DETROIT — As global pressure mounts for plastics recycling, North American automakers plan to heed the call by switching to instrument panels made entirely from one material.
Consider the array of current and upcoming products in an area once considered future fancy:
Engineers at General Motors Corp. and Ford Motor Co.'s Visteon parts-making unit said they plan within two to four years to have instrument panels on the road that are made entirely from thermoplastic olefins. Instrument panels are the largest interior system outside of seats.
Meanwhile, auto-parts interior supplier Textron Automotive Co. has developed the first instrument panel skin made from castable thermoplastic urethane. The panel, recently launched on Chrysler Corp.'s 1998 LH-series sedans, can be married to PU foam and a reaction injection molded PU substrate.
Auburn Hills, Mich., resin supplier Solvay Engineered Polymers teamed with GM's Saturn division to develop the first TPO cover skin on a North American vehicle. Those olefin-based skins could prime the pump for an all-TPO instrument panel.
Those projects and others point to a significant mind-set change, said Robert Pett, chairman of the Vehicle Recycling Partnership, a research consortium based in Highland Park, Mich., that is backed by the Big Three automakers.
``Automakers have shown much more awareness [of recycling],'' said Pett, senior staff technical specialist with Ford's research laboratory in Dearborn, Mich. ``Among their design guidelines is the need to have materials compatible with each other in a major chunk of the car. As long as they stay in one family, it's much easier to separate and reuse the material.''
The cause for the shift could be both regulatory and consumer-driven. Several European countries are reviewing end-of-life vehicle legislation designed to cut down plastic automotive shredder residue, called ASR, that goes to landfills, said plastics industry consultant Robert Eller of Robert Eller Associates Inc. in Akron, Ohio.
Some automakers in Europe, including GM and Daimler-Benz AG, are seeking one-material solutions, Eller said.
``An important share of global car designs originate from Europe,'' said Eller, who recently completed a study on skin, foam and substrate materials for interior systems. ``Both TPO skins and TPU skins will have significant penetration.''
At the same time, the ``X generation,'' or the next generation of car buyers, is more conscious of environmental issues, said Visteon materials engineer Anthony Brooks. Demographic studies have made automakers aware that marketing to those younger consumers requires a focus on green design, he said.
Visteon plans to make new TPO cover skins for instrument panels that better withstand temperature extremes without warping, Brooks said. The Ford-owned parts supplier is developing one-material instrument panels that include olefin foams, polypropylene substrates and even a paint material with an olefin base.
``We've been at this for seven years, and we're just beginning to understand the tiger we've got by the tail,'' Brooks said. ``We need to qualify and quantify the size of the beast.''
Other materials like PVC may not go away easily. The resin, used separately and with ABS as a skin substance, has advantages both in cost and fit and finish, said David Reed, staff project engineer at GM's Warren, Mich.-based North American Operations Materials and Fastening Center.
TPO skins cannot match the soft, luxurious feel of a PVC skin. A soft instrument panel, similar to leather, has become steadily more important to the car-buying public, Reed said.
Except for a few, scattered exceptions, TPO skins are not used now. And virtually no models have both a TPO skin and substrate.
``Right now, we're stuck with PVC because it has the designed combination of customer appeal and cost,'' Reed said. ``But we see real breakthroughs in TPO skins.''
Reed thinks Ford can develop a good all-TPO product within the next few years. ``First, we need to optimize the surface feel and make a good, harmonious combination,'' he said.
Some work already has been done by GM's Saturn division in Spring Hill, Tenn. In 1997, the carmaker replaced a painted instrument panel skin made from PVC with an unpainted TPO material. Now, the molded-in-color piece is used for all of Saturn's car lines, said Beth Wodrich, original equipment manufacturing marketing manager for Solvay Engineered Polymers.
Wodrich said the application, using Solvay's Sequel TPO, was the first hard TPO instrument panel skin in North America. The company is performing experiments to make soft instrument panels from TPO resins, Wodrich said. But cost is still a factor.
``Normally, PVC has a set of properties difficult to match,'' she said. ``It can be extruded in thin sheets and molded or thermoformed. We're trying to do the same process with TPOs.''
Textron is focusing on urethane, which can be matched to PU foam and a RIM substrate of similar materials. Other automakers plan to use the company's TPU-based castable instrument panel cover, now used by Chrysler, said Jeff Rose, vice president of technology for Troy, Mich.-based Textron Automotive.
Textron designed the panel to allow an air bag cover with an invisible seam to be rotationally molded with the part, Rose said. By doing so, Textron took about 30 percent of the weight from the air bag system and created a lower-cost panel, he said.
The part is used on the 1998 Dodge Intrepid, Chrysler Concorde, New Yorker LHS and its sportier European version. The soft-feel cover replaced PVC, a material that Chrysler was willing to forego, said Terry Anderson, Textron's director of research and development.
``In Europe, [automakers] don't see PVC as a friendly material,'' Anderson said. Several models there already use a RIM substrate and urethane foam, he said.
Yet, Anderson said recycling techniques for PU are not as refined as for TPOs. The material commonly is broken down into a liquid polyol by a chemical process called glycolysis that is still in its infancy.
That continues to fuel the debate over the future of instrument panels as a recycling target.
``The great dream of polypropylene suppliers is to make an olefin skin, foam and substrate,'' Eller said. ``However, it's not that simple. It's clearly going to have to evolve in stages.''