| 摘要 |
866,938. Laminates. FORMICA INTERNATIONAL Ltd. April 17, 1959 [April 23, 1958], No. 12924/58. Class 140. [Also in Group XI] A method of making a laminated electricallyheated heating panel comprises forming a core by placing a layer of metal (preferably aluminium) foil on the top of a stack of thermosetting resin impregnated sheets 1-5, preferably of paper topped by the sheet 6 which may comprise 50% asbestos impregnated with a thermosetting, resin adhesive, the assemblage is then partly cured by heat and pressure and the foil is partly etched away to leave at least one tortuous current path 8. The core is then placed between the layers 10-13, each being impregnated with the resin, that in the layer 10 acting also as an adhesive, and at least one of the exterior sheets 13 being of decorated paper surfaced with a thin resin-impregnated cellular paper sheet. The assembly is then completely cured by heat and pressure. Phenol-formaldehyde resin is used for the inner layers, and urea/ melamine formaldehyde resin for the decorated, and melamine-formaldehyde resin for the surfacing layer or layers. |
