| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a composite pipe having a heat insulating property and a heat retaining property suitable for a hot water supply pipe, a heating pipe or the like, preventing seam cracking, having an adhesive degree between a resin pipe and a foamed resin layer as can be drawn off by manpower, superior in workability, and capable of suppressing giant bubbles. SOLUTION: The composite pipe 15 is characterized by that the foamed resin layer 14 is provided in a roughened outer surface of the resin pipe 12 by an extrusion foaming method.</p> |
