Method of stretching films according to an overbias or overstretch profile
US6358457B1 · kind B1 · utility
14Cited by
43References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1998 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | Nov 13, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of biaxially stretching a polymeric film along an overbias stretch profile having the steps of (a) imparting a sufficiently high temperature to the film to allow a significant amount of biaxial stretch; and (b) biaxial tenter stretching the film to a final first direction stretch parameter and a final second direction stretch parameter, wherein at least 75% of the final first direction stretch parameter is attained before no more than 50% of the final second direction stretch parameter is attained, and wherein the final first direction stretch parameter is no greater than the final second direction stretch parameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.