|Mazda CX-5 bumpers. Top: Front bumper, Bottom: Rear bumper. Click to enlarge.|
Mazda Motor Corporation has developed, jointly with Japan Polypropylene Corporation, resin material for vehicle parts that maintains the same rigidity as parts made with conventional materials while achieving significant weight reduction. Using this material, the parts manufactured are thinner than those using conventional resin, resulting in a significant reduction in the resin required to manufacture parts.
When the material is used for both front and rear bumpers, it contributes to weight reduction of approximately 20%. In the bumper production process, this reduced thickness allows for a shorter cooling period for molding, and by using computer-aided engineering (CAE) technology, the fluidity of the resin material has also been optimized.
As a result, bumper molding time, previously 60 seconds, has been halved to 30 seconds, leading to major reductions in the amount of energy consumed in the production process.
Mazda plans to adopt the lightest bumpers in the class (displacement between 1500 to 2000 cc) using this resin material in the all-new Mazda CX-5 SUV to go on sale this spring, as well as other upcoming new models.
Bumpers are positioned at the very front and rear end of a vehicle and their weight has a major impact on fuel economy and driving performance. On the other hand, bumpers are multi-functional, requiring both rigidity to absorb impact, and molding and painting properties suitable for excellent exterior design.
Mazda blended two components found in polypropylene and rubber, the constituents of resin, that have different properties, and succeeded in distributing them in a double-layer structure in line with the required function for the surface and the inside of the base bumper material. As a result of this achievement, the surface has excellent paint film adhesion and the inner section retains high rigidity and impact absorption, with reduced thickness.