The distinctive black of carbon fibre reinforced plastics is now appearing in car body structures. At the VDI plastics in automotive engineering conference and exhibition in Mannheim, Germany, Dr Jochen Töpker, CFRP vehicle project manager at BMW, said the i3 Megacity and i8 Vehicle designs draw upon experience in Formula 1 monocoque crash performance as well as lightweight components in the K1200R Sport motorcycle. BMW is using thermosetting epoxide-based resin transfer moulding (RTM) for the i3 CFRP cell, Tšpker said. He said the i3 and i8 designs are "practically steel-free", adding: "If these set a precedent, we are turning a big wheel. We are trying not to use metal and in the longer term, crash performance will be achieved with a CFRP chassis instead of aluminium."
Krino Bornemann is responsible at Volkswagen in Wolfsburg, Germany, for CFRP technology in low fuel consumption vehicles. At the VDI conference, he discussed a new advanced RTM (aRTM) process to reduce CFRP production costs through 15-20% faster cycle times, which the company is using on the VW XL1 concept car. Bornemann classified processing by production volume. Pre-impregnated fabric preforms in simple tools offer 60-80min cycle times, suitable for volumes of less than 5,000 vehicles per year. For 50,000-300,000 vehicles per year, he highlighted two processes: RTM with resin injection into dry fabric, in more complex tools, in cycle times of 4-40min; and hot compression moulding of fully consolidated thermoplastic fabrics and inserts (such as organic sheet) in cycle times of 1-3min.
Audi technology network manager Heinrich Timm said in a press briefing that the company's lightweight aluminium and CFRP Audi Space Frame (ASF) saves weight and improves handling, safety, braking energy and acceleration. Timm said for CFRP to break through into volume vehicles the industry needs to find suitable cycle times for large series production and reduce processing costs by 90% compared to 2010 levels. Also, designs need to allow for carbon fibre anisotropy, as longitudinal strength is high, but transverse strength low.