FEP vs. Unfilled PTFE
Both FEP and unfilled PTFE are thermoplastics. There are 28 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is FEP and the bottom bar is unfilled PTFE.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 0.43 | |
| 0.45 |
| Elongation at Break, % | 300 | |
| 300 |
| Flexural Modulus, GPa | 0.6 | |
| 0.4 |
| Flexural Strength, MPa | 24 | |
| 50 |
| Tensile Strength: Ultimate (UTS), MPa | 20 | |
| 25 |
Thermal Properties
| Glass Transition Temperature, °C | 60 | |
| -35 |
| Heat Deflection Temperature At 1.82 MPa (264 psi), °C | 50 | |
| 70 |
| Heat Deflection Temperature At 455 kPa (66 psi), °C | 70 | |
| 120 |
| Maximum Temperature: Autoignition, °C | 630 | |
| 630 |
| Maximum Temperature: Mechanical, °C | 200 | |
| 270 |
| Melting Onset (Solidus), °C | 260 | |
| 330 |
| Specific Heat Capacity, J/kg-K | 1170 | |
| 1050 |
| Thermal Conductivity, W/m-K | 0.22 | |
| 0.24 |
| Thermal Expansion, µm/m-K | 95 | |
| 120 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 2.0 | |
| 2.1 |
| Dielectric Strength (Breakdown Potential), kV/mm | 22 | |
| 14 |
| Electrical Dissipation At 1 MHz | 0.00065 | |
| 0.00017 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 16 | |
| 18 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.1 | |
| 2.2 |
| Limiting Oxygen Index (LOI), % | 80 | |
| 90 |
| Refractive Index | 1.4 | |
| 1.4 |
| Water Absorption After 24 Hours, % | 0.010 | |
| 0.0093 |
Common Calculations
| Stiffness to Weight: Axial, points | 0.11 | |
| 0.12 |
| Stiffness to Weight: Bending, points | 12 | |
| 12 |
| Strength to Weight: Axial, points | 2.6 | |
| 3.2 |
| Strength to Weight: Bending, points | 7.6 | |
| 8.7 |
| Thermal Diffusivity, mm2/s | 0.088 | |
| 0.11 |
| Thermal Shock Resistance, points | 35 | |
| 34 |