Characteristic:

This type of graphite is made of flake graphite. The manufacturing process consist in direct action of strong oxidizer on graphite crystals under high pressures and temperatures conditions. During this process proceed crystals exfoliation, therefore graphite after reheating posses the expansion possibility (multiple volume increase). That's why it becomes soft and flexible. The expansion process starts in temperature above 100^oC but for complete expanding the necessary temp. is 950^oC - in longer time.

Prameters:

The most important parameters of expandable graphite is purity and potential expansion which is defined by solid volume attained after complete expanding of 1 gram of material. The significant are also: pH reaction and humidity (below 1%). For the best type of graphite (with big flakes and high purity) the expansion is of the order of 400 ml/g. All types of graphite are packing in sacks of 25 kg and big bags- 1000 kg..

Main application:

Sealing materials. The basic application of expandable graphite is production of flexible graphite. It is use as a sealing material mainly. For this manufacture is used the best type of graphite (with high purity). Directly for packing production is used the flexible graphite in film and yarn form. This material has to include limited amount of elements which have an harmful influence of machine parts and corrosion inhibitor additive.

Metallurgy and foundry.

Graphite, thanks to perfect thermal-insulating ability, high temperature resistance and chemical stability expandable, is used as a stabilizing coat and risers exothermic casting powder. Better for this application are more economical types of graphite. They are in pure form or in composite with another filling material. The powder of hot riser heads or hot-rolled sections result in: the solidification and metal self-cooling delay; insulation of atmospheric gas effect; surface improvement (to some degree) because of direct graphite action.

Other application.

Bacause of precious expandable graphite properties it is used also as: a component of incombustible, refractory plastics, heat-resisting shields or antifire coats. Graphite, after expanding, is perfect insulating material, radiation and temperatures (to 2500^oC) resistant.