1. The BMW i production concept: Life and Drive modules.
With the BMW i3, the BMW Group is set to launch an electrically powered production vehicle onto the market that represents a new form of sustainable mobility in urban areas. As the first premium electric vehicle, the BMW i3 rises to the social, ecological and economic challenges of our time. With its groundbreaking vehicle architecture, the concept calls for the use of modern lightweight construction materials as well as innovative production processes. Sustainability plays a prominent role for the BMW Group in this area as well. The BMW i3 was the first vehicle project for which sustainability objectives were agreed and subsequently pursued with the same vigour as cost, weight and quality objectives. The aim is also to reduce the environmental impact of production as much as possible, focusing on aspects such as energy supply and water consumption, solvent emissions and waste treatment. It is an objective to which all the locations in the BMW i production network are committed – including Moses Lake in Washington State (carbon fibre production) and Wackersdorf (processing into carbon fibre laminates). Both these facilities are operated by SGL Automotive Carbon Fibers (ACF), a joint venture set up by the BMW Group and the SGL Group. They are joined by the BMW Group’s own plants in Dingolfing, Landshut and Leipzig.
The innovative architecture of the BMW i3 comprises two elements: the aluminium Drive module – which incorporates the powertrain, chassis, battery, and structural and crash functions – and the Life module or passenger cell, made from carbon-fibre-reinforced plastic (CFRP). The LifeDrive concept and use of CFRP allows production times to be cut by half compared to those required for an equivalent car built along conventional lines. The process is less investment-intensive as the high costs required for a conventional press shop and paintshop are no longer an issue and the Life and Drive modules can be manufactured alongside one another. The use of CFRP on the scale required for the BMW i models is without parallel in the automotive industry worldwide and the BMW Group has also assumed a leading role in this area.
2. The dawn of a new era – building cars with CFRP.
Rigorous commitment to lightweight construction is especially important for electrically powered vehicles because, alongside battery capacity, vehicle weight is the limiting factor in its operating range: the lighter a vehicle, the greater its range. In order to compensate for the extra weight of the electrical components, BMW i makes extensive use of lightweight construction techniques and innovative materials in its vehicles. The Life module of the BMW i3 is made primarily of carbon-fibre-reinforced plastic (CFRP). This innovative material is produced by the SGL Automotive Carbon Fibers (SGL ACF) joint venture.
Carbon fibre production using hydroelectric power / Moses Lake, USA.
The SGL ACF factory in Moses Lake in the USA produces carbon fibres from a polyacrylonitrile-based thermoplastic textile fibre precursor. In a complex multi-stage process, the various constituent elements of the fibre are removed by gasification, eventually leaving a fibre that consists of virtually pure carbon with a stable graphite structure. This fibre is j