Flexible graphite is produced worldwide by companies specialized in fine-grain graphites and carbons. The main uses of this material are in sealing applications. With its remarkable properties, flexible graphite, which is harmless to the environment, is one of the best replacements for asbestos-based materials.
ELEVEN REASONS TO USE FLEXIBLE GRAPHITE
The original structure of flexible graphite gives it remarkable properties :
Compressibility : Flexible graphite is compressible up to a maximum density of 2.25. The choice of initial density is a big factor in optimizing the characteristics of the finished product.
Elastic recovery : Flexible graphite has a capacity for elastic recovery of about 10% in volume, making it possible to maintain compressibility and tightness over a broad temperature range.
Creep/relaxation : Flexible graphite has a very low creep rate in its service temperature range and holds up to high seating pressures.
Lubrication : Flexible graphite is self-lubricating and has a low coefficient of friction (less than 0.10 with steel).
Processing : Flexible graphite is easy to cut using conventional manufacturing equipment.
Ageing : Flexible graphite is one of the non-metallic materials least affected by ageing. This property is not influenced by temperature.
Chemical inertness : Flexible graphite, which contains no binders, withstands most chemicals : mineral acids and solvents (see documentation and corrosion table of carbons and graphites).
Temperature resistance : In a reducing or inert atmosphere, flexible graphite retains its characteristics over a broad range of temperatures, from – 196° C to + 2500° C (sublimation temperature 3500° C). In the presence of oxygen, graphite forms CO or CO2 from 450°C (550°C for the grade with passive inhibitor). The rate of oxidation depends on the area in contact with the oxidizing medium.
Anisotropy : Flexible graphite is anisotropic. Its mechanical properties and conductivity are very different between the directions parallel and perpendicular to the flakes.
Radiation performance : Flexible graphite resists ageing from high levels of radiation : no visible effect at 1022 neutron/cm2.
Removability : Flexible graphite adheres very little to the surfaces in contact with it.