Paint free cars? To paint or not to paint—Dupont gives automakers the option with Shine-E Rynite thermoplastics

Automotive Industries, August, 2003 by Brent Haight

Dupont's Shine-E Rynite is a thermoplastic polyester designed to replace painted metal with lower cost, lighter weight molded parts that have the option of being painted or used as-is.

"We engineered Shine-E Rynite for automotive body panels that can be painted on-line, right next to metal body parts on existing OEM paint lines," says William Hsu, vice president, technology at Dupont Engineering Polymers, "including E-coat 200 degrees C ovens. The result is parts with a Class-A automotive finish and a very close match to adjacent pars.

"Shine-E Rynite promises to extend the boundaries of metal replacement in painted automotive body panels and in unpainted components for off-road vehicles and other uses," adds Hsu.

According to Dupont, the paintability and structural properties of Shine-E Rynite allows automakers to replace more sheet metal to reduce weight and gain major cost and style benefits.

Dupont is offering two grades of Shine-E Rynite--Rynite RE8000 targets the appliance industry, while RE8001 targets automotive applications. The first applications will likely be in [he appliance area, with commercialization of Rynite RE8000 scheduled for later this year.

"In the automotive realm, because it is an online paint process, there is a lot of development work and specification work that needs to be done," says Hsu. "We've started that work and we expect the first commercialization of RE8001 within a two-to-three-year time frame."

One of the features of Shine-E Rynite is that the dimensions and mechanical properties of the molded parts are virtually unaffected by humidity and the coefficient of linier thermal expansion is lower than that of many plastics.

"We Tailored Shine-E Rynite for low warp-age and dimensional stability," says Hsu. "Shine-E Rynite is a terrific material for unpainted parts with molded-in-color and a mirror-like surface. It provides excellent color stability at elevated temperature, dimension al stability and structural properties, too."