| 摘要 |
PURPOSE:To obtain a rigid PVC pipe having a pricisely expanded end part, in high efficiency, by heating and deforming a PVC pipe with a hot mold to a desired shape, and cooling and solidifying the shaped pipe in a cooling mold. CONSTITUTION:Expansion of the diameter of one end of a rigid PVC pipe 5 is carried out by (1) inserting the end part to be shaped between the hot molds 2 and 3 thereby deforming the end to the desired shape, (2) removing the shaped pipe from the molds 2 and 3, and (3) cooling and solidifying the pipe on a cooling mold 10. The PVC pipe on the cooling mold 10 is pref. cooled externally by blasting cooling fluid as well as internally by the cooling mold. |
