George Johnson runs his fingertips over the slick, automotive Class A surface of a Dodge Viper hood and tries to put into perspective the molding technology that made it. Resin transfer molding once was limited largely to making prototypes chiefly in mom-and-pop molding shops, he said. Today the production method can mold entire bodies for as many as 5,000 cars a year.
The proof is Chrysler Corp.'s showpiece $55,000 Viper, said Johnson, market development specialist at Production Molding Composites in Madison Heights, Mich.
``People who buy that car expect a lot. Quality standards get tougher all the time. They're the toughest in the industry,'' he said.
Walt Bartkowiak, vice president and general manager at Production Molding, said: ``The Viper was the first real production [car] using resin transfer molding. We were the [experimental operation] and went to 20 Vipers a day. It was an experiment that worked.''
In the past, an RTM shop might turn out three or four pieces a day, he said. But now his facility routinely produces 223 pieces a day. He reports genuine interest from makers of specialty vehicles, heavy-duty trucks, agricultural equipment such as combines and personal watercraft.
``Resin transfer molding deserves more attention than it's been getting, and I'll put a bug in the ear of anyonewho'll listen. We'd like people to look at resin transfer molding again,'' Johnson said.
Lower tooling costs produce some of the growing allure of RTM. For example, a personal watercraft project under way at Production Molded Composites will go into production with just two tools. Building the speedy little boat with hand lay-up required 24 tools for the same volume of about 5,000 units a year, Bartkowiak said.
In agricultural products, RTM over foam cores may replace steel for the roof and parts such as panels that mainly meet appearance and cover-up needs. In addition to weight savings, there also will be the advantage of sound deadening that is inherent with use of the urethane cores, Bartkowiak said.
Truck builders, he said, are looking at the process for parts such as hoods, cabs and sleeper cabs, now the bailiwick of sheet molding compound. He expects production of some truck components to begin within six months or a year.
``Interest is higher than ever. People weren't talking resin transfer molding. Now they are,'' he said.
One key reason for the company's success has been the attention paid to eliminating warping and scrap in the automated manufacture of the precisely engineered, continuous-strand fiberglass preforms, he said. Another is the electronic control of resin flow and the molding process.
Yet another is the company's strict maintenance policy on its aluminum and nickel-shell tooling.
``It's preventive maintenance and we're pro-active on a clockwork basis,'' said John Moore, process and development manager.
Production Molding Composites has about 150 employees and 90,000 square feet of manufacturing and office space. The company is part of APX International, which was formed last year by the merger of Aero Detroit, Pioneer Engineering and Autodynamics. APX International has annual sales of about $150 million.