Fluorinated Ethylene Propylene
FEP stands for Fluorinated Ethylene Propylene, and it is a type of fluoropolymer that shares similarities with other fluoropolymers like PFA (Perfluoroalkoxy) and ETFE (Ethylene Tetrafluoroethylene). However, each material has distinct characteristics that set them apart from one another:
FEP (fluorinated ethylene propylene) is chemically a copolymer of hexafluoropropylene and tetrafluoroethylene. It was developed as a melt processable version of PTFE. As such, it inherits all the chemical resistance and non-stick properties of PTFE whilst offering the ability to be extruded and thermoformed.
Holscot manufacture a wide variety of products for a broad assortment of industries out of FEP, including Heat Shrink Sleeving for the Print, Paper, Lamination and similar industries. We are able to cover / coat in-line, lights / lamps, metal, glass and ceramic rods, or flexible elastomers e.g. Silicone, Viton cord etc. We regularly produce a variety of formed pieces for use in aero, space, chemical, medical, pharma and bio fields, and more recently begun supplying FEP for use in EV battery operated vehicles.
Properties of FEP (compared to PFA and ETFE) include:
- Chemical Structure: FEP, PFA, and ETFE are all fluoropolymers, meaning they are composed of carbon and fluorine atoms. However, they have different chemical structures:
– FEP is a copolymer of hexafluoropropylene (HFP) and tetrafluoroethylene (TFE).
– PFA is a copolymer of perfluoroalkoxy alkane (the perfluorinated version of polyethylene glycol) and TFE.
– ETFE is a copolymer of ethylene and tetrafluoroethylene.
- Melting Point: FEP typically has a lower melting point compared to PFA and ETFE. This lower melting point can be advantageous in certain processing techniques where lower temperatures are required.
- Temperature Range: ETFE usually has the broadest temperature operating range among the three. It can withstand temperatures from approximately -200°C to +150°C (-328°F to +302°F). PFA has a slightly lower temperature range, while FEP generally has the narrowest range, with a lower limit of around -200°C to +205°C (-328°F to +401°F).
- Mechanical Properties: ETFE is known for its exceptional mechanical strength and toughness. It is significantly stronger than both FEP and PFA, making it more resistant to physical stress and impact.
- Chemical Resistance: PFA typically offers the best overall chemical resistance among the three fluoropolymers. While FEP and ETFE also provide good chemical resistance, PFA is more resistant to a broader range of aggressive chemicals. A list of
- Transparency: FEP and ETFE are known for their excellent optical clarity and high transparency with good transmittance of UV rays and visible rays up to 98%, making them suitable for applications requiring good light transmission. PFA, on the other hand, is slightly less transparent. Also, FEP has the lowest refractive index of all Fluoropolymers provides low light reflection. Refractive index of water. Virtually invisible in water.
- Non toxic. FDA approved
- Electrical Properties: All three fluoropolymers—FEP, PFA, and ETFE—are excellent electrical insulators.
- Cost: In general, PFA is the most expensive among the three, while ETFE is usually more expensive than FEP but less expensive than PFA.
- Non-stick quality unsurpassed by any Fluoropolymer.
- No Degradation: FEP retains its properties even after prolonged exposures to harsh chemical environments. Able to withstand long periods in harsh weather without the material breaking down (e.g. becoming cloudy in colour or brittle). Excellent resistance to ozone, sunlight and weather.
- Non-porous.
- Inert to body tissue.
In summary, while FEP, PFA, and ETFE are all fluoropolymers with excellent properties, they differ in terms of chemical structure, temperature range, mechanical strength, chemical resistance, transparency, and cost.
Holscot’s Fluoropolymer experts can help you choose the most appropriate fluoropolymer for your specific application based on the required properties and performance characteristics.
Trade Names for FEP resins include DuPont Teflon™, Daikin Neoflon™, Dyneon Hostaflon™, NiFlon, Sinoflon.
Technical Data for FEP:
| Property | Value | Units | Method |
|---|---|---|---|
| Mechanical Properties | |||
| Tensile Strength, 23°C | 2100-3050 14.5-21 |
psi MPa |
|
| Elongation at break, 23°C | 240-300 | % | |
| Flexural Strength, 23°C | No break at flexure | D 790 | |
| Impact Strength, Izod | No break | ||
| Yield Strength At 23°C | 1740 12 |
psi MPa |
|
| Density | 2.12-2.17 | gm/cu.cm | |
| Thermal Properties | |||
| Coefficient of Linear Expansion 20-100 °C | 12 x 10-5 | K-1 | D 696 |
| Melting Point | 253-282 | °C | |
| Thermal Conductivity | 1.45 0.209 |
Btu/hr-.ft-deg F W/m/deg K |
|
| Service Temperature | -250-200 | °C | |
| Processing Temperature | 370-395 | °C | |
| Electrical Properties | |||
| Dielectric Strength, short time, 2mm | MV m-1 | ||
| Surface Arc-Resistance | >300 (does not track) |
sec | D 495 |
| Volume Resistivity, dry, @ 50% RH | >1018 | ohm-cm | D 257 |
| Surface Resistivity, @ 100% RH | 1016 | Ohm/sq | D 257 |
| Dielectric Constant, 60 to 2 x 109 cps | 2.1 | ε | D150-81 |
| Dielectric Strength | 13-100 | kV mm-1 | D149 |
| Dissipation Factor @ 60 Hz – 1 MHz | <0.0001 | D150-81 | |
| Other Properties | |||
| Refractive Index | 1.344 | nD 25 | D 542 |
| Water Absorption | <0.1 | % | D570-81 |
| Flame Rating+ | VE-0 | UL-94 | |
| Limiting Oxygen Index | 95 | % Oxygen | D 2863 |
| Resistance to Weathering | Excellent | ||
| Specific Gravity | 2.1-2.3 | D792-66 (1979) |
|
| Coefficient of friction | 0.27–0.67 | D 1894 | |
Why Holscot?
- Proven manufacture, knowledgeable project management experience and excellent customer service all come as part of the package when working with Holscot.
- If you buy from Holscot, you will be buying directly from the manufacturer, based in the UK, not an agent or intermediary.
- Access to Holscot proprietary in-house manufacturing techniques and expert engineers.
- Holscot is a world leader in providing Fluoropolymer solutions, with more than 50 years experience supplying customers worldwide
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