What is the preparation process of carbon fiber?

The carbon fiber preparation process can usually be divided into the following steps:

1. Raw material processing: First of all, the preparation of carbon fiber requires the selection of appropriate raw materials, and polyacrylonitrile (PAN) fiber is generally used as the raw material. The processing of raw materials includes the removal of impurities and pre-stretching to improve the quality and performance of the fibers.

2. Fiber stretching: After raw material processing, the PAN fiber is stretched. This step will make the molecular structure of the fiber more orderly, straighten the fiber, and enhance its mechanical properties. Parameters such as stretching temperature and stretching speed need to be precisely controlled.

3. Pyrolysis and carbonization: The stretched fibers are pyrolytically and carbonized. Pyrolytic carbonization removes non-carbon elements from PAN fibers through high-temperature treatment and transforms them into pure carbon fibers. The pyrolysis carbonization temperature of carbon fiber is usually above 1000°C, and the specific temperature and time are determined according to the requirements of the fiber.

4. Shaping and curing: Shape and solidify the pyrolytically carbonized carbon fibers. Shaping can be performed by weaving, weaving, spinning, etc. to obtain carbon fiber products of different shapes. Curing refers to impregnating the resin into the fiber, and combining the fiber and the resin to form a solid structure through thermal curing, light curing, etc.

5. Surface treatment and coating: In order to enhance the interfacial adhesion and wear resistance of carbon fiber, its surface is usually treated and coated. Treatment methods include cleaning, scraping, drilling, etc. to increase the contact area between fiber and resin. The coating can choose materials such as polyimide and epoxy resin to improve the surface properties of carbon fiber.

Through the above preparation process, carbon fiber products with properties such as high strength, light weight, corrosion resistance and wear resistance can be obtained.