US3797221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
False twist-crimped polyester yarns and process for their production
Assignee: Teijin Ltd
•
Filing: 1971-04-05
•
Granted: 1974-03-19
•
Expires: 1991-04-05
Abstract
Abstract A false twist-crimped polyester yarn having a density d of 1.3800 < OR = d < OR = 1.3950 (g/cm3) and a total percentage crimp (TC) of TC > OR = 30% is produced by false twisting a polyester multi-filament having a birefringence ( Delta n) of 0.030 < OR = Delta n < OR = 0.145 while heat setting the filament in the twisted state at 160* to 210* at a draft (dr) which satisfies the following equation:
Inventors
- 👤 M Ikeda
- 👤 M Tsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:55
CPC Classifications
D; D02; D02G; D02G1/00; D02G1/02; D02G1/0286; D01; D01F; D01F6/00; D01F6/58; D01F6/62; D02G1/0206; D02G1/022
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
10 words
-250. $N + 38 $ DR $ -150.$N + 17
Claim 2
Dependent Claim
45 words
A modified false twist-crimped polyester yarn having a density (d) of 1.3800 < or = d < or = 1.3950 (g/cm3), a total percentage crimp (TC) of TC < or = 20 (%), and a torque (Tq) of Tq < or = 26 (T/25 cm).
Claim 3
Dependent Claim
73 words
A process for producing a false twist-crimped polyester yarn which comprises false twisting a polyester multifilament having a birefringence ( Delta n) of 0.030 < or = Delta n < or = 0.145 while heat setting the filaments in the twisted state at 160* to 210*C. at a draft (dr) which satisfies the following equation: -250 . Delta n + 38 > or = dr > or = -150. Delta n + 17.
Claim 4
Dependent Claim
26 words
The process of claim 3 wherein the polyester multifilament has a birefringence ( Delta n) of 0.06 < or = Delta n < or = 0.135.
Claim 5
Dependent Claim
14 words
The process of claim 3 wherein the heat setting temperature is 170* to 200*C.
Claim 6
Dependent Claim
42 words
A process for producing a modified false twist-crimped polyester yarn which comprises subjecting the false twist-crimped polyester yarn obtained in claim 3 to a second heat setting at a temperature exceeding the temperature at which the yarn has been initially heat set.
References Cited (Backward Citations)
GB746992A
Cited
US2980492A
Cited
US3587220A
Cited
US3458986A
Cited
US3601972A
Cited
US3534541A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |