Method of uniaxially expanding a fluoropolymer product
US8298462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2004 |
| Grant date | Oct 30, 2012 |
| Priority date | — |
| Expiry date | Dec 22, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2027/18
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to a method of uniaxially expanding a fluoropolymer product including the steps of expanding a green fluoropolymer product in a first direction to create a first-expanded fluoropolymer product, and expanding the first-expanded fluoropolymer product in the same first direction. As a result with the subject invention, it has been found that ultra-high expansion and a variety of different porous/fibril structures can be achieved by using subsequent expansion steps in the same direction. Various considerations exist with such methodology, including the selection of rates of expansion of both steps, the amount of expansion of both steps, pre-heating and cutting the product between expansion steps. Although the present invention can be used with various fluoropolymer products, it is particularly well-suited for use with PTFE.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.