| 摘要 |
<p>PURPOSE:To improve heat resistance and seal performance so as to strengthen a joint to a connection member by providing an electric heating wire inside a non-crosslinking thermoplastic resin layer formed integrally with a pipe-shaped crosslinking thermoplastic resin layer and filling an engaging hole, formed in the connection member, with the crosslinking thermoplastic resin layer. CONSTITUTION:An electrofusion joint 1 is manufactured by inserting into an injection mold a non-crosslinking polyolefin layer 3 burying or winding an electric heating wire 4 and an insertion part 6a of a connection member 6 having an engaging hole 7 coated with a degenerated polyolefin layer 8 and by injecting crosslinking polyolefin to be integrally laminated thereafter by forming a crosslinking polyolefin layer 2. The joint is connected to a connection terminal, when the electric heating wire 4 is electrified, the non-crosslinking polyolefin layer 3 is fused and melted integrally with a connection unit 5 to be connected. The electrofusion joint 1 is excellent in its shape holding quality, because the crosslinking polyolefin layer 2 bears a burden of heat resisting strength, and excellent in its seal performance because the non-crosslinking polyolefin layer 3 is integrally melted with the connection unit 5 to be connected.</p> |
