According to a news release from Henkel, Volvo is adopting high performance, lightweight composite transverse leaf springs for more models following the company’s successful introduction several months ago on its premium crossover SUV, the XC90. Volvo is now also using the concept on its new S90 luxury sedan and V90 station wagon models.
Henkel says its Loctite MAX 2 flagship two-component polyurethane composite matrix resin system was critical to the development of the leaf spring, which was produced by Benteler-SGL using high-speed resin transfer molding (RTM). Henkel estimates that total volumes could reach close to 200,000 per year by the end of 2017.
“The composite leaf springs are another example of how a close cooperation between our partner Henkel and us in development of new processes and matrix resins — as well as adhesives and binders — can lead to the successful large-scale production of new composite concepts,” said Frank Fetscher, Business Development Manager at Benteler.
According to Henkel, the transverse leaf spring, when incorporated into the rear suspension, saves 9.9 lbs compared to steel coil springs normally used in cars. Volvo operates on the basis of what it calls the “Scalable Platform Architecture” (SPA) principle, which makes it possible for innovative concepts like the leaf spring that are successfully implemented on one vehicle to be easily adapted for use on other models.
Henkel says its experience and expertise in 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 mold and impregnate the fiber preform without disturbing its positioning. Its high cure rate — substantially faster than epoxy resins — further adds to the speed of production,” Henkel wrote.