US3736218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shrinkable permeable texture film
Assignee: WR Grace and Co
•
Filing: 1970-10-19
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Granted: 1973-05-29
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Expires: 1990-10-19
Abstract
Abstract POLYETHYLENE FILMS, HIGHLY PERMEABLE TO OXYGEN, ARE MADE BY SINTERING GRAINS OF HIGH-DENSITY POLYETHYLENE, IRRADIATING THE RESULTING SHEET TO ABOUT 3 MEGARADS, MELTING OUT THE SINTERED STRUCTURE, AND IRRADIATING A SECOND TIME. WHEN THE SHEET IS STRETCHED, OXYGEN PERMEABILITY IS INCREASED AS MUCH AS 10 TIMES.
Inventors
- 👤 R Gregorian
- 👤 C Kirk
- 👤 J Cote
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:10
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/04; B29C67/00; B29C67/02; B29C67/04; B29D; B29D7/00; B29D7/01; B29C35/00; B29C35/02; B29C35/08; B29C35/0866; B29C2035/0877; B29C2791/00; B29C2791/001; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0608; B29K2023/065; B29K2995/00; B29K2995/0037; B29K2995/005; B29K2995/0053; B29L; B29L2007/00; B29L2007/008; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355
Claims Analysis
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |