Reinforced plastic tube - comprises a knitted tubular sheath impregnated with heat setting resin

摘要

Resin is coated from an annular extruder onto a rotating former adn a sheath is knitted around the former by a circular knitting head. The resin is cured by heating and a fibre roving is wound round the formers before it is again coated with resin and another sheath knitted around it. The resin may be polyester, and the sheat yarn and roving may be of glass, boron, carbon, or metallic fibres. A uniformly strong tube in both radial and axial directions is economically produced.