Transitioning to adhesives that don't hinder recycling could be one of the stickiest challenges that packaging thermoformers face in meeting the new mandate by the Retail Council of Canada that clamshell food packaging be made from PET by next year.
“PET thermoform containers use non-friendly adhesives compared to the bottle stream,” said Mike Schedler, technical director for the National Association for PET Container Resources in Sonoma, Calif. “It costs so much to remove them that it makes the process inefficient because it increases processing time.”
The major problem is that most thermoformed PET clamshells in grocery stores use pressure-sensitive labels applied at the store, and usually the entire label is covered with adhesive, said Dave Cornell, technical director of the Association of Postconsumer Plastic Recyclers in Washington.
Cornell said the glues are often so strong that the label cannot be removed from the plastic, which prevents it from being properly recycled.
By contrast, adhesives on PET bottles “are almost all a hot melt applied in a thin strip [covering about 10 percent] of a wrap-around label, [with] the labels applied at high speed on a conveyor line by machinery,” Cornell said. “PET bottles do not have many pressure-sensitive labels. So, the bottle experience does not help the thermoform experience very much.”
To help PET thermoformers and companies switching to PET from other resins such as polystyrene and polypropylene, APR, in conjunction with NAPCOR, introduced a new test protocol June 30 to determine the impact of labels and adhesives on PET thermoformed package recycling.
“The testing program should define what works and what does not,” Cornell said.
“This protocol will play a pivotal role in allowing PET thermoformed packaging to be recycled in the most efficient way possible,” added Allen Langdon, vice president of sustainability for the RCC, which represents more than 43,000 retail stores and online merchants in Canada. Products that pass the protocol will be posted on the APR website.
The main reason for the uniform testing program? “The Canadian grocers want to make the adhesives compatible with what's on bottles so that the materials in the recycling stream won't be incompatible,” Schedler explained.
RCC said all suppliers to Canadian grocers should participate in the testing protocol process.
“We urge all suppliers to get involved so that our members will know the appropriate labels to use for their private-label and in-store packaging,” Langdon said.
Adhesive makers must register their products with APR by July 15. APR will then test and certify those adhesives as working with existing cleaning systems already in place for PET bottles. By Jan. 1, companies that supply thermoform packaging to Canadian grocers must meet APR-certified adhesives guidelines.
To register, and for more information about the test protocol, visit the APR website, plasticsrecycling.org/pet-thermoforms.
“This could have a huge impact nationwide in Canada — not just in Ontario,” added Schedler. “The bottom line from the conversion of all thermoformed packages in Canadian grocery stores to PET is not insignificant. This will give recyclers a huge new chunk of business.”