Lightweight design innovations for motor vehicle manufacture
While some people enthuse about the ‘steel of the 21st century’, others warn against expecting too much from the use of carbon fibre materials in large-scale motor vehicle production for reasons of technology and cost. While proponents provide proof of feasibility with automotive bodies manufactured entirely from carbon fibre reinforced plastic and / or individual bumper beam or tailgate components made from this miracle material with the high-tech image, the devotees of conventional materials tend to be dismissive: too expensive, not suitable for large-scale production, too difficult to recycle. Nevertheless both sides are aware that textile research institutes have had encouraging research successes.
A new milestone has now been set by the Cluster for Lightweight Design in which eleven research institutes have pooled their expertise. After two years’ work it is a fact: Germany will be one of a small number of countries who in a few years time will be able to automate the manufacture of fibre composite components in reproducible qualities for medium and large series production. The Cluster has the aim of developing materials and technologies to the level of series production for the effective use of textile reinforced plastic components. Thanks to this interdisciplinary collaborative research – detailed information about this is provided at the Techtextil stand of the coordinating Institute of Textile Machinery and High Performance Material Technology (ITM) of the Technical University of Dresden – knowledge and user data is available with which the processing costs and the energy input required can be tangibly reduced. To demonstrate the perform future a demonstrator was produced in a very rigid topological structure using a hybrid construction. The robust lightweight component is a strong candidate for use as a support structure in motor vehicles and consists of duroplastic and thermoplastic components on the basis of textile reinforced structures.
Continuing focus on cost question
Nevertheless the technological advances are not able to avoid the question of carbon fibres still costing too much. Carbon fibre reinforced plastic components are derived from crude oil and have a price per kilogram of EUR 200; at EURO 2.50 the cost of comparable steel components is 80 times (!) less expensive. This disproportionate cost currently leads progressive thinkers in automotive design such as Dr. Stefan Kienzle, head of research and prototyping of lightweight design, material and production technologies at Daimler AG, to only see complex carbon fibre reinforced plastic components as a ‘short-term goal’, while generally increasing expertise in carbon in his company. As Heinrich Timm, head of technology networks at Audi AG, explained to textile technicians in Dresden, lightweight design is essential and in spite of the high material costs it is a ‘key factor’ in emission reduction. High performance fibres in composite components are a valuable addition to the portfolio of lightweight design materials. For example the Audi A8 Coupé already has 21 components made from carbon fibre reinforced plastic. His view is that against the background of the increasing global demand for carbon fibre reinforced plastic components up 17 percent year on year, the challenge is to industrialise the processing technology which for decades has been regarded as a ‘cottage industry’.
Thomas Strobel is a future thinker and he believes that textile research, which is developing in particular fibre-based high-tech materials and substrates as well as the technologies required to do so, faces a number of other challenges in addition to radical cost reduction. Lightweight textile-based design will only have a potential in the longer term when from an energy and environmental perspective there is a satisfactory resolution of the methods for raw material recovery at least to the degree that this has been done for metal. And: in the medium term carbon fibres do need to be manufactured from a different raw material than crude oil.
Source – S. George
Pedestrian-friendly bonnet with integrated 3-D textiles as impact protection – joint development by Dresden and Aachen based textile researchers (Nils Bolk and Matthias Haupt of ITM Dresden)