Aesthetics contribute significantly to the customer’s buying decision of an automobile. This is traditionally achieved through painting. Sustainability and cost challenges have led automakers to look at substituting painting through molded-in color polymers in decorative bezels like pillar appliques. These appliques and bezels have a unique mix of material requirements that include color tone, gloss, stiffness, scratch resistance and weathering. Polycarbonates are an interesting class of polymers that has the potential to meet these challenging requirements. This paper reports the work done in evaluating a polycarbonate compound in piano black shade to meet the functional and aesthetic requirements. The results prove that the material can substitute painting thereby resulting in significant cost savings. This is a ready to mold material used in injection molding process.
This modified polycarbonate material has been explored for thin wall appliques and bezels with thickness of 2.7 mm. These trims have critical functional requirements such as newness retention, load versus deflection criteria, gap and flush aspects under sun load. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis. Complete product performance was validated for predefined key test metrics such as structural durability, thermal aging, cold impact, scratch resistance and weathering criteria. This part met required specifications. The combination of material, optimized part and tool design led to weight savings, good surface quality, dimensional stability under sun load, grill integration and considerable cost reduction.