Plastics Recycling
Granulator and Shredder Rotor / Stator Knives
Engineered to cut through contamination, glass fibre and reinforced polymers. D2 and M2 HSS options, with optional TiN or CrN PVD coating to extend service interval by 2–3× on the same line.
Working principle
How the rotor-stator shear cut works
Open-rotor and closed-rotor geometries cut by impact shear, not by slicing. The geometry choice, hook angle and clearance angle are dictated by substrate, throughput and contamination class.
A granulator rotor carries a ring of knives rotating past a stationary bed knife. Material enters the cutting gap and is sheared by impact, not by the kind of clean slicing a slitter performs. Open-rotor (cut-and-throw) geometries push the cut product out of the cutting chamber with the same rotation; closed-rotor (scissor-cut) geometries rely on a downstream screen to size the output.
The two failure modes we see most often —micro-chipping on glass-fibre and progressive welding on sticky polymer —both trace back to the same root cause: edge preparation and clearance angle were specified for the wrong substrate family.
Open rotor (cut-and-throw)
3 or 5 blades. Lower friction, higher throughput. Best for film, fibre, low-density feedstock.
Closed rotor (scissor-cut)
3 or 5 blades + matched bed. Cleaner cut, tighter granulate. Best for rigid plastic and engineering polymer.
V-cut / claw profile
For shredders. Aggressive bite on bulky post-consumer parts and purgings.
