Die Geometry
Precision steel cutting requires exact clearance angles because dull bevels crush fluting before severance occurs. Rule tip radius defines the micro dimension at the apex of a steel creasing or cutting blade used in carton conversion. Converting lines set this parameter by grinding the apex to a specific fraction of a millimetre to prevent substrate rupture during high speed die cutting.
Substrate thickness dictates the exact sizing because heavy corrugated boards demand wider apex profiles than thin folding boxboards. Lowering the apex width too far causes premature fracture along the fold line. Increasing the radius excessively prevents clean scoring and leaves a rounded hinge that fails packaging structural integrity tests.
Press Pressure
Cylinder force adjustments compensate for minor caliper variations across large paperboard sheets. Converting machines apply downward tonnage to press the steel rule into the backing matrix. High tonnage flattens the apex prematurely if the steel grade lacks sufficient hardening.
Operators adjust impression depth to match the calibrated apex dimensions of the tooling. Tool wear alters the cutting edge over extended production runs. Continuous friction rounds off the sharp profile and forces higher press pressures to achieve complete separation.
Matrix Clearance
Channel width selection depends directly on the steel blade geometry and the caliper of the paperboard. Folding cartons rely on accurate channel placement to form crisp ninety degree folds without cracking the outer liner. Die makers calculate channel width by doubling the board thickness and adding the apex dimension.
Incorrect channel sizing tears the surface fibres during the folding stroke. Proper clearance supports the board during the crease formation and ensures clean panel alignment on automated packaging lines.
