Recycling process cuts shredder residue sent to landfills: Recovery Plastics International uses skin floatation technology to sort recyclable plastics - Materials

Automotive Industries, May, 2002 by Andrea Wielgat

It took a little company in Salt Lake City and an exact science to figure out how to recycle leftover shredder materials used in the automotive industry.

Automakers for years have been recycling the metal used in vehicles -- worth about 75 percent of a vehicle's weight.

It's the remaining 25 percent -- made up of plastics, textiles and glass -- that has perplexed OEMs for years. Companies could not figure out how to sort, recycle and reuse the numerous plastics and other materials used in the interior of the vehicle. The material -- known as shredder or fluff -- headed for landfills at a cost to the automaker and ultimately the consumer.

But Recovery Plastics International (RPI) has done what no one has been able to do before: sort and recycle the leftover plastic materials so they can be reused with current production molds and processes to make standard parts.

RPI, established in 1980, had developed and built several pilot and full-scale plants for the recovery of plastics used in, among other things, beverage bottles, milk jugs and detergent containers when DaimlerChrysler came calling in 1996.

"They came to us and said 'We have various plastics that our cars are made out of and would it be possible to separate them and put them back into a form to be used in vehicles'," says Ronald Kobler, president of RPI.

At that time no one had been able to cost-effectively sort and recycle the 50 plastics used in a vehicle and 3 million tons of shredder material headed for landfills each year, Kobler says.

RPI via the funding of the Vehicle Recycling Partnership -- made up of DCX, Ford Motor Co. and General Motors Corp. -- set out to sort the numerous substances in shredder material.

"We had to devise a process to get rid of light materials," Kobler says. "Then we had to get rid of rocks, metals and debris to get the plastics isolated."

Through a scientific process RPI was then able to extract three major types of plastics, which make up 85 percent of the plastics used.

"The skin flotation is where you attach air bubbles to specific types of plastics in order to make the separations," Kobler says.

Basically, RPI adds chemicals and hot water to shredder. Reacting with specific plastics, the chemicals cause air bubbles to attach to the plastics and make them float. The plastics are subsequently skimmed off the top.

Once the plastic was separated it was recycled back into pellets.

Eventually, those pellets were then supplied back to 26 DaimlerChrysler suppliers who recently turned the recycled pellets into 54 plastic parts using current production processes and molds. DaimlerChrysler, as part of its Concepts for Advance Recycling and Environmental (CARE) Car II demonstration program, retrofitted the parts into two Jeep Grand Cherokees. The automaker, which has said it would like to produce vehicles that are 95 percent recoverable by 2005, showed the vehicles at this year's New York auto show.

The recycled parts meet the same material specifications required for production vehicles but could save $10 to $20 per vehicle compared to virgin plastic, says DaimlerChrysler.

"Automobiles are already one of the most recycled products on the planet," Bernard Robertson, senior vice president of engineering technologies and regulatory affairs, has said about the project, "but this technology presents the first real world solution to recycle the remaining 25 percent of a vehicle that still goes to a landfill."

With RPI's process only about 5 percent of a vehicle's waste heads to the landfill.

But the process isn't just good for mother earth. It's also good for automaker's pocketbooks: DCX estimates that this technology could save the auto industry $320 million a year.

First a full-scale plant must be built using RPI's process. Kobler expects that to come within the next two years.

"There's lower cost. There's landfill diversion," Kobler says. "You're closing the loop on recycled plastics."

RELATED ARTICLE: Plastics that can be recycled:

Polypropylene

Filled polypropylene

ABS

Plastics that cannot be economically reclaimed:

Nylon

PMMA

Polycarbonate