Flexible graphite is a soft sheet form of compressed natural graphite made from exfoliated mineral flake(crystalline) graphite. Due to its flexible texture, it is referred to as flexible graphite to distinguish it from other forms of graphite materials: flake graphite, amorphous graphite, artificial graphite (hard graphite), graphite electrodes, graphite/carbon fiber, etc. Sometimes flexible graphite is also referred to by a manufacturer’s brand name like grafoil.
Natural mineral graphite is unique. It is a non-metallic mineral, but is thermally and electrically conductive like metal. It is formed with element carbon, the same as the hardest mineral – diamond, but graphite is the softest mineral. Natural mineral graphite is inert to most chemicals, resistant to heat up to several thousand degrees. All these characteristics contribute to the mineral graphite crystalline structure. In the structure, the hexagonal bond is strong, but the bond between layers is weak. By breaking the bond between layers, the mineral graphite can be exfoliated several hundred times bigger. By compressing the exfoliated graphite into sheet form, flexible graphite is made.
Flexible graphite inherits all the unique characteristics of mineral graphite and is being used in a wide range of industrial applications. It is an excellent sealing material and can be used for making chemical resistant and high-temperature resistant gaskets, seal parts, compression packing, etc. Flexible graphite is naturally a solid lubricant and can also be used in various metal fabrication processes or other mechanical processing works. Using its directional heat conductivity characteristics, flexible graphite can be used as liners in industrial furnaces, as well as in electronic devices to control and spread heat flow. Flexible graphite can also be used in many other applications including EMI (electromagnetic interference) shielding and gasketing, stress sensing, vibration damping, spark plasma sintering(SPS), and other thermal, electronic or electrochemical applications.