Engine bay

Engine bay is the vehicle area where most of the noise and heat sources are concentrated. With innovative lightweight and multifunctional components, Autoneum helps automobile manufacturers to address new regulations for pass-by noise and CO2 emissions.

Autoneum offers the following products for application in the engine bay:

  • Engine and e-motor encapsulations

  • Frunks

  • Hoodliners
  • Outer dashes

  • Engine- and body-mounted absorbers

  • Engine top covers
  • Outer trunk floor insulators

Brochure engine bay (2 MB) | PDF
Hybrid-Acoustics PET


Textile-based and correspondingly lightweight underbody systems of Autoneum absorb noise and therefore simultaneously reduce the interior and exterior noise of cars. They also enhance the aerodynamics of a vehicle. This leads to lower fuel consumption and reduced vehicle emissions.

Autoneum offers among others the following products for underbody application:

  • Under floor and under engine shields

  • Under battery shields

  • Battery electromagnetic shields

  • Wheelhouse outer liners
  • Outer tunnel insulators

  • Outer floor insulators

  • Heatshields
  • Battery and spare wheel pans

Brochure underbody (2 MB) | PDF

Technologies for the engine bay

Hybrid-Acoustics PET
Sustainable noise protection in the engine bay

With Hybrid-Acoustics PET, Autoneum has adapted its textile interior technology Hybrid-Acoustics for use in the engine compartment. The patented innovation is based on a unique fiber material that acts as an insulator and absorber at the same time. Among others, Hybrid-Acoustics PET is used to encapsulate electric motors, thereby reducing noise directly at the source and particularly attenuating high-frequency sounds of the electric drive unit. This key technology accordingly ensures optimum noise protection in the passenger cabin and greater driving comfort.

At the same time, components made of Hybrid-Acoustics PET convince with their low weight. Compared to conventional insulators, they are up to 40 percent lighter and thereby contributing to a greater driving range. They are also flameproof and find application as powertrain-mounted insulators for combustion engines thanks to their temperature resistance of up to 180°C.

The parts, which consist to a large extent of recycled PET fibers, are produced waste-free and are completely recyclable – an outstanding life cycle assessment compared to equivalent components in the engine bay.

Key Technology for Engine Encapsulations

Innovative engine encapsulations enhance the efficiency and sustainability of vehicles: The heat storage in the engine bay achieved with the encapsulations reduces fuel consumption at the next cold start, which in turn leads to lower vehicle emissions.

Autoneum recognized the growing importance and far-reaching potential of the thermo-acoustic insulation of vehicles at an early stage and has developed an innovative material: Theta-FiberCell combines the benefits of the fiber absorber Theta-Fiber and foam absorber Theta-Cell. Theta-FiberCell, the key technology for engine encapsulations launched on the market in 2012 is based on Autoneum’s long-standing experience and takes into account customer-specific product requirements such as optimum noise protection and integrated thermal insulation. The high temperature stability entailed by this thermal insulation is also of major importance for vehicle manufacturers: Theta-FiberCell is barely flammable and can withstand temperatures of up to 200°C.

Theta-FiberCell also appeals due to its lightweight and displays high resistance towards engine vibrations. Theta-FiberCell can be used for engine encapsulations mounted onto the engine or vehicle.

As well as the acoustic absorption of interior (by up to four decibel) and exterior (by up to eight decibel) noise, the fiber-foam solution enables heat to be stored for long periods after the vehicle has been parked. After being switched off for 12 hours, the temperature of an engine with Theta-FiberCell encapsulation is six degrees higher than one without this special insulation.

This difference in temperature results in a higher engine oil temperature and less internal friction of the engine which in turn enhances the efficiency and sustainability of vehicles. Each six degrees increase in engine oil temperature reduces CO2 emissions by three grams per kilometer driven.

Multifunctional Non-Woven Technology

With Theta-Fiber, Autoneum offers a robust and multifunctional non-woven material for treatment in the engine bay. Up to 70 percent recycled fiber material is used for manufacturing components based on the semi-structural Theta-Fiber material technology.

Theta-Fiber stands out against conventional non-woven components above all thanks to its high temperature resistance: While traditional thermoplastic materials are able to withstand temperatures of up to 150°C, noise and thermal insulation parts based on Theta-Fiber can also be applied at temperatures of up to 200°C.

Compared to traditional heavy engine covers made of solid plastic, Theta-Fiber engine covers achieve weight savings of up to 60 percent, reduce the interior and exterior noise of vehicles and insulate heat generated by the engine.

Due to its high temperature stability, resistance to vibrations, lightweight, good acoustic properties and integrated thermal insulation, Theta-Fiber is a core element of Autoneum’s innovative engine encapsulations.