I bought this specifically for preparing cardboard to be composted. The unit is powerful and has no problem shredding down cardboard boxes. My only complaint is that during normal operations the unit will frequently stop running and indicate that the bin is full when it is not. Tapping on the top of the machine causes it to resume shredding. I suspect there is a faulty connection or sensor causing the issue. I didn’t want to bother with returning it so I am just using it. If it stops working entirely I will take it apart and disable the bin full sensor. It is a powerful and relatively inexpensive shredder for cardboard that apparently has poor quality control.