DETROIT — Two of the world's largest automotive interiors suppliers are making plans to move away from PVC for instrument-panel covers.
Both Troy, Mich.-based Delphi Automotive Systems and Southfield, Mich.-based Lear Corp. said they are developing new olefinic materials for their next generation of instrument panels.
While suppliers don't expect PVC skins to disappear, they could face heated competition from other thermoplastics.
In Delphi's case, the next generation is today. The supplier, newly spun off from General Motors Corp., is providing potentially the first thermoplastic olefin skin on a North American-built vehicle, said Norm Kakarala, development engineer at Warren, Mich.-based Delphi Interior Systems, a unit of Delphi Automotive.
The supplier is the largest independent auto-parts producer worldwide, racking up $28.5 billion in 1998 sales.
Delphi's TPO skin is used on DaimlerChrysler AG's 1999 Mercedes M-class sport utility vehicles made in Vance, Ala. Production of the new skins, integrated into Delphi's instrument-panel assemblies, started late last year at the supplier's Matamoras, Mexico, plant.
Lear, with sales of $9.1 billion last year, is looking into new technology using expanded polypropylene bead foam. The molded foam can make an entire, energy-absorbing instrument panel, integrating skin, substrate and reinforcing beam.
The structural PP instrument panel could be on the road in as few as three years, said Tom Ottman, manager of Lear's instrument panels. The one-piece instrument panel saves about 30 percent in weight, Ottman said.
U.S.-based automakers are challenging the industry to come up with new instrument-panel materials that shy away from PVC, Ottman said.
``All of them are pushing us to look more into polypropylene materials for an entire panel,'' Ottman said. ``It's not just our battle, but a commitment from our customers.''
Lear and Delphi's announcements were made March 1 during the SAE International Congress and Exposition in Detroit. Automakers want to replace PVC because PVC's plasticizers tend to fog windows, and the material is prone to degrade over time from sun exposure, Kakarala said.
Engineers have been working for years on TPO skins that could replace PVC in lower-end applications. But to date, nothing has been entirely successful, Kakarala said.
``The technology is still fairly new,'' Kakarala said. ``TPO materials have only been used regularly for about six years. We needed time to develop the material.''
Like PVC, problems with TPO materials have included their tendency to fade over the life of the vehicle, Kakarala said. That led to a need to paint the panels, driving up costs. PVC is similar in cost to TPO but does not require painting, he said.
Delphi thinks it may have found a solution while working with Houston-based Mytex Polymers, a joint venture between Exxon Chemical Co. and Mitsubishi Chemical Co. The companies have developed a TPO with new stabilizing agents that prevent the material from fading, Kakarala said.
The agents, called hindered-amine-light stabilizers, are released gradually into the TPO instead of all at once. That time-release activity blocks sun exposure for as long as 10 years, Kakarala said.
Still, the material must be painted to achieve the right surface finish, he added. The company is looking at new systems to eliminate the need for primer — which adds both cost and emissions to the painting process.
Other companies, including Montell Polyolefins, are attempting to add color into the mold during production and eliminate painting.
Lear has thrown its hat in the ring with Fagerdala World Foams AB, an expanded PP supplier located near Stockholm, Sweden. Fagerdala, which recently launched a U.S. plant in Marine City, Mich., has jointly developed a prototype model for a new, unpainted instrument panel.
The panel integrates heating and air-conditioning ducts, showcases the radio and controls in a large center console and includes a seamless air-bag door. The material can withstand temperatures of 266° F without shrinking or fading, said Peter Nystrom, Fagerdala research and development manager.
Lear is considering using PP foam for other interior parts, such as door panels or headliners, Ottman said.
The activity at Delphi and Lear follows a trend predicted by the University of Michigan's Office for the Study of Automotive Transportation. By 2007, PVC use in instrument panel skins will decline to about half of all vehicles on the road, according to the Ann Arbor, Mich.-based research center.
Today, PVC commands a robust 81 percent share of the North American market, the center reported.
Meanwhile, the study predicted TPO skins would rise to about 31 percent of the market from a negligible amount today.
