Closed-Loop Nylon Recycling Captures Award for Dupont

DuPont Composite Recycle Technology has received the 2004 environmental award for New Technology in Materials and Processes from the Environmental Division of the Society of Plastics Engineers for its closed-loop nylon recycling process.

The recycling process can convert parts made of glass- or mineral-filled nylon 6 or 66 into first-use quality material in a way that is economically viable and environmentally responsible. In addition to employing breakthrough technology, the program is unique in that it inspires collaboration along the value chain to help promote the long-term economic viability for recycling.

Composite Recycle dissolves used polyamide then filters away contaminants and fillers. The molecular weight of the recovered polyamide is increased to whatever level is desired for the final application. This process generates resin that is essentially equivalent to virgin nylon.

Since DuPont Engineering Polymers and DENSO announced a joint development program to test the viability of this technology by converting used radiator end tanks into new radiator end tanks, DENSO has completed material and in-use component testing. The results indicate: “this technology can be one of the most effective recycling technologies for increasing the recycle ratio of End of Life Vehicles (ELV) in the future,” according to DENSO.

The European Union ELV directive requires that 85 percent of a vehicle, measured by weight, be capable of recovery and reuse by the end of 2005 (the current figure for recycling is about 75 percent, which primarily relates to the metal content).

“The promise of value grows greater with each development activity,” said William Hsu, vice president and chief technical officer of DuPont Performance Materials. DuPont Engineering Polymers is a unit of the DuPont Performance Materials business platform.

“The ability to reclaim large glass and mineral filled nylon components such as radiator end tanks or potentially other components made of nylon can help automakers meet new regulations, but the benefit to society is that the landfill waste is reduced,” he said.

“This technology enables automakers to proceed with more practical recycle programs for many plastics parts,” said Hiroyuki Wakabayashi, general manager of DENSO material engineering department.

DuPont Engineering Polymers has led the industry in developing new technologies to help manage the lifecycle of plastics. “Through years of discovery and breakthrough, we realize there is no single, silver bullet as it relates to recycling nylon and engineering plastics,” said Hsu. “Our vision is to collaborate with our partners along the value chain to understand what needs to be done and then employ technology and lifecycle tools to develop materials solutions that are safe, economically sustainable and reduce overall environmental footprint.”