Arc-resistant properties of PTFE composites

PTFE (polytetrafluoroethylene) has been used as material for breaker nozzle that has very high light reflectance, thermal and chemical stability, good electrical resistance and low loss factor. Though PTFE is better than any other polymer, it cannot be used for a long time in the high temperature arc environment. So, inorganic materials are used as filler in PTFE to improve the endurance in such environments of high voltage and current. It is necessary to compound PTFE with inorganic fillers because the pure PTFE used for high voltage and current breaker nozzle suffers inner explosion as well as surface degradation. The arc resistance of PTFE composites was increased with increasing filler content. But those values were different for different kinds of fillers and their content. The arc resistance of BN filled PTFE composites was better than that of Al/sub 2/O/sub 3/ or TiO/sub 2/ filled PTFE composites. The most important factor of fillers seems to be the light reflectance of the ultraviolet light.