PET bottles made from 100 percent recycled resin are the most sustainable, Lori Carson readily admits.
But the current recycling market is not ready to support a large influx of brand owners wanting to go completely green and still maintain expected quality.
Carson, commercial operations director at PET recycler Phoenix Technologies International LLC believes a 50 percent target for recycled PET use in new bottles will help companies meet their environmental goals while not compromising the recycling stream.
This new guideline comes from the Bowling Green, Ohio-based recycler as it sees more and more companies committing to using 100 percent reusable, recyclable or compostable packaging in the years ahead.
There's certainly room these days for individual companies to use 100 percent recycled PET in their bottles, but that's only because there are other firms that use much less.
If everyone bum rushes the recycling market looking for recycled PET, quality problems could arise, Phoenix warns.
"If you are just looking at sustainability then, of course, 100 percent is better. In the truest, simplest sense of dialog about recycling and recycled material and packaging, obviously the simplest look at it says 100 percent is better, Carson said.
But the squeeze that would be put on the market if everyone moved to that level would result in degradation of supply, she said.
Recycled PET, while maintaining its strength during reprocessing, can tend to darken over time when subjected to multiple heat histories. There are additives and modifiers to help, but only to a certain point, she said.
"Every time you are melting PET you are making it darker. That's just a fact. There's no getting around that," Carson said. "It becomes harder and harder to recover from that."
Phoenix has learned over that past 25 years that an overall 50-50 mix of recycled and virgin resin is a realistic sweet spot that would maintain the aesthetics of the bottles while not straining the marketplace.
"If some of the market is at 100 and some of the bottles are at 20, you are probably going to be fine," she said. "We think that 50 percent (overall average) is about the right place where you can run those materials and not see a large change in quality in what the package looks like."
Moving above that number, Carson said, "you are going to have a harder time meeting the general aesthetics."
That's not a problem in the current market, she said, but the recycling company felt the need to come out with some guidelines because it sees more and more companies announcing 100 percent commitments.
"Today, the market is not there. But just based on all of the announcements that are coming out, we're saying stop and think about some of this stuff," Carson said. "We're just trying to put out a cautionary statement."
The National Association for PET Container Resources put 2016 recycling at 28.6 percent for bottles. And not all those recycled bottles end up making new bottles as there are markets for textiles, carpeting and strapping, for example.
"Bottles that use 50 percent [recycled] PET are still 50 percent virgin. Because that percentage is still relatively low, when you introduce those bottles into the recycling stream, we anticipate minimal visual impact on subsequent lifecycles," said Ron Ott, Phoenix chief operating officer, in a statement. "The same doesn't hold true when bottles are at 100 percent [recycled] PET."
A way to help create enough recycled PET to avoid this potential future problem is to increase the bottle recycling rate. But that is a challenge, the company said.
Light weighting bottles, a trend in the packaging industry, actually helps with this issue, Carson said. That's because the darker colors that can result from multiple heat cycles is less noticeable in thinner container walls.