Non Contact Laser Profiling Verification Baseline Setup in Board Converting
Establish an isolated vacuum datum and calibