US3723583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Orientation of tubular polypropylene film
Assignee: EIDP Inc
•
Filing: 1971-02-10
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Granted: 1973-03-27
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Expires: 1991-02-10
Abstract
Abstract A process for orienting tubular polypropylene film to minimize shrinkage and total haze of the oriented film comprising reducing the temperature drop and maintaining a low bubble hoop stress prior to quenching.
Inventors
- 👤 R Hovermale
- 👤 G Ostapchenko
- 👤 H Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:35
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/001; B29C48/0018; B29C48/0019; B29C48/09; B29C48/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
16 words
A process of claim 1 wherein the temperature of the expanding film is maintained above 130*C.
Claim 2
Dependent Claim
38 words
A process of claim 1 wherein the temperature drop of the film is regulated by a heating means on the exterior of the tube having a fluid circulating therethrough at a temperature of about from 50* to 155*C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |