US4058582A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Simultaneous stretching of multiple plies of polymeric film
Assignee: Celanese Corp
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Filing: 1973-05-30
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Granted: 1977-11-15
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Expires: 1993-05-30
Abstract
Abstract An improved process for the manufacture of stretched polymeric films. In this process more than two plies of polymeric film are simultaneously stretched. The process of this invention is particularly applicable to those films which must remain free of surface irregularities. For example, the properties of microporous polymeric films are significantly improved by the process of this invention.
Inventors
- 👤 Harvey S. Bierenbaum
- 👤 John A. Penoyer
- 👤 Daniel Zimmerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:32
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/023; B29K; B29K2105/00; B29K2105/04; Y; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
59 words
In a process for forming microporous film in which an elastic, non-open celled film is cold-stretched in the longitudinal direction, said cold-stretched film thereafter hot-stretched in the longitudinal direction to form said microporous film, the improvement which comprises cold-stretching more than two plies of said non-open celled film and hot-stretching more than two plies of said cold-stretched film simultaneously.
Claim 2
Dependent Claim
59 words
In a process for forming microporous film in which an elastic, non-open celled film is cold-stretched in the longitudinal direction, said cold-stretched film thereafter hot-stretched in the longitudinal direction to form said microporous film, the improvement which comprises cold-stretching more than two plies of said non-open celled film and hot-stretching more than two plies of said cold-stretched film simultaneously.
Claim 3
Dependent Claim
55 words
In a process for forming polymeric film in which film is stretched to produce a final stretched film, the improvement which comprises stretching more than two plies of said film simultaneously by holding the edges of said film plies and moving said edges outwardly whereby said film plies are stretched simultaneously in the transverse direction.
Claim 4
Dependent Claim
55 words
In a process for forming polymeric film in which film is stretched to produce a final stretched film, the improvement which comprises stretching more than two plies of said film simultaneously by holding the edges of said film plies and moving said edges outwardly whereby said film plies are stretched simultaneously in the transverse direction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-14 | 1981-05-16 | 1981-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-14 | 1985-05-16 | 1985-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-14 | 1989-05-16 | 1989-11-15 | $7700.00 | Window Closed / Lapsed |