The designation Teflon (FEP, fluoroethylene propylene) is a brand name of DuPont for polytetrafluoroethylene
(PTFE).DIN/VDE designation 6Y. It is the insulating material with the highest temperature range, which can be between -100°C and +200°C. The permittivity is 2.2. In addition, fluoroethylene propylene has very good properties in terms of resistance to UV light, oil and other liquids. Teflon is not halogen-free but non-flammable. The layability is rated as poor.