Monday, March 01, 2010

Unusual Recyling Mix

I've not seen this before - a combination of recycling symbols on the same package.

The package is a 7 (Other), but it is 5 (polypropylene) compatible. How is this determination made? The SPI website doesn't have anything on classification, so what does it mean to be comparible?

Certainly I understand polymer comptability from both a practical and thermodynamic viewpoint, but I'm not sure that just any old processor would be willing to take a "polypropylene compatible" bottle from just anybody. That seems like a unworthy risk. The bottle manufacturer can suddenly say that their bottle is compatible with another resin stream? If anybody knows, please inform me as I am quite curious.

P.S. Today's "Ph.D. Commics" is terrific.

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