| 摘要 |
PURPOSE:To prevent deterioration of the surface of rubber and generation of black water, by a method wherein blow molding of thermoplastic resin is performed and the inner circumferential surface of a rubber hose is covered with the resin under a state wherein the rubber hose is fitted in a blow molding die. CONSTITUTION:A bellowslike rubber hose 2 molded beforehand is put into a blow molding die 4, to begin with, in a connecting hose 1. Then blow-moldable thermoplastic resin 3a in a cylindrical state, for example, polyethylene, vinyl chloride, modified vinyl chloride elastomer and polypropylene are passed through the inside of the rubber hose 2. Then blow molding is performed by clamping the blow molding die 4. The connecting hose 1 is completed by performing cutting of an unnecessary part by unloading a product by breaking the die 4 after completion of the molding. As it does not happen that a polymer of the rubber and a filler are brought into contact with water directly and deterioration of the surface of the rubber and generation of black water resulting from residual chlorine in city water can be prevented. |
