Carbon Fiber Production Method
At present, industrial production of carbon fiber can be divided into three categories according to the raw material route: polyacrylonitrile (PAN) -based carbon fiber, pitch-based carbon fiber and viscose-based carbon fiber. Carbon fibers made from viscose fibers must be graphitized by high-temperature stretching. The carbonization yield is low, the technology is difficult, the equipment is complicated, and the cost is high. The products are mainly used for ablative materials and heat insulation materials. Carbon fiber is produced from asphalt with rich raw material sources and high carbonization yield. However, due to the complex preparation of raw materials and low product performance, it has not been developed on a large scale. High-performance carbon fibers can be made from polyacrylonitrile fiber precursors. The production process is simpler than other methods, and the product has excellent mechanical properties and a wide range of uses. Therefore, it has made great progress since its introduction in the 1960s and has become today The mainstream of carbon fiber industrial production.
The production of polyacrylonitrile-based carbon fibers mainly includes two processes of raw silk production and raw carbonization. The production process of raw silk mainly includes the steps of polymerization, defoaming, metering, spinning, traction, water washing, oiling, drying and collection. The carbonization process mainly includes processes such as laying, pre-oxidation, low-temperature carbonization, high-temperature carbonization, surface treatment, sizing and drying, and winding and winding. According to different product specifications, carbon fiber is currently divided into aerospace-grade and commercial-grade, also known as small-strand tow or small tow and large tow -strand tow or large tow) Carbon fibers above 48K are often referred to as large tow carbon fibers, including 48K, 60K, 120K, 360K and 480K. Astronautics-grade carbon fiber is mainly 1K, 3K, 6K. The development of 14K and 21K is mainly used in defense military and high technology, as well as sports and leisure products, such as aircraft, missiles, rockets, satellites and fishing rods, golf clubs, tennis rackets and so on. Industrial grade carbon fiber is used in different civil industries, including: textiles, medical and health, mechanical and electrical, civil construction, transportation and energy.