Amorphous carbon is one of the most inert fillers, except in oxidizing environments where glass performs better. Carbon adds to the creep resistance, increases the hardness and raises the thermal conductivity of PTFE. Carbon-filled compounds have excellent wear properties, in particular when combined with graphite. The combination of the above properties makes carbon/graphite compounds the preferred material for non-lubricated piston rings. The use of a softer carbon has the additional advantage that it lowers tool wear during machining, thus allowing machining to very close tolerances. Carbon-containing compounds have some electrical conductivity and are therefore antistatic.

Material Properties

Carbon filled PFTE has excellent mechanical and wear properties. It was developed to provide a PTFE based material with improved mechanical strength. PTFE on its own has excellent frictional properties, elasticity and wear resistance but relatively poor mechanical strength and tends to fail in high PV applications.

Carbon in itself is a brittle material with poor wear properties and mechanical strength. However with the two combined in Carbon Filled PTFE formulations, the resultant material has excellent mechanical and wear properties, retains the excellent frictional properties and is an excellent choice for seals and rings in dynamic and high pressure applications. Carbon filled PTFE also provides good thermal conductivity, low permeability and is also electrically conductive making it a good choice for anti-static applications.

Applications

Carbon fillers allow for machining to close tolerances as tool wear is lower during the machining. The product has a deep black appearance and gives smooth machined surfaces and will not scuff mating parts such as polished balls (ball valves).