Injection-molded plastic products like six-pack loops and tampon applicators come high on the environmental hit list. Company researchers are competing to come up with a variety of improved corn starch-based plastics that will turn these and other damaging castoffs into food for microbes.
Both St. Lawrence Starch Company Ltd. in Ontario, Canada, and Archer Daniels Midland Co. (ADM) in Decatur, Ill., have commercialized degradable corn starch plastic for garbage bags, mulch bags and other film products. These major players are now busy commercializing second-generation research to improve degradability and broaden applications of corn starch plastic to include the heftier injection- and blow-molded products.
The St. Lawrence and ADM technologies are relatively similar. Basically, plastic with sufficient corn starch content breaks down by exposure to microorganisms and enzymes in the soil, increasing the surface area of the plastic and acting as a catalyst for chemical degradation.
The notion of mixing plastic with corn starch has been around for some years and can be traced to a British bag maker who in 1974 found that adding starch enabled the firm to use less plastic. Enhanced degradability was a bonus. The patents then bounced around for several years and in 1985 came to rest with St. Lawrence, which claims it was the first to get polyethylene corn starch film on to the market.
Archer Daniels Midland acquired its patents from the same source as St. Lawrence in October 1987. Like its competitor, the $7 billion food ingredients company doesn't produce plastic products but sells starch to manufacturers who license the degradable plastics technology.
St. Lawrence's corn starch plastics cost 5 percent to 15 percent more than conventional polyethylene, but Manager of Business Development Wayne Maddever says consumers are willing to pay extra for this type of packaging. It can also provide good advertising for companies that use it. Larger corporations such as Kimberly Clark are now looking seriously at the technology, although most interest so far has come from smaller entrepreneurial companies, Maddever says.
"We keep leaning on the big companies; when they'll do something it's difficult to tell, but probably over the next two or three years," Maddever says.
Archer Daniels' degradable products are more expensive than conventional plastics because the currently modest level of production drives up costs, according to Jerry Petak, the business development manager for degradable products. "We feel over time these costs will be reduced," he says.
How does ADM plan to market the more expensive plastic? By pushing companies to look beyond their ledger sheets to wider concerns such as diminishing landfill space and the moral imperatives of environmental cleanup.
"It's a new product with a new concept," Petak says. So far most sales have been to regionally based manufacturers. Larger companies are still asking what's in it for them.
Petak points out that no equipment changes are necessary to accommodate the new plastic. Perhaps another selling point is that by converting to degradable plastics, companies will be well positioned to comply with legislation being debated at federal and state levels. Analysts say it's only a matter of time before state and local governments require the use of degradable plastics.
Already, 16 states require that six-pack loop connectors be photo-degradable, and some municipalities have already restricted their landfills to degradable plastic waste.
Grant Ferrier is editor of the Environmental Business Journal in San Diego, Calif.