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Preparation method of para-aramid low-denier fiber filament

A para-aramid fiber and fiber technology, which is applied in the field of preparation of para-aramid low-denier fiber filaments, achieves the effects of stable operation, excellent mechanical properties and stable quality

Active Publication Date: 2017-06-30
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to propose a method for preparing para-aramid low-denier fiber filaments, focusing on solving the problems at the back end of the spinning process, including the process parameters of spinnerets, washing and drying in the low-denier spinning process, A complete set of supporting spinning processes such as washing, drying machine winding, etc., through the cooperation of processes, the stable and high-quality production of para-aramid low-denier fiber filaments can be realized

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0012] The preparation method of the para-aramid low denier fiber filament that the present invention proposes comprises the following steps:

[0013] (1) Dissolving para-aramid resin with an inherent viscosity between 6.0-6.5 and a water content of less than 0.5% in concentrated sulfuric acid with a concentration of 99.5-100.5%, and obtaining the first spinning stock solution after dissolving, the second The mass percentage concentration of the first spinning stock solution is 18-21%. Under the condition of temperature of 80-90°C and vacuum degree of -0.09~-0.1MPa, the first spinning stock solution is subjected to defoaming treatment for 2-5 hours. The first spinning stock solution after defoaming treatment is filtered by 2-3 stage-by-stage filtration, the filter mesh size is 5-30um, and the second spinning stock solution is obtained; the filtration precision increases step by step from front to back. Keep the temperature constant during defoaming and filtration. After degas...

Embodiment 1

[0020] The para-aramid fiber resin with inherent viscosity of 6.0 and water content of 0.2% is dissolved in concentrated sulfuric acid with a concentration of 99.5%. The mass concentration of the spinning dope obtained after dissolving is 19.2%, and the temperature of the dope is maintained at 85°C. Then degassing for 5h under the condition of vacuum degree -0.09MPa. Then filter. The filtration adopts 2-stage step-by-step filtration method, and the filter mesh specifications are 20um and 10um respectively. During defoaming and filtration, keep the stock solution temperature constant. After degassing and filtering, the spinning dope is transported to the spinning box by a high-pressure delivery pump. All spinning positions are kept warm to ensure that the temperature of the spinning dope remains constant.

[0021] After being continuously metered by the metering pump, the spinning dope is transported to the spinning assembly for spinning. The spinneret hole diameter of the...

Embodiment 2

[0026]The para-aramid fiber resin with inherent viscosity of 6.5 and water content of 0.3% is dissolved in concentrated sulfuric acid with a concentration of 99.5%. The mass concentration of the spinning dope obtained after dissolving is 19.8%, and the temperature of the dope is kept at 90°C. Then degassing for 3 hours under the condition of vacuum degree -0.095MPa. Then filter. The filtration adopts a 3-level step-by-step filtering method, and the filter specifications are 20, 10 and 5um respectively. During defoaming and filtration, keep the stock solution temperature constant. After degassing and filtering, the spinning dope is transported to the spinning box by a high-pressure delivery pump. All spinning positions are kept warm to ensure that the temperature of the spinning dope remains constant.

[0027] After being continuously metered by the metering pump, the spinning dope is transported to the spinning assembly for spinning. The diameter of the spinneret holes in...

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Abstract

The invention relates to a preparation method of a para-aramid low-denier fiber filament, belongs to the technical field of chemical fiber spinning, and particularly relates to a preparation method of a para-aramid low-denier (25-100D) fiber filament. The problem of wire breaking needs to be solved in the spinning process of the para-aramid low-denier fiber filament to ensure the production stability and the tow performance stability. According to the preparation method of the para-aramid low-denier fiber filament, a selected spinneret cap is used for reducing the risk of extruded cross flow and doubling of a para spinning solution; an alkali liquor with proper concentration is used for washing primary tows, thereby quickly neutralizing sulfuric acid and improving the strength of the tows; and by adopting flat washing and drying modes, the risk of wire breaking in the washing and drying links is reduced. By using the method, the spinning process of the para-aramid low-denier filament is stable and easy to operate, and the obtained fiber is excellent in mechanical property and stable in quality.

Description

technical field [0001] The invention relates to a method for preparing para-aramid low-denier fiber filaments, and belongs to the technical field of chemical fiber spinning. Background technique [0002] Para-aramid fiber is a high-performance material with excellent properties such as high strength and high modulus, high temperature resistance, acid and alkali resistance, and light weight. It is widely used in national defense, aerospace, and many civilian fields. The common preparation process of para-aramid fiber includes dope preparation and spinning. The stock solution is prepared by dissolving poly-p-phenylene terephthalamide (PPTA), the resin used for spinning, in concentrated sulfuric acid, then continuously filtering and defoaming online, and finally transporting it to the spinning system by a booster pump for metered spinning. The principle of para-aramid fiber spinning is dry jet wet spinning. That is, the precisely metered spinning dope is compressed and extrud...

Claims

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Application Information

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IPC IPC(8): D01D5/06D01D1/10D01D1/02D01D5/12D01D10/06D01F6/62D01F6/84
CPCD01D1/02D01D1/103D01D1/106D01D5/06D01D5/12D01D10/06D01F6/62D01F6/84
Inventor 庹新林王晓工
Owner TSINGHUA UNIV
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