Process for producing corrugated multi-layer tubing having layers of differing plastic characteristics
US5460771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1994 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Feb 7, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2023/18
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for producing polymeric tubing which is resistant to permeation by organic material contained therein which has at least one region defined by a plurality of outwardly extending annular ridges. In this method, tubular polymeric material having a first outer diameter and composed of at least three overlying polymeric layers is introduced into a mold device upon exit of the tubular polymeric material from a suitable extrusion device, the surface of the mold device having at least one region defined by an annular depression in an essentially cylindrical surface. Once the tubular material is introduced, it is expanded to a second outer diameter such that the tubular material deformably contacts the mold surface. The corrugated tubular material then exits from the die device after completion of the expansion step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.