Materials
Fluoropolymers are a group of high performance plastics. They have almost universal chemical resistance and excellent heat resistance, low friction coefficient, high electric insulation and high service temperatures for continuous operation. Applications can be found in all processes, where stainless steel is not sufficiently corrosion resistant. Fluoropolymers are used in valves, pumps, pipes, heat exchangers and many other products. Operating limitations due to mechanical properties of fluoropolymers can be considerably extended by appropriate combinations with other materials (like steel, stainless steel, fiberglass, carbon fiber, peek,...) in composite components.
| property | standard | unit | PTFE | PFA | FEP | ETFE | PCTFE | PVDF | ECTFE |
|---|---|---|---|---|---|---|---|---|---|
| specific gravity | ISO 1183 | g/cm^3 | 2,14 - 2,19 | 2,12 - 2,17 | 2,12 - 2,17 | 1,71 - 1,78 | 2,10 - 2,16 | 1,75 - 1,78 | 1.67 - 1,70 |
| max. service temperature | °C | 260 | 260 | 205 | 180 | 180 | 170 | 180 | |
| flammability | not flammable | not flammable | not flammable | not flammable | not flammable | not flammable | not flammable | ||
| absorption of water (@23°C) | % | <0,05 | <0,05 | <0,05 | <0,05 | <0,05 | <0,05 | <0,05 | |
| melting point | ASTM 2116 | °C | 327 | 300 - 310 | 253 - 282 | 265 - 275 | 185 - 210 | 165 - 178 | 240 - 247 |
| coefficient of thermal expansion (lin.) | DIN 52612 | 10^-5/K | 10 - 16 | 10 - 16 | 10 - 14 | 8 - 12 | 4 - 8 | 4 - 18 | 4 - 8 |
| heat conductivity (@23°C) | W/K*m | 0.23 | 0.22 | 0.2 | 0.23 | 0.19 | 0.17 | 0.15 | |
| specific heat (@23°C) | kj/kg*K | 1.01 | 1.09 | 1.17 | 1.95 | 0.92 | 1.38 | ||
| oxygen index | ASTM 2863 | % | >95 | >95 | >95 | 30 | >95 | 43 | 60 |
| tensile strength (@23°C) | ISO 527 | N/mm^2 | 29 - 39 | 27 - 32 | 19 - 25 | 36 - 48 | 31 - 42 | 38 - 50 | 41 - 54 |
| tensile strength (@150°C) | N/mm^2 | 14 - 20 | 15 - 21 | 4 - 6 | 8 - 12 | 1 - 2 | 7,5 - 10,5 | 3,5 - 4,5 | |
| yield stress (@23°C) | ISO 527 | N/mm^2 | 10 | 14 | 12 | 24 | 40 | 46 | 34 |
| elongation at break (@23°C) | ISO 527 | % | 200 - 500 | 300 | 250 - 300 | 200 - 500 | 80 - 250 | 20 - 250 | 200 - 300 |
| modulus of elasticity (@23°C) | ISO 527 | N/mm2 | 400 - 800 | 650 | 350 - 700 | 500 - 1200 | 1000 - 1200 | 1200 - 1800 | 1200 - 1800 |
| limiting bending stress (@23°C) | ISO 178 | N/mm2 | 18 - 20 | 15 | 25 - 30 | 52 - 63 | 55 | 50 | |
| Shore hardness | DIN 53505 | 55 - 72 | 60 -65 | 55 - 60 | 63 - 75 | 70 - 90 | 73 - 85 | 70 - 80 | |
| permittivity at 100Hz | IEC 60250 | <2,1 | <2,1 | <2,1 | 2.6 | 2,3 - 2,8 | 2,3 - 2,6 | ||
| volume resistivity | IEC 60093 | Ohm*cm | >10^18 | >10^18 | >10^18 | >10^16 | >10^18 | >10^15 | >10^15 |
| surface resistivity | DIN 53482 | Ohm | >10^16 | >10^16 | >10^16 | >10^14 | >10^16 | >10^13 | >10^12 |
| dielectric strength | IEC 60243-2 | KV/mm | >40 | >50 | >50 | >40 | >40 | >40 | >40 |