Fluorinated Ethylene Propylene (FEP)
FEP is a chemical copolymer of hexafluoropropylene and tetrafluoroethylene. FEP possesses a combination of mechanical, chemical, electrical, temperature and friction-resisting properties. Invented by DuPont, common FEP brand names include DuPont Teflon® FEP, Neoflon® from Daikin and Dyneon® FEP from Dyneon/3M. FEP is very similar in composition to the fluoropolymers PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxy polymer resin).
Benefits of Fluorinated Ethylene Propylene
- Chemical resistance
- Good dielectric properties
- Melt processable
- High surface lubricity
- Highly resistant to extreme temperatures
- Excellent corrosion resistance
- Exceptional optical clarity
- Greater flexibility than PTFE coatings
- Available in a wide range of thicknesses for electrical, chemical and release applications
FEP Properties versus PTFE Coating Properties
Between PTFE and FEP, the mechanical, thermal, chemical, electrical and vapor properties of each are very different. FEP is slightly more flexible than a PTFE coating, adding on to its multipurpose uses. However, PTFE withstands repetitive folding, whereas FEP does not due its soft texture.
FEP share PTFE's useful properties of low friction and non-reactivity because it is easily formable. FEP coatings are softer than PTFE coatings, melting at 500 °F and it is also highly transparent and resistant to sunlight. Although FEP is highly transparent it remains the same color throughout the time it is being used.
FEP has a poorer co-efficient of dynamic friction, so FEP coatings are preferred over PTFE coating services for valve and pump linings, pipe liners and release applications.