Relating to carbon and graphite material there are many commercial and academic terms being used: carbon, graphite, graphene, mineral graphite, flake graphite, amorphous graphite, natural graphite, artificial graphite, etc. Here we want to focus on flexible graphite 101: what is flexible graphite?
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 commonly called flexible graphite. Flexible graphite is a generic commercial term. People may also call it by a manufacturer’s brand name such as grafoil.
Flexible graphite inherits many characteristics of natural mineral graphite. It is considered as a non-metallic material, but thermally and electrically conductive like metal. Formed with the same element carbon as diamond, but flexible graphite is the softest material with a score 1 of 10 on Mohs hardness scale. Flexible graphite is inert to most chemicals, resistant to heat up to several thousand degrees. All these characteristics contribute to the mineral graphite atomic 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. Essentially flexible graphite is made of compressed exfoliated mineral graphite.
Flexible graphite is being used in a wide range of industrial applications:
- Gasket and Seal Flexible graphite is an excellent sealing and gasket material and can be used for making chemical resistant and high-temperature resistant gaskets, seal parts, compression packing, etc.
- Lubrication Flexible graphite is a solid lubricant and can also be used in various metal fabrication processes or other mechanical process.
- Heat Managerment 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. Flexible graphite is also being used in the newest development of graphene manufacturing.