The Mobility Alliance, a strategic alliance between Henkel and RLE International designed to drive automotive innovation, has examined and validated the potential of high-performance structural foam for lightweighting in automotive body and closure parts.  The study revealed that fiber-reinforced polymer components with structural foam ribbing and reinforcements could save more than 40 kg of weight per car versus conventional all-metal designs.

As the automotive industry continues to focus on lightweighting, the reengineering of body components becomes more important as they are some of the largest parts of vehicles.  Lightweighting betters fuel consumption and decreases carbon emissions, but the engineering limit on thickness and steel grades are a challenge as thickness reductions can create problems in meeting the required mechanical strength and crash protection.  The Mobility Alliance is addressing this challenge with a new perspective and new processes.

David Caro, Head of Global Engineering, OEM Design, Automotive & Transportation at Henkel, explained The Mobility Alliance’s process by saying, “In a radical new approach, we investigated the possibilities of overcoming these constraints by replacing traditional all-metal designs with hybrid fiber and structural foam reinforced polymer solutions.  The results of our study have confirmed that we can achieve significant further weight reductions without compromising the safety in typical crash scenarios by optimizing the stiffness of fiber reinforced plastic frames or carriers with selective foam ribbing and reinforcements, with competitive costs.”

The project included all major body and closure parts of a sport utility vehicle, including bumpers, fenders, pillars, doors, side panels, and tailgate.  The hybrid parts feature a solid frame or carrier molded in higher percent fiber-reinforced polymers and selective reinforcements using Henkel’s epoxy-based Teroson EP structural foam.  The foam is injected into the carrier at predefined sections, expands in the e-coat oven and creates a stiff connection between the hybrid component and adjacent parts in the body-in-white.

The crash simulations performed in the study strictly adhered to demanding international automotive standards, and the hybrid designs with Henkel’s Teroson EP structural foam were found to pass all these tests well within the limits of deformation and intrusion while offering substantial weight savings versus conventional all-metal components.  In some cases, including the side doors, the hybrid structural plastic and foam solution exceeded the expected performance when compared with the all-aluminum design.