Sealing solutions to meet the ever-changing demands of automotive applications

The automotive market relies heavily on effective sealing in critical locations. At Alfa Sealing, we believe that a thorough understanding of elastomer materials and behaviours is key to the development of optimum automotive seals.  That’s why we also specilise in the development of custom elastomer parts and products including gaskets and O-rings.

In automotive industry, there are lots of different seals are used, there is no standard sealing solution for this application, thus with a wealth of industry-specific knowledge behind us, our engineers are able to help you select the correct product, sizes and materials for your application.

Seals used in a passenger car

Air Conditioning

A car’s air conditioning system is complex, with a multitude of O-Ring’s running throughout the pressure lines to and from a belt-driven/electric compressor. Every connection point needs to be sealed in order to ensure optimum performance.

Requirements for sealing air conditioning systems

  • Operate under relatively high pressure
  • Fit into small installation spaces
  • Minimize wear to maximize seal life
  • Fulfills environmental legislation for zero leakage requirement

Sealing Solution

Custom-designed engineered molded components can incorporate multiple parts into a single product, allowing placement into the limited space available in air conditioning systems. Materials engineered to prevent stick-slip, extend seal and system life where air conditioning use is limited.


The battery provides the power to a number of critical systems in the car and without it, the vehicle is inoperable. Start-stop options as well as hybrid powertrains to minimize emissions, have challenging impacts on new battery technologies. Drivers expect to start their car whatever the weather, first time, every time. For that kind of operational dependability, reliable sealing and battery venting is needed.

Requirements for sealing batteries

  • Outstanding reliability
  • Extended seal life
  • Operation in temperature extremes


Probably the most safety critical of all automotive applications , it is vital that when needed the brakes will activate instantaneously.

Requirements for sealing brakes

  • Consistent quality over high volumes
  • Media resistant to brake fluids

Sealing Solution
The quality of braking components are ensured with materials specially compounded on mixing lines dedicated to brakes.

Drivetrain & Transmission

 The drivetrain and transmission of a vehicle adapts the output of an engine to the drive wheels. Engines operate at relatively high rotational speeds and the transmission reduces that speed to the slower wheel speed, increasing torque in the process.

Requirements for Sealing of Transmission :

  • Advanced rotary sealing solutions
  • Low friction to optimize the transmissions operation
  • Outstanding wear resistance to extend transmission life
  • Resistance to the lubricants within the transmission

Sealing Solution

Complex sealing configurations combine a number of advanced seals that seal in lubricants, prevent ingress of external media and provide maximum performance in rotary applications due to unrivaled low friction.


Electronic Control Unit (ECU)

Sophisticated electronics that control key functions of the car are housed in the metal/plastic box of an ECU. Often situated in the engine compartment or other areas subject to environmental conditions, good sealing is vital as failure is not an option.

Requirements for Sealing of ECUs

  • Effective sealing of casings to reliably exclude any media that may affect sensitive electronics
  • Materials must stand up to the harsh conditions of the engine including temperature extremes and salt spray from the road
  • Low media permeation (e.g. from transmission oil)

Fuel Systems

Running at extreme temperatures and high pressures, secure and reliable sealing is required throughout the fuelling system – in the fuel injectors, the common rail system, the fuel lines and fuel tank.

Requirements for sealing the fuel system

  • Operate in a wide temperature range,
  • Operate in a wide temperature range, very low to very high
  • High pressure performance

Optimized performance for efficient engine operation

Sealing Solution
A wide range of seals are available for the different sealing environments within the fuel system. They are composed of specialized materials that have been engineered to withstand gasoline, diesel and bio-fuels, as well as temperature and pressure extremes

Ride Control

The objective of ride control systems is to combine steering stability with good handling characteristics while maximizing passenger comfort. The ride control system incorporates the suspension system and shock absorbers.

Requirements for sealing ride control

  • Low friction avoiding stick-slip
  • Wear resistant
  • Chemical resistant

Safety Systems

Today’s cars include a wide range of safety solutions to protect drivers and passengers from various types of collisions. This includes airbags installed to surround the front and rear seats.

Requirements for sealing airbags

  • Absolute quality throughout production over very high volumes
  • Small seals with tiny flashfree holes

Thermal Management

Engines operate at high temperatures and to maximize life of certain engine components, the engine needs to be cooled using fluid that flows through the radiator.

Requirements for sealing engine cooling systems

  • Operate in combination with high rotational speeds and high pressure
  • Reliable low-friction sealing to reduce CO2 and save fuel
  • Withstand coolants and lubricants and operate in poor lubrication conditions

Automotive specific compounds

Main used materials

Compounds adpated to the automotive industry requirements are headed below. According to the application, we offer specific compounds such as:

  • ACM (polyacrylate): Used in the automotive area because of its good oil compatibility (motor oil, gearbox oil, ATF oil).

  • AEM ( acrylate – ethylene – methyl): Contrary to ACM, AEM does not resist to ATF oils and gearbox oils. However, it has a good compatibility with standard mineral oils and engine coolant. It also well resists to temperature from -40°C to +150°C.

  • NBR (Nitrile): NBRis the most used rubber in the automotive field because of its excellent oil resistance, low price and good mechanical properties. Its weaknesses (ozone resistance, low temperature resistance) can be improved using specific NBRs.

  • HNBR (Hydrogenated nitrile): HNBRis used in the automotive to replace NBR when this one reach its limits. Indeed, ozone resistance and low temperature resistance are improved. Moreover, it has a good biodiesel and LPG resistance.

  • FKM (Fluoro elastomer): FKMis the automotive base material for high temperatures (up to 250°C). It has a good Ozone/UV resistance. It has also a good compatibility with biodiesel, LPG, fuel and hydrocarbon. It is mainly used to make automotive oil seals. FKM has also very good resistance to fuel.

  • VMQ (Silicone) – Fluorosilicone (FMVQ): Siliconecan be used into automotive applications with low temperatures (-60°C). Silicone offers a weak resistance to oils and chemical products. Depending on the fluid used, Techné proposes FMVQ (fluorinated silicone) which offers a better resistance.

  • EPDM (Ethylene Propylene Diene Monomer): EPDMis mainly used for automotive applications with no contact with oils. It has an excellent Ozone/UV resistance as well as brake liquids with glycol.When it is vulcanised with peroxide, its temperature resistance can go up to 150°C.