| 摘要 |
760,931. Laminated and coated paper, fabrics, etc; coating webs. MARIAN, J. Sept. 14, 1953 [Sept. 12, 1952; Sept. 12, 1952], No. 25317/53. Classes 96 and 140. Sheet material having a hard, resistant surface is made by coating one face of absorptive sheet material such as paper or fabric with a thermo-setting resin in liquid state which penetrates only partly through the sheet, drying, with the aid of heat, subjecting the still hot or reheated material to heat and pressure to cure the resin, and immediately winding the material into a roll with the impregnated surface facing outwardly. Alternatively, an impregnated strip and an mitreated strip of absorptive material may be brought together and subjected jointly to the drying and curing steps whereby they are united together, and the resulting laminated strip is wound into a roll with the resin-treated surface on the outside. An adhesive-coated metal strip may be interposed between the impregnated and unimpregnated strips. The surface of the absorptive sheet that is to be exposed to view may be decorated or printed. The impregnating resin may be melamine- or urea-formaldehyde while the adhesive for coating the metal strip may be an aqueous emulsion of polyvinyl chloride-acetate resin to which may be added, a phenol- or urea-aldehyde resin. As shown, a web 14 of alpha-cellulose paper that has been impregnated by immersion in a liquid urea-formaldehyde resin and then surfacecoated with an aqueous solution of a melaminealdehyde resin, a web 58 of aluminium coated on both sides by immersion in an aqueous emulsion of polyvinyl chloride, and an untreated web 88 of paper, are led upwards from the treating and unwinding room through slots 84 into a drying and curing chamber with heatinsulating walls 96. The webs come together and are carried jointly by a tensioned band of steel or wire-reinforced rubber, which may be gas-permeable, past two series of hot-air nozzles 130. Hot air may also be injected at 126 and allowed to escape at 128, while additional heat may be applied by infra-red lamps 136 and electric heaters 138 and 140. The combined web passes under pressure rollers 144, is cured while passing between the band and a heated drum 100, passes around some of the rollers 144, through smoothing rollers 154, and out of the chamber through a slot 156. After trimming by a circular knife 160, the web is wound while still hot into a roll 168 with the impregnated surface facing outwards. The impregnating, combining, drying, curing, and winding-up steps may be separated, e.g. when using a flat press with heated press platens. |
