FKM Rubber Material O-Ring Seals
FKM is a copolymer made of highly fluorinated hydrocarbons and was developed in the 1950s. FKM seals have excellent resistance to media, ozone and aging. The material is also very stable in fuels, petroleum-based oils and greases as well as aliphatic and aromatic hydrocarbons.
It is unstable to polar solvents (e.g. acetone, MEK and ethyl acetate), low molecular weight organic acids (formic and acetic acid), glycol-based brake fluids, ammonia, amines, bases and superheated steam. There are copolymers, terpolymers and tetrapolymers with fluorine contents between 65% and 71%. In this way, FKM can be designed precisely to the specific requirements in terms of media resistance and cold flexibility. This is an advantage, in particular for the reliable protection of applications in the chemical and pharmaceutical industries with aggressive media and process temperatures of over 140°C, which materials such as EPDM or HNBR cannot handle.
As a peroxide-crosslinked material, Freudenberg Sealing Technologies' newly developed 75 FKM 239961 meets the latest regulatory requirements for materials in direct product contact in the food, beverage and pharmaceutical industries. Its extreme purity, media resistance and temperature resistance also make it suitable for use as static or dynamic seals in a wide range of applications. O-rings and diaphragms can now be manufactured from this material. In fact, customer-specific molded parts will also be produced in the future.
Material properties of FKM in technical applications
Fluoroelastomers can be used at temperatures from -25 °C to 200 °C and are mainly used for seals in the automotive and commercial vehicle industry, in oil production, as well as in the chemical and aerospace sectors. Special types of FKM are even flexible at -40 °C. In general industry, FKM is suitable for high speeds and temperatures, such as radial shaft sealing rings in pumps and gearboxes.
