US3325575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for biaxially orienting polyolefin tubing with cooling during stretching
Assignee: Imperial Chemical Industries Ltd
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Filing: 1962-04-12
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Granted: 1967-06-13
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Expires: 1982-04-12
Abstract
No abstract record available.
Inventors
- 👤 Last Anthony Graham Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:54
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
118 words
A TUBULAR PROCESS OF STRETCHING AND ORIENTING POLYPROPYLENE FILM TO BIAXIALLY ORIENT IT TO OBTAIN A HIGHLY SHRINKABLE FILM, IN WHICH THE TUBE OF UNORIENTED POLYPROPYLENE, AT A TEMPERATURE BELOW ITS MELTING POINT AT WHICH IS CAN BE UNIFORMLY EXPANDED TO BIAXIALLY ORIENT IT, IS EXPANDED BY INTERNAL GASEOUS PRESSURE, AND IS HAULED OFF AS A BIAXIALLY ORIENTED POLYPROPYLENE FILM, CHARACTERISED IN THAT THE FILM IS COOLED BY CIRCUMFERENTIALLY, UNIFORMLY APPLIED DRAUGHTS OF AIR AT LEAST ON THE SHOULDER OF THE STRETCHING TUBES AND UNDER CONDITIONS OF TEMPERATURE OF THE TUBE BEFORE STRETCHING IT AND INTERNAL GASEOUS PRESSURE SUCH THAT THE HOOP STRESS IN THE POLYPROPYLENE TUBE JUST BEFORE IT COMMENCES TO STRETCH IS AT LEAST 16.5 P.S.I.
Claim 2
Dependent Claim
118 words
A TUBULAR PROCESS OF STRETCHING AND ORIENTING POLYPROPYLENE FILM TO BIAXIALLY ORIENT IT TO OBTAIN A HIGHLY SHRINKABLE FILM, IN WHICH THE TUBE OF UNORIENTED POLYPROPYLENE, AT A TEMPERATURE BELOW ITS MELTING POINT AT WHICH IS CAN BE UNIFORMLY EXPANDED TO BIAXIALLY ORIENT IT, IS EXPANDED BY INTERNAL GASEOUS PRESSURE, AND IS HAULED OFF AS A BIAXIALLY ORIENTED POLYPROPYLENE FILM, CHARACTERISED IN THAT THE FILM IS COOLED BY CIRCUMFERENTIALLY, UNIFORMLY APPLIED DRAUGHTS OF AIR AT LEAST ON THE SHOULDER OF THE STRETCHING TUBES AND UNDER CONDITIONS OF TEMPERATURE OF THE TUBE BEFORE STRETCHING IT AND INTERNAL GASEOUS PRESSURE SUCH THAT THE HOOP STRESS IN THE POLYPROPYLENE TUBE JUST BEFORE IT COMMENCES TO STRETCH IS AT LEAST 16.5 P.S.I.
References Cited (Backward Citations)
US2444059A
Cited
US2461976A
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US2461975A
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US2947031A
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US2990306A
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US3009208A
Cited
US3061876A
Cited
US3141912A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-06-12 | 1970-12-12 | 1971-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-06-12 | 1974-12-12 | 1975-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-06-12 | 1978-12-12 | 1979-06-13 | $7700.00 | Window Closed / Lapsed |