Industrial blow molding has found a new niche - blow molded rear-seat backs for cars.
Plastic seat backs offer a cost reduction and lighter weight than traditional rear seats, which combine a tubular steel frame and sheet metal, said Keith Kauffmann, engineering leader for Dow Automotive.
Kauffmann outlined the project during an automotive session at Antec in Cincinnati.
Audi AG is using the blow molded seat backs on its TT, sold in Europe, from seats supplied by Lear Corp. The seat went into production last summer, Kauffmann said. The molder is MÃ¶llertech GmbH of Bielefeld, Germany.
The material is a polycarbonate/ABS from Dow.
The TT seat won the safety award at last year's Society of Plastics Engineers Automotive Division Innovation Awards. Kauffmann said the rear seats had to pass demanding European standards, including an impact test that simulates luggage in the trunk slamming against the rear seats in a high-speed frontal crash, and measures deflection of the seats. The seat back has to be able to flex, but not break.
Midland, Mich.-based Dow developed the concept of a blow molded seat back, then pitched it to the automotive industry, Kauffmann said. Extrusion blow molding imparts a hollow, double-shell structure, for strength. That's one reason Dow picked blow molding over injection molding for the rear-seat back, he said.
For the Audi TT, using plastic rear-seat backs saved about 2.6 pounds per seat-or 5 pounds per vehicle, he said. Blow molds also have a shorter lead time, and are cheaper than a series of stamping dies to make the same part.
``Bottom line for this program, they achieved about $1.2 million in savings,'' Kauffmann said. ``And this is attributed only to the tooling savings.''
Kauffmann said blow molded rear-seat backs will appear on two cars for U.S. consumers - the Impala from General Motors Corp. and the Fusion from Ford Motor Co.