Fluorinated ethylene propylene
Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the polytetrafluoroethylene (PTFE) resins in that it is melt-processable using conventional injection molding and screw extrusion techniques. Fluorinated ethylene propylene was invented by DuPont and is sold under the brandname Teflon FEP. Other brandnames are Neoflon FEP from Daikin or Dyneon FEP from Dyneon/3M.
| FEP | |
|---|---|
| CAS Registry Number | 25067-11-2 |
| Density | 2150 kg/m3 |
| Flexural modulus(E) | 586 MPa |
| Tensile strength(t) | 23 MPa |
| Elongation @ break | 325% |
| Folding endurance | Varies |
| Notch test | |
| Melting point | 260 °C |
| Maximum operating | |
| temperature | 204 °C |
| Water absorption (ASTM) | <0.01 % after 24 hours |
| Dielectric constant (Dk) | |
| at 1MHz | 2.1 |
| Dissipation factor | |
| at 1MHz | 0.0007 |
| Arc resistance | < 300 seconds |
| Resistivity at 50% R.H. | > 1016 Ω m |
FEP is very similar in composition to the fluoropolymers PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxy polymer resin). FEP and PFA both share PTFE's useful properties of low friction and non-reactivity, but are more easily formable. FEP is softer than PTFE and melts at 260 °C; it is highly transparent and resistant to sunlight.