New recycling technologies could keep more plastic out of landfillsv

New recycling technologies could keep more plastic out of landfills

It feels good to recycle. When you sort soda bottles and plastic bags from the rest of your garbage, it seems like you’re helping the planet. The more plastic you put in the blue bin, the more you’re keeping out of landfills, right?Get more news about Plast Recycling Maskine,you can vist our website!

Take flexible food packages. Those films contain several layers, each made of a different type of plastic. Because each type must be recycled separately, those films are not recyclable. Even some items made from only one kind of plastic are not recyclable. Yogurt cups, for instance, contain a plastic called polypropylene (Pah-lee-PROH-puh-leen). When this gets recycled, it turns into a gross, dark, smelly material. So most recycling plants don’t bother with it.

Only two kinds of plastic are commonly recycled in the United States. One is the type used in soda bottles. That’s called PET, short for polyethylene terephthalate (Pah-lee-ETH-uh-leen TAIR-eh-THAAL-ayt). The other is the plastic in milk jugs and detergent containers. That’s high-density polyethylene, or HDPE. Together, those plastics make up only a small fraction of plastic trash. In 2018 alone, the United States landfilled 27 million tons of plastic, according to the U.S. Environmental Protection Agency. A mere 3 million tons was recycled.

Low recycling rates aren’t just a problem in the United States. Only 9 percent of all the world’s plastic trash has ever been recycled. Twelve percent was burned. Seventy-nine percent has piled up on land or in waterways. Researchers reported those estimates in 2017 in Science Advances.Even when plastic does get recycled, it isn’t good for much. Recycling changes the consistency of a plastic. So recycled plastics have to be mixed with brand-new material to make sturdy products. What’s more, recycling a bunch of different colored plastic together creates a dark mixture. That means a lot of recycled plastic can only be used to make items whose color doesn’t matter, such as benches and dumpsters.

Plastic recycling clearly has a lot of room for improvement. And with plastic piling up everywhere from mountaintops to the seafloor, there is an urgent need for better recycling. Luckily, chemists around the world are on the case. Some are trying to make it easier to recycle more types of plastic. Others are trying to turn recycled plastic into more useful products. Both strategies could cut how much plastic winds up in landfills or oceans.One big challenge to recycling is that every type of plastic must get processed separately. “Most plastics are like oil and water,” says Geoffrey Coates. He’s a chemist at Cornell University in Ithaca, N.Y. Plastics just don’t mix, he says. Take, for example, a detergent container. The jug may be HDPE plastic, but its cap is polypropylene. What would happen if a recycling plant melted those two plastics together and tried to make a new jug from the blend? “It would basically crack down the side,” Coates says. “It’s crazy brittle. Totally worthless.”

That’s why all the plastic in the recycling bin first goes to a material recovery facility. There, people and machines sort trash. Sorted plastics are then washed, shredded, melted and remolded. The system works well for simple items like soda bottles and milk jugs. But it doesn’t work for items like deodorant containers. A deodorant bottle, cap and crank could all be different plastics.Food packaging films made of different plastic layers are even harder to take apart. Every year, 100 million tons of these films are made worldwide. Those films all go to landfills, says George Huber. He’s a chemical engineer at the University of Wisconsin–Madison.

Huber and his colleagues came up with a way to sort these pesky mixes of plastics. The researchers use different liquids to dissolve different plastic parts off an item. The trick is choosing the right liquids to dissolve only one plastic at a time, Huber says. This strategy was described last November 18 in Science Advances.