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Patent US3233023A successfully refreshed from Google Patents.
US3233023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spinning of polypropylene
Assignee: Imperial Chemical Industries Ltd
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Filing: 1963-02-21
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Granted: 1966-02-01
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Expires: 1983-02-21
Abstract
No abstract record available.
Inventors
- 👤 Benson Richard William Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:22
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/22; D01D5/23; D01F; D01F6/00; D01F6/02; D01F6/04; D01F6/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PROCESS FOR THE PRODUCTION OF CRIMPED FILAMENTS OF ISOTACTIC POLYPROPYLENE COMPRISING PRODUCING ISOTACTIC POLYPROPYLENE FILAMENTS HAVING AN INTRINSIC VISCOSITY OF BETWEEN ABOUT 1.5 AND 2.5 AND A BIREFRINGENCE OF BETWEEN ABOUT 10X10-3 TO 19X10-3, SAID PRODUCING STEP INCLUDING THE STEPS OF MELT SPINNING A POLYPROPYLENE OF INTRINSIC VISCOSITY BETWEEN 1.0 AND 6.0 AT A SPINNERET TEMPERATURE BETWEEN 175*C. AND 320*C. TO FORM FILAMENTS AND WINDING UP THE FILAMENTS AT BETWEEN ABOUT 1000 AND 5000 FEET PER MINUTE, SAID PROCESS FURTHER COMPRISING SUBSEQUENTLY DRAWING THE FILAMENTS AT BETWEEN 10*C. AND 140*C. AT A DRAW RATIO OF BETWEEN ABOUT 1.2 AND 4.0 AND RELAXING THE DRAWN FILAMENTS TO PRODUCE SPONTANEOUS CRIMPING.
Claim 2
Dependent Claim
110 words
A PROCESS FOR THE PRODUCTION OF CRIMPED FILAMENTS OF ISOTACTIC POLYPROPYLENE COMPRISING PRODUCING ISOTACTIC POLYPROPYLENE FILAMENTS HAVING AN INTRINSIC VISCOSITY OF BETWEEN ABOUT 1.5 AND 2.5 AND A BIREFRINGENCE OF BETWEEN ABOUT 10X10-3 TO 19X10-3, SAID PRODUCING STEP INCLUDING THE STEPS OF MELT SPINNING A POLYPROPYLENE OF INTRINSIC VISCOSITY BETWEEN 1.0 AND 6.0 AT A SPINNERET TEMPERATURE BETWEEN 175*C. AND 320*C. TO FORM FILAMENTS AND WINDING UP THE FILAMENTS AT BETWEEN ABOUT 1000 AND 5000 FEET PER MINUTE, SAID PROCESS FURTHER COMPRISING SUBSEQUENTLY DRAWING THE FILAMENTS AT BETWEEN 10*C. AND 140*C. AT A DRAW RATIO OF BETWEEN ABOUT 1.2 AND 4.0 AND RELAXING THE DRAWN FILAMENTS TO PRODUCE SPONTANEOUS CRIMPING.
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) | 1969-01-31 | 1969-08-02 | 1970-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-31 | 1973-08-02 | 1974-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-31 | 1977-08-02 | 1978-02-01 | $7700.00 | Window Closed / Lapsed |