Two-shaft shredders are used for size reduction of most materials. The shredders utilize two counter rotating shafts with close tolerance cutters that shear products into strips of uniform widths. Shred width matches the thickness of the cutters. Hooks on the cutters help pull material into the cutters and limit the length of the shredded pieces.
The shafts of two-shaft shredders rotate at slow speeds, typically 15-35 rpm. Slower rotation requires greater gear reduction and provides greater torque yielding higher cutting force. Faster rotation allows for faster shredding but at the expense of cutting force. Proper motor sizing balances cutter force requirements with production requirements.