Advancements in thermoset composites for automotive lighting applications

Thermoset composites are in continuous improvement for use in automotive lighting. The focus is on bulk molding compounds (BMC) from LYB, which offer processability to mold complex designs while providing superior dimensional and thermal stability than other materials used in the same applications. Each application requires specific properties for best performance and this paper will describe the kinds of materials developed to meet the future demanding needs of this market. Typically, molded BMC surfaces are nonuniform, resulting in defects that can negatively affect optics if directly metallized. BMC reflectors are then typically coated with a base coating of acrylic for a defect-free surface enabling metallization. This paper will report the development of a BMC that achieves an as-molded, defect-free, and smooth surface for direct metallization without a layer of base coat required. One benefit is the elimination of a secondary process of applying the base coat prior to the metallization process. The base coating process tends to soften the precise design features of headlamp reflectors. As the industry continues toward LEDs, these reflectors are becoming smaller and more intricate which can become distorted by a base layer coating and can negatively affect the key performance of the metallized part.