A further development of the classic Polytetrafluoroethylene (PTFEGlossaryPTFEPolytetrafluoroethylene ), with additional modifier Perfluorpropylvinylether. Due to a five times lower molecular weight and a more homogeneous crystal structure, the single particles merge a nearly pore-free polymer structure. Compared to PTFEGlossaryPTFEPolytetrafluoroethylene , the tightness as well as the barrier effect at the same wall thickness are doubled. This is particularly advantageous at high working temperatures. PTFEGlossaryPTFEPolytetrafluoroethylene -TFM has a universal chemical resistance. Sticking of any contaminations is prevented by an extreme smooth surface. Special methods allow a simple and safe heat seal. This material is ideal for e. g. digestion vessels or gaskets.