetate. In Fig. 3 (not shown) only one set of rollers is employed; the two films of cellulose acetate and fabric are applied simultaneously, one perforated pipe projects a spray of acetone between the surfaces of the backing B and first film A and another sprays acetone against the surface of the fabric F and the second film A behind it. Metal shields are provided to protect both descending films from acetone vapour. In another modification only one set of rollers and one spray pipe or spray gun is employed, the material being passed through the apparatus twice, the first film being applied during the first passage, and the fabric and second film during the second passage. The laminating may also be carried out by hand, the solvent being applied with a brush and the films and fabric being applied in turn and pressed down firmly by rollers or other means. A worn or damaged surface of the laminate may be repaired by applying a cellulose acetate film by this last method. Specifications 442, 066, and 481,015 are referred to.