PIPE JOINT AND ITS METHOD FOR MANUFACTURING

PROBLEM TO BE SOLVED: To provide a method for manufacturing can effectively conduct the process of winding a hygroscopic expansion non-woven fabric around a core of an injection molding machine and can prevent a molding defect from being produced on a pipe joint, when the pipe joint having the hygroscopic expansion non-woven fabric on the whole inner circumferential surface is insert-molded. SOLUTION: The method for manufacturing of the pipe joint 1 includes the first process of preliminarily forming the cylindrical hygroscopic expansion non-woven fabric 71 by heat-pressing the predetermined area A of the central part of the same in the axial direction so that the diameter of the area B of the end part in the axial direction is larger than the diameter of the area A of the central part in the axial direction, the second process of placing the preliminarily formed hygroscopic expansion non-woven fabric 72 on a core of an injection-molding machine, the third process of making a cavity forming the joint body with a separable cavity mold, and the fourth process of injecting a resin into the cavity. The diameter of the end area of the preliminarily formed non-woven fabric in the axial direction is larger than the diameter of the core, and the diameter of the central area in the axial direction is smaller than or as large as the diameter of the core. COPYRIGHT: (C)2010,JPO&INPIT