GB793441A - A process of making sandwich-type laminated materials - Google Patents

Abstract

793,441. Laminates. ARMSTRONG WHITWORTH AIRCRAFT, Ltd., Sir, W. G. Sept. 21, 1955 [Jan. 11, 1955], No. 793/55. Drawings to Specification. Class 140. In making flat or curved laminates by bonding at least one thermosetting resin-impregnated laminate to a core of honeycombed woven glass fabric or of foamed or expanded natural or synthetic rubber or plastic material, by means of pressure set up by use of a vacuum bag, a layer of absorbent material such as felt and a layer of non-impregnated fabric, e.g. nylon or glass fabric, are placed between the vacuum bag and the laminate during consolidation of the laminate, the layer of non-impregnated fabric being next to the laminate. The felt and fabric layers may also be used in conjunction with a vacuum bag during consolidation of a number of laminµ laid up on a mould block to form a laminate to which the core is subsequently bonded. Before forming a laminate superposed on a core of honey-combed woven glass fabric, a single layer of thermosetting resinimpregnated fabric is applied to the surface of the core and allowed to cure without pressure, after which further layers of the thermosetting resin-impregnated glass fabric are applied and consolidated. The component layers of each outer laminate may be of woven glass fabric impregnated with a polyester resin catalysed by benzoyl peroxide and accelerated by cobalt naphthenate. The mould block, which may be of wood, plaster of Paris, or a thermosetting resin-impregnated laminate, may be coated with wax, and the wax coating may be trued as described in Specification 793,442, [Group V], which is referred to.