US2634459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of crystalline vinylidene chloride polymer tubing whose walls do not cohere
Assignee: Dow Chemical Co
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Filing: 1951-02-03
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Granted: 1953-04-14
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Expires: 1971-02-03
Abstract
No abstract record available.
Inventors
- 👤 Carroll R Irons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:20
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/001; B29C48/0018; B29C48/0019; B29C48/09; B29C48/10; B29C71/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
IN A METHOD OF MAKING FILM IN TUBULAR FORM FROM A NORMALLY CRYSTALLINE VINYLIDENE CHLORIDE POLYMER WHICH COMPRISES EXTRUDING THE POLYMER IN TUBULAR FORM FROM A DIE DOWNWARDLY INTO A COOLING BATH IN WHICH THE TUBE IS SUPERCOOLED, FROM THE POINT OF CONSTRICTION TO A LEVEL NEAR THAT OF THE BATH, AND THEREAFTER IS STRETCHED TO EFFECT ORIENTATION, THE IMPROVEMENT WHICH CONSISTS IN INTRODUCING, CONTINUOUSLY AND AT A UNIFORM RATE, A FINELY DIVIDED SOLID ANTISTICKING AGENT, SELECTED FROM THE GROUP CONSISTING OF MICROPULVERIZED MICA AND MICROPULVERIZED STARCH, SUSPENDED IN A GAS STREAM, INTO THE SPACE BETWEEN THE EXTRUSION DIE AND THE LUBRICATING LIQUID WITHIN THE HOT TUBE, WHILE VENTING CONTINUOUSLY THE GASEOUS SUSPENDING AGENT, THEREBY TO COAT THE INTERNAL WALLS OF THE TUBE WITH AND TO EMBED PARTIALLY THEREIN THE SOLID ANTI-STICKING AGENT.
Claim 2
Dependent Claim
133 words
IN A METHOD OF MAKING FILM IN TUBULAR FORM FROM A NORMALLY CRYSTALLINE VINYLIDENE CHLORIDE POLYMER WHICH COMPRISES EXTRUDING THE POLYMER IN TUBULAR FORM FROM A DIE DOWNWARDLY INTO A COOLING BATH IN WHICH THE TUBE IS SUPERCOOLED, FROM THE POINT OF CONSTRICTION TO A LEVEL NEAR THAT OF THE BATH, AND THEREAFTER IS STRETCHED TO EFFECT ORIENTATION, THE IMPROVEMENT WHICH CONSISTS IN INTRODUCING, CONTINUOUSLY AND AT A UNIFORM RATE, A FINELY DIVIDED SOLID ANTISTICKING AGENT, SELECTED FROM THE GROUP CONSISTING OF MICROPULVERIZED MICA AND MICROPULVERIZED STARCH, SUSPENDED IN A GAS STREAM, INTO THE SPACE BETWEEN THE EXTRUSION DIE AND THE LUBRICATING LIQUID WITHIN THE HOT TUBE, WHILE VENTING CONTINUOUSLY THE GASEOUS SUSPENDING AGENT, THEREBY TO COAT THE INTERNAL WALLS OF THE TUBE WITH AND TO EMBED PARTIALLY THEREIN THE SOLID ANTI-STICKING AGENT.
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) | 1956-04-13 | 1956-10-13 | 1957-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-13 | 1960-10-13 | 1961-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-13 | 1964-10-13 | 1965-04-14 | $7700.00 | Window Closed / Lapsed |