17th March 2017, Paris
Henkel’s Loctite Max 2 two-component polyurethane composite matrix resin system has proved crucial in the development of the new leaf springs now being supplied to Volvo.
Speaking at this week’s JEC World in Paris, Frank Kerstan, Henkel’s global programme manager for automotive composites, explained that the leaf springs are being produced by Benteler-SGL via high-speed resin transfer moulding (RTM).
“Following their successful introduction several months ago on the premium crossover SUV, the XC90, Volvo is now also using the products on its new S90 luxury sedan and V90 station wagon models,” he said. “Total volumes could reach close to 200,000 per year by the end of 2017.”
In all three car models, the transverse leaf spring incorporated into the rear suspension saves a significant 4.5 kg compared to steel coil springs normally used in cars, leading to an important improvement in fuel efficiency and a reduction in carbon dioxide emissions. The leaf spring also helps provide a smoother ride and improved NVH (noise, vibration, harshness) behaviour.
Furthermore, by eliminating coil springs that would otherwise protrude into the trunk area, the transverse leaf spring leaves more space for luggage.
Volvo operates on the basis of what it calls the “Scalable Platform Architecture” (SPA) principle, which makes it possible for new concepts that are successfully implemented on one vehicle to be easily adapted for use on other models.
Henkel’s experience and process know-how in resin transfer moulding (RTM) was important in obtaining short cycle times necessary for high series production of the composite parts. The low viscosity of Loctite Max 2 enables it to rapidly fill the mould and impregnate the fibre preform without disturbing its positioning. Its high cure rate — substantially faster than epoxy resins — further adds to the speed of production.
“Together with Benteler SGL, Henkel is very proud of this composite innovation and the fact that we now have our lightweight technology implemented in three Volvo models,” said Kerstan.
This cooperation was further facilitated last year with the opening of Henkel’s Composite Lab state-of-the-art test facility in Heidelberg, Germany.
“Here, automotive customers can work with Henkel experts to develop and test composite parts, and also optimize production process conditions,” Kerstan added. “They can carry out trials on Henkel’s own HP-RTM equipment, which has resin injection units for polyurethanes and epoxies coupled to a 380-ton press.”