ROHACELL® composites for automotive design

The reduction of fossil energy use and harmful CO2 emissions is a social challenge. Evonik Industries offers a variety of products to meet these goals. The PMI-based structural foam ROHACELL® saves enormous quantities of weight in car bodies.

Apart from energy-conscious driving and power train improvements, weight reduction in vehicles is the preferred method for saving fuel and reducing CO2 output. While the weight-reduction potential of conventional metal structures is approximately 10%, sandwiched composite structures made of ROHACELL® and CFRP can save 50% and more of weight in the outer skin. This has been documented in studies involving a Golf V or the Lotus Exige. Based on the light-weight demo model of the Lotus Exige, engineers were able to prove that the use of cover layers of approx. 0.7 mm CFRP and 2 mm ROHACELL® 71 IG-F not only resulted in weight savings of 30% in the cladding, but also in a significant improvement of the inherent stiffness compared to a conventional CFRP structure.

This is of particular interest for future urban vehicles or electrical cars, in which reduced weight will significantly contribute to downsizing the power train and improving range. Super sports vehicles and Formula 1 cars already use Boliden sandwich structures with ROHACELL for further gains in acceleration and handling because of lower weight.

  • ROHACELL® can easily be shaped into 3D cores with thermoforming processes. Thanks to its high temperature resistance, the material allows for short cycle times over 100 °C with advanced resin and inline coatings.
  • ROHACELL® is free of FCKW, meets the heavy metal requirements of the End of Life Vehicles Directive 2000/53/EC and is listed in the IMDS.
  • Studies of KTH in Stockholm, Cranfield University, and Lotus Engineering have documented the positive crash properties of ROHACELL®. Simulation values for the crash behavior of ROHACELL® are available upon request.

ROHACELL® Triple F—a new structural foam for large-quantity series production

Sandwich cores for fiber-composite components are currently mainly designed in flat structures. As part of its LiteCon joint venture, Evonik is now producing ready-foamed, complex three-dimensional structural cores for CFRP sandwich components in industrial series production for volumes of up to 50,000 complex 3D sandwich components per annum. Thanks to its excellent mechanical properties, even at higher temperatures, ROHACELL® Triple F can be used in high-pressure RTM or wet-pressing processes for the quick and efficient production of sandwich components with light foam cores for the automotive industry, for example in car bodies, chassis and mounted parts.