Method for manufacturing expanded polytetrafluoroethylene products
US5874032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1996 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Apr 15, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/753
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved method is provided for extruding ePTFE tube (12) for use in medical applications. A tube (12) of PTFE is extruded, preferably in an extrusion process, using counter-rotated die components (22, 26). The die component (16) is maintained at a constant temperature during processing. The resulting green tube (12) has enhanced fibrous state formation in a direction perpendicular to the direction of extrusion. The PTFE green tube (12) is then subjected to secondary operations such as stretching and expansion to yield medical product. The ePTFE tube (12) structure is defined by nodes interconnected by elongate fibrils. Both the nodes and fibrils are substantially randomly tilted with respect to the longitudinal axis of the tube (12). This particular structure yields a tube (12) which exhibits a high degree of radial tear strength useful in medical applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.