Manufacturing method for improving strength of carbon fibers

A manufacturing method and carbon fiber technology, which are applied in the chemical characteristics of fibers, textiles and papermaking, etc., can solve the problems of carbon fiber radial defects and reduce carbon fiber strength, and achieve the effects of reducing radial defects, improving strength, and improving uniformity.

Pending Publication Date: 2020-05-05
CHINA PETROLEUM & CHEM CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] Using the existing sodium thiocyanate solution wet spinning process to prepare polyacrylonitrile-based raw silk as raw material, when manufacturing carbon fiber industrial production, the pre-oxidation process uses air as the medium, and the pre-oxidized silk skin-core structure is easy to appear, forming carbon fiber radial Defects, reducing carbon fiber strength and other issues

Method used

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  • Manufacturing method for improving strength of carbon fibers
  • Manufacturing method for improving strength of carbon fibers
  • Manufacturing method for improving strength of carbon fibers

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1～10

[0026] Embodiments 1 to 10 are production methods for producing 12K carbon fibers from polyacrylonitrile-based precursors prepared by a sodium thiocyanate solution wet spinning process. The specific processes include oxidation, low-temperature carbonization, high-temperature carbonization, surface treatment, washing, sizing, Drying, winding and winding production process. In the production process of Examples 1-10, the process parameters of low-temperature carbonization, high-temperature carbonization, surface treatment, water washing, sizing, drying, and winding are the same as those of Comparative Example 1, but the oxidation production process involved in Examples 1-10 The processing parameter (step 1) is different from comparative example 1, and concrete steps are as follows:

Embodiment 1～8

[0028] Step 1: Oxidation. The oxidation is divided into four zones, the concentration of oxygen in the reaction atmosphere of the first zone, the second zone, and the third zone is increased, and the oxidation is carried out in an atmosphere with a higher oxygen concentration. Oxidation The fourth zone reaction is oxidized in an air atmosphere.

[0029] The temperatures of the four oxidation furnace zones are 237°C, 245°C, 256°C, and 265°C respectively. The draw ratios between each oxidation furnace were 1.03, 0.93, 0.92, 0.95, respectively. The residence time of each oxidation furnace is 8, 8, 8, and 6 minutes respectively, and the total pre-oxidation time is 30 minutes. Oxidation is carried out by controlling the reaction atmosphere with different oxygen concentrations.

Embodiment 9

[0031]The temperatures of the four oxidation furnace zones are 240°C, 248°C, 260°C, and 270°C respectively. The draw ratios between each oxidation furnace were 1.05, 0.85, 0.85, 0.85, respectively. The residence time of each oxidation furnace is 5, 5, 5, and 5 minutes respectively, and the total pre-oxidation time is 20 minutes. Other experimental parameters and steps are the same as in Example 8.

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Abstract

The invention provides a manufacturing method for improving the strength of carbon fibers. According to the manufacturing method, in a carbon fiber production process, oxidation controlled by a pre-oxidation process is carried out in four regions sequentially, and concentrations of oxygen in reaction atmospheres of a first oxidation region, a second oxidation region and a third oxidation region are increased. Since in the oxidation process, more oxygen is diffused and enters core parts of the fibers from skin parts of the fibers to participate in an oxidation reaction, an oxidation reaction speed and a cyclization reaction speed are quickly increased, the total oxidation time is effectively shortened, the total oxidation time is controlled to be 20-32 min, the electric consumption of an oxidation furnace during oxidation can be effectively reduced, and the production operation cost is greatly reduced. Meanwhile, the method also can improve the uniformity of the oxygen in fiber radial distribution, the phenomenon of skin core structures of pre-oxidized fibers is alleviated, the radial defects of the carbon fibers are reduced in the carbonization process, and the strength of the carbon fibers is improved.

Description

technical field [0001] The invention relates to the technical field of carbon fiber oxidation, in particular to a manufacturing method capable of rapid oxidation, reducing fiber defects and improving carbon fiber strength. Background technique [0002] High-performance carbon fiber has a series of excellent properties such as high strength, high modulus, high temperature resistance, fatigue resistance, high electrical and thermal conductivity, and low thermal expansion coefficient. It has been widely used in aviation, aerospace, automobile industry, medical equipment, civil engineering, sports and leisure and other fields. . With the widening of carbon fiber in aerospace and industrial applications, the requirements for carbon fiber strength are getting higher and higher. However, the highest value of carbon fiber strength produced by carbon fiber manufacturers in industrialized production is far from the theoretical maximum value of carbon fiber strength. Carbon fiber stren...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): D01F9/22
CPCD01F9/22
Inventor季春晓黄翔宇黄胜德吴嵩义毕建东袁玉红宋文迪
OwnerCHINA PETROLEUM & CHEM CORP