The importance of elastomers in automotive industry if often underestimated. As a rule rubber is considered as auxiliary material only and cannot compete with metals and engineering plastics in terms of elastic module, and temperature-expansion coefficient. Nevertheless there are automotive functions which cannot be performed without rubber with account no to tires only. Elastomer know-hows offered by LANXESS qualified experts are highly competitive with the latest plastic developments
Sealing profiles The versatility of elastomer applications within automotive industry can be demonstrated by the example of sealers. Along with external impact protection sealing profiles allow to decrease friction and noise coefficients, adjust side windows height, avoid creak and vibration and often play an important role in the interior design. Electrically insulating rubber blends eliminate corrosion effect; the sealers made of such materials often house lighting systems and sensors. In order to protect sealers from UV radiation, oxygen and ozone they are usually made of rubbers based in EPDM, such as Buna EP material from LANXESS which has saturated backbone chain resistant to hazardous factors. Some EPDM-based rubbers do not contain carbon black and thus are available in any color
High quality under extreme conditions The most of other automotive rubber parts is not visible to drivers. For example even flat metal sealers are frequently coated with butadiene-nitrile rubber. The thin rubber film creates micro densifications between two metal parts. Under high loads with rubber is squeezed-through the trim effectively sealing narrow gaps even under 120-200 bars pressure from combustion products is created. The long-term application can be performed under up to 120°C but even under 300°C the sealants maintain their pressure resistance within 16 hours. EVM rubbers such as Levapren from LANXESS are likewise applied in sealants which are used in similarly aggressive environments. Levapren feature only insignificant swelling when contacting with oil. It is capable to withstand contact with coolant-cutting fluids and long-term thermal effect of up to 170°C temperature. Furthermore it can withstand short-term effect of up to 200°C temperature and keeps its elasticity even in freezing temperatures.
Tougher requirements for hoses Sealing technologies are also applied in fuel and hydraulic systems of a vehicle. The contact with brake fluids and oils always posed a problem with application of standard rubbers, such as crude one that is why it was decided to apply specialty elastomers such as butadiene-nitrile rubber. During the recent years more and more aggressive additives and polar fuel agents such as biodiesels and alcohols obtained from renewable sources toughen the requirements for high performance rubbers. So one of the problems which can be solved with modern elastomers is represented by air springs applied in automotive design. The material of choice for the task is usually chloroprene rubber such as Baypren from LANXESS. Along with excellent oil resistance as well as outstanding elasticity the important factor of part's long service life is its exceptional adhesion to polyamide fibers of cord fabric.
Engine bearers and transmission However high performance rubbers are also applied to perform other automotive functions. For example if hermetic encapsulation of fluid or gas is required, rubber membranes are used. The membranes coated with Perbunan material which are used in pressure regulators for high precision fuel injection in engine cylinder contribute to inhibition of vibrations. The rubber also prevents extension unwanted or hazardous from mounting bearers to other vehicular parts. Crude rubber which is used to produce fairly soft vulcanizates probably seems an ideal material for this application however under high-temperature conditions its service life is reduced greatly. One of the alternatives is represented with EPDM rubbers. Due to special molecular design new EPDM rubber grades can maintain product shape longer even when subjected to long-term loads.
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