Tefzel® is a modified ETFE (ethylene-tetrafluoroethylene) fluoropolymer available as pellets or as powder for rotational molding. Tefzel® combines superior mechanical toughness with an outstanding chemical inertness that approaches that of Teflon® fluoropolymer resins. Tefzel® features easy processibility, a specific gravity of 1.7, and high-energy radiation resistance. Most grades are rated for continuous exposure at 150°C (302°F), based on the 20000-hour criterion.
Tefzel® ETFE fluoropolymer resins are processed by conventional melt-extrusion techniques and by injection, compression, transfer, rotational, and blow molding processes. The relatively high flow rate of these resins provides higher rates with less draw-down, as compared to those required for Teflon® FEP and PFA. Reciprocating screw injection molding machines are preferred. Long extruder barrels, relative to diameter, should be used to provide residence time for melting these high-temperature resins. What makes this material unique is the crosslinking process that it undergoes. The crosslinking process creates bonds between the ETFE polymers, making the material stronger and having a higher temperature rating. Crosslinked ETFE wires, such as the one described in MIL-W-22759/32, are lightweight and fluid, oil, and moisture resistant.
Applications
- Wires and cables insulation and cover
- Coating of flaps and pumps, production of lab utensils
- Components of electromechanisms, products shaping and extruded tubes
Advantages:
- Higher strength than normal ETFE
- Resistant to cold flow and abrasion
- More resistant to radiation effects
- (to 5 x 107RADS)
- Higher maximum temperature than normal ETFE
- Tin Coating = 150°C Max.
- Silver Coating = 200°C Max.
- Good outgassing characteristics
Disadvantages:
- Some ETFE insulations fail flammability in a 30% oxygen environment
- Less flexible than extruded ETFE
- More difficult to work with than PTFE Teflon
