| 摘要 |
<p>PCT No. PCT/FI89/00151 Sec. 371 Date Feb. 7, 1991 Sec. 102(e) Date Feb. 7, 1991 PCT Filed Aug. 16, 1989 PCT Pub. No. WO90/02285 PCT Pub. Date Mar. 8, 1990.A spiral-wound tube formed of a hollow section 1 is provided wherein the hollow section is joined together by extruder welding or gluing. The hollow section is coextruded and comprises an outer layer (2) of pastic with a homogenous surface and good weldability. An intermediate layer 3 is provided of a modified polymer and an inner layer (4) is also provided. The interior space defined by the tubular layers (2, 3, 4) is preferably rectangular in cross-section.</p> |
