What is oil resistance?
Oil resistance describes how well a material can withstand contact with oils or oil-containing media (mineral oils, greases, fuels). Oil resistance is crucial for components that are used in machines, vehicles or systems in which lubricants, hydraulic fluids or fuels are used.
Without suitable oil resistance, swelling, softening, cracking or premature failure of the material may occur due to reduced mechanical strength. Particularly in the area of the Elastomers oil resistance plays an important role, as this means that softeners can be washed out or replaced. At the same time, oils and fats themselves can have a softening effect and thus soften the material.
Typical oil-resistant material groups
The most important oil-resistant elastomers include
- Acrylonitrile butadiene rubber (NBR): widely used, good price-performance ratio, oil and fuel resistance at moderate temperatures
- Hydrogenated NBR (HNBR): extended temperature range, additionally improved ageing and ozone resistance
- Fluororubber (FKM): excellent resistance to oils, fuels and aggressive chemicals at high temperatures
- Chloroprene rubber (CR): medium oil resistance combined with good weather resistance
- Polyurethane elastomers (PU): high abrasion resistance and good oil resistance, especially under mechanical stress
Use of oil-resistant materials
Oil-resistant materials are used for Seals, Sealing lips, Valves, Vibration dampers, hoses, bearing bushes and Rubber-Metal Composite Parts used in automotive, mechanical engineering, hydraulic and conveyor technology. The choice depends on the type of medium (mineral oil, synthetic oil, fuel), temperature, pressure and mechanical load. At high temperatures or with aggressive additives, high-performance elastomers such as FKM or HNBR often indispensable.
The selection of a suitable material often requires a compromise between material costs, Temperature resistance, oil resistance and Resistance to ageing, as these properties partly influence each other.