The amount of plastics used in cars is increasing as manufacturers strive to reduce weight. According to one estimate, approximately two million metric tons of plastic were present in end of life vehicles in the United States in 2014. And that number will be rising annually.
It’s easy to remove plastic bumpers, shred them and recycle the plastic. Getting at the massive amounts of plastic elsewhere in the car, particularly the interior, is challenging, but technically possible. The economics are fuzzy. The environmental benefit is compelling.
The residue left after dismantling and decontamination of old cars, large appliances and construction debris is shredded and then processed using magnets, eddy current separators and inductive metal detection equipment to recover most of the metals. Screening and air separators are also used.
Raw shredder residue is 21 percent plastic, 13 percent rubber, 7 percent wood, 31 percent, foam/textiles/paper/film mixture, 11 percent wires and metal, and the remainder is tiny fines of various materials. Further processing yields a residue steam that is 84 percent plastic.
Of, course, that’s a mishmash of many types of plastic. And there are residual automotive fluids from plastics used in fuel tanks, residues of paints and barrier materials and the presence of heavy metals. “A number of technologies are available to overcome these challenges,” said Brian Riise, the company’s R&D director. Technologies used by MBA Polymers yield streams of polypropylene (filled and unfilled), ABS, high-density polyethylene and high-impact polystyrene.
Still problems remain. There are color issues. Residual semi-volatile organic compounds create odors that pretty much rule out re-use in interior automotive applications. Mechanical properties do not match those of virgin materials. MBA Polymers does not recommend use of its products for use in toys, medical parts or any food or oral contact applications due to possible contamination from “legacy” metals. Products are, however, RoHS and REACH compliant, according to MBA. Glossy surfaces are ruled out due to contamination. Processes may have to be adjusted to reduce heat.
Given all that, MBA Polymers has still built a significant business from selling plastics reclaimed from end-of-life vehicles. Plants in the United Kingdom, Austria and China have a combined capacity of 120,000 metric tons for automotive, electronic (more on that later) and other waste.
Recycled plastics typically have lower selling prices than virgin plastics, but special requirements can boost the cost. “Our costs, however, are fairly stable because they are not tied to oil prices, but it’s clear that low virgin plastic prices have hurt the entire plastic industry–including ourselves,” a spokesman for MBA Polymers told The Molding Blog.
The real payoff, of course, is environmental.
The Institute of Scrap Recycling Industries estimates that recycling of plastics from shredder residue could potentially result in annual savings of energy equivalent to 28.5 million barrels of oil, savings of 40 million cubic meters of landfill space, elimination of 1.6 million to 4.8 million metric tons of carbon dioxide and savings of 151 million cubic meters of water.
That is significant, and hats off to MBA Polymers for putting all the facts on the table in an interesting and thorough way at Antec. Now it’s time for corporate sustainability and procurement managers to step up the plate.