In an article published on April 6, 2017 by news provider Plastics News, reporter Jim Johnson informed about a new study showing that the choice of labels, inks, and glues can impact the recyclability of polyethylene terephthalate (PET) drinking bottles.
The study was performed by the U.S. company Plastic Technologies, Inc. (PTI), specializing in the technical development of PET. To conduct their research, PTI purchased the top-selling 500 mL water bottles from stores in the U.S., Mexico, India, and Europe. According to the study, using the wrong type of label material, glue, or inks can result in the contamination of recycled PET. For example, “bits of paper fiber and glue that remain on PET after the separation process can burn and cause black marks when flake is later heated,” Jonhson explained. He further illustrated how cheaper inks that bleed during the water-based separation process “can contaminate recycled flake and cause discoloration of recycled plastic.” Johnson reported that all label samples used by PTI “caused color and clarity change in the wash process,” and that label ink bleeding was the most common phenomenon observed.
The study concluded that using the label substrate compatible with PET recycling, together with soluble inks and glues, could improve overall recyclability of PET.
Jim Johnson (April 6, 2017). “Study: Labels impact PET bottle recyclability.” Plastics News