FEP film and sheets

FEP is short for Fluoroethylenepropylene and is used to protect the sight or gauge glass from aggressive mediums.
Applying glass protection extends the life of the glass and reduces the need for glass changes.

The material is milky-white transparent, has good resistance to chemicals and high pH values. A sight or gauge glass wears out quickly when exposed to high pH values, for example at a pH of 12 and a temperature of 200°C, the glass wears out about 8 mm per month!

By default, mica is applied as a glass protection to extend the life / stand time of the sight or gauge glass. In some situations mica is affected by the medium, in which case the use of the thicker FEP (or Kel-F®/PFTE) is necessary.

The material properties of FEP and PFTE are very similar; FEP is less milky in color and more transparent than PFTE. Despite using the FEP or PFTE protection disc, with milky color, you can see well through the sight or gauge glass to monitor your process.

Technical information

Available in thicknesses from 0,01mm to 2,4mm, for glass protection, approximately 1.5 mm thickness is used as a standard.

  • Excellent thermal stability: Usable throughout a wide thermal range -200 to +200°C
  • Chemical Inertness: Resists almost all chemicals, such as strong acid, strong alkali, salt, and organic solvent.
  • Anti-stick property: The lowest surface energy of all Fluoropolymer films; displays excellent mould release and anti-stick properties.
  • Electrical reliability: High electrical insulation characterised by low-dialectic constant and dissipation factor and by high dialectic strength over a wide range of temperature and frequency.
  • Resistance to weathering: Inert to outdoor exposure; with unchanged mechanical and physical properties after 10 years.
  • Non-flammability: Will not burn in air or gas having an oxygen concentration of less than 95%.
  • High transparency: Transparent, with excellent transmission of ultraviolet rays and visible rays; lowest refractive index of all Fluoropolymer films; characterised by very low light reflection.

* PFTE = Kel-F