| 摘要 |
PURPOSE:To reduce the weight of an outer casing, eliminate the generation of rust on it, lessen the change in temperature in its longitudinal direction and improve its resistibility for compression and fatigue by embedding reinforcing fibers within a specific range of number in a flexible pipe having more than one layer of thermoplastic resin in its longitudinal direction. CONSTITUTION:An outer casing is formed by a composite material made of a layer of thermoplastic resin 2 in which 2-10 pieces of reinforcing fibers 1 are embedded. Consequently, the outer casing obtains such a dimensional stability that is approximately the same degree as that of a conventional spiral pipe made of steel wire. Further this outer casing is excellent in resistibility for compression, creep and fatigue, althrough it is made of resin. As the reinforcing fiber 1, fibers of glass, carbon and kepler are preferable. Of those plastic resins 2, polyether ether ketone, polycarbonate, etc. are preferable, in view of such points that they are uniformly excellent in bending elasticity, tensile strength, dimensional stability, creep resistibility, fatigue resistibility, formability, etc. when they are combined with the reinforcing fibers 1. |
