Flexible Graphite

Flexible graphite is a structural compact foil (paper) or sheet made by chemically treating ordinary graphite powder to obtain graphite interlayer compound, and then expanding it at high temperature to get expanded graphite, which is then pressed, baked at high temperature and impregnated. It retains the excellent properties of natural graphite while adding its unique flexibility, resilience, and sealing performance. It can be made into flexible graphite products and graphite sealing products. It is widely used in the sealing of valves, pumps, and reaction vessels under high temperature, high pressure, and corrosion-resistant media. Recently, flexible graphite has been widely used to make fuel cell bipolar plates. In addition to maintaining the electrical conductivity, thermal conductivity, and corrosion resistance of graphite, its simple preparation process also makes it an excellent material for reducing bipolar plate costs.

Excellent Heat Resistance
Flexible graphite can be used up to 3000 °C in a vacuum or reducing atmosphere. It has an extremely low thermal expansion coefficient. It will neither become brittle or crack at low temperatures nor become soften or creep at high temperatures.
Good Sealing Performance
Flexible graphite has high compression resilience, with a general compression ratio of up to 50% and a resilience rate of no less than 20%. When the compression ratio is 12%, the resilience rate can reach 70%. It has a low stress relaxation rate, generally only 1/3 times of that of asbestos sheet. Even it is treated at 100 °C for 22h, its stress relaxation rate generally will not exceed 5%. Additionally, flexible graphite is also impervious.
Good Chemical Resistance
Flexible graphite has excellent stability in almost all acids, bases, salts, organic solvents, oils, and seawater. However, it may corrode in aqua regia, chromic acid, concentrated sulfuric acid, and concentrated nitric acid.
Radiation Resistance
Flexible graphite does not deteriorate and its properties do not change under long-term exposure to various kinds of radiation. This property makes it can b e used as a good sealing material in the nuclear industry and aerospace devices.