Teflon
Teflon
■ Teflon
The scientific name of Teflon is polytetrafluoroethylene or PTFE for short, which is the most frequently used common material when compared to fluoride polymers. Among of all thermoplastic resins, PTFE has the best resistance to heat and chemical reagents and high frequency, armed with unique low friction and low viscosity.
Teflon is the none-melt-processible fluoride polymer, accounting for more than 60% of all fluoride polymers; other melt-processible fluoride polymers include PVDF, FEP, E-CTFE, PVF, E-TFE, PFA, CTFE-VDF, etc. PTFE is the first discovered fluoride polymer, with overall properties better than others.
■ PTFE has three different appearances:
1. Resin particles: used in casting parts, sheets, extruded pipes and bars, etc.
2. Power: used in compressed sheets.
3. Aqueous dispersion: used in the manufacture equipment of coating and fibre.
There is also filled–grade FTPE, which is mixed by resin particles and other bulking agent. The bulking agent can reinforce its mechanical properties without affecting its original resin properties. We can know PTFE properties and its status among fluoride polymers from following table.
■ Comparison table of properties of various fluoride polymers:
For more information, please slide to the right.
| PTFE | FEP | PFA | E-TFE | E-CTFE | CTFE | PVDF | |
|---|---|---|---|---|---|---|---|
| Specific gravity | 2.13~2.20 | 2.14~2.17 | 2.12~2.17 | 1.70 | 1.68~1.69 | 2.1~2.2 | 1.75~1.78 |
| Tensile strength (Mpa) | 13.7~34.3 | 18.6~19.6 | 29.4 | 45.1 | 48 | 31.4~41.2 | 38.2~51.0 |
| Elongation (%) | 200~400 | 250~330 | 300 | 100~400 | 200 | 80~250 | 100~300 |
| Modulus of bending elasticity (Mpa) | 0.34~0.62 | 0.66 | 0.66 | 1.37 | 1.65 | 1.74 | 1.37 |
| Continuous Operating Temperature (max,℃) | 260 | 200 | 260 | 150~180 | 160~180 | 180~200 | 150 |
| Loading deformation temperature (℃,451kPa) | 121 | 70 | 73 | 104 | 116 | 126 | 149 |
| Volume resistivity(Ω-cm) | >1018 | >1018 | >1018 | >1080 | 1015 | 1.2*1018 | 2.0*1014 |
| Dielectric constant(1kHz) | <2.1 | 2.1 | <2.1 | 2.6 | 2.3 | 2.3~2.7 | 7.72 |
| Dielectric tangent(1kHz) | <0.0002 | 0.0002 | <0.0002 | 0.0008 | 0.0015 | 0.023~0.027 | 0.018 |
