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US3936999A
Expired / Lapsed
US
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False twist-crimped polyester yarns production
Assignee: Teijin Ltd
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Filing: 1973-12-19
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Granted: 1976-02-10
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Expires: 1993-12-19
Abstract
Abstract A false twist-crimped polyester yarn having a density (d) of 1.3800</=d</=1.3970 (g/cm3) and total percentage crimp (TC) of TC 30% is produced by false twisting a polyester multi-filament having a birefringence ( DELTA n) of 0.030</= DELTA n</=0.145 while heat setting the filament in the twisted state at 160 DEG to 210 DEG at a draft (dr) which satisfies the following equation: -150( DELTA n) + 17</=dr</=0.9 x 104( DELTA n2)-29 x 102( DELTA n)+248.
Inventors
- 👤 Morio Ikeda
- 👤 Mamoru Tsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:30
CPC Classifications
D; D02; D02G; D02G1/00; D02G1/02; D02G1/0286
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
90 words
A process for producing a false twist-crimped polyester yarn which comprises false twisting undrawn polyester multifilament yarn obtained by melt-spinning at a speed of 2500-5000m/min., having a birefrigence (Δn) of 0.030-0.145 and a density of not greater than 1.3720, while heat-setting said yarn in the twisted state at a first temperature of 160°-210°C, at a draft (dr) expressed by the equation: -150(Δn) + 17 ≦ dr ≦ 0.9 × 10.sup.4 (Δn.sup.2) - 29 × 10.sup.2 (Δn) + 248 and then subjecting the false twist-crimped yarn to a second heat-setting temperature.
Claim 2
Dependent Claim
90 words
A process for producing a false twist-crimped polyester yarn which comprises false twisting undrawn polyester multifilament yarn obtained by melt-spinning at a speed of 2500-5000m/min., having a birefrigence (Δn) of 0.030-0.145 and a density of not greater than 1.3720, while heat-setting said yarn in the twisted state at a first temperature of 160°-210°C, at a draft (dr) expressed by the equation: -150(Δn) + 17 ≦ dr ≦ 0.9 × 10.sup.4 (Δn.sup.2) - 29 × 10.sup.2 (Δn) + 248 and then subjecting the false twist-crimped yarn to a second heat-setting temperature.
Claim 3
Dependent Claim
32 words
A process according to claim 1 wherein a modified false twist-crimped yarn is produced by subjecting the false-twist crimped yarn to a second heat setting temperature of 100°-230°C under controlled relaxation conditions.
Claim 4
Dependent Claim
27 words
A process according to claim 1 wherein the amount of relaxation in the second heat setting is 0-40% based on the length of the false twist-crimped yarn.
References Cited (Backward Citations)
GB746992A
Cited
US2980492A
Cited
US3587220A
Cited
US3458986A
Cited
US3601972A
Cited
US3534541A
Cited
US3797221A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |