US3257490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing flat dimensionally stable, biaxially oriented polypropylene film
Assignee: EIDP Inc
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Filing: 1962-10-17
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Granted: 1966-06-21
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Expires: 1982-10-17
Abstract
No abstract record available.
Inventors
- 👤 Hovermale Ralph Allen
- 👤 Rae James Gerken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:47
CPC Classifications
B; B29; B29C; B29C59/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A PROCESS FOR IMPROVING THE DIMENSIONAL STABILITY AND SHEET FLATNESS OF BIAXIALLY ORIENTED POLYPROPYLENE FILM WHICH COMPRISES, IN COMBINATION, THE STEPS IN SEQUENCE OF (1) SUBJECTING A BIAXIALLY ORIENTED POLYPROPYLENE FILM, WHICH HAS BEEN ORIENTED BY STRETCHING FROM 2 TIMES TO 10 TIMES ITS ORIGINAL DIMENSIONS IN THE MACHINE AND TRANSVERSE DIRECTIONS, TO A HEAT TREATMENT AT A TEMPERATURE IN THE RANGE OF FROM 120*C. TO 150*C. FOR A TIME BETWEEN 1 SECOND AND 10 SECONDS WHILE PERMITTING SAID FILM TO RETRACT BETWEEN 10% AND 30% IN ITS TRANSVERSE DIRECTION DIMENSION AND UP TO 15% IN ITS MACHINE DIRECTION DIMENSION; AND (2) THEREAFTER STRETCHING SAID FILM IN THE MACHINE DIRECTION BY AN AMOUNT BETWEEN 0.5% AND 5% OF ITS LENGTH WHILE BEING MAINTAINED AT A TEMPERATURE BETWEEN 100*C. AND 150*C.
Claim 2
Dependent Claim
130 words
A PROCESS FOR IMPROVING THE DIMENSIONAL STABILITY AND SHEET FLATNESS OF BIAXIALLY ORIENTED POLYPROPYLENE FILM WHICH COMPRISES, IN COMBINATION, THE STEPS IN SEQUENCE OF (1) SUBJECTING A BIAXIALLY ORIENTED POLYPROPYLENE FILM, WHICH HAS BEEN ORIENTED BY STRETCHING FROM 2 TIMES TO 10 TIMES ITS ORIGINAL DIMENSIONS IN THE MACHINE AND TRANSVERSE DIRECTIONS, TO A HEAT TREATMENT AT A TEMPERATURE IN THE RANGE OF FROM 120*C. TO 150*C. FOR A TIME BETWEEN 1 SECOND AND 10 SECONDS WHILE PERMITTING SAID FILM TO RETRACT BETWEEN 10% AND 30% IN ITS TRANSVERSE DIRECTION DIMENSION AND UP TO 15% IN ITS MACHINE DIRECTION DIMENSION; AND (2) THEREAFTER STRETCHING SAID FILM IN THE MACHINE DIRECTION BY AN AMOUNT BETWEEN 0.5% AND 5% OF ITS LENGTH WHILE BEING MAINTAINED AT A TEMPERATURE BETWEEN 100*C. AND 150*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) | 1969-06-20 | 1969-12-20 | 1970-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-06-20 | 1973-12-20 | 1974-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-06-20 | 1977-12-20 | 1978-06-21 | $7700.00 | Window Closed / Lapsed |