DETROIT - Designers at DuPont Co. think a car's wheel well would be a wonderful place to put a radiator. While they admit they have significant problems to overcome, the Wilmington, Del., company's engineers announced they have been working to develop a flexible heat-exchange device - a radiator - made of nylon.
A nylon radiator would be far lighter and less expensive than existing metal radiators, while offering automotive designers a chance to produce custom shapes that could fit almost anywhere on a vehicle, DuPont executives said at a Feb. 27 news conference at the SAE International Congress and Exposition, held Feb. 27-March 3 in Detroit.
The problems are, first, that nylon is hygroscopic - that is, it attracts and absorbs moisture.
Second, engineers rightfully think of nylon as an insulating material, and DuPont often has promoted that property for applications in which nylon's resistance to heat is beneficial.
Although he conceded that making a heat-exchanging device seemingly is antithetical to nylon's inherent insulating properties, John R. Lewis, director of engineering materials, said those properties are not a problem.
``The nylon design is almost completely composed of thin nylon layers through which the coolant flows, rather than conventional metal fins that merely conduct heat away from metal tubing,'' Lewis said.
``The heat-transfer efficiency comes from the much greater surface area that coolant is exposed to through the thin-walled construction,'' he said.
DuPont has developed experimental radiators made from laminated nylon sheet that has fine tubing molded into it in the laminating process. The sheets are attached to an injection molded end cap.
The company has tested the nylon heat exchangers on diesel engines on 5-ton trucks used by the U.S. Marine Corps and on commercial heating, ventilation and air conditioning equipment, executives said. DuPont also tested its nylon radiators on smaller vehicles.
DuPont executives did not say when they expect the nylon radiator concept to be made commercially.