Dimensional Specification
Vertical distance from the surface of a paperboard substrate to the apex of a raised crease or score line. Precise bead height ensures that the board folds along the intended axis without rupturing the top liners or coating layers. It represents the volume of material displaced into the female matrix during the converting process.
Folding Performance
Board thickness and moisture content dictate the specific clearance needed for a clean crease. If the bead height is insufficient, the score will not provide enough relief for the fold, leading to erratic folding angles on automated packing lines. High speed folder gluers require consistent heights to maintain throughput and avoid jams.
Excessive height causes the surface to crack or create unsightly ridges on the exterior of the carton.
Tooling Adjustment
Measuring this property usually involves optical micrometers or digital depth gauges capable of sub-micron precision. Operators adjust the pressure of the creasing rules against the anvil or matrix to achieve the target value. Variations in the caliper of the incoming board require immediate recalibration of the die pressure to keep the bead height within the tolerance specified for the production run.
Correct adjustment prevents the internal delamination of the plies from becoming visible on the finished product.
