Seatback design saves weight and cost

Paul Boughton
A design team from BMW, working with engineers from JSP and other specialists, 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 Seatback started in July 2007. The team’s idea was to use an innovative 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.

The new sandwich seat back design offers great versatility to BMW who have integrated its manufacture into their 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 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 this 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.’

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, a global company which developed the first EPP and is now the world’s largest supplier. JSP’s designers work closely with automotive engineers in their quest for weight-saving, impact-absorption, vehicle safety and manufacturing efficiency, and are known for their innovative track-record. ARPRO is 100 per cent recyclable.

For more information, www.jsp.com

Recent Issues