Flexible graphite foil is made from exfoliated graphite flake and is produced through an extensive calendaring process to give a thin flexible graphite foil with no binder or resins.
Because of the excellent properties such as thermal stability, high and low temperature resistance, impermeability and corrosion resistance, etc. Flexible graphite foil is widely used in fields of industrial sealing, heating elements for high temperature applications and insulation/heat shields.
To meet some special applications and high-quality requirements, products with special properties are available, for example we have the width of 60″ (1.5m), low and even non-sulfur content or tensile strength of 70 bar (1015 psi) and above.
Graphite has several advantages over other materials. It is resistant to thermal shock. It is the only material in which mechanical properties increase with temperature. It has a low CTE for geometrical stability. It is easily machined. It does not melt but sublimes at very high temperature (3,400ºC), and finally, its density is lower (five times less than copper) which means lighter electrodes. Graphite removes material better than copper or copper-tungsten while wearing slower. The wear rate tends to diminish as the discharge increases, unlike copper, whose wear increases at higher currents. Therefore, graphite is suited for the machining of large electrodes since working with a high current intensity provides decreased roughing time.
Although graphite is prone to abnormal discharge, this can be eliminated through quality flushing, and lowering the intensity of discharge during negative polarity machining. However, as a result of this tradeoff, machining tungsten carbides is more difficult than with copper-tungsten electrodes. Also, since graphite is a ceramic, it is sensitive to mechanical shock, and consequently must be handled and machined with care. -Mersen