A vehicle’s front combination light usually comprises dozens of components, clips, and screws. Covestro have a new, different idea: a headlamp module concept composed of a reflector/housing, collimator lens, bezel, and outer lens cover that results in significantly fewer parts. Multi-shot molding of their Makrolon® TC8030 thermally-conductive and DS801 dimensionally-stable polycarbonates, and a moulded-in-place design strategy, allow the low/high beam LED modules and their corresponding reflectors to be produced less expensively through elimination of added heat sinks, attachments, and other components. The polycarbonate bezel uses multi-shot molding to consolidate the turn signal and DRL while hiding sensors behind a lidar-transparent mask. Beyond reducing system complexity and costs, simplifying assembly and saving valuable space, this novel approach also reduces weight.
Future headlamps will integrate electronics such as lidar, radar, and cameras along with the light sources. This will require use of thermally-conductive materials to dissipate the heat generated by the electronics and light sources. Covestro say their headlamp demonstrator is the first of its kind to do so. The low/high beam reflectors are made of Makrolon DS801 for high reflectivity of visible light. The reflectors can be molded directly into the housing made of TC8030 with multi-shot moulding and vario-thermal mold control techniques. This eliminates the need to attach the reflector with brackets and fasteners, which saves weight.
The DS801 material provides a metallisable, smooth surface finish similar to unfilled polycarbonate, and can enable greater lumen output compared to other systems. The single, metallisable component yields beam performance that remains stable regardless of the operating temperature of the LED lamp system due to its low, isotropic thermal expansion.
The demonstrator uses only a few different materials: polycarbonate, ABS, a scratch-resistant coating for the outer lens, and metallisation on the reflectors.