| 摘要 |
PROBLEM TO BE SOLVED: To provide a complex tube excellent in pressure resistance, lightweight and inexpensively manufactured. SOLUTION: In this complex tube, an intermediate layer 12 formed by spirally winding a drawn polyethylene resin sheet is laminated on the outer peripheral surface of an inner layer 11 tubularly formed of polyethylene resin, and an outer layer 13 made of polyethylene resin is further laminated on the intermediate layer 12. The inner layer 11 is provided with a plurality of hollow parts 11a respectively extending along an axial direction, at equal spaces in a circumferential direction.
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