A design team from BMW in Landshut, working with engineers from JSP and other specialists, has achieved weight savings of 15% and cost savings of 10% in the construction of rear seatbacks 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 Seatback started in July 2007. The team’s idea was to use a three-part structure to create a lighter seatback, capable of passing statutory impact tests and BMW’s own test schedule.
At its centre is a section of energy-absorbing ‘ARPRO’, with an injection-moulded carrier facing the passengers and a layer of carpet facing the luggage compartment. All three components contribute to impact resistance. ARPRO is an Expanded Polypropylene (EPP) used extensively for automotive parts as well as for packaging and other applications requiring great lightness and strength (it is made by JSP).
BMW has integrated the new seatback manufacture into its cockpit production facility. “The seatback sandwich technology can also be extended into other models and other applications,” said BMW Head of Technology-Interior Section, Karl Niebauer.
BMW calculate that the weight saving totals 1.2 kg on an already ‘weight-reduced’ component.
Other claimed benefits include a reduced number of components, the elimination of numerous process steps, and improved recyclability.
Paul Compton, JSP President and Chief Executive Officer – Europe, said that the highly-successful design project was an excellent illustration of ARPRO’s ability to help automotive designers push traditional boundaries: “Our business approach at JSP is working with designers to exploit ARPRO’s extraordinary versatility. With BMW’s Sandwich Seatback the result is a win on all fronts – economics, manufacturing efficiency, environmental benefits and – not least – passenger safety and functionality.”