The profiles are particularly flexible fibre tows, pre-impregnated with thermoplastic resin in various dimensions. They will be compiled by SGL Carbon on the basis of its own 50k carbon fibre at its site in Innkreis, Austria, and subsequently processed by the injection moulding experts at Koller to form a skeletal plastic component.
The composite component will replace the previous steel-based windshield. Production of the carbon fibre profiles will start in the remainder of 2020 and will then be ramped up gradually over the next few years for the BMW Group model launch.
In the vehicle, the windshield is a connecting element between the roof frames and thus has an important stabilizing function. The carbon fibre profiles add the required stiffness and crash safety to the component. At the same time, they help to significantly reduce the weight of the roof and thus also support the driving dynamics. The injection moulding process also enables particularly complex and material-efficient structures. In the BMW Group model, this innovative component concept will cut weight by 40 percent compared to conventional steel designs of the component while creating important space for cable ducts and sensors.
The production of the carbon fibre profiles themselves is also particularly geared to material and process efficiency in large-scale production. The profiles consist of several smaller fibre strands, the so-called rods, and are manufactured using the modern continuous pultrusion process. During product and process development it was one key objective to ensure that material loss during production is almost completely avoided.
"At SGL Carbon, we have been working on the development of thermoplastic carbon fibre profiles for use in injection moulding for some time already. This development work is now beginning to pay off. Due to the many advantages and competitive costs, we see a great potential for the technology to be used in other automotive projects too," explained Sebastian Grasser, head of the automotive segment in the business unit composites - fibres & materials at SGL Carbon.
“Innovative lightweight construction with hybrid designs has developed into a strategically conclusive concept for Koller Group's OEM customers," confirmed Max Koller, CEO of Koller Group. “SGL Carbon's high level of material expertise, combined with the process know-how of KOLLER Kunststofftechnik and KOLLER Formenbau, create the basis for a promising future in innovative lightweight construction technologies. With this order, the BMW Group has confirmed its confidence in the successful cooperation between SGL and Koller; we are particularly pleased about this.”
