Introduction Of Graphite Felt

Graphite felt is divided into three types: pitch-based graphite felt, polyacrylonitrile-based (PAN-based) graphite felt and viscose-based graphite felt due to the difference of the original felt. In the chemical industry, it can be used as a filter material for high-purity corrosive chemical reagents.

Carbon felt is graphite felt after high temperature treatment above 2000 ℃ in vacuum or inert atmosphere, and the carbon content is higher than that of carbon felt, reaching more than 99%. At the end of the 1960s, graphite felt was already available in the world. Graphite felt is divided into three types: asphalt-based, polyacrylonitrile-based graphite felt and viscose-based graphite felt due to the difference of the original felt.

Among them, the asphalt represented by Kureha Chemical of Japan is the mainstream in the thermal insulation industry. In Europe and the United States, thermal insulation felts are basically based on adhesives, while most of them in China are based on polyacrylonitrile. In the process, the polyacrylonitrile-based carbon felt or viscose-based carbon felt is cut into the required size, rolled into a cylinder and placed in a container made of graphite material, and the graphite container is placed in a high-temperature furnace (the high-temperature furnace is a graphite tube furnace, an intermediate frequency , high-frequency induction furnace or high-temperature furnace with other heating forms), protected by vacuuming or high-purity inert gas, heated to 2200-2500 °C at a heating rate of 100-300 °C/h, and then naturally cooled to 100 °C. .

Polyacrylonitrile-based graphite felt is stronger than viscose-based graphite felt and has strong oxidation resistance, but has poor flexibility, high bulk density and good thermal insulation performance. In addition to the high purity, high temperature resistance, corrosion resistance, and non-melting properties of bulk graphite, they also have the advantages of elasticity, arbitrary folding, tailoring, and graphite yarn stitching. The main purpose of graphite felt is as heat preservation and heat insulation material of single crystal silicon smelting furnace. In the chemical industry, it can be used as a filter material for high-purity corrosive chemical reagents. Under the condition of non-oxidizing atmosphere, the use temperature of graphite felt can reach about 3000℃.