A large segment of the beverage industry went to tethered caps decades ago following public outcry about shrapnel-like aluminum pull tabs from beer and soda cans posing health and ecological risks.
All those sharp-ended metal ring pulls glimmering at beaches and parks shined a light on the growing problem.
So did singer Jimmy Buffett, who bemoaned cutting his heel when he stepped on a pop top and blew out his flip flop in his 1977 hit song "Margaritaville."
The beverage industry responded to the problems, according to Jay Yuan, the principal of Houston-based Stress Engineering Services Inc. He has worked in the U.S. packaging industry for 24 years.
"The invention of stay-on tabs caught fire in the 1970s. That's the technology that eliminated one of the nation's most common pieces of litter. What is the equivalent for plastic caps?" Yuan asked.
He posed a question that design engineers must answer relatively soon during Plastics News' Plastics Caps & Closures 2020 virtual event.
By 2024, the European Union is requiring all single-use plastic beverage containers with volumes of 3 liters or less to have closures that remain affixed to the bottles.
So, now it's the plastics industry's turn to do something about all its colorful caps littering beaches and swirling in ocean gyres.
Michael White, business development manager of beverage closures at Bolton, Ontario-based Husky Injection Molding Systems Ltd., said the legislation passed by the EU in 2019 is resonating in North America.
"We believe it's basically the first domino to fall," White said. "The states of California and Maine are looking at introducing similar legislation. And Canada is looking at criteria there. The thinking is that by tethering small closures to the bottle itself, it's more likely to be recycled than simply discarded."
Husky representatives have been active with an EU steering committee formed to help establish the standards there. White said the minimum performance guidelines call for closures to withstand a minimum of 15 openings and closings without the tether being compromised as well as a separation, or pull force, of 25 newtons in the vertical or horizontal direction.
"This is a value that all closure developers in the industry are targeting currently," White said, adding the value could change before the law is enacted in 2024.
The pending requirements raise a slew of design considerations as to the bottle neck type of tether to use – lanyard loop, helical tether, hinged or other – as well as branding, shelf differentiation, sustainability and the consumer experience.
"We see this as an opportunity for brand owners and converters alike," White said. "It's a way to talk about sustainability on the shelf. You can promote the fact the closure is tethered to the bottle. The brand is making an effort to promote sustainability."
And, any time you have an opportunity to tell a story about something new related to your product, "It's a good thing," White added.