Patent US3231653A successfully refreshed from Google Patents.
US3231653A
Expired / Lapsed
US
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Pressure isolation in the manufacture of thermoplastic tubular film by extrusion
Assignee: EIDP Inc
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Filing: 1964-07-09
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Granted: 1966-01-25
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Expires: 1984-07-09
Abstract
No abstract record available.
Inventors
- 👤 Goldman Max
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:42
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
151 words
THE PROCESS COMPRISING: EXTRUDING THERMOPLASTIC POLYMERIC MATERIAL IN THE FORM OF A TUBULAR SHEET IN ITS FORMATIVE STATE; ADVANCING THE TUBULAR SHEET AT A PREDETERMINED INITIAL RATE; MAINTAINING THE INTERNAL PRESSURE OF THE TUBULAR SHEET IN ITS FORMATIVE STATE SUBSTANTIALLY THAT OF THE EXTERNAL PRESSURE TO PREVENT THE TUBULAR SHEET FROM RUPTURING; QUENCHING THE TUBULAR SHEET TO A TEMPERATURE BELOW ITS FORMATIVE STATE; MAINTAING SUFFICIENT PRESSURE WITHIN THE TUBULAR SHEET TO PREVENT COLLAPSE AND TO PROVIDE, WHEN THE TUBULAR SHEET IS HEATED TO A TEMPERATURE WITHIN ITS ORIENTATION TEMPERATURE RANGE, AN EXPANSION TO A DIAMETER OF AT LEAST 2 TIMES THE ORIGINAL DIAMETER OF THE SHEET; HEATING THE TUBULAR SHEET TO A TEMPERATURE WITHIN THE ORIENTATION TEMPERATURE RANGE; ADVANCING, WHILE EXPANDING, THE HEATED TUBULAR SHEET AT A RATE AT LEAST 2 TIMES THE INITIAL RATE OF ADVANCEMENT; AND COOLING THE TUBULAR SHEET WHILE MAINTAINING THE SHEET SUBSTANTIALLY AT ITS EXPANDED DIAMETER.
Claim 2
Dependent Claim
151 words
THE PROCESS COMPRISING: EXTRUDING THERMOPLASTIC POLYMERIC MATERIAL IN THE FORM OF A TUBULAR SHEET IN ITS FORMATIVE STATE; ADVANCING THE TUBULAR SHEET AT A PREDETERMINED INITIAL RATE; MAINTAINING THE INTERNAL PRESSURE OF THE TUBULAR SHEET IN ITS FORMATIVE STATE SUBSTANTIALLY THAT OF THE EXTERNAL PRESSURE TO PREVENT THE TUBULAR SHEET FROM RUPTURING; QUENCHING THE TUBULAR SHEET TO A TEMPERATURE BELOW ITS FORMATIVE STATE; MAINTAING SUFFICIENT PRESSURE WITHIN THE TUBULAR SHEET TO PREVENT COLLAPSE AND TO PROVIDE, WHEN THE TUBULAR SHEET IS HEATED TO A TEMPERATURE WITHIN ITS ORIENTATION TEMPERATURE RANGE, AN EXPANSION TO A DIAMETER OF AT LEAST 2 TIMES THE ORIGINAL DIAMETER OF THE SHEET; HEATING THE TUBULAR SHEET TO A TEMPERATURE WITHIN THE ORIENTATION TEMPERATURE RANGE; ADVANCING, WHILE EXPANDING, THE HEATED TUBULAR SHEET AT A RATE AT LEAST 2 TIMES THE INITIAL RATE OF ADVANCEMENT; AND COOLING THE TUBULAR SHEET WHILE MAINTAINING THE SHEET SUBSTANTIALLY AT ITS EXPANDED DIAMETER.
References Cited (Backward Citations)
US3141912A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |