CNC Creasing Wheel & Perforation Dieline Guide

1. The Mechanics of Rotary Creasing

A creasing wheel does not cut fibers; instead, it compresses the inner fluting and deliberate delaminates the linerboard along a precise hinge centerline. This creates a neat, low-resistance fold line without cracking the printed outer liner.

• With-Flute Creasing: The wheel travels parallel to the corrugated arches. The tool easily crushes the flute peaks with moderate pressure (2.0–3.5 bar).
• Across-Flute Creasing: The wheel crosses perpendicular to the fluting walls. Higher pressure (3.5–5.5 bar) is required to overcome the structural arch resistance and prevent the crease line from wandering into adjacent valleys.

2. Wheel Diameter & Tangential Steering Lag

Creasing wheels range from 26 mm (small radius for tight intricate box folds) to 60–90 mm (large radius for B/C/BC flute corrugated). Because the wheel has a broad arc of contact with the board floor, the CNC tangential steering motor must steer the wheel ahead of direction changes:

3. Perforation Rules: Cut vs. Tie Ratios

When folding heavy double-wall cardboard or creating tear-open tear strips, a solid crease may cause liner bursting. Rotary perforation wheels or programmed knife skip-cuts provide controlled tear resistance:

• 75% Cut / 25% Tie (e.g., 6 mm cut / 2 mm tie): Easy hand-tear strips for retail shipping boxes and courier envelopes.
• 50% Cut / 50% Tie (e.g., 3 mm cut / 3 mm tie): Moderate resistance for folding heavy double-wall packaging along sharp 90° bends.
• Micro-Perf (1.5 mm cut / 0.5 mm tie): Clean, nearly invisible tear line for vouchers and tickets.