Patent GB-1377518-A (GB)
Title: Continuous production of fibre-reinforced shaped bodies
IPC: B29C70/52
Filed: 1971-12-21
Abstract: 1377518 Fibre reinforced moulding GRILLO-WERKE AG 21 Dec 1971 [22 Dec 1970 3 May 1971] 59433/71 Heading B5A [Also in Divisions E1 and F2] An article comprising a polyester/thermoplastics resin blend, or an epoxide resin, reinforced with glass continuous fibre reinforcements, or woven or unwoven fibre webs, is produced by drawing the reinforcements 3, by means of devices 17, from reels 4 through guide means, which arranges it in its desired alignment, and through the uniform section bore of a die 2 in which the reinforcement is impregnated with the resin at a location 5, upstream and downstream of which are provided heating means for respectively preheating the reinforcement, and hardening the resin within the die 2. The preheating renders a priming on the glass fibre tacky, causing the fibres to adhere into a contiguous structure. The location 5 is 1/3 of the way along the die, and is cooled by a circulating medium. The resin is supplied to the die either by gravity, by a pump 12, or by constant pressure compressed air, and is preheated by a heater 15 near to its hardening temperature, to which the reinforcement is also heated by the preheating in the die 2, and which temperature is automatically maintained, by the cooling means at the location 5, to enable impregnation of the reinforcement at a low resin viscosity. The resins employed have a shrinkage on hardening which preferably does not exceed 1À5%, and preferably of 0À1 to 1%, and a peroxide, e.g. tertiary butyl peroxide, may be employed in the resin to prevent it hardening appreciably below a desired temperature, and to enable low viscosity resins to be employed facilitating impregnation of the reinforcement. The section is cut transversely, whilst held by clamps 19, by a saw 18 at a location which is either fixed when the extrusion is effected intermittently, or which may be displaceable when extrusion is continuous, the cut length being removed by a device 21 on to a roller table 20. The extrusion may be effected at any angle between the vertical and horizontal. With a cylindrical extrusion the resin may be injected from an annular die slit, or circularly disposed die nozzles, or as in Fig. 4 (not shown) which illustrates a resin die distribution arrangement for an H section extrusion. Where the extrusion is of tubular section or includes axially extending bores, the reinforcements are fed through the die around a stationary or moving mandrel around which fibrous reinforcements in one or more helical coils may be delivered, e.g. to reinforce against transverse stresses when screws, rivets or expanding dowels, are inserted in the bores for fixing accessories to the section, or when joining the sections in an assembly. Examples are given, Figs. 6-14 (not shown), (see Divisions F2P and E1J) of applications of various article sections to a tow bar, window or door frames, ladder steps, and as the interengaged links of a roller blind. Various arrangements of coil and longitudinally extending reinforcement layers are illustrated for tubular or bored sections comprising; Figs. 15 and 16 (not shown), either a single fibrous coil or a pair of coils of opposed hand intermediate inner and outer longitudinally extending reinforcement layers; Fig. 17 (not shown), a pair of fibrous coils of the same hand separated by a layer, and located intermediate inner and outer layers of, longitudinally extending reinforcement layers; or Fig. 18, an inner layer of axially extending reinforcement, a fibrous reinforcement coil 113, a reinforcement layer 114 comprising a helically wound woven fibre band, and an outer longitudinally extending reinforcement layer 115.