A ballistic separator is a mechanical sorting device with oscillating paddles that run the length of the sorting deck. Alternating sets of paddles are 60 to 120 degrees out of phase from the adjacent paddle to provide agitation of the material stream on top of the deck. The agitation has a different effect on the commingled waste stream causing a separation of rigid items off one end and flexible items off the other. The paddles usually have a mesh opening in the deck to allow the fines, such as glass, to drop through the deck to provide another separation.
When used in sorting waste, the rigid items are? containers like plastic bottles, glass, aluminum cans, steel cans. The flexible fraction is plastic wrap and different paper grades like cardboard, mixed office paper, and newsprint. (video)