Predicting Set off Migration in Stacked Packaging Board under Non Uniform Compression
Predicting set-off migration requires calculating local pressure peaks across board caliper variations to set safe pile heights and barrier coat weights.
Structural Die Cut Stress
Mechanical Tolerance
Permanent deformation within corrugated board occurs when a die cutting operation exceeds the compression resistance of the fluting and liners. Structural die cut stress characterizes the magnitude of unwanted physical crushing applied to the board edges during the cutting cycle. This phenomenon originates when steel rules compress the substrate beyond its elastic recovery limit.
High pressure settings during production prevent a clean separation of the fiber, leaving the edges weakened and prone to structural failure during subsequent storage or transport.
Production Variable
Precision in setting the height of the cutting rule relative to the counter plate determines the severity of edge compression. Excessive force causes the rule to penetrate too far into the material, which destroys the internal fluting architecture and creates a fracture point. Operators adjust the machine pressure by monitoring the board thickness across the sheet after the cutting process finishes.
Correct calibration ensures that the steel rule severs the material cleanly while maintaining the internal geometry of the corrugation. When the rule engages with too much force, the board thickness decreases at the crease lines, which causes a loss of vertical stacking strength.
Quality Threshold
Engineering limits for acceptable deformation depend on the expected load requirements for the final container. Packaging for heavy items demands a higher tolerance for edge integrity because crushed board reduces the maximum top to bottom compression strength of the box. Laboratory testing methods involve measuring the caliper at the cut edge and comparing the result against the original board thickness.
A reduction in thickness exceeding a set percentage signals that the die cutting process is compromising the physical performance of the packaging. Uniformity in the cut edge maintains the stability of the box walls throughout the supply chain.