Patent ID: 7568644

Claim:
A cutting method comprising: providing a cutting system, the cutting system comprising: a first-stage cutting system comprising: a fixed cutter comprising: a first set of fins extending inwardly from a first wall of the fixed cutter, the fins separated by gaps; and a second set of fins extending inwardly from a second wall of the fixed cutter, the fins separated by gaps; wherein the first set of fins and the second set of fins are staggered with respect to one another so that the fins of the first set are aligned with the gaps separating the fins of the second set; and a first set of rotary cutters having sharpened cutting surfaces and being mounted on a first axle and positioned to rotate through the gaps between the first set of fins; and a second set of rotary cutters having sharpened cutting surfaces and being mounted on a second axle, separated from and parallel to the first axle, the second set of rotary cutters positioned to interleave and counter-rotate with the first set of rotary cutters and to rotate through the gaps between the second set of fins; a second-stage cutting system comprising: a fixed cutter comprising fins separated by gaps; a rotary cutter mounted on a third axle and comprising sharpened teeth that are positioned in register with the gaps of the second-stage fixed cutter so that the teeth rotate through those gaps; a chute positioned to channel material emerging from the first-stage cutting system into the second-stage cutting system; a comb positioned adjacent the rotary cutter and fixed cutter of the second-stage cutting system, the comb comprising a plurality of ridges and grooves facing the rotary cutter; a transmission system coupling the third axle to the comb; and a motor driving the third axle and the comb; introducing a material to be cut into the first-stage cutting system of the cutting system; counter-rotating the first and second axles so that the first-stage rotary cutters shred the material; advancing the material, or allowing the material to advance, through the chute and into the second-stage cutting system; and rotating the third axle so that the second-stage rotary cutter shears the shredded material against the second-stage fixed cutter, and the comb moves with motion oblique to that of the second-stage rotary cutter.