Claims
- 1. In melt-spinning process for spinning continuous polyamide industrial filaments in a path from a spinning pack at a spinning speed controlled by a positive mechanical withdrawal means that controls the speed of the filaments in the range of from about 440 yds./min. to about 1,000 yds./min. whereby said filaments are oriented to a birefringence level, the improvement for decreasing said birefringence level of the filaments comprising: directing a gas into a zone enclosing said path, said zone extending from said spinning pack to a location between the spinning pack and the positive mechanical withdrawal means; maintaining said zone under superatmospheric pressure of less than 0.03 kg/cm.sup.2 and increasing the velocity of the gas as it leaves the zone to a level greater than the velocity of the filaments to reduce the birefringence level of said filaments.
- 2. The process of claim 1, said polyamide being polyhexamethylene adipamide.
- 3. The process of claim 1, said polyamide being polycaproamide.
- 4. The process of claims 1, 2 or 3, said gas being air, the temperature of said gas being from about -20.degree. C. to about 250.degree. C.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 06/857,289, filed Apr. 30, 1986, now U.S. Pat. No. 5,034,182.
US Referenced Citations (23)
Foreign Referenced Citations (5)
Number |
Date |
Country |
48-43563 |
Dec 1973 |
JPX |
56-13806 |
Mar 1981 |
JPX |
60-134015A |
Jul 1985 |
JPX |
627194 |
Sep 1978 |
SUX |
1220424 |
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GBX |
Non-Patent Literature Citations (2)
Entry |
Research Disclosure No. 10418, Dec. 1972, "Improved Dry-Spinning Apparatus". |
Fiber World Sep. 1984, pp. 8-12 "Physical Limits of Spinning Speed", Ziabicki, Andrzej. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
857289 |
Apr 1986 |
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