Teflon® Coatings
Teflon® coatings were Invented at DuPont's Jackson Laboratory in 1938. Teflon® coatings are the original fluoropolymer coatings. The versatility of these coatings allow application onto a wide variety of substrates, part sizes and configurations.
Teflon® industrial coatings spray on like paint and bake to a tough, inert finish. By combining heat resistance with almost total chemical inertness, excellent dielectric stability and a low coefficient of friction, Teflon® industrial coatings offer a balance of properties.
DuPont Teflon® industrial coatings can be used on carbon steel, aluminum, stainless steel, steel alloys, brass and magnesium as well as non-metallics such as glass, glass and carbon fibre, some rubber and plastics. Optimum adhesion is usually obtained by roughening the surface before applying the coating.
The Impreglon Group is a licenced Teflon® applicator and is the first choice should such coatings be specified or required.
Thanks to a variety of coating types, the unique properties of DuPont Teflon® industrial coatings can become an integral surface component on any kind of part, from clutches that engage easier and valves that resist wear, to coil springs that become silent. With proper equipment, Teflon® industrial coatings can even be applied to specific areas of complex geometric parts, such as the internal threads of a nut.
Nonstick
Very few solid substances will permanently adhere to a Teflon® finish. Although tacky materials may show some adhesion, almost all substances release easily.
Low Coefficient of Friction
The CoF of Teflon® coatings is generally in the range of 0.05 to 0.20, depending on the load, sliding speed, and the particular Teflon® coating used.
Non-wetting
Since surfaces coated with Teflon® are both oleophobic and hydrophobic, they are not readily wetted. Cleanup is easier and more thorough and, in many cases, surfaces are self-cleaning.
Heat Resistance
Teflon® industrial coatings can operate continuously at temperatures up to 260°C.
Unique Electrical Properties
Over a wide range of frequencies, Teflon® coatings have high dielectric strength, low dissipation factor, and very high surface resistivity. By special techniques, it can even be made electroconductive enough to be used as an anti-static coating.
Cryogenic Stability
Many Teflon® industrial coatings withstand severe temperature extremes without loss of physical properties. Teflon® industrial coatings may used at temperatures as low as -270°C.
Chemical Resistance
Teflon® coatings are normally unaffected by chemical environments. The only chemicals known to affect all Teflon® industrial coatings are molten alkali metals and highly reactive fluorinating agents.
Advantages of Teflon® coating:
- Unaffected by almost all chemicals
- Continuous use at high temperatures
- Slippery non-stick surface
- Outstanding dielectric properties
- Improved resistance to cold flow or creep
- Reduction in wear and friction
- Improved dimensional stability
- Increased stiffness and surface hardness
Types of Teflon® coating.
1. Teflon® PTFE
PTFE (polytetrafluoroethylene) nonstick coatings are usually two-coat (primer/topcoat) systems. These products have the highest operating temperature of any fluoropolymer (260°C), an extremely low coefficient of friction, good abrasion resistance, and good chemical resistance. PTFE is available only in water-based liquid form.
2. Teflon® FEP
FEP (fluorinated ethylene propylene copolymer) nonstick coatings melt and flow during baking to provide nonporous films. These Teflon® coatings provide excellent chemical resistance. In addition to low friction, FEP coatings have excellent nonstick properties. Maximum use temperature is typically 200°C. FEP is available in water-based liquid and powder forms.
3. Teflon® PFA
Like FEP, PFA (perfluoroalkoxy) nonstick coatings melt and flow during baking to provide nonporous films. PFA offers the additional benefits of higher continuous use temperature (260°C), higher film thicknesses and greater toughness than PTFE or FEP. This combination of properties makes PFA an excellent choice for a wide variety of uses, especially those involving chemical resistance. PFA is available in both water-based liquid and powder forms.
4. Tefzel® ETFE
ETFE is a copolymer of ethylene and tetrafluoroethylene and is also sold under the Tefzel® trademark. Although not fully fluorinated, ETFE has excellent chemical resistance and can operate continuously at 150°C. This resin is the toughest of the fluoropolymers and can be applied at film builds up to 1000 microns to provide a highly durable finish. ETFE is available in powder form.
5. Teflon® One Coat
These solvent-based liquid coatings are formulated with special blends of fluoropolymers and other high-performance resins to improve toughness and abrasion resistance. Because the film components stratify during baking, most of the fluoropolymer properties (such as low friction and nonstick character) are retained. The resins provide adhesion and abrasion resistance. These products can sometimes be applied to smooth, clean metal. Bake requirements vary, depending on the specific coating.
6. Teflon® Dry Lubricant
Dry lubricant coatings are special versions of Teflon® technology designed to provide lubrication under high-pressure/velocity (PV) conditions. These products are solvent-based, one-coat systems.
