All the talk about rising fuel prices and the potential for higher fuel standards from the federal government may be raising hopes that the North American auto industry will embrace more plastics as part of an effort to make cars lighter and more efficient.
But don't count on it.
The North American auto industry is designed to turn out high levels of cars primarily using steel body panels, and so far, there simply is not a strong business case to replace steel with plastics.
``I don't see it yet,'' said Jeff Helms, chief engineer for materials engineering, testing and standards, and product development for Ford Motor Co. He spoke during an Oct. 9 panel discussion at the Society of Plastics Engineers' Automotive Thermoplastic Polyolefin conference in Sterling Heights.
Assembly lines are built to make large numbers of cars and trucks and to make them in a specific set of manufacturing steps that make it more difficult to substitute plastics, such as the high-heat ovens used in painting. There are exceptions for low-level production cars - 50,000 annually or less - but the system as a whole is not currently designed for high levels of thermoplastics use, Helms said.
``If I get my production levels low enough, if I can find the sweet spot, then I can make a business case,'' he said.
Detroit-based General Motors Corp. also is interested in lightweight solutions, said Fabio de Souza, global commodity purchasing manager for GM's fluids and resins group. But he agreed that the business case has to make sense.
Dearborn, Mich.-based Ford is interested in the potential of weight savings in future product designs, especially if the federal government changes the Corporate Average Fuel Economy Standards, and that would include plastics, Helms said. But for now, large uses of plastics are not a ``short-term goal,'' he said.
The auto industry is using plastics more in some regions - particularly Europe and Asia, noted Robert Eller, president of Robert Eller Associates LLC. Thermoplastics are winning new business in Europe replacing steel for fender modules.
Cie. Plastic Omnium, for example, already is making a talc-filled polypropylene fender module used on BMW AG's X5. The module includes the headlight and other parts, and the molder has signed an innovation agreement to work with French carmaker PSA Peugeot Citroen on future projects including fender, roof, fascia and front-end modules.
Carmakers in emerging markets like China and India may introduce a plastic-bodied car as part of an attempt to turn out low- cost vehicles, Eller said.
For long-term growth in plastics, the industry as a whole has to collaborate to find the best resins and the best parts for those resins. When plastics were first used to replace structural steel in instrument panels, the industry made the mistake of trying to do a simple material replacement, said Pat Stewart, chief engineer of cockpit and interior systems for Troy, Mich.-based Delphi Corp. It took a lot of time to work out the manufacturing bugs, while failing to take advantage of plastics' ability to integrate more parts than steel.
By planning in advance for the best places to use plastics, automakers and their suppliers can determine how best to use the material, said Steve Dwyer, senior vice president automotive - Americas for Basell Polyolefins in Elkton, Md. A sports utility vehicle tailgate designed to use polyolefin from the start can be created to hide gaps caused by heating and cooling.
``We have to show the complete case,'' Dwyer said.