Makrolon® polycarbonate drives innovation in thick light bar
GM, Valeo and Covestro collaborated to create an advanced light bar design for the headlamp, which features a larger and brighter daytime running lamp for improved visibility in clear or inclement weather. In addition to improved safety, the thick light bar also allowed GM to create a unique brand differentiation for the vehicle. Nonstandard, multi-shot thick molding, tooling and processing were instrumental for achieving the light bar’s unique styling and functionality.
The team aimed to design a light bar that looks like crystals, with low yellowness after a long cycle time. With the part’s large, complex shape, the tooling needed a modified surface and special ejection design to properly eject the thick light bar. Since there was a risk of high stress in the part, dimensional accuracy and warpage were also areas of concern.
To meet color and optical clarity requirements, Makrolon® LED2245 polycarbonate from Covestro was manufactured using a different process than standard polycarbonate. As a result, this grade offers high optical clarity in extremely thick cross-sections and provides crystal color development to reduce the yellowness that often occurs in traditional, unlit thick polycarbonate parts. Additionally, Valeo used a proprietary molding process for a low-stress part with high clarity and minimal shrink and warpage.
Automotive lighting plays a dual role, contributing to a vehicle’s safety and its distinctive styling. This light bar illustrates how using Covestro materials can create new opportunities to enhance both of these important aspects.
Why Makrolon® LED2245 polycarbonate was the right solution for the light bar
- Good optical quality Offers high optical clarity in extremely thick cross-sections.
- Unique aesthetics Custom color development enables crystal-like appearance and effects.
- Dimensional accuracy Maintains the desired size with minimal shrink and warpage.
- Replicated micro-optics Enables replication of micro-optic surfaces.