Fluorinated Ethylene Propylene

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. Properties include

  • Excellent thermal stability. Retains its properties in temperatures from -200 to 200 Deg C.
  • Chemically inert to almost all chemicals and solvents.
  • Retains its properties even after prolonged exposures to harsh chemical environments.
  • Non-stick quality unsurpassed by any plastic.
  • High transparency with good transmittance of UV rays and visible rays up to 98%.
  • Long term weatherability. Excellent resistance to ozone, sunlight and weather.
  • Lowest refractive index of all plastics provides low light reflection. Refractive index of water. Virtually invisible in water.
  • Non toxic. FDA approved
  • Non porous.
  • Inert to body tissue.
  • Electrical reliability. A low dielectric constant and high dielectric strength.

Trade Names for FEP resins include DuPont Teflon™, Daikin Neoflon™, Dyneon Hostaflon™, NiFlon, Sinoflon.

Mechanical Properties
Tensile Strength, 23°C2100-3050
Elongation at break, 23°C240-300%
Flexural Strength, 23°CNo break at flexureD 790
Impact Strength, IzodNo break
Yield Strength At 23°C1740
Thermal Properties
Coefficient of Linear Expansion 20-100 °C12 x 10-5K-1D 696
Melting Point253-282°C
Thermal Conductivity1.45
Btu/hr-.ft-deg F
W/m/deg K
Service Temperature-250-200°C
Processing Temperature370-395°C
Electrical Properties
Dielectric Strength, short time, 2mmMV m-1
Surface Arc-Resistance>300
(does not track)
secD 495
Volume Resistivity, dry, @ 50% RH>1018ohm-cmD 257
Surface Resistivity, @ 100% RH1016Ohm/sqD 257
Dielectric Constant, 60 to 2 x 109 cps2.1εD150-81
Dielectric Strength13-100kV mm-1D149
Dissipation Factor @ 60 Hz – 1 MHz<0.0001D150-81
Other Properties
Refractive Index1.344nD 25D 542
Water Absorption<0.1%D570-81
Flame Rating+VE-0UL-94
Limiting Oxygen Index95% OxygenD 2863
Resistance to WeatheringExcellent
Specific Gravity2.1-2.3D792-66
Coefficient of friction0.27–0.67D 1894

Case Study

Elan Vital UK

Elan Vital UK were looking to develop an apparatus to analyse breath with the aim of early detection of health problems. This necessitated the patient blowing into...

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