PTFE Products Properties
| Property | Units | Unfilled | 25%
w/w Glass |
15%
w/w Graphite |
25%
w/w Carbon |
55% w/w Bronze + 5% MoS2 |
|---|---|---|---|---|---|---|
| Relative Density | - | 2.17 | 2.25 | 2.2 | 2.1 | 3.7-3.9 |
| Maximum Tensile Strength | kg/cm2 | 105-300 | 125-200 | 140-210 | 120-155 | 105-140 |
| Elongation at Break | % | 200-400 | 200-300 | 200-300 | 100-150 | 90-130 |
| Hardness | Shore D | 50-55 | 55-70 | 55-65 | 60-65 | 66-70 |
| Volume Resistivity | ohm, cm | 1018 | 2 x 1015 | 106 | 104 | 107 |
| Surface Resistivity | ohm | 1017 | 1015 | 1014 | 107 | 109 |
| Permittivity at 23°C 105 -107 Hz dry | - | 2.02 -2.09 | 2.25-2.50 | Conducting Filler | Conducting Filler | Conducting Filler |
| Linear Thermal Expansion | ||||||
| -Parallel to direction of Moulding | % | 2.35 | 2.20 | 2.14 | 1.88 | 1.50 |
| -Perpendicular to direction of Moulding | % | 2.30 | 1.00 | 1.58 | 1.12 | 1.10 |
| Thermal Conductivity | 10-4 Cal/cms deg. C | 6 | 9 | 11 | 13 | 19 |
| Continuous Service Temperature | °C | -250 to + 260 | -250 to + 260 | -250 to +260 | -250 to +260 | -250 to +260 |
| °F | -420 to +500 | -420 to +500 | -420 to +500 | -420 to +500 | -420 to +500 | |
| Coefficient of Friction (Dynamic) | - | 0.06 | 0.12 | 0.07 | 0.13 | 0.13 |
| Flammability | Non Flammable | Non Flammable | Non Flammable | Non Flammable | Non Flammable | |
| Resistance to Weathering | - | Excellent | Excellent | Excellent | Excellent | Excellent |
| Chemical Resistance |
PTFE is chemically inert and unaffected by all know chemicals, except alkali metals, fluorine under certain condition and some fluorine compounds at elevated temperatures. Filled PTFE has inferior chemical resistance because of the presence of particular fillers, but superior mechanical and electrical properties, as compared to unfilled PTFE. |
|||||