Tubular materials
US5665297A · kind A · utility
4Cited by
10References
37Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1994 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Aug 24, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Tubular workpieces of oriented polymers such as polyethylene polyester and PVC are formed by drawing a workpiece over an expanding former in the absence of any force perpendicular to the axis of the workpiece. The processes do not require the use of any liquid lubricant. They enable greater degrees of expansion and hence orientation in the direction perpendicular to the axis to be achieved and result in products of improved appearance and strength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.