Patent US3567539A successfully refreshed from Google Patents.
US3567539A
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US
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Method of making a tubular thermoplastic laminate
Assignee: WR Grace and Co
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Filing: 1967-08-11
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Granted: 1971-03-02
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Expires: 1987-08-11
Abstract
Abstract A LAMINATED THERMOPLASTIC FILM IS PRODUCED BY PASSING SLIGHTLY INFLATED, IRRADIATED POLYETHYLENE TUBING THROUGH A CIRCULAR DIE, COATING A MOLTEN ETHYLENE VINYL ACETATE COPOLYMER ONTO THE TUBING WHEREBY THE POLYURETHANE IS HEATED TO ITS ORIENTATION TEMPERATURE WHILE THE COPOLYMER IS COOLED TO A TEMPERATURE SUITABLE FOR HOT BLOWING, AND IMMEDIATELY EXPANDING THE LAMINATE AS IT LEAVES THE DIE BY INTERNAL AIR PRESSURE.
Inventors
- 👤 Henry G Schirmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:38
CPC Classifications
B; B32; B32B; B32B27/00; B29; B29C; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/0016; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21; B29C48/0018; B29C48/0019; B29C48/10
Claims Analysis
Total Claims: 0
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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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |