90% of the carbon fiber in the market is polyacrylonitrile, and the remaining 10% is artificial silk or petroleum pitch. They share a common feature, that is, the carbon content is very high. In the process of manufacturing, some gas or liquid can be used to react with carbon fiber to achieve a specific effect. This paper introduces the manufacturing process of polyacrylonitrile based carbon fiber as an example.
Polyacrylonitrile is first mixed with other resins, such as methacrylate or methyl methacrylate, and a certain catalyst is added to the chemical reaction. After the end of the reaction, they are spun into silk threads in different ways. A particular chemical is added to the spinning.
It is necessary to stabilize its chemical properties between carbonization, which is done by heating. The fiber is heated in the air for 30~120 minutes, and the temperature is about 200 c ~300 C, which makes the atomic bond pattern rearranged and the oxygen molecules are out. The seemingly simple process is very complex in fact, and many factors have to be carefully controlled.
Carbonization and graphitization
Carbonization is to heat the fiber to 1000 degrees Celsius, remove the non carbon atoms inside, and increase the purity. Graphitization is heated to about 2000 degrees, which further improves the content of carbon atoms. Finally, the carbon content of the fiber can reach about 95%.
After graphitization, the surface of the fiber can not be well combined with the epoxy resin or other materials, so some chemical treatments are needed to increase the roughness of the surface. In order to prevent the fiber from being damaged in the process of weaving or winding, it can also be glued on the surface to protect the fiber.
The carbon fiber after manufacture is subject to certain quality inspection. The common fiber tests include density, strength, tensile modulus, sizing dosage, high temperature resistance and others. In order to avoid trouble, all data must be monitored strictly during manufacturing, including time, temperature, airflow and chemical composition, so that the quality of the products produced is better. In addition, carbon fiber dust may cause skin allergy. If inhaled into the lungs, it can not be discharged. Therefore, it is necessary to wear goggles, gloves, masks, and work clothes when operating.
Shenzhen CN Technology Co.,Ltd is a professional manufacturer and distributor of carbon fiber products. Such as roll wrapped carbon fiber tubes,Hot press carbon fiber sheets,cnc carbon fiber cutting,carbon fiber chamfered.