HNBR has a good resistance to some refrigerants. The media resistance compares to that of NBR. It leads to considerable improvement in resistance to heat, ozone and ageing, and gives it very good mechanical properties, e.g. HNBR is obtained by fully or partially hydrogenating NBR. Hydrogenated acrylonitrile-butadiene rubber The temperature application range is from –55☌ to +175☌. The temperature range of applications is somewhat more restricted than that of silicone. In addition to the standard FKM materials, a number of special compounds with different compositions of polymer chains and varying fluoro contents (65% to 71%) are developed for special applications.įKM is generally not resistant to hot water, steam, polar solvents, glycolbased brake fluids and low-molecular organic acids.Īlthough fluorosilicone elastomers have the same mechanical properties as silicone, they are far more resistant to oils and fuels. The standard FKM material for O-rings has excellent resistance to mineral oils and greases, aliphatic, aromatic and chlorinated hydrocarbons, fuels, non-inflammable hydraulic pressure fluids HFD and many organic solvents and chemicals. Other key benefits are its excellent resistance to ageing and ozone, very low gas permeability (excellent for vacuum application) and the fact that it is self-extinguishing. Typical applications for perfluoro elastomers include the chemical, oil and semi conductor industries, high vacuum technology, and the aerospace industry.įKM materials are noted for their very high resistance to temperatures and chemicals. They combine the positive properties of PTFE with the elastic behaviour of FKM.īecause this material group is considerably more expensive, perfluoro elastomers are only used if other materials cannot meet the specifications and if safety requirements justify the higher expenditure. The chemical and heat resistance of perfluoro elastomers are similar to those of PTFE. 80☌ and 100☌ increases flexibility and supports the installation.ĭepending on the core material, the temperature application range is from –55☌ to +200☌. Warming the material in water or oil to between approx. The core material is chosen to suit the temperature range and medium.īecause of its limited flexibility, great care is required during installation. This results in a combination of very high chemical and thermal load bearing ability and the elastic properties of standard commercial elastomers. Another advantage of the cover is its very low coefficient of friction. The extremely high chemical resistance of the cover protects the elastic core material against the chosen medium.
They are used at very high thermal and chemical loads. Seamless FEP-encapsulated O-rings have an elastic core in FPM or VMQ. They can be used between –45☌ and +130☌ (peroxide-cured –50☌ to +150☌).įEP is a thermoplastic material with similar properties to PTFE. EPDM materials are totally unsuitable for use with all mineral oil products (lubricants, fuels). Special qualities are recommended for glycol-based brake fluids. Peroxide-cured compounds are suitable for higher temperature ranges and have a much lower compression set.ĮPDM has a good resistance to hot water and steam, detergents, caustic potash solutions, sodium hydroxide solutions, silicone oil and greases, many polar solvents, many diluted acids and chemicals. They are divided into sulphur- and peroxide-cured types. The temperature application range is from –40☌ to +100☌.ĮPDM materials generally have a high resistance to hot water, steam, ageing and chemicals, and are suitable for a wide range of temperature applications. They have average resistance to mineral oils, and are suitable for use with many refrigerants. The material is resistant to ageing and ozone, and can be used with mineral oils and greases, silicone oils and greases, non-inflammeble fluids HFA and HFB and water up to of 50☌, as well as pure aliphatic hydrocarbons.Ĭhloroprenes have excellent resistance to ozone, ageing and weathering and also good mechanical properties. Polyurethanes differ from classic elastomers in that they have much higher mechanical properties for example a high resistance to abrasion, wear and extrusion, a high tensile strength and tear resistance. The temperature application range is from –30☌ to +150☌ (for a short time +175☌). The material is resistant to weathering and ozone and can be used with enriched mineral oils, water and refrigerants.
AEM has a higher resistance to low and high temperature than ACM and based on its entire properties can be classified between ACM and FKM. The temperature application range is from –20☌ to +150☌.ĪEM is like ACM mainly used by the automotive industry. ACM is used mainly by the automotive industry as it is resistant to engine, transmission and ATF oils even at high temperatures.