Cargill, Dow to begin commercial production of corn-made plastics

MINNEAPOLIS, Jan 12: Cargill Inc and Dow Chemical Co have announced plans to produce commercially a durable "natural" plastic made from corn rather than petroleum, reports AP.

The plastic made from renewable resources performs as well and costs about the same to produce as plastic made from non-renewable hydrocarbons, the companies said Tuesday. It can be used in items as varied as clothing and food containers.

"To think that what is grown in a field can now be converted into plastic is really quite amazing," said Jim Stoppert, president and chief executive of Cargill Dow Polymers, the 50-50 joint venture between the two companies.

Cargill is among companies that already use corn to produce ethanol, a gasoline additive touted as reducing reliance on oil, but which relies on federal subsidies to remain competitive.

Cargill and Dow have invested more than $300 million to build a new plastic manufacturing plant in Blair, Nebraska, where Cargill has produced ethanol and animal feed at its corn wet milling plant since 1995.

By reducing reliance on petroleum, producers would be less affected by rapid swings in oil prices but could find themselves at the mercy of volatile grain markets.

The new CDP factory is to open at the end of 2001 and will produce more than 300 million pounds (135 million kilograms) annually of the plant-based plastic, called polylactide or PLA.

Initially, the plant will not increase the amount of corn ground by Cargill in Blair because the corn on hand will be shifted to higher-value products, such as the PLA, said Pat Gruber, CDP's vice president, technology and operations.

However, farmers could reap huge benefits from the technology in the future, and additional jobs could be created in rural areas as products from renewable resources are developed, Stoppert said.

The Cargill-Dow partnership already has the capacity to make almost 9 million pounds (4 million kilograms) of plant-based plastic per year at a Minneapolis-area plant. The company plans to double that capacity this year and plans to begin construction of a large plant in Europe in 2002. After that, CDP hopes to open a new plant every 18 to 24 months and begin licensing the technology to others, Stoppert said.

The technology has been in development for about 10 years, he said.

By 2010, CDP expects to be producing more than 1 billion pounds (450 million kilograms) of PLA annually from plants around the world, Stoppert said.

"That's a very small number compared to the overall plastics industry," he said.

World consumption of the top five plastic resins totaled more than 220 billion pounds (100 billion kilograms) in 1996, according to statistics provided by the American Plastics Council, which said consumption was growing at more than 5 per cent a year.

The production process, trademarked as NatureWorks, enables the company to capture the carbon removed from the air by plants during photosynthesis. Carbon is stored in plant starches, which can be broken down into natural plant sugars, which then are used to make the PLA.

CDP now uses sugars from corn to make its new plastic because it is abundant and inexpensive. The company's researchers are working on techniques to use the process to create plastics from many other plants, including wheat, sugar beets and agricultural waste such as corn husks and wood pulp.

Clothing containing the new plastic is wrinkle resistant, drapes better and is more comfortable because it wicks moisture away from the body, Stoppert said. Shirts containing PLA already are being worn in Japan and have been well received, he said.

When used for packaging, the plant plastic is fully degradable, the company said. The environment also benefits because production of PLA uses 30 per cent to 50 per cent less fossil fuel than is required to make conventional plastic resins.