The most advanced recycling operations in the world divert 75 percent or more of community waste away from landfills. In their efforts to achieve 100 percent recycling, or so-called Zero Waste, three products have proved particularly stubborn:
The trouble is twofold: Diapers tend to be made of composite materials, including more than one type of plastic, and there is, of course, the organic waste.
Gary Liss, a recycling consultant in Northern California who sits on the board of several nonprofit recycling groups, including Zero Waste USA, said he knew of one model for recycling diapers, still in the trial stage in Santa Clarita, Calif., that involves separate curbside pickup for used diapers and then the pulling apart and cleaning of the constituent parts. But it’s expensive, Mr. Liss said, and economics are a big part of any recycling equation.
One way to pay for an approach like this would be for diaper manufacturers to include in the diaper’s sales price the cost of picking up used diapers and peeling them apart. But that is unlikely to happen anytime soon.
They are inexpensive and great for lugging light loads. But they are a nightmare for recycling plants, because they are so diaphanous that they float and cling and wrap and gum up multimillion-dollar machinery.
They’re such a problem at Recology, an advanced recycling operation in San Francisco, that it used to shut down twice a day so that workers with box knives could cut the plastic bags out of the spinning discs that help separate paper from cans and bottles.
In 2012, San Francisco banned plastic bags at retail stores, but they still show up at the recycling plant and force workers to do regular cleanings — “like clearing your lungs,” said Robert Reed, Recology’s spokesman.
They are a perfect example of composites, a vexing category for recyclers that includes a wide range of items, like furniture or consumer packaging that binds different materials together, such as plastics and metal and paper fibers. See, too: diapers. (The juice-box industry says a typical nonrefrigerated carton, as it’s called, includes 74 percent paper, 22 percent polyethylene and 4 percent aluminum.)
Those layers help preserve drinks, but also make the boxes extremely difficult to pull apart.
And to recycle, you must first sort. “It’s like separating an egg yolk from an egg,” Mr. Liss said of the composites problem. “It’s much easier to do before you stir it up.”
One possible solution is to create packaging that allows the materials to be more easily separated. Mr. Liss said an industry recycling group, The Carton Council, had been created to address the problem by developing additional sorting equipment. “The good news is that the industry is trying to figure it out,” Mr. Liss said. “They saw the problem, and they’re stepping up to address it.”