Providing a home: MBA Polymers Inc., Richmond, Calif., has been created to give a boost to durable goods plastics recycling

Recycling Today, Nov, 2002 by Brian Taylor

The question from recyclers is a common one: Can a steady market be created to recycle engineering plastic components that make up a growing portion of the automotive, appliance and electronics streams?

For the past decade, MBA Polymers Inc., Richmond, Calif., has been working to answer that question in the affirmative.

Michael Biddle, an engineer who formerly worked for General Electric Co., Cummins (Engines) Inc. and Dow Chemical Co., founded a plastics recycling research and development and consulting firm in 1992. Two years later, he and co-founder Trip Allen turned that firm into today's MBA Polymers, a California company that operates what is widely considered to be one of the most advanced plastics recycling plants in the world, recycling highly mixed plastic-rich residue generated by various durable goods recyclers in North America, Asia and Europe.

Progress, acknowledges Biddle, has been slow but steady. He estimates that some 10 million metric tons of durable goods plastics hit the scrap market or waste stream each year. His hope is that MBA can lead a charge that will create an established end market for this material.

A GROWTH PATTERN

Without question, manufacturers around the world are using more plastic to make their products with each passing year.

The trend has been especially noticeable from makers of computer equipment and small appliances. Televisions, audio equipment and other personal entertainment devices are encased almost exclusively in plastic now. The laptop computers that are increasingly replacing desktop and tower units have an even higher percentage of plastic than their predecessors.

Plastic components are being pressed, molded and extruded in record numbers, offering a voluminous stream of material to recyclers. Along with this blessing of high volume, however, is the challenge of a wide diversity of plastic resins and compounds used by manufacturers.

Since MBA's origins, Biddle has been working with manufacturers to help them improve the recyclability of their products through their design and materials choices.

Several industries have made efforts to minimize the number of different resins they use, and--in the best cases--use a predominant resin in a particular product for purposes of easier recyclability.

But the stream of products made over the past two decades often consists of combinations of plastic types fastened together with screws, glues and other fasteners and adhesives.

SORTING IT OUT

The terms "shredding" and "downstream sorting" are most commonly linked to metals recycling, but MBA Polymers is among the companies moving plastic recycling toward the same model.

The company itself, though, does not usually shred. "The raw material we receive has most often already been shredded by a metals or electronics recycler," says Biddle. Material may come directly from auto shredder operators such as nearby Simsmetal America, or it may come from downstream separator operators such as Huron Valley Steel Corp., Belleville, Mich.

There is nothing easy about the sorting task facing MBA, especially for an operation that Biddle says accepts material derived from nearly anything with a cord, as well as quite a few things with engines.

The feedstock entering MBA's Richmond plant comes from a variety of recyclers operating throughout the world. Although the pre-shredded material is largely nonmetallic, incoming material arrives in a variety of conditions and with a wide array of chemistries. "When we receive our material, some has as much as 10 percent metals content, while on the low-end it can have negligible amounts of metal."

While many scrap recyclers are in business primarily to harvest metal, MBA is producing a product that must be completely free of even metallic fragments, which would be considered a contaminant.

Thus, one of the first tasks facing MBA Polymers is removing and recovering the metallic portion of its incoming stream. Further downsizing and an array of mechanical sorting techniques, such as classification, magnets and other metal separation equipment, are deployed to remove the metals.

Further shredding and screening then takes place to separate different types of plastic from one another. "It is definitely complicated," Biddle says of the process of sorting the various plastic types. "Density sorting methods are not particularly helpful because most plastics are very close in density," he notes.

After the plastics have been shredded into small flakes, the series of separating steps takes place to sort plastics into resin groups that include polypropylene (PP), HIPS (high-impact polypropylene), ABS (acrylonitrile butadiene styrene), polycarbonate (PC) and PC/ABS blends.

Once separate streams of flakes have been created, the flakes can be extruded into cylindrical or spherical bb-sized pellets that can be used by plastics molding companies or original equipment manufacturers.

POINT A TO POINT B

In just a decade, MBA's progress thus far has helped convince Biddle that both sufficient raw materials and sufficient end markets for MBA pellets exist to make the company's model a successful one.