Method for relining underground pipelines
US5469891A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1994 |
| Grant date | Nov 28, 1995 |
| Priority date | — |
| Expiry date | Apr 18, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L73/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
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.degree. to 75.degree. C. and a ratio (Emod, T=20.degree. C.)/(Emod, T=75.degree. 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.