| 摘要 |
PURPOSE:To manufacture a multi-layer tube joint which can form an outer layer and an inner layer with good bonding properties by injection molding the cylindrical outer layer, heating the outer layer to the extent in which the same is not deformed, incorporating the outer layer into an inner layer injection molding mold and injection molding a cylindrical inner layer on the inner peripheral side of the outer layer. CONSTITUTION:A cylindrical outer layer 1 is injection molded by using an outer layer injection molding outer mold 3 and an outer layer injection molding inner mold 3'. Then, the outer layer 1 is heated at the temperature in which the same is not deformed. Then, the heated outer layer 1 is again incorporated into the outer layer injection molding outer mold 3, and as an inner molded, an inner layer injection molding inner mold 5 with the diameter smaller than that of an outer layer injection mold inner mold 3' by the wall thickness of an inner layer 2 is used, and the inner layer 2 is formed by injecting an inner layer forming material on the inner peripheral side of the outer layer 1. Cracks, therefore, are hard to be generated on the outer layer 1 by secondary injection pressure when the heated outer layer 1 is incorpo rated in the inner layer injection molding mold 5 and the inner layer forming material is injected, and also cracks and the like are not generated by the shrinkage of the outer layer 1 and large distortion is not generated between the inner and outer layers 2 and 1 to provide the sufficient bonding strength between the inner and outer layers 2 and 1. |
