UTICA, MICH. — Two of the world's largest automotive-parts suppliers are taking the recycling of thermoplastic olefins to new areas of the vehicle and new levels of technology.
Delphi Automotive Systems of Troy, Mich., and Visteon Automotive Systems of Dearborn, Mich., have programs in the works to make TPO cover skins for large interior systems such as door panels and instrument panels.
Those covering panels long have been under the thumb of PVC, polyurethane and other materials.
Visteon's work could change that. The supplier, owned by Dearborn-based Ford Motor Co., wants to replace entirely the PVC door-panel skins made at the Utica plant with ones made from TPOs. Visteon has developed a low-pressure molding process to make complete door panels, including olefinic foam and skins.
The project is significant. The Utica plant is one of the largest injection molding facilities in the world. It manufactures more than 15 million door panels annually.
By the end of the year, the plant will start seeking contracts to make all-olefinic interior doors, said Gerald Dominick, manager of advanced manufacturing engineering at Visteon's Utica plant.
``We want to be the technology leaders in olefins,'' Dominick said during a recent interview at the 2 million-square-foot plant. ``Olefins are the kings of recycling. And recycling is the right thing to do both for social and economic reasons.''
Delphi, recently spun off from Detroit-based General Motors Corp., already has gone commercial with TPO skins. In Delphi's case, the company started with instrument panels, a large, complex part.
The supplier is making the first TPO covering pieces in North America, for the 1999 Mercedes-Benz 3-series sport utility vehicles assembled in Vance, Ala. The instrument panel includes more than 30 percent recycled content on its base layer, underneath the skins' covering layer.
The current work just scratches the surface of what should be coming, said Suresh Shah, senior staff research scientist with Delphi's Interior Systems unit, based in Warren, Mich.
``The future depends on how effectively the industry can develop an interior panel that is 100 percent recycled,'' Shah said. ``We'd like to grind up whole interior panels and put the material back into the substrate. We're getting indirect signals that our customers would like to use that if there's no cost penalty.''
That is the rub, however. A completely olefinic interior system — with polypropylene-based substrate, foam and skin — typically is more expensive than interiors with PVC or ABS-modified PVC skins and polyurethane foam.
TPO skins also have a history of difficulties with scratch and mar resistance and too much stiffness. But new additives are easing those concerns, experts said.
On the other hand, PVC/PU interiors give automakers separation anxiety. The parts are cost-prohibitive to separate and reuse.
``It's like making a hard-boiled egg,'' said Aashir Patel, technical specialist at Visteon's Utica plant. ``Once it hardens, you can't take it back and make an omelet from it.''
That is why single-material, olefinic interiors are the dream of carmakers looking to recycle cost-effectively. In Europe, stringent recycling goals are pushing technology in that direction. In North America, the threat of legislation and global platforms are causing the same concerns.
U.S.-based automakers don't want to make one set of panels in Europe and another in North America, said Ron Price, marketing development manager with Houston-based Exxon Chemical Co. He expects a major boom in TPOs in North American car interiors.
By 2002, cover skins for car interiors in North America will use a total of about 20 million pounds of TPOs, compared with 3 million to 5 million pounds today, Price said. By 2004, that figure could double to 40 million pounds, Price said.
Already, more than a dozen models in Europe use TPO cover skins, Price said. And Japanese carmakers also are considering the resin.
Visteon thinks it has developed a way to make TPOs cost-competitive with other materials. Visteon's low-pressure molding allows the TPO skin to be bonded mechanically with cross-linked olefin foam and a PP substrate injected into the mold.
The process, using lower-tonnage machines and lighter pressure, is less capital-intensive and eliminates the need for spray adhesives, Patel said.
Visteon's Utica plant has invested $25 million to $30 million since 1994 to add 11 low-pressure production presses and one for product development, Dominick said. Half of those presses were added in the past three years as the company began developing TPO door panels.
The machines, all with clamping forces of 1,500 tons, use 2,000 pounds per square inch of pressure or less, about 10 percent of what is used by conventional injection presses. The low-pressure process allows the plant to cut costs by making thinner parts, said Utica plant manufacturing engineer Daniela Olejnik. Each door panel weighs 30 percent less, or about 4 pounds per door less, than a PVC-based door panel, Olejnik said.
The plant will start by incorporating post-industrial plastic into its parts. Eventually, as the need arises, the company will seek post-consumer TPO from discarded vehicles and elsewhere, Dominick said.
Visteon hopes to patent its deceptively simple, closed-loop process. It uses scrap TPO blended with virgin material into a base — the structural half of the door panel. A cosmetically perfect TPO cover piece — using virgin material — then is molded with the substrate.
Now, all Visteon must do is convince its customers, including mother Ford. Once validation trials are completed this summer, the supplier hopes to launch its first single-resin-family door panel with a customer in the fall.
Delphi also is headed toward an all-olefinic panel, taking its first steps on the Mercedes program.
At its Matamoros, Mexico, plant, Delphi seamlessly replaced PVC resin with TPO cover material on the same sheet-extrusion line, Shah said.
The base layer, including recycled plant scrap, and the top layer are extruded at the same time through separate nozzles coming together into one fitting, Shah said.
However, the panels still use urethane foam to save costs, Shah said. To make an olefinic interior would require a switch by Delphi to either low-pressure molding or vacuum forming techniques, he said.
``PP foam is expensive,'' Shah said. ``We would have to reduce costs by reducing part thickness or by other means. It's easy to be 100 percent recyclable, but the cost of the part needs to be the same or lower than that of the virgin material that is replaced.''
Recycled TPO is being found in other areas, too. Hematite Automotive Products Inc. of Guelph, Ontario, is regrinding TPO bumper fascias and forming a blended powder with other additives. The material then is extruded or injection molded into parts to deaden noise or for air- and water-management systems.
The company has created a new family of products, called SoundGuard, that uses the repowdered TPO for sound-deadening parts, such as dash-insulation parts or door water shields. The recycled TPO also is used for air- and water-management parts.
With a line of recycled and virgin products, the company has added injection presses to its Wixom, Mich., plant. Hematite now has eight presses with clamping forces of 250-850 tons at the plant, opened in 1997. The extruded parts are made in Guelph.
The material is in the approval stage with various U.S.-based carmakers, said Dale R. Snyder, Hematite director of sales and marketing.
The time is ripe for recycled TPOs in the industry, Snyder said. The firm recorded about $50 million in sales last year, he said.
``In Europe, the change is already taking place,'' he said. ``But even here, the subject is without a doubt on everyone's lips. We're targeting recycling as a means to drive a lot of our future business.''