JPS5722024A - Pipe-forming method - Google Patents

Abstract

PURPOSE: To obtain a pipe having a smooth surface without forming of voids, by winding a fiber assemblage impregnated with an uncured thermosetting resin onto a core bar, and hot-pressing the assemblage from its outside through an unadhesive rubber elastic tube to cure the resin.

CONSTITUTION: A fiber assemblage 2 impregnated with an uncured thermosetting resin (e.g. carbon fiber/epoxy resin-type lunidirectonal prepregnate or the like) is wound onto a core bar 1 (e.g. a silicone resin or the like), and then inserted into a rubber elastic tube 4 (e.g. a silicone rubber tube or the like) unadhesive to the thermosetting resin. In this case, a heat-shrinkable film 3 (e.g. PP or the like) may be prewound onto the whole surface of the fiber-wound body. Thereafter, the assemblage is received in an outside pipe 5, and heated while being pressed by pressurized air. After the resin is cured, the assemblage is cooled at a room temperature, and a product is taken out. The rubber tube 4, the heat-contracting film 3 and the core bar 1 can be easily detached from the product. This method can inhibit formation of voids in the product more effectively, as compared with a known metod using the shrinking power of a tape only, so that a pipe having an extremely smooth surfce can be obtained.

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