Dispersion spinning process for poly(tetrafluoroethylene) and related polymers

A technology of dispersion, matrix polymer, applied in the direction of one-component synthetic polymer rayon, wet spinning, textile and papermaking, etc., can solve the problems of hindering fiber sintering, difficulty and so on

Inactive Publication Date: 2000-01-12
EI DU PONT DE NEMOURS & CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In most cases, the high concentration of salt in the intermediate fiber structure even prevents the formation of sintered

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0056] The solution preparation process is as follows: 1.58 kg of carboxymethyl cellulose (CMC) with a moisture content of 6.2 wt % and a degree of substitution of about 0.30 is placed in 17.7 liters of soft water at about 1.0° C. to make a slurry. After the CMC was wetted, 12.3 kg of 23% sodium hydroxide solution was added to the water / CMC mixture at 4.5°C. The resulting mixture was stirred under vacuum (approximately 29 mm Hg) for 1 h and then filtered through a 50 μm polypropylene felt bag filter into a membrane degasser operating at approximately 29 mm Hg vacuum. The viscosity of the obtained solution at 25°C was 3516 mPa·s.

[0057] The above solution stream was combined with a stream of TEF 3311 poly(tetrafluoroethylene) (PTFE) dispersion (supplied by DuPont, Wilmington, DE) with relative flow controlled so that the weight ratio of PTFE to CMC was 8.1, and the combined stream was statically mixed in-line Mix in a mixer. The resulting mixture was then pumped through a s...

example 2

[0063] Fiber spinning was essentially as in Example 1 except that the draw ratio was set at 7.73.

[0064] The yarn obtained had a linear density of 770 dtex. Its strength is 1.67g / dtex.

example 3

[0066] Fiber spinning was essentially as in Example 1 except that the draw ratio was set at 6.31.

[0067] The obtained yarn had a linear density of 882 dtex. Its strength is 1.48g / dtex.

[0068] After ion exchange washing, a sample of the intermediate fiber structure was analyzed for sodium content by emission spectroscopy as a means of determining the sodium concentration in the dried and sintered fiber structure. The sodium content was measured at 570 ppm.

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Abstract

A process for preparing a dispersion spun fluorinated polymer fiber wherein the intermediate fiber structure, immediately before sintering, contains primarily ions characterized as fugitive ions.

Description

[0001] The present invention relates to a process for spinning dispersions of poly(tetrafluoroethylene) or related polymers into fibers or forming such dispersions into shaped articles, wherein the sintered fluorinated polymer structure is substantially free of process salts , acid and other impurities. Background of the invention [0002] The excellent stability of poly(tetrafluoroethylene) and related polymers to light, heat, solvents, chemical attack, and electrical stress allows the use of such polymers and articles made from such polymers in a variety of The use is quite popular. However, due to the complexities involved in melt and solution processing of such polymers, it is difficult to spin or shape them by conventional methods. [0003] A method for forming or spinning poly(tetrafluoroethylene) and related polymers is to form or spin the polymer from a mixture of the polymer particle aqueous dispersion and viscose, wherein xanthic acid Cellulose is a soluble form of...

Claims

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Application Information

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IPC IPC(8): D01D5/06D01F6/00
Inventor N・L・布朗肯贝克勒J・M・东克尔斯二世W・F・克诺夫
Owner EI DU PONT DE NEMOURS & CO
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