The most common forms of Aflas® (100 or 150 series) are categorized within ASTM D 1418-01 as FEPM. These grades are alternating copolymers of tetrafluoroethylene and propylene, with a fluorine content of ~54.
Such chemical structures offer excellent heat resistance, exceptional chemical resistance (significantly to alkalis and amines), along with high electrical resistivity. Aflas® rubber compounds are resistant to a wide range of chemicals such as acids, alkalis and steam (up to +170°C), offering superior resistance to strong bases in comparison with FKM.
A common weakness of Aflas® compounds, however, is low temperature performance in aromatic oils and only limited resistance to mineral oils. Service temperatures are -5°C (25°F) to +200°C (+400°F).
The AFLAS® 200 Series is a terpolymer composed of tetrafluoroethylene, propylene and vinylidene fluoride. The AFLAS® 200 Series offers a good balance of chemical resistance and improved low-temperature performance and is categorized in ASTM D 1418-01 as class FKM, type four.