Premium materials for premium cars
Audi relies on mineral-reinforced thermoplastic for Audi A7 spoiler
Premium cars impress consumers with superior style and functionality. Achieving both requires an equally high-performing material. So, when the material originally selected to form the distinctive spoiler of the Audi A7 did not meet the automaker’s high standards, Audi turned to a newly developed mineral-reinforced thermoplastic from Covestro.
The Audi A7 spoiler is composed of two components: a structural part and cover that are glued together. For the structural part, Audi sought a material with strength, UV protection and chemical resistance to gasoline and cleaning agents. The cover required a paintable, high-quality, Class A surface with uniform surface quality to match adjacent metal parts, and a low-gap design.
To meet the market need for this and other demanding exterior automotive applications, including large horizontal offline painted roof spoilers, Covestro developed Makroblend ® UT235 M. This 15% mineral-filled grade offers a very low coefficient of linear thermal expansion (CLTE), high heat resistance, improved flow and an excellent surface. Also, the materials’ easy flow and easy release properties enable manufacturers to considerably reduce scrap – and therefore costs – during production.
Covestro provided technical expertise related to part design and the injection molding process, resulting in an optimized mold design and cooling system that further enhanced this application.
It’s worth noting that this component – with its unique H-shape – would be nearly impossible to produce with conventional metal forming processes. It’s yet another reason Covestro is the go-to materials supplier for exterior auto parts with complex curves and geometries.
The main properties of Makroblend® UT235 M (PC+PET blend) are:
- Low coefficient of thermal expansion CLTE
- Class-A surface
- High dimensional stability
- Very good paintability
- High heat resistance