I worked as a temp for a plastic co. running their grinder. They molded plastic trim pieces for the auto and rv industry. We used to get in mixed boxes (different colors) and it was just marked a special # and after being ground it was mixed back into the new plastic. I would average about 10 boxes ground up a day at 1100 lb ea. but going thru a large hammermill the pieces looked like small dog food chunks when they came out. I could shove stuff 4' wide and 7' long into it. Would have a hammering headache for a couple of hours afterwords.