| 摘要 |
PROBLEM TO BE SOLVED: To continuously and efficiently produce a composite pipe consisting of outer and inner layer pipes independently laminated each other, excellent in the dimensional accuracy of both pipes and having high roundness. SOLUTION: A thermoplastic resin is continuously extruded from a first extrusion molding machine 1 to be molded into a tubular form and this extrudate is cooled to form an inner layer pipe 2 which is, in turn, taken over by a first taking-off machine 4. Subsequently, the inner layer pipe 2 is passed through the crosshead die 6 of a second extrusion molding machine 5 arranged at an almost right angle to the advance direction of the pipe 2 and a thermoplastic resin 7 is continuously extruded from the second extrusion molding machine 5 to be molded on the outer peripheral surface of the inner layer pipe 2 to form an outer layer pipe 8 and, after cooling, the obtained composite pipe P having a two-layered structure is taken off by a second taking-off machine 11. |
