The quest for lower-cost, lighter-weight, less-polluting vehicles is a never-ending task, but it promises to become even more challenging for automotive engineers in coming years thanks to mounting pressure to improve fuel economy and curb greenhouse gases. And it is a task in which materials will begin to play an increasingly important role.
Because materials are such a crucial component of the automotive industry, each year Ward's Auto World devotes much of its September issue to analysis of how their use is shaping the upcoming model year and the future.
Most experts say tomorrow's vehicles will become an even more diverse combination of materials than they are now, and predict the materials war will continue to rage on.
But which materials will win and lose always is the subject of hot debate. Will lightweight alternative materials eliminate steel? Will your next sports car or minivan have a plastic body?
In the following pages, WAW gives you the behind-the-scenes story on what's happening in the materials marketplace for the '99 model year.
he idea of making cars out of plastic started atCorp. four years ago as a means of building a $6,000 car for China and other developing markets, where the only competition would be motorcycles and ox carts. Somewhere along the way the China market lost its appeal and engineers and suppliers set their sights higher - a lot higher.
Now they're talking about whipping Porsche's butt.
How isgoing to do it? Like the guy said in The Graduate: One word. Plastics.
At the University of Michigan's Management Briefing Seminars in Traverse City, MI, last month, Lawrence J. Oswald, executive engineer-body engineering at Chrysler's Liberty operations says new plastic processing techniques could make it possible to build a midengine sports car that outperforms the much-heralded Porsche Boxster for half the price. The '98 manufacturer's suggested retail price for the Boxster is $41,765. Chrysler's target price is "under $20,000."
Chrysler already has a driveable prototype of such a car called the Plymouth Pronto Spyder (although its body is actually steel painted to look like plastic), as well as three other plastic-bodied concepts: the low-cost China car - now called the Composite Concept Vehicle (CCV) - the Pronto Lite, a small minivan; and the ESX 2, a high-mileage vehicle aimed at meeting the Partnership for New Generation Vehicle (PNGV) goal of a midsize family car that gets 80 mpg.
All are interesting, but it's the sexy Spyder that is getting the most attention - both internally at Chrysler and from automotive journalists. The low-slung body was designed to suggest a very low center of gravity and look like an alligator ready to pounce on its prey. It's powered by a healthy 225-hp 2.4L supercharged 4-cyl. engine.
Interest in using the homely CCV - modeled after the old Citroen Deux Chevaus 2CV - to storm new markets in developing countries has waned, confirms Mr. Oswald in an interview. Instead, he says, the company has decided to switch the plastic car emphasis to "extending the technology so we can get products more for existing markets like the U.S. and Europe, where people demand features like Class A surfaces, bright colors and meeting all the safety standards."
The newer concepts are not as simple in construction as the CCV, which consists of four giant plastic parts bolted to a steel ladder frame chassis and held together with adhesive. Even so, Mr. Oswald says the most complex plastic body is far simpler than others made of steel.
"When I heard the steel folks bragging they reduced the part count on the Ultralite Steel Auto Body from 240 to 180 pieces, I went 'whoopee.' We got (our part count) down to 16 on the CCV and about 22 or 24 on the ESX. And that includes the door inners and outers. If you've got four doors, you've got eight pieces just in the doors."
Because the Pronto Spyder is a 2-seat open roadster without a roof, it lends itself to different "body breakup," Mr. Oswald says. The CCV uses big inner and outer body pieces, but for the Spyder, Chrysler engineers are experimenting with a tub-like design that provides the body strength and stiffness needed. Even so, the design still only requires a few big plastic parts.
Chrysler executives, engineers, suppliers and public relations folks all make the usual disclaimers about how it's "too soon to tell" if Chrysler will build any of these cars. Many significant concerns remain, and Mr. Oswald says he won't be able to prove out most of them with a high level of confidence until mid-1999. If Chrysler then decides to go into production, the earliest that vehicles would be available in showrooms would be 2003, Mr. Oswald says.
