Carbon felt in the vacuum or inert atmosphere after more than 2000 degrees under high temperature treatment for graphite felt, carbon content than carbon felt, up to more than 99%. At the end of 60s the world has a graphite felt good supply. Because of the different selection of raw graphite felt for pitch based and PAN based graphite felt and viscose based graphite felt three.
The Japan Kureha chemical as a representative of the asphalt in the insulation industry mainstream, Europe and the United States insulation felt basically to adhesives based, and China is most clear polypropylene based as raw material. Process of polyacrylonitrile based carbon felt or rayon based carbon felt cut into the desired size, rolled into a cylindrical shape is arranged in a graphite material container, graphite container is placed in a high temperature furnace (high temperature furnace graphite tube furnace, medium frequency, high-frequency induction furnace or other forms of heating furnace), vacuum pumping or through a high purity inert gas protection, to 100 to 300 DEG / h of the heating rate of heating to 22 to 25 DEG C; and naturally cooling to 100 DEG C to obtain.
PAN based graphite felt than viscose base graphite felt strong and strong antioxidant capacity, but poor flexibility, volume density, good insulation properties. They have the advantages of high purity, high temperature resistance, corrosion resistance, non melting and so on, but also can be flexible, can be folded, cut and can be used with graphite yarn stitching and so on. Graphite felt is mainly used as a single crystal silicon smelting furnace insulation, thermal insulation materials. In the chemical industry can be used as a filter material of high purity corrosive chemical reagents. Under the condition of non oxidizing atmosphere, the temperature of graphite felt is up to 3000.