Biodegradable corn products may become plastics of future
The Associated Press
Some of the nation's abundant supply of corn already is being converted into environmentally friendly plastics and fibers for use in products ranging from mattress pads and golf shirts to soda cups and minidisc wrappers.
Biodegradable corn products are now more expensive than traditional plastics, but if they catch on they could provide hope for struggling farmers and give birth to a new industry.
"Anything that can be made from a barrel of crude oil can be made from a kernel of corn," said Randy Cruise, a corn farmer in central Nebraska, who was only slightly exaggerating. "I think we're just getting started in this whole arena."
Corn plastics are being developed by Cargill Dow at its plant outside Blair, where refined corn sugar is converted into polylactide or PLA. The sugar is fermented and distilled to extract the carbon, the basic building block for commercial-grade plastics and fibers.
PLA, in pellets the size of BBs, is being pressed into packaging for food, plastic wrap, foam and dinner ware. It is spun into fabrics at plants in North Carolina, Hong Kong and Japan and marketed under the Ingeo brand of clothing and blankets. Cargill Dow — a joint venture between privately held food giant Cargill and Dow Chemical — says Ingeo means "ingredients from the earth."
DuPont is in the early stages of developing a similar product, but it still includes some petroleum. The company is part of a consortium that got $19 million from the Energy Department to develop a way to turn corn stalks and leaves into a polymer from which plastic can be made.
Perhaps the greatest appeal of corn plastics is their green credentials. It takes about a month for plastic bags made from corn to degrade in a compost heap, said Randy Klein of the Nebraska Corn Board. A similar, oil-based plastic bag could take centuries to decompose.
Coca-Cola used 500,000 cups made from corn plastics at the Winter Olympics in Salt Lake City. Instead of creating a large trash problem, used cups were simply composted.
"The product performed beautifully. They go back to nature in 40 days," said Frederic Scheer, president of Los Angeles-based Biocorp North America, the food-service company that supplied the cups.
Before giving its stamp of approval to corn plastics, the Sierra Club is waiting for independent studies of the products' biodegradability.
"If it's what it appears to be, it will be tremendous," spokeswoman Laura Kresbach said.
The biggest demand for corn plastics has been overseas, including in Taiwan, where packing components are developed for the many products it exports to the United States. Taiwan bans petroleum-based plastic shopping bags and disposable plastic tableware.
Electronics giant Sony was involved in the early development of corn plastics and has wrapped its minidiscs in a corn-based film made by Cargill Dow for two years. Cargill Dow also recently reached an agreement with Taiwan-based Wei Mon Industry to promote and distribute corn-plastic packaging materials.
IPER, one of Italy's largest supermarket chains, has been working with the natural-based packaging from Cargill Dow for nearly a year for film containers and heat-sealable film overlays.
Just a few miles from Cargill Dow's plant near Blair, Wilkinson Manufacturing has made food packaging out of aluminum and petroleum-based polystyrene. Now it is trying corn-plastic containers for bakery and deli items, said Joe Selzer, vice president of marketing and sales. It's still in the research and development stage, Selzer said, and he declined to identify the test markets.
While the corn-based plastic now is more costly — Selzer declined to say how much more — he's convinced that will change.
"There's no doubt one day this product will be able to compete with petroleum-based products," Selzer said.
Biocorp North America's corn-based plates are about 5 percent more expensive than traditional plastic, and the cups can be 25 percent more costly. But Scheer said the price would decline as production went up with demand — which he would expect to see within five years.
That could amount to a highly productive new use of the nation's corn supply, which is heavily subsidized and so abundant that it is widely converted into corn-based sweeteners and animal feed.
Cargill Dow thinks a billion pounds of PLA could be harvested annually within a decade. That would mean 10 percent of the nation's corn supply would be converted into plastics and fibers.