Looks like the issue is the feed stock, non-uniform particle size distribution and significant differences in aspect ratio. All the different pieces are clumpin

Looks like the issue is the feed stock, non-uniform particle size distribution and significant differences in aspect ratio. All the different pieces are clumping up because of the particle interlocking. Maybe consider a grill sorter on the outlet of your size reduction system, allow <1cm particles through and rehandle larger particles back into whatever is chopping, or add secondary size reduction.