| 摘要 |
PCT No. PCT/SE92/00471 Sec. 371 Date Apr. 18, 1994 Sec. 102(e) Date Apr. 18, 1994 PCT Filed Jun. 25, 1992 PCT Pub. No. WO93/00548 PCT Pub. Date Jan. 7, 1993.The invention relates to a material wherein the main constituent is PVC for manufacturing pipes to be used for relining underground pipelines by the pipe in a folded condition being drawn into the pipeline and being engaged with the inside surface of the pipeline by temperature increase. By the addition of polymer thermoplastic elastomers which can be mixed with PVC the material has a glass transition temperature ranging from 45 DEG to 75 DEG C. and a ratio (Emod, T=20 DEG C.)/(Emod, T=75 DEG C.)>20. The invention also relates to a method for restoring underground pipes by relining such pipes with a pipe which has been folded after the extrusion.
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