Qualities

NBR - (acrylonite -butadiene rubber) Tradename f.ex. Perbunan® or Nitrile®

NBR is the most common standard material for O-rings because of its good mechanical properties and reistance to mineral oil-based lubricants and greases. These properties are usually determined by the content (ACN between 18% and 50%). A low ACN content ensures good flexibility at low temperatures, but offers limited resistance to oils and fuels; as the ACN content increases, the low temperature flexibility reduces and the resistance to oils and fuels improves.

Our standard NBR material for O-rings offers an average ACN content to suit a wide range of applications with balanced properties. It has good mechanical-technoligical values such as high abrasion resistance, as well as low gas permeability and good resistance to mineraloil-based lubricants and greases, hydraulic oils H, H-L, H-LP, non-inflammable pressure liquids HFA, HFB, HFC, aliphatic hydrocarbons, silicone oils and greases, and water to approx. 80°C.

NBR is generally not resistant to aromatic and chlorinated hydrocarbons, fuels with a high aromatic content, polar solvents, glycol-based brake fluids and non-inflammable hydraulic fluids HFD. It also has a low resistance to ozone, weathering and ageing, but in most applications this has no negative effect.

FPM/FKM -(Fluoro rubber) Tradename f.ex Viton®

FPM/FKM materials are noted for their very high resistance to temperatures 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.

The standard FPM/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.

FPM/FKM is generally not resistant to hot water, steam, polar solvents, glycolbased brake fluids and low-molecular organic acids.

EPDM - (ethylene propylene diene rubber)

EPDM materials generally have a high resistance to hot water, steam, ageing and chemicals, and are suitable for a wide range of temperature applications. They are divided into sulphur- and peroxide-cured types. Peroxide-cured compounds are suitable for higher temperature ranges and have a much lower compression set.

EPDM 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. Special qualities are recommanded for glycol-based brake fluids. EPDM materials are totally unsuitable for use with all mineral oil products (lubricants, fuels). They can be used between -45°C and +130°C (peroxide-cured -50°C to 150°C).

HNBR - (hydrogenated acrylonitrile-butadiene rubber) Tradename f.ex Therban®

HNBR is obtained by fully or partly hydrogenerating NBR. It leads to considerable improvement of the resistance to heat, ozone and ageing, and gives it very good mechanical properties. The media resistance compares to that of NBR.

VMQ- (silicone rubber)

Silicone rubbers are noted for its wide thermal range and excellent resistance to ozone, weathering and ageing. Compared with other elastomers, silicone's mechanical properties are on the low side. Generally, silicone materials are physiologically harmless; they are also used by the food and medical industries.

The standard silicone material can be applied at temperatures from -55°C to +200°C and is resistant to water(up to 100°C), alphatic engine and transmission oils, animal and plant oils and fats.

Silicone is generally not resistant to fuels, aromatic mineral oils, steam (short term up 120°C possible), silicone oils and greases, acids and alkalis.