Tool Dimension
The thickness of the steel strip used to indent the paperboard during the die-cutting process establishes the width of the crease. Choosing the correct creasing rule width is essential to prevent both surface cracking and inadequate fold definition in finished cartons. This dimension is typically matched to the caliper of the board being converted to ensure optimal deformation.
Fiber Deformity
The steel rule must press into the board to delaminate the internal structure without cutting the outer liner. If the rule is too narrow, the excessive localized pressure tears the top fibres and ruins the print surface. A wider rule spreads the force across a broader area, creating a gentler crease that allows the board to delaminate internally, which in turn reduces the force needed to bend the panel at the folder-gluer.
This delamination is necessary for multi-ply paperboard, where the layers must separate to form a clean bead on the inside of the fold.
Scoring Tolerance
The alignment between the creasing rule and the matrix channel dictates the consistency of the folding line. Precise rule selection prevents the board from slipping during the downward stroke of the press. This mechanical precision guarantees that the resulting carton has straight, true edges for automated packing.
