A highly polished metal surface is coated with a colloidal aqueous dispersion of P.T.F.E. it is force dried and sintered, until a continuous film is formed. These capacitors can withstand higher temperatures than polystyrene film but the material is expensive.
Range of values up to 0.05μf
Power factor 0.0002
Operating temperature up to 2500C
Applications: High temperature capacitor. Less costly.