The plastics industry's on-again, off-again relationship with biodegradable materials took a turn for the better Jan. 11 when Cargill Dow Polymers LLC unveiled plans to build a $300 million biodegradable polymer plant in Blair, Neb. The plant, set to begin operating in late 2001, will have annual capacity of about 300 million pounds of NatureWorks-brand polylactide resin. Cargill Dow is a 50-50 venture between Dow Chemical Co. of Midland, Mich., and agricultural products giant Cargill Inc. of Minnetonka, Minn.
The new materials will be made completely from renewable resources, such as corn, by processing natural plant sugars. The resins are expected to compete with polyethylene, polypropylene, polystyrene and PET in bottles, films, fibers and nonwoven applications in fabric.
At a news conference in New York, Cargill Dow also announced plans by 10 North American and European manufacturers to use NatureWorks polylactide in their products. The list includes Interface Inc., an Atlanta firm that claims to be the largest commercial carpet manufacturer in the world; and Hoechst Trespaphan GmbH of Neunkirchen, Germany, the world's second-largest producer of oriented PP film.
Cargill Dow officials said polylactide resins will have uses in everyday items such as clothing, cups, food containers, candy wrappers and home and office furnishings.
"To think that what is grown in a field can now be converted into plastic is really quite amazing," Jim Stoppert, Cargill Dow Polymers chief executive officer, said in a news release. "The NatureWorks process allows us to tap into the natural raw materials contained within plants and create plastics with performance that is equal to or better than those made from nonrenewable sources."
"The cost and performance achieved with NatureWorks [polylactide] enables it to meet the needs of a wide variety of applications that currently use plastics or other traditional materials such as cotton, paper, glass, wool and silk," said Pat Gruber, Cargill Dow's vice president of technology.
Cargill Dow currently is producing about 9 million pounds of polylactide each year at a semicommercial pilot plant in Minneapolis. Capacity at that site will double this year.
Polylactide resins are expected to sell for 50 cents to $1 per pound when the Blair plant begins production next year, according to John Ohman, Cargill Dow marketing director.
"We've set that as our target price range," Ohman said. "As we build economies of scale, prices will go down."
The economic value of biodegradable products has to equal the environmental benefits for the product to succeed, he added.
"We don't want to diminish the environmental impact, but if we were just doing this to make compostable materials, we wouldn't be building a plant like this," he said. "You need the environmental piece, but you need cost and performance too. That's the hard lesson earlier biopolymers learned. People aren't buying biodegradable products out of the goodness of their hearts."
Using agricultural resources to produce plastic also would allow resin makers to escape the highly cyclical pricing that afflicts standard, petroleum-based plastics such as PE.
"In a general sense, producers want to break away from the petroleum cycle and get into high-end products," Ohman said.
The Blair site was picked because of its proximity to a Cargill lactic acid plant there. Cargill produces 75 million pounds of lactic acid from fermented corn dextrose in Blair, and Cargill Dow plans to build a similar lactic acid plant by late 2001.
The site, which will employ 100, also offered good supply-chain costs and production advantages because of its closeness to major transportation routes.
Long-term plans call for building a similar polylactide plant in Europe in 2002. Wheat probably will be used as the feedstock there, because it is more plentiful in that region than is corn, Ohman said.
The track record for biodegradable plastics — those that would degrade completely and therefore not take up space in landfills — has been spotty at best.
Mobil Chemical Co. and First Brands Corp. made unsuccessful tries at commercializing biodegradable trash bags in the late 1980s and early 1990s. In the past 18 months, Monsanto Co. has stopped production of its Biopol-brand biodegradable plastics, and ACX Technologies, a spinoff of the Adolf Coors Co., dissolved it Chronopol unit, which was to have built a polylactide plant in Colorado.
Other efforts are pushing forward. Wilmington, Del.-based DuPont is developing a natural polyester product, while in Japan, Shimadzu Corp. and Kobe Steel Ltd. are developing their own polylactide plans. However, neither of those ventures has been commercialized.
Elsewhere, Biocorp Inc. of Redondo Beach, Calif., continues to produce biodegradable plastic bags, cutlery, cups and plates made with Mater-Bi, a biodegradable resin made by Novamont SpA of Milan, Italy. Biocorp also distributes Mater-Bi for Novamont in North America. ECM BioFilms Inc. of Mentor, Ohio, also markets a biodegradable resin for use in bags and other items.