Patent US3385918A successfully refreshed from Google Patents.
US3385918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion process and apparatus for isotactic polypropylene
Assignee: BX Plastics Ltd
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Filing: 1966-03-23
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Granted: 1968-05-28
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Expires: 1986-03-23
Abstract
No abstract record available.
Inventors
- 👤 James Jack
- 👤 Godfrey Austin King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:52
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/908; B29C48/03; B29C48/09; B29C48/10; B29C48/901; B29C48/919; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
189 words
A PROCESS FOR THE PRODUCTION OF A QUENCHED TUBE OF ISOTACTIC POLYPROPYLENE FOR CONVERSION INTO BIAXIALLY ORIENTED FILM WHICH COMPRISES EXTRUDING A SOLID UNPERFORATED TUBE OF THE POLYPROPYLENE DOWNWARDLY OVER A FORMER COMPRISING AT LEAST TWO SEPARATED DISCS LYING AT RIGHT ANGLES TO THE AXIS OF THE TUBE AND HAVING A SHAPE IDENTICAL TO THE DESIRED CROSS-SECTION OF THE QUENCHED TUBE AND BEING BELOW THE SURFACE OF A BATH OF QUENCHING LIQUID, WHILE PASSING THE TUBE THROUGH A TUBULAR SLEEVE AROUND THE FORMER AND BELOW THE SURFACE OF THE BATH OF QUENCHING LIQUID AND HAVING THE INNER SURFACE THEREOF SPACED FROM THE OUTER SURFACE OF THE TUBE, AND DRAWING QUENCHING LIQUID DOWNWARDLY THROUGH THE SPACE BETWEEN SAID SLEEVE AND SAID TUBE AT SUCH A RATE THAT RAPID QUENCHING OF THE TUBE OCCURS WITHIN THE SLEEVE AND BOILING OF THE QUENCHING LIQUID IN THE BATH AND WITHIN THE SLEEVE IS AVOIDED, THE WIDTH AND SHAPE OF THE SLEEVE RELATIVE TO THOSE OF THE TUBE AND THE DISTANCE OF THE SLEEVE BELOW THE SURFACE OF THE QUENCHING LIQUID BEING SUCH AS TO PRODUCE A QUENCHED TUBE HAVING THE DESIRED CRYSTALLITE FORM.
Claim 2
Dependent Claim
189 words
A PROCESS FOR THE PRODUCTION OF A QUENCHED TUBE OF ISOTACTIC POLYPROPYLENE FOR CONVERSION INTO BIAXIALLY ORIENTED FILM WHICH COMPRISES EXTRUDING A SOLID UNPERFORATED TUBE OF THE POLYPROPYLENE DOWNWARDLY OVER A FORMER COMPRISING AT LEAST TWO SEPARATED DISCS LYING AT RIGHT ANGLES TO THE AXIS OF THE TUBE AND HAVING A SHAPE IDENTICAL TO THE DESIRED CROSS-SECTION OF THE QUENCHED TUBE AND BEING BELOW THE SURFACE OF A BATH OF QUENCHING LIQUID, WHILE PASSING THE TUBE THROUGH A TUBULAR SLEEVE AROUND THE FORMER AND BELOW THE SURFACE OF THE BATH OF QUENCHING LIQUID AND HAVING THE INNER SURFACE THEREOF SPACED FROM THE OUTER SURFACE OF THE TUBE, AND DRAWING QUENCHING LIQUID DOWNWARDLY THROUGH THE SPACE BETWEEN SAID SLEEVE AND SAID TUBE AT SUCH A RATE THAT RAPID QUENCHING OF THE TUBE OCCURS WITHIN THE SLEEVE AND BOILING OF THE QUENCHING LIQUID IN THE BATH AND WITHIN THE SLEEVE IS AVOIDED, THE WIDTH AND SHAPE OF THE SLEEVE RELATIVE TO THOSE OF THE TUBE AND THE DISTANCE OF THE SLEEVE BELOW THE SURFACE OF THE QUENCHING LIQUID BEING SUCH AS TO PRODUCE A QUENCHED TUBE HAVING THE DESIRED CRYSTALLITE FORM.
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) | 1971-05-28 | 1971-11-27 | 1972-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-05-28 | 1975-11-27 | 1976-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-05-28 | 1979-11-27 | 1980-05-28 | $7700.00 | Window Closed / Lapsed |