Cartons keep your chicken broth, soy milk and orange juice fresh, but their melding of multiple materials – paper coated with plastic and aluminum – has made this product packaging traditionally difficult to recycle.
But now cities across the U.S., from Los Angeles to New York, are making carton recycling more convenient for their residents by offering curbside and drop-off carton recycling programs.
There are two types of cartons; the first kind, aseptic or shelf-stable cartons, is made from paper with a thin layer of polyethylene plastic and aluminum to preserve products without refrigeration. You’ll find aseptic cartons in the non-refrigerated aisles of a supermarket to store broth, soup, soy milk and even wine.
The second type of carton – refrigerated cartons – is used to package juice, milk and egg substitutes and, as the name suggests, is found in the refrigerated section of the grocery store.
A common misconception about refrigerated cartons is that their paper is coated with wax, said Anna Collinson, project consultant at recycling and waste management company Resource Recycling Systems. The company supports the Carton Council, a group of carton manufacturers and other organizations that aim to increase carton recycling.
Refrigerated cartons contain no wax, Collinson said; instead, they have a thin layer of polyethylene plastic over the paper.
Carton recycling: coming soon to a city near you
Once a material with relatively few local recycling options, a growing number of U.S. cities like Boston and New York now offer recycling programs for cartons.
In 2008, only 18 percent of U.S. households had access to carton recycling programs, according to the Carton Council. Since the Council formed in 2009, that number has nearly doubled to almost 36 percent, with 40 million households in over 40 states now able to recycle cartons curbside or at a drop-off center.
The city of Dallas announced Thursday that its residents can now recycle cartons at the curb, making it the first major city in Texas to offer a carton recycling program. This summer, Los Angeles also started accepting cartons in its curbside recycling program.
The Carton Council assisted both Dallas and Los Angeles establish their new programs, helping the cities locate processers to break down the cartons into their material streams and manufacturers to turn the materials into new products.
How are cartons recycled?
Separating the carton’s plastic and aluminum layers from its paper isn’t as difficult as one may imagine and doesn’t even require specialized or high-tech equipment – just a hydro pulp machine, which is common to many paper mills.
Cartons are placed in the hydro pulp and agitated like a washing machine, until the aluminum and plastic layers detach from the paper.
“It looks like a giant blender,” Collinson said.
The aluminum and plastic are skimmed off the top of the machine, revealing paper fiber that goes into the paper recycling market. Collinson said that much of the paper fiber from cartons ends up with companies that manufacture tissue and paper towels or molded paper products.
“The paper [from cartons] is pretty valuable,” she said. “Because the color and design is printed on the plastic layers, the paper is clean underneath, so no de-inking is required as part of the recycling process.”
The leftover plastic is extruded into high-density plastic mold, which can be used to make plastic shipping crates and building products.
Though recyclable on its own, the scrap aluminum is not separated from the plastic and becomes what is called a poly/al mix, Collinson said. Aseptic cartons with both plastic and aluminum layers represent such a small percentage of cartons in the U.S., so the market for their leftover aluminum is small.
While cartons may make up a fraction of the nation’s waste compared to newspaper or plastic bottles, Collinson said that setting up recycling programs for cartons is still worthwhile.
“Cartons seem like a small portion of the waste stream,” she said. “But cartons are mostly paper, which is a valuable material that can be recovered and made into new product.”
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