| 摘要 |
PURPOSE:To obtain a composite pipe with a uniform foam adhesive layer and a uniform radial thickness by providing a metal pipe with a processing of reducing a pipe diameter after a resin pipe is inserted in the metal pipe. CONSTITUTION:Three or more ribs that have triangular cross sections in their axial directions are provided by extrusion, etc. on the outer surface of a resin pipe in its circumferential direction at approximately equal spacings. Then, an adhesive which generates expansiveness immediately after mixing of two fluids is applied to an inner surface of a metal pipe or the outer surface of the resin pipe and the resin pipe is inserted in the metal pipe before the layer of the adhesive expands. After the above process, the metal pipe is revolved while it is passed through the space between the upper and bottom molds that have circular surfaces, and by shaking up and down severely the top force against the bottom force the diameter of the pipe can be reduced regardless of the radial thickness of the metal pipe. By the above method the resin pipe can be arranged concentrically with the metal pipe when the adhesive layer is expanded. |
