DuPont Lightens Up

DuPont has been working with auto manufacturers to refine some of its high-performance engineering plastics, and even invent some new ones. It's all being done in the name of lightweighting vehicles -- to boost fuel efficiency and reduce carbon dioxide emissions -- and improve their performance.

Whether the vehicles are automobiles aimed at consumers, or heavy commercial trucks, lightweighting efforts have moved to the top of the list for DuPont's Performance Polymers division. Working more closely with the auto manufacturers, the company has helped them design parts that are optimized for plastic, not metals. This helps ensure that the resulting components not only weigh less, but also meet specs for strength and the part's specific functions.

Click on the image below to see three examples of DuPont's new materials.

Sometimes, this means tailoring the formulations of existing product lines, and at other times, it means developing entirely new products. In the first category, DuPont partnered with ElringKlinger to make two injection-molded oil pans for large, heavy-duty truck engines manufactured by Mercedes-Benz. The components, made of DuPont's Zytel polyamide resin, weigh half as much at 9.9 lb (4.5 kg) and 13.9 lb (6.3 kg) as they would if made from aluminum. The design also reduces noise by 2 dB, and resists chip impact from stones and gravel over the typical lifespan of a truck engine.

To make the oil pans, ElringKlinger used a heat-stabilized, lubricated Zytel grade that is not only lighter in weight than aluminum, but equally strong. This material also let the company integrate other parts that could not be integrated with a metal oil pan, such as fluid level sensors and oil pickup pipes. ElringKlinger arrived at the materials and design combination after four years of R&D, including a lot of endurance tests and prototypes. Euro 6 emission standards call for limits on diesel engines as strict as those on gasoline engines, which are set to go into effect in 2014.

Working with PSA Peugeot Citroen, DuPont is co-developing a new technology for making thermoplastic composites, called Vizilon TPC, that's still in R&D. It's being designed for structural and load-bearing parts, as well as components designed to protect against crashes, for body-in-white, underhood and suspension uses. As we've previously reported, developing composite processes for structural body-in-white applications, especially those that can be commercialized for high-speed automotive production, is no easy task.

Today, this family includes continuous glass fiber woven reinforced sheets that can be overmolded, David Glasscock, global business manager, DuPont Performance Polymers thermoplastic composites, told Design News in an email. It's specifically aimed at replacing metal. "We believe large-scale adoption of lightweighting technologies that significantly reduce vehicle mass will require a number of breakthroughs best achieved through collaborative efforts throughout the value chain," he told us.

When asked whether this technology might also include carbon fibers as a reinforcing material, Glasscock wrote: