This question came up recently in a newsroom discussion over our recycling setup (a cardboard box with “aluminum cans” written on the side – I take it to my town recycling when full).
My understanding was that crushed cans can confuse the machinery used in single-stream systems (places where you put all recycling into the same bin). The machines “see” the shape of items when determining where to put paper, glass, ferrous metal, aluminum, plastic, etc., but crushed cans don’t look like cans so they can go in the wrong place, fouling the system.
On the other hand, as I understood it, if you’re in a place where you have to manually separate cans from paper, glass, etc. – like my town – then crushing cans to save space is fine. They get shipped straight to wherever aluminum goes to get recycled, regardless of shape.
I wasn’t entirely sure this was right, however, so I asked Jeff Weld, director of communications for Casella, which has the recycling contract for many New England towns and cities including Concord NH, where I am at the moment. He told me of a further complication.
Weld said that for Casella, crushed aluminum cans are no problem even when a collection is single-stream because “We use eddy currents to sort aluminum from ferrous metals, so it’s not a shape issue.”
Eddy currents are one of those things that make electromagnetism seem like magic. Aluminum isn’t attracted to magnets, obviously, but if you spin a magnet near aluminum or other material that conducts electricity, it creates a current within the material that can literally push it around. Eddy currents are used to send aluminum cans flying off a conveyer belt into their own bin, separate from the non-metallic stuff. Very cool.
So in conclusion: if you’re in a Casella-contracted community, crush your cans even if it’s single-stream. If you’re not sure who has the contract and if your town uses single stream collection, it’s probably best to leave your beer and soda cans in their natural state. If you manually separate your recycling, crushing is fine.
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I would collect aluminum cans from the various places I worked. After saving them up for a few months, I would load up the truck and take them to the recycling center in Merrimack. If I included cans from friends I would have around 400 to 600 pounds of aluminum. That made some pretty good walking around money. There was one restriction. I couldn’t mix other types of aluminum in with the cans. The aluminum from the cans is used to make more cans and other types of aluminum would contaminate the load. I crushed everything with a machine I made so it wasn’t any big deal.
“I crush everything with a machine I made” – that sentence pretty much sums you up, Earle!
Man power that’s how I crush them. Grab the top and bottom of a can give it a good twist then compress.
Real men do it against their forehead!
Girls can crush cans too, fellas. I do a roadside litter patrol in my neighborhood regularly, and I step on the cans to crush them to fit in my litter tote bag. No refund, but I refuse to live in a littered neighborhood, so this is what I have to do.