Claims
- 1. A process for manufacturing a fiber of poly-p-phenylene terephthalamide having a modulus greater than 1100 grams per denier and tenacity of greater than 18 grams per denier, the polymer of said fiber having a Crystallinity Index of at least 75%, comprising the steps of:
- exposing a wet never dried fiber of poly-p-phenylene terephthalamide having absorbed therein 20 to 100% of water based on the weight of dry fiber and having an acidity of less than 60 and a basicity of less than 10, to a turbulent, heated atmosphere wherein the atmosphere, in the direct vicinity of the fiber being exposed, has a flow of greater than Reynolds Number 10,000 throughout the duration of the exposure, the atmosphere has a temperature of 500 to 660 degrees,
- the exposure is for a duration of 0.25 to 3 seconds, and
- the fiber is maintained at a tension of 1.5 to 4 grams per denier.
- 2. The process of claim 1 wherein the acidity is less than 10.
- 3. The process of claim 1 wherein the Crystallinity Index of 75 to 85%.
- 4. A process for manufacturing a fiber of poly-p-phenylene terephthalamide having a modulus greater than 1100 grams per denier and tenacity of greater than 18 grams per denier, the polymer of said fiber having a Crystallinity Index of at least 75%, comprising the steps of:
- heating a wet fiber of poly-p-phenylene terephthalamide having absorbed therein 20 to 100% of water based on the weight of dry fiber and having an acidity of less than 60 and a basicity of less than 10, in an atmosphere having a flow of greater than Reynolds Number 10,000 throughout the duration of the heating, to a temperature of 500 to 660 degrees for a duration of 0.25 to 3 seconds, at a tension of 1.5 to 4 grams per denier
- to, first, dry the fiber and compact the polymeric material therein by evaporation of the water from the fiber and, second, as the fiber is drying, heat treat the fiber and order the polymeric material in the fiber by increasing the temperature inside the fiber structure.
- 5. The process of claim 4 wherein the acidity is less than 10.
- 6. The process of claim 4 wherein the fiber has a Crystallinity Index of 75 to 85%.
Parent Case Info
This application is a continuation-in-part of Ser. No. 868,667, filed May 30, 1986, now abandoned.
US Referenced Citations (12)
Foreign Referenced Citations (5)
Number |
Date |
Country |
55-11763 |
Mar 1980 |
JPX |
55-11764 |
Mar 1980 |
JPX |
59-192713 |
Nov 1984 |
JPX |
2044668 |
Oct 1980 |
GBX |
2044669 |
Oct 1980 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Journal of East China Institute of Textile Science and Technology, vol. 10, No. 2, (1984), pp. 30-34. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
868667 |
May 1986 |
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