When the auto industry first began talking about moving away from PVC in auto interiors, Lon Offenbacher, Patrick Stewart and the rest of their engineering group thought polyolefins were the material to bet on, with thermoplastic polyolefin skin a likely PVC replacement.
That was 20 years ago, when Offenbacher and Stewart were part of General Motors Co.'s interior group. When the interiors group was spun off as part of Delphi Corp. in 1999, the team continued its research and development, looking at ways to make a TPO skin that was more flexible and could compete with PVC or urethane skins. The research continued as the interiors group was sold to outside investors to create Inteva Products LLC in 2008.
And at the same time, the auto industry was undergoing an evolution, forced both by an economy demanding cost cuts and consumers who wanted smaller, less expensive vehicles — but didn't want to sacrifice interior quality.
After two decades, those two lines have reached an intersection at the instrument panel on General Motors' 2013 crossover vehicles — which include the Chevy Traverse, Buick Enclave and GMC Acadia — with an all-polyolefin structure made by Inteva, including the substrate, polypropylene foam-in-place and TPO skin.
“I had to field a lot of questions over the past 20 years,” said Offenbacher, now CEO of Troy-based Inteva, “like, ‘Are we ever going to see this on a vehicle?' “
The project won an award from the Society of Plastics Engineers during the SPE TPO Automotive Engineered Polyolefins conference Oct. 1-3 in Troy.
In addition to the all-polyolefin breakthrough for Inteva, the project also points up the need for increased collaboration between an automaker and its supplier, and improved production capabilities possible with the project, said Stewart, Inteva vice president and executive director of interior systems.
When GM started working with Inteva for the crossover update, it needed to get the project through the pipeline quickly, he said.
“We told them that the only way to get the product you want within your time line was that we needed to fully control the value stream,” Stewart said.
The all-polyolefin system took advantage of Inteva's in-house capabilities not only in injection molding and skin forming, but also its proprietary compounding for TPO skin.
The instrument panel, with foam in key spots to provide a soft touch and skin for an upgraded look and feel, also plays into the industry's increased interest in interiors, he noted.
In the early 2000s, automakers looking to cut production costs stripped interiors down to basics with hard plastics that could double as both substrate and trim. Consumers noticed, however, complaining about the “plasticky” vehicles.
Now midpriced vehicles like GM's crossovers, and even some low-priced cars, are getting a multiple-layer treatment with skins and foam, while Inteva's continued tweaking of TPO has created a skin that can compete with PVC or urethane.
“The pendulum has swung back,” Stewart said.
Improved interiors in small and midsize vehicles will be important for car buyers looking to cut fuel costs with a smaller car, but who expect the quality, look and feel of a larger car, according to Stewart.
All-polyolefin production, however, still helps the company control costs because scrap can be more easily recycled in-house — especially compared to a part produced with a polycarbonate/ ABS structure, urethane foam and PVC skin.
A TPO skin also stands up to sun damage better than PVC, and that helps to gain consumer approval, he said.
Current production trends should maintain a stable price for polyolefin for years to come, which along with Inteva's continuing research should ensure its use, Stewart said.
“It was a 20-year trend to get here, but it's not just going to be a 20-year payoff,” he said.
Meanwhile, Inteva has tripled production capacity in Pune, India, with a new manufacturing plant and testing center that opened Sept. 12. But the bulk of that new production will be non-plastics parts for door latches, window regulators and motors, the company said. The site will employ 266.