PTFE is available in virgin & filled compounds to improve the basic characteristics to match very diverse application & optimization for specific end uses.
Grades | Filler content by weight | Properties |
Virgin PTFE | ---- | Excellent chemical Resistance, outstanding electrical Properties & Excellent flexural properties. |
Glass filled PTFE | 15-25% | Higher compressive strength, Better wear resistance & Excellent chemical resistance. |
Carbon / Coke filled PTFE | 25-35% | Higher compressive strength, Better thermal conductivity & Better wear resistance. |
Graphite filled PTFE | 0.15 | Good chemical resistance, Higher compressive strength, Improve frictional properties. |
Bronze filled PTFE | 40-60% | Good thermal conductivity, Very low cold flow Higher compressive strength, Excellent wear resistance. |
Bronze plus Molybdenum Disulphide Filled PTFE | 55+5% | Improved frictional properties, Good thermal conductivity, Very low cold flow, Higher compressive strength & Excellent wear resistance. |
Caution:
The presence of filler generally causes following negative features in compounds
Reduction in tensile strength & break elongation
Reduction in volume & surface resistivity
Lower chemical resistance depending upon type of filler
Reduction in coefficient of linear thermal expansion
Difficulty in processing & fabrication