Both FEP and PTFE are fluoropolymer materials with similar properties, but they do have some differences.
FEP stands for fluorinated ethylene propylene and is a copolymer of hexafluoropropylene and tetrafluoroethylene. It has a lower melting point (about 260°C) than PTFE, and is also more transparent and flexible. FEP is often used as a non-stick coating for cookware and bakeware, as well as in electrical applications, due to its excellent insulation properties.
On the other hand, PTFE stands for polytetrafluoroethylene and is made up of only tetrafluoroethylene monomers. It is known for its exceptional chemical resistance, low coefficient of friction, and high temperature resistance (up to 327°C). PTFE is commonly used in non-stick coatings for cookware, as well as in manufacturing of seals, gaskets, and bearings.
In summary, while both FEP and PTFE are fluoropolymers and share some similarities, their different melting points, transparency, and properties make them more suitable for specific applications.