A U.S. subsidiary of an international diversified plastics manufacturer is helping to lead the way in the move

toward increasing the manufacturing of automotive components from plastic.

Plastic Omnium Industries Inc. makes all the fuel systems for BMW's Z3 roadster, Chevrolet's Corvette and GM's U minivan at its 160,000-square-foot plant in Anderson, S.C. It also makes all the bumpers for the Z3 and half the bumpers used in the minivans: the Chevy Venture, the Opal Sentra, the Pontiac Transport and the Oldsmobile Silhouette.

That's about 1,500 fuel systems and 1,800 bumpers a day, turned out by 400 employees using state-of-the-art equipment. The plant opened in 1995, but had its first full year of production last year, estimated Philippe Claye, president of Plastic Omnium Industries Inc., a wholly-owned subsidiary of Plastic Omnium SA of France.

As head of the U.S.-based subsidiary, Claye oversees a development center near Detroit and a small assembly plant in Spartanburg, SC, where the bumpers moulded in Anderson are fitted with a reinforcing beam of aluminum, side and front lights, a license-plate holder and, in some cases, a headlight cleaning system, before being shipped to the nearby BMW plant.

U minivan parts are shipped to a GM plant at Doraville, Ga, near Atlanta; the Corvette fuel tanks are destined for a Bowling Green, KY, plant.

The plant also makes the side grilles and other trim for the Z3, forming them by injection molding PC/ABS. The gas tanks are made by blow molding and co-extrusion of layers of HDPE combined with adhesives and EVOH, a barrier that prevents gas vapors from escaping.

The plastic tanks are not only lighter weight than metal gas tanks, they are safer, said Claye. "If you have a fire in the car, a metal tank will explode. Plastic will burn, but not explode."

The plastic tanks can also be made to fit specific spaces more easily than metal, he added. For example, engineers solved the problem of the Corvette's limited space by creating two small fuel tanks rather than one larger one. "We had to redefine a very tricky design to get enough space," Claye said.

The adaptability of plastic is especially important in European cars, which tend to be smaller than U.S. models, he said. He estimated that plastic fuel systems are used in 99 percent of cars for the European market, and in 50 percent of those manufactured for the United States. "It's growing fast," he added.

Manufacturing the Tanks
Three massive Krupp Kautex blow molding machines have been adapted to mold each of the three fuel systems built by Plastic Omnium. The molds create a six-layered tube of material using two layers of virgin HDPE, one of reground HDPE, two of adhesives, and one of EVOH in an overhead system. Then it is extruded downward into a mold.

It comes out the other side of the mold as a gas tank, ready for cooling and removal of flashing. These bits of flashing will be added to others, then reground and reused as one of the layers of HDPE. "Very little matter is lost," Claye said.

After cooling, the tank goes to finishing centers located elsewhere in the plant. There, custom-built machines cut holes for valves and a central unit, including fuel pump and gauges. The attachments are then welded on by Plastic Omnium's custom designed and built machines, as well as by hand.

In the final step, the fuel tank is immersed in a tank of water to check for leakage. A lack of bubbles indicates that the tank has an airtight seal.

Fabricating the Bumpers
Plastic Omnium's bumper assembly operation is tied directly into computers at BMW, so that bumpers can be completed in the same sequence that cars are being built. "Red bumper for Europe, green for the U.S., yellow for Japan," said Claye, creating a hypothetical scenario. "The sequencing center has to build the bumpers within the next hour," Claye said.

The bumpers are made from a thermoplastic olefin (TPO) which is molded in one of two high-pressure injection molding machines: a 40-ton Husky and a smaller Engel. As bumpers exit the machines, an employee manually marks them with production numbers, snips off the bits of plastic which held them in the machine and lightly sands the edges.

Another employee then fits narrow strips of masking tape around the edges of areas which are to be left free of paint.

Bumpers then proceed to a painting system which the company purchased from Air Industry Systems of France. The bumpers are fitted with more masking tape, washed and "flamed" to make them more accepting of paint.

Painting TPO
Plastic bumpers made from TPO have been around for some time, although bumpers were still made of metal as late as 15 to 20 years ago, Claye said. TPO has long been the material of choice for European cars. U.S. automakers have tried other materials, but are coming around to TPO, he added.

"The big problem at first was how to paint TPO," Claye said. However, he added, that problem has since been eliminated through advances in technology.

In Plastic Omnium's case, it is done using three different applications which are performed by robots in sealed chambers. An adhesion promoter goes on first, followed by a basecoat of paint in whatever color the automaker desires, then a two-component clearcoat with a polyurethane base that makes the finish extremely tough, Claye said.

Robots spray on the three coats in sealed rooms, where windows are coated with grease to catch any stray bits of dust. After 20 minutes of hot-air drying in an oven that reaches 270F, they then exit the paint line.

Employees next inspect the painted parts, strip off masking tape, and send those that require polishing to a specialized machine using 3M technology.

Then it is on to the assembly plant in Spartanburg, the BMW plant in Greer, and eventually, the open road.

Preparing for the Future
Sales for Plastic Omnium SA are expected to top $1.3 billion. The company has been given the QS 9000 designation recognized by the Big Three U.S. automakers: GM, Ford and Chrysler. Its employees at first were trained at an area technical college because the company needed a lot of new employees fast. Now, however, it has its own training center for technicians.

The development center in Rochester Hills, MI, is where Plastic Omnium "prepares for the future," Claye said. It contains offices for sales and purchasing executives and technical development engineers, who by summer will have developed testing equipment for all the U.S.-made automotive products.

For example, Claye said he sees the Anderson plant getting into one of the newer trends in auto manufacturing, a combined bumper and fender made of plastic. A Plastic Omnium plant in Mexico is already making the part for the new Volkswagen Beetle, he said. "You have to develop new products for the customer," he added.

In addition to its automotive facilities, Plastic Omnium has other U.S. plastics plants, including a high-performance plastics operation in Houston, TX, and a plant in Reidsville, NC, making waste containers.

Plastics Machining & Fabricating
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