Creasing Groove
A prefabricated creasing strip provides the precise groove necessary to form a crisp fold in paperboard during the die cutting stage. When the steel rule descends, it forces the board into the counter matrix channel, which creates a permanent hinge.
Width Calculation
Mechanical calculators determine the groove dimensions based directly on the caliper and type of the packaging board being processed. The width of the counter matrix channel corresponds to the rule thickness plus twice the board thickness, adjusted slightly for the density of the substrate. If this calculation is incorrect, the crease will either be too loose to fold squarely or too tight, causing the top liner of the board to rupture during high speed folding carton assembly.
Accurate width protects the scoring lines from premature wear.
Material Selection
Synthetic materials such as presspaper and plastic form the structure of these creasing strips. Durability during a production run depends on the resistance of the counter matrix channel to the abrasive action of repeated board compression. During setup, operators use a locator strip to align the matrix perfectly with the creasing rule before gluing the channel down to the cylinder or cutting plate.
Once positioned, this alignment ensures that the folding resistance remains uniform across millions of impressions.
