In Business, Creating Sustainable Enterprises & Communities

GREEN PLASTICS HIT THE MARKET

In Business, May-June, 2006, Vol. 28, No. 3, p. 27

Over a decade after their introduction, compostable plastic products made from biodegradable polymers gain a foothold in commercial and consumer marketplaces.

Nora Goldstein

MORE THAN 10 YEARS have gone by since we began studying biodegra-dable polymers and their use in products designed for composting. Capacity has grown significantly for these biodegradable resins, creating the potential for lower unit costs. Without doubt, there is intense interest to see the price of compostable products decrease so that their use can be expanded. It's particularly exciting to see major companies use these polymers to provide green plastics.
Cedar Grove Composting operates two large-scale facilities in the Seattle, Washington region that process yard trimmings and commercial and residential source separated organics. When Cedar Grove initially began receiving food residuals, it was limited to preconsumer vegetative materials. Installation of the Gore Cover System technology at its original Maple Valley site and its new facility in Everett, Washington allowed Cedar Grove to accept postconsumer food residuals as well. As with most organics diversion programs, the desire to continue use of plastic bags to line collection containers arose. Cedar Grove would not allow conventional plastic bags, but did agree to test the use of the biodegradable variety. The company bags a considerable amount of compost, and in general, sells to higher value end markets. It was not willing to compromise the quality of its compost product by accepting bags and other biodegradable items such as cups and cutlery that would not biologically degrade. New products include bags, bin liners, utensils and plates.
Four brands of biodegradable bags have met Cedar Grove's criteria. They include BioBag, BioTuf by Heritage Bag, Eco Film/EcoWorks from Cortec Corporation and Nat-Ur, Inc. The BioBag brand is made of Mater-Bi, a blend of cornstarch and biodegradable and compostable polyesters, and vegetable oil. Heritage Bag's BioTuf brand is made from a proprietary mix of organic materials, including PLA and EcoFlex (from BASF). Cortec's EcoFilm/EcoWorks contains biobased polyester made from corn (no polyethylene or starch is used). The Nat-Ur bags are made from Cereplast biobased resins that include various starches and PLA.
HIGH PROFILE DEVELOPMENTS
Sustainability “speak” on the part of major corporations is leading to some significant commitments on the environmental front, which also could blow the market wide open for bio-degradable resins. One of the more dramatic corporate announcements came from Wal-Mart. In November 2005, the company announced that Sam's Club stores would begin using containers made from PLA produced by NaturWorks, LLC. According to an article in SustainableBus-iness.com, the stores started with packaging for cut fruit, strawberries, herbs and brussel sprouts, which account for over 100 million containers a year. In general, Wal-Mart CEO Lee Scott set a corporate goal of reducing its solid waste generation by 25 percent by the end of 2008.
Along with this high profile being given to biodegradable packaging must come a dose of reality - achieving the “cradle to cradle” goal requires having the final “cradle” available and accessible. In our “speak,” that final cradle is a composting facility that provides the controlled aerobic environment for these products to biodegrade. An article in the April 30, 2006 edition of Packaging Strategies on biodegradable and compostable package claims, opened with the following statement: “While biodegradable packaging continues to make market inroads, certification specialists have expressed concern that few standards are being followed by marketing departments that are making exaggerated, undefined, or even uncertified claims regarding their packaging's biodegradability and compostability. Corn-based PLA resins in particular will not degrade unless products are placed in a controlled industrial compost that contains the right mix of moisture, heat and microbes. Minneapolis-based NatureWorks specifies on its website that its PLA materials will be transformed and deteriorate in about 47 days if composting conditions meet global testing standards.”