Expanded polypropylene on the move
The largest single use of expanded polypropylene (EPP) in an automotive will be on sale in autumn 2008. The anti-submarine ramp (which keeps the passenger from sliding under the seatbelt during harsh braking) in the rear seat bench of the new Volvo XC 60 is made of ARPRO, the EPP produced by manufacturer JSP, based in Windsor, UK.
‘Versus regular seats, its weight savings are 35%,’ Sales and Marketing Director Frank Tolle told Materials World at JSP’s factory in Cheb, Czech Republic. He estimates that reducing a car’s weight by 100kg using ARPRO could cut fuel consumption by 900l over its lifetime.
JSP’s ARPRO is used in 23m cars each year, said Paul Compton, Executive Vice President and Chief Operating Officer (Europe).
Traditionally, the material was mainly applied to bumpers and doors, but it is increasingly being used throughout the car.
Expanded polypropylene has been used for some time in Jaguar and Land Rover’s side doors, seats and car boots, says Corinne Bowmar-Scothern, Project Engineer for the automotive firm. ‘Industry wide, more people are focusing on passenger safety, as far as side impact goes, and companies may be specifying more of the EPP blocks behind the door trim for crash protection.
‘It is also good to use to increase the stiffness of a seat, without compromising the weight,’ she adds.
First developed in the 1980s, EPP is produced in a closed cell format. The extrusion process for JSP’s ARPRO EPP uses air, water and steam, meaning no hazardous blowing agents are applied.
The material’s density can range from 18g/l to 250g/l, ‘which has high energy absorbancy and is still four times lighter than a compact component,’ said Tolle.
The company has predicted that use of the material will grow by five per cent in 2008 due to increasing requirements for lightweight and energy absorbing materials in the automotive sector, as well as in emerging applications.
ARPRO has also been used to create children’s furniture that can withstand 100kg, as well as a collapsible airborne search and rescue platform, launched this year by Escape International, based in Paris, France.
The platform weighs less than 50kg but can carry over 10 people. The ARPRO lining, which can resist temperatures of -30 to 50ºC, protects it from impact.
To meet increasing demands from growing markets, Compton says JSP’s plant capacity will be extended from 7,000t to 14,000t.
Further information: Arpro