| 摘要 |
<p>PURPOSE:To easily fabricate a thermoplastic corrugated pipe having the ring type top and root portions with its metal core buried. CONSTITUTION:A corrugated pipe 11 having the ring type tops 12 and roots 13 and circumferencial wall where the metal core 14 is buried in the thermoplastic layer 15 is divided into units 11A at the position of the top portion 12 and the predetermined number of units 11A are mutually coupled with the electromagnetic induction bonding.</p> |
