The Tepex continuous-fiber-reinforced composites from LANXESS are being used in large-scale production of various structural components for lightweight automotive design. The lightweight rear seat shell of the Audi A8, developed by Faurecia Automotive Seating and manufactured using the hybrid molding process, created a weight saving of 45 percent compared with sheet steel.

Traditionally, seats comparable to those in the Audi A8 have been made using metal shells screwed onto a substructure, a time-consuming process of welding numerous individual parts together in several steps. Using the polyamide-6-based Tepex dynalite 102‑RG600(2)/47% and the short-glass-fiber-reinforced Durethan BKV30H2.0 polyamide 6, an over-molded material also from LANXESS offers strength, lightweighting benefits and cuts production costs when compared with traditional manufacturing means.

“The reason that our composite material was chosen for this structure was the fact that it is around 45 percent lighter than a comparable metal design but can also be produced cost-effectively, thanks to the high degree of functional integration. It can also withstand the high mechanical loads in a crash,” explained Henrik Plaggenborg, head of Tepex Automotive at the LANXESS High-Performance Materials (HPM) business unit.

Tilmann Sontag, project manager at the Tepex Automotive group of HPM, commented on the new process, “In the hybrid molding process, by contrast, a ready-to-install component is created in a single process step. The pre-contoured and heated semi-finished composite product is formed directly in the injection molding tool for this purpose and equipped with numerous functions by means of injection molding. This simplifies subsequent assembly and leads to considerable savings in production costs.”

In addition to reinforced ribs, the piping groove for securing the seat cover in place, as well as numerous holders, are integrated into the component. The clips to attach the seat shell are also directly injected. “The shell can be assembled easily and quickly without screws using the clips and disassembled again for servicing purposes,” Mr. Sontag added.

Tepex dynalite is used in other large-scale applications of structural lightweight automotive design such as front ends, brake pedals, underbody paneling components, reinforcing structural inserts for body detachable parts as well as carriers for the door and electronic modules. LANXESS predicts that the composite material will be used in the future to manufacture highly complex seat systems in autonomous driving.