This, of course, is not the first time someone has decided to try to redefine how vehicles are designed and built using plastics. Henrybecame enamored with the idea in the 1930s. On Nov. 2, 1940, he demonstrated with an axe how a new plastic material made largely from soybeans and fashioned in the shape of a decklid for a 1941 Ford could resist direct blows. The following year, the world's first experimental plastic automobile body was completed in Dearborn, MI.
Since then, lots of plastic cars have come and gone, from the Pontiac Fiero, and GM "dustbuster" minivans to the highly successful Corvette. But Chrysler's push may be the first where the use of plastic is the foundation of a new manufacturing process.
During the next 10 months or so, Chrysler and its plastic and molding suppliers will study repair techniques for the plastic bodies, heat sag, weatherability, shatter resistance of the body material in cold temperatures, surface appearance and body material cost.
Meeting government-required crash tests - especially side impacts - is another concern, Mr. Oswald says. Current bodies can meet crash-test requirements with the aid of special steel hoops and door beams embedded in the plastic. That adds weight and assembly complexity, and Mr. Oswald says he would like to minimize the use of steel reinforcement beams in the plastic structures.
One of the most problematic issues is surface finish. Fred P. Keller, chairman of Cascade Engineering, the molder working with Chrysler on this project, says that the plastic has a 15% glass content to give it the structural strength it needs, but this makes it extremely difficult to mold in a high-gloss finish that would look similar to those on typical steel cars.
Although smaller parts have been successfully molded with a glossy finish, Mr. Oswald is hoping market research will show consumers will accept a matte finish similar to that on the current Spyder concept.
Mr. Keller adds that while a glossy finish is very difficult to achieve, the plastic body offers up new types of finishes and textures that could fascinate future buyers.
Whatever the concerns, the program is moving ahead steadily. Husky Injection Molding Systems has announced plans to build a $10 million research and development facility for the project in Novi, MI. The facility should have the capability to mold a four- to 12-piece car body in plastics.
Another plastic supplier "partner" also has been chosen to be a second source for plastic material in case the polyethylene terephthalate (PET) supplied by Hoechst Group's Ticona unit doesn't work out.
The new plastic is "Hivalloy" engineering resin, an alloy of polypropylene and polystyrene supplied by Montell Polyolefins.
However, Mr. Oswald and other insiders warn not to read too much into Husky's announcement. It planned to have a showroom for its giant new presses, anyway, that would do tryout parts. If nothing comes of the Chrysler plastic car program, Husky still will use the facility to show off equipment to other customers.
Creating a vehicle body from large injection-molded parts can save 70% in tooling costs and reduce assembly labor by 50% while chopping mass by half, Mr. Oswald says. Other major cost savings are achieved by eliminating painting operations. Molding the color in the plastic body eliminates the need for a paint shop, which can cost $100 million to $350 million. Controlling paint shop emissions costs millions more annually.
Typically, big structural automotive plastic parts such as those used on the Lotus Esprit Turbo and Dodge Viper are made via the structural reaction injection molding (SRIM) or resin transfer molding (RTM) process. In these processes, preformed mats of glass fiber are placed into giant "clam shell" molds, injected with thermoset resins, heated and compressed.
But RTM and SRIM techniques are slow and expensive, with cycle times as long as 10 minutes. And they produce thermoset plastic parts which can't be remelted and are more difficult to recycle than thermoplastic.
With Chrysler's strategy, body panels are made from thermoplastic polyethylene terephthalate (PET) - pop bottles are made of the same stuff - with 1 5% glass reinforcement added to give it more rigidity.
The secret to the fast cycle time is a sophisticated process where special gates in the mold are opened and closed in concert with the injection of pressurized gas at various intervals to quickly distribute the molten plastic throughout the mold. Detailed computer simulations helped refine the process.
Will any of these cars see the light of day? Cascade Engineering's Mr. Keller says Chrysler's top brass is "backing the program to the hilt. They are really behind this effort to make plastics work and they have the vision to see this could really be a new way to do automotive bodies."
Nowadays that's about as close to a yes as you're going to get.