A design team from BMW in Landshut, working with engineers from expanded polypropylene maker JSP, has achieved weight savings of 15 per cent and cost savings of 10 per cent in the construction of rear seat backs for the BMW 5 Series.
Manufacturing has just begun in Wackersdorf for delivery to BMW assembly plants in Germany and China.
The design project began in 2005 and series development of the new sandwich seat back started in July 2007. The team’s idea was to use a three-part structure to create a lighter seat back, capable of passing statutory impact tests and BMW’s own test schedule.
At its centre is a section of energy-absorbing Arpro expanded polypropylene with an injection-moulded carrier facing the passengers and a layer of carpet facing the luggage compartment. All three components contribute to impact resistance.
BMW calculates that the weight saving totals 1.2kg on an already ’weight-reduced’ component.