High-Speed Rotary Slitter Knives & Circular Cutting Blades for Paper, Tissue & Corrugated Converting

Specify M2 high-speed steel at HRC 62–64 for tissue converting above 400 m/min. The molybdenum and tungsten carbides in M2 maintain edge geometry under the thermal cycling generated by ultra-high-speed cutting, delivering 2–3× longer campaign life than D2 on lightweight tissue grades (12–18 GSM).

Fiber dust is primarily caused by excessive shear clearance (>0.10mm on tissue) or rough blade surface finish (Ra >0.6μm) that tears fiber bundles rather than shearing cleanly. Specify matched shear pairs with pre-verified clearance (0.02–0.05mm for tissue, 0.05–0.10mm for kraft paper) and Ra ≤0.4μm surface finish. This reduces airborne dust by 60–70% compared to standard industrial knife grades.

For corrugated board (B/C/E flute), crush cutting against a grooved anvil roll is the standard method. The anvil blade compresses and fractures the paper fibers cleanly without requiring precise shear clearance maintenance. Shear slitting is reserved for lightweight coated papers and tissue where fiber pull must be minimized. For corrugated applications above 200 m/min, specify tungsten carbide anvil blades to resist the compressive wear from multi-ply board stock.

Paper slitter knives on tissue converting lines (400–600 m/min) typically require regrinding every 40–60 operating hours due to the high cutting speeds and abrasive mineral fillers in tissue paper. For kraft paper and board converting (200–300 m/min), the regrind interval extends to 80–120 hours. M2 HSS and D2 knives can be reground 4–6 times before the OD falls below minimum operational diameter. We offer a regrinding service with hardness re-verification and CMM dimensional check included.

Uneven slit quality (clean cut on one side, fiber pull on the other) indicates uneven blade mounting or differential thermal expansion across the arbor. Verify that all knives on the arbor are ground to ±0.002mm thickness tolerance and that the arbor shaft runout is ≤0.02mm T.I.R. Thermal expansion can be mitigated by using matched metallurgy (all D2 or all M2) across the full knife set, ensuring uniform thermal expansion coefficients during high-speed operation.