What is flexible graphite or Grafoil®?
Flexible graphite, or Grafoil® 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. The name Grafoil® is the original brand name of flexible graphite owned by GrafTech, a company founded in 1886. Grafoil® was first introduced by Union Carbide in the 1960’s.
Synonyms for flexible graphite: graphite foil, graphite sheet, graphite paper
Other brand names for flexible graphite: MinGraph®, Sigraflex®, Flexicarb®
Physical Properties of Grafoil®
Flexible graphite is 95% – 99% carbon. It inherits many characteristics from natural mineral graphite. Flexible graphite is considered a non-metallic material, but is thermally and electrically conductive like metal. Formed with the same elemental carbon as diamond, flexible graphite is the softest material with a score 1 (out of 10) on the Mohs hardness scale. Flexible graphite is inert to most chemicals, and resistant to heat up to several thousand degrees. All of these characteristics contribute to the mineral graphite atomic structure. The hexagonal bond in the structure 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. Flexible graphite is primarily made of compressed exfoliated mineral graphite.
Flexible Graphite Atomic Structure
Industrial Applications for Grafoil®
- 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 Management: 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.