| 摘要 |
PURPOSE:To suppress the orientation relaxation of a resin and prevent the generation of a welding shrinkage by conducting a proper treatment such as cutting work or annealing after the injection molding of a fused joint, thereby setting the molecular orientation of the resin in the fused joint part with a member to be connected less than a specified numerical value. CONSTITUTION:As a fused joint member 10, for example, a socket 11 made of PE(polyethylene) resin, the inner surface of which is cut, is used, and a PE resin pipe 1, for example, as a pipe to be connected pipe is connected thereto. In the socket 11, the surface layer in the inner surface of a body molded by injection molding is cut by only a thickness of Amm to retreat the inner surface, whereby the inner diameter of the socket 11 is made equal to the outer diameter of the PE resin pipe 1. In this case, the molecular orientation of the PE resin is set less than 50%. The fused joint part having the molecular orientation less than 50% is formed by removing the surface layer of the molded body in a thickness of 2mm or more. Further, the fused joint part is formed by annealing the molded body within the temperature range of (the melting point-50 deg.C) to (the melting point) of the resin for 1-7 days. |
