GB1463293A - Manufacture of fibre reinforced composites - Google Patents

Abstract

1463293 Continuously moulding constant or variable section articles NATIONAL RESEARCH DEVELOPMENT CORP 19 March 1974 [21 March 1973] 13664/73 Heading B5A [Also in Divisions B8 and A6] An apparatus for use in the production of elongate fibre-reinforced articles comprises a shaping aperture defined by the surfaces of two circumferentially co-operating rolls, means upstream of the aperture for bathing continuous fibre reinforcement in a bonding material, feed means downstream of the aperture for pulling reinforcement through the aperture, and independent means for rotating the rolls to vary the aperture dimension. Oppositely rotating .rolls 8, Fig. 1, having peripheral grooves of varying depth, and reciprocating, tapered mandrel 9 define an annular aperture, Fig. 2, of cyclically varying size. Continuous strands and acid-etched aluminium foils 6 are drawn through resin bath 3, distributer plate 5 and the aperture by driven rolls 1 to form a succession of tapered, hollow articles 11 of constant wall thickness, e.g. golf club shafts. The mandrel is forwarded by roll driven pinion 103 whose smooth section 106 allows hydraulic or pneumatic jack 105 to return the mandrel quickly. The mandrel may be moved by other mechanical, hydraulic or electromechanical means. The mandrel is heated by radiant oven 114, and the rolls by electric elements 110, 112. The emerging articles 11 may be wrapped in heat shrinkable cellophane to provide a bonding pressure, cut by circular saw 116, and then part-cured by heat. The mandrel may be replaced by continuously fed, connected, preformed cores. Only one roll may be grooved. The aperture formed by the rolls may be symmetrical about a plane containing the aperture axis and lying perpendicular to a plane containing the roll axes. The aperture may be of any shape, and may be used with a similarly-shaped mandrel, e.g. of triangular shape, Fig. 3. The depth of the or each groove may increase at a constant rate, or the or each groove may be stepped. Upper roll 8 may be mechanically braked to provide an annular aperture of constant size to provide articles of constant section. The mandrel may be omitted. The fibres, e.g. of glass, carbon, boron or polypropylene, form a composite material with a thermosetting resin, e.g. a polyester or an epoxy, or with a thermoplastic resin, e.g. a polyimide. The composite forms one or more layers in the article providing the principal flexoral stiffness. Other layers provide a means of transmitting shear. Shear stiffness may be provided by winding fibres from bobbins rotating about the mandrel upstream of the aperture.