Sealing materials

General ranges of application The areas of application of elastomer materials cover a wide range. The different elastomers may be characterized as follows:

NBR (Nitrile Butadiene Rubber): Good mechanical properties at operating temperatures of -30 °C to +100 °C. NBR is mainly used for mineral oil and grease seals.
FKM (Fluorine Rubber): Characterized by high flame retardance, low gas permeability, very good ozone, weathering and ageing resistance. The operating temperature range of fluorine rubber lies between -20 °C and +200 °C (up to +230 °C for short periods). FKM is also frequently used for mineral oil and grease seals operating at high temperatures.
EPDM (Ethylene Propylene Diene Rubber): EPDM exhibits good heat, ozone and ageing resistance. It also exhibits high elasticity, good low-temperature behaviour as well as good electrical insulation properties. The operating temperature range lies between -45 °C and +150 °C. EPDM is frequently used for brake fluid (based on glycol) and hot water seals.
HNBR (Hydrogenated Nitrile Butadiene Rubber): HNBR exhibits good mechanical properties. Operating temperatures range between -30 °C and +140 °C (up to +160 °C for short periods) in contact with mineral oils and grease.
Q (Silicones, HTV): Silicone rubbers are characterized by high thermal resistance, high flexibility at low temperatures, good dielectric properties, and above all, high resistance against oxygen and ozone. Depending on the design type, possible operating temperatures range from -60 °C to +200 °C (in some cases, also up to +230 °C for short periods). Special types may be deployed for operating temperatures down to -90 °C.
CR (Chloroprene Rubber): In general, chloroprene vulcanisates exhibit high resistance against ozone, weathering, chemicals and ageing. In addition, high flame retardance, good mechanical properties and high flexibility at low temperatures. Operating temperatures range between -40 °C and +100 °C (up to +120 °C for short periods). Besides other applications, CR materials are used to manufacture seals against coolants, outdoor seals and seals used in the adhesives industry.
ACM (Polyacrylate Rubber):Although ACM exhibits very good ozone, weathering and hot-air resistance, it possesses only medium strength, low elasticity and relatively poor low-temperature properties. Operating temperatures lie between -20 °C and +150 °C (up to +175 °C for short periods). Owing to their especially high resistance to high-additive lubricating oils (also containing sulphur) at high temperatures, ACM materials are mainly used in the automobile sector.
FFKM (Perfluor Rubber): Perfluor elastomers are characterized by a universal resistance against chemicals similar to that of PTFE as well as high thermal resistance. They exhibit very low swelling values in practically all media. Depending on the mixture composition, the operating temperature range lies between -25 °C and +240 °C. FFKMs mainly find application in the chemical and processing industry, and are used in all applications involving aggresive media and high temperatures.