GB567427A - Improvements in and relating to articles of laminated material and method of making same - Google Patents

Abstract

567,427. Compound sheet materials. JABLONSKY, B. April 9, 1943, No. 5729. [Class 140] Compound fibrous sheet material comprises skin laminµ bonded by a thermosetting adhesive and core laminµ bonded by a thermoplastic adhesive. As shown, an air-screw blade comprises a core formed by inner laminµ 1, 2, 3, 4, 5 and 6 of wood and a skin formed by outer laminµ 7, 8, 9 and 10 of wood, whose density may be higher than the density of the core laminµ. The skin laminµ may be thinner than the core laminae. A few skin laminµ may follow the shape of the surface of the core and envelop the greater part of it, and the end face 11 not enclosed by the skin laminµ may be coated with a moisture- and heat-resisting varnish. The laminµ may be of wood, paper, pulp, or textile fabric, and may be interleaved with thin metal sheets, wire netting or gauze. The skin may be of wood and the core or part thereof of wood, paper, pulp or textile fabric. The core laminae may be preshaped as described in Specification 563,900, [Group V]. The adhesive may be applied by brushing, spraying, dipping, or impregnating the laminae, or solid films of the adhesive may be interleaved with the laminµ, which films can contain a fibrous filler. An adhesive may be incorporated in the laminµ during manufacture, e.g. in a paper machine. Laminµ may be united by a thermoplastic adhesive to form a core, which is then placed between skin laminµ provided with a thermosetting adhesive and united with them by moulding under heat and possibly pressure. Alternatively, the core laminµ provided with a thermoplastic adhesive and the skin laminµ provided with a thermosetting adhesive may be united at the same time by moulding under heat and possibly pressure. Core laminae may be bonded together by a thermoplastic adhesive to form boards and a pile of such boards provided with a thermoplastic adhesive is arranged between skin laminae provided with a thermosetting adhesive and the whole united. The thermoplastic and thermosetting adhesives are preferably so chosen that the same bonding temperature and time are required for both. Additional laminµ may be inserted or higher pressure used where greater strength is required.