Does crushing your aluminum cans prevent eddy current separators from working well? Should we not crush cans?

Question

I was told that aluminum cans need to be full size in order for the magnets to induce current into the cans better and give enough force to adequately separate them. I did a search and could not find any info verifying this. It seems odd to me that it would make that much of a difference or that the equipment couldn't be designed to work well with crushed cans.

Actually, I just got a response from a company that makes the machines. They do indeed say the machines do not work as well.

"For instance on a 14" series EC unit, a whole can would be tossed 3-4 feet from the centerline of the rotor. A flattened can 2 ½ feet and a hockey puck 1 ½ feet, so the splitter position would be nearer to the drum surface perhaps causing some product going in with the cans. "

So crushing cans can make it more expensive to recycle since they get more contamination in with the aluminum and vice versa.

Answer 1

I worked in a recyling plant one summer (during my college days). The seperator worked just fine on both crushed and uncrushed cans.

I don't remember any difference. I don't remember any cans that didn't go to their proper bins.

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Answer 2

actually, I believe it works better on crushed cans, but as mentioned, not noticeably. The crushing centralizes the metal and changes the mass per unit volume slightly. making the can easier to recognize.
When the cans hit the induction furnace they melt faster if crushed and less is burned up.