Patent US4415522A successfully refreshed from Google Patents.
US4415522A
Expired / Lapsed
US
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Process for the continuous production of high modulus filament of polyethylene
Assignee: BTG International Ltd
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Filing: 1981-02-27
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Granted: 1983-11-15
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Expires: 2001-02-27
Abstract
Abstract A process for the production of a high modulus filament of polyethylene which comprises heating high density polyethylene to a temperature above its melting point, extruding the polymer to form a filament, subjecting the filament immediately after extrusion to a tension under such conditions that the filament is shaped without substantial orientation of its molecules, cooling the filament at a rate of cooling in excess of 15° C. per minute, and drawing the filament to a high draw ratio.
Inventors
- 👤 Giancarlo Capaccio
- 👤 Francis S. Smith
- 👤 Ian M. Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:39
CPC Classifications
D; D02; D02J; D02J1/00; D02J1/22; D02J1/223; D01; D01D; D01D5/00; D01D5/08; D01D5/088; D01D5/0885; D01D5/098; D01F; D01F6/00; D01F6/02; D01F6/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
85 words
A process for the continuous production of a high modulus filament of polyethylene of Mw not greater than 200,000 and Mn not less than 5,000, which process comprises heating high density polyethylene to a temperature above its melting point, spinning a filament therefrom, quenching the filament at a rate of cooling in excess of 15° C. per minute and drawing the filament to a draw ratio of at least 17 to give a material having a 0.5% secant modulus greater than 158 g per dtex.
Claim 2
Dependent Claim
85 words
A process for the continuous production of a high modulus filament of polyethylene of Mw not greater than 200,000 and Mn not less than 5,000, which process comprises heating high density polyethylene to a temperature above its melting point, spinning a filament therefrom, quenching the filament at a rate of cooling in excess of 15° C. per minute and drawing the filament to a draw ratio of at least 17 to give a material having a 0.5% secant modulus greater than 158 g per dtex.
Claim 3
Dependent Claim
20 words
A process according to claim 1 wherein the spun filament has a birefringence of not more than 3.5×10 -3 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |