If recyclers were able to collect as high a percentage of used detergent bottles as they do milk bottles, the quality, flexibility and durability of the resulting recycled-content product would improve, says a corporate environmental consultant. Such a move also might bring economy to the market. High density polyethylene homopolymer milk bottles are premium-priced, in part because they are uncolored, and are more plentiful in curbside and dropoff collection programs.
John McDonald, consultant for environmental affairs at Continental Plastic Containers Inc. in Norwalk, Conn., said laundry detergent and household cleaner manufacturers are urging increased recycling of copolymer HDPE.
``They're saying `You've helped the dairy industry, now help the others,'*'' McDonald said.
More copolymer HDPE from detergent bottles would increase flexibility and durability of the recycled-content product, he said, adding that there also would be fewer of the stress crack problems that plague homopolymer.
Recyclers seem to note an increase in the demand for copolymer.
John C. Neubauer, president and chairman of Blueberry Plastic Mill Corp. in Des Moines, Iowa, applauded the move, saying ``it preserves the homopolymer for higher-value purposes.''
He added, ``I've been surprised by the oil bottle industry,'' which has resisted the use of more-durable copolymer HDPE in consumer packaging, partly due to the desire for a particular, or uniform, oil bottle color.
The result is an oil bottle with a higher level of less flexible homopolymer, which increases the potential for leaks, he said.
Continental Plastic Containers makes multilayered homopolymer/copolymer bottles for several companies, including Procter & Gamble Co., based in Cincinnati.
``Our supply [of both kinds of HDPE] is in balance. We get enough homopolymer milk bottles, but we need more copolymer. We're encouraging our suppliers to give longer-term assurances'' that their continued HDPE shipments will include more copolymer, according to McDonald.
``Also, the quality of our supply has increased significantly in the past 18 months, especially with regard to consistency. We like the color sortation work that's going on,'' he said.
To this point, the recycled portion of a typical Continental recycled-content container consists of half homopolymer and half copolymer.
``This varies by bottle in terms of functionality, for example,'' McDonald said.
