Ethylene Tetrafluoroethylene / Perfluoroalkoxy
| Symbol: | ETFE or PFA |
| Crystallinity: | Crystalline* |
| Trade Names: | Tefzel, Teflon |
Description:
ETFE is a fluorocarbon copolymer marketed in the U.S. by DuPont under the name TEFZEL. It is tough with high impact strength and good mechanical properties to 302°F. Its other properties approach those of Teflon. Like FEP and PFA, Tefzel is very corrosive and quite viscous. All fluoropolymers are essentially flame retardant.
Processing Considerations:
- Residence Time: Residence time is typically 2 to 4 minutes.
- Back Pressure: Back pressure runs 150 PSI (1500 plastic pressure) or less.
- Drying: ETFE or PFA may need to be dried. If required, dry at 250°F for 2 hours.
- RPM: RPM runs between 30 – 100.
Screw Design Based on:
- Medium Compression Ratio
- Medium Transition Length
- Medium Meter Channel Depth
Other Information:
- Mixer: When required, the mixer must be a low shear mixer like Reiloy Westland Corporation’s Eagle.
- Barrier: Barrier screws are not recommended for processing ETFE or PFA.
- Custom Design: A screw specifically designed for ETFE is recommended for optimum processing results.
- Recommended Valve: A smear tip or 3 piece free flow depending upon the viscosity of the resin.
- Screw & Barrel Material Recommendation: Highly corrosive requiring only special alloys for manufacturing of screws and barrels. If corroding, dark color or black specks occur.
*Material is very viscous and requires slow injection to avoid melt fracture (cloudy or frosty).
Various additives and/or fillers can have an effect on a resin’s process behavior. For more detailed information, please contact Reiloy Westland Corporation.