LANXESS thermoplastic composite for Audi A8 rear seat

The rear seat housing of the LANXESS demonstrates the role of the company’s continuous fiber reinforced composites in the mass production of automotive structural components.

LANXESS (Cologne, Germany) announced the use of its Tepex continuous fiber reinforced composite for the rear seat of the Audi A8. The car is available with two independently adjustable electrically adjustable rear seats. The outer casing is developed by the Faurecia car seat (Stadthagen, Germany) and is manufactured using a hybrid molding process. Polyep-6 based Tepex dynalite 102-RG600 (2) / 47% was used for this purpose. Short glass fibers from LANXESS are also used to enhance Durethan BKV30H2.0 polyamide 6 for overmolding.

LANXESS cited this application as an example of how its Tepex continuous fiber reinforced composites can be found in the mass production of various structural components for light-duty automotive designs.

“The reason why our composites were chosen for this structure is that it is about 45% lighter than similar metal designs, but because of its high functional integration, it can also be produced cost-effectively. It can also withstand high mechanical loads in collisions,” Henrik Plaggenborg, head of Tepex Automotive, a division of Netac’s Performance Materials (HPM) business, explained.

So far, similar seats have been made primarily from metal shells that are screwed onto the lower structure. Manufacturing metal shells is time consuming because they consist of many separate components that must be joined together by a few steps of soldering.

“In contrast, in a hybrid molding process, ready-to-install components can be created in a single process step. For this purpose, preformed and heated semi-finished composite products are formed directly in the injection mold and are molded by injection. This feature simplifies subsequent assembly and saves on production costs,” said Tilmann Sontag, Project Manager, HPM Tepex Automotive Group.

In addition to the ribs, the duct slots for securing the seat cover in place and the plurality of brackets and guides (for example for seat ventilation and cable brackets) are integrated into the component. The clip for attaching the seat shell is also injected directly.

“The housings can be assembled quickly and easily without the use of clip screws and disassembled for repair. These clips are very stable and meet all relevant safety requirements,” Sontag said.

LANXESS provides comprehensive support for project partners to develop seat covers and complete rear seat systems. For example, HPM determines the material data for the composite and overmolded materials required for Faurecia’s structural simulation to calculate the mechanical resilience of the safety components. In addition, several strategies for accurately and reproducibly forming semi-finished composite products were analyzed in stereo simulation. These findings were incorporated into the recommendations of the design tools and processes.

“For example, we recommend using a special clamping element to secure the plasticized composite insert to the injection molding tool,” says Sontag.

Tepex is developed and produced by the company’s subsidiary Bond-Laminates GmbH (Brilon, Germany). Tepex dynalite is used in the production of front ends, brake pedals, underbody components, reinforcement inserts for body detachable parts and large carriers for doors and electronic modules. LANXESS expects composite materials to be used in the future for the manufacture of backrests and armrests as well as seat shells for new highly complex seating systems for autonomous driving.

According to Plaggenborg, “We are thinking, for example, that the freely rotatable, rotatable or detachable seat is not only lightweight, but also meets all collision requirements and is equipped with a variety of integrated functions such as seat belts, infotainment systems. And a comfort system.”