GB869992A - Improvements relating to bodies consisting of synthetic resinous material reinforcedwith cords - Google Patents

Abstract

869,992. Moulding fibre-resin articles. HUTTER, U., and HANLE, E. May 15, 1958 [May 17, 1957], No. 15665/58. Class 87(2). [Also in Group XXXIII] In the production of propeller blades or vanes, fuselages or car bodies, cords in the form of a parcel of separate fibres, e.g. glass, synthetic or natural fibres, uniformly impregnated with a polymerisable and still plastic synthetic resin, e.g. epoxy or unsaturated polyester resin are laid side-by-side on the surface of a mould 21, Fig. 2. The cords, as they are laid, are compressed, e.g. by a spatula or by tongs 32, Fig. 3, to a substantially rectangular cross-section which varies in shape along each cord and from cord to cord to give the requisite wall thickness at each point. Lines 40, Fig. 2, may be provided on the mould surface to indicate the breadth to which the cord has to be flattened. A glass fibre tissue 5, Fig. 8, embedded in a similar synthetic resin' may be laid on the mould before the cords 3 are applied and a second resin-impregnated glass fibre tissue 5<SP>1</SP> may be laid on top of the completed layer of cords. The mould is cooled while the cords are being laid and is later heated to cure the resin. Adjacent cords may be formed in pairs from a single cord so that a loop or connecting eye is formed at one end of the final article. A propeller blade may comprise two such shells made in complementary moulds, each shell being filled with a foam substance and the two shells bonded together by means of a layer of resin-impregnated foam substance in the middle and resin-impregnated cord around the edge, in a flattened, compressed condition. The attachment end of the vane may be cylindrical to conform with the cylindrical sleeve 15, Fig. 7, of an attachment fitting having a flange 14 with holes drilled at 19. A polymerisable synthetic resin adhesive is employed between the shell ends 17 and the sleeve 15, a bandage of cords 18 of synthetic resin-impregnated fibre is applied, and polymerisation of the resins is effected. The mould which is supported on a rigid frame consists of a foundation layer 23, Fig. 8, of perforated sheet metal provided with a layer 24 of artificial stone or wood cement. Over this are laid grid shaped or strip shaped electric resistance heaters 25 which are covered by a layer 26 of artificial stone or wood cement to which the desired form is imparted by smoothing with a spatula and by grinding. The rear side of the mould is provided with chambers to receive a cooling medium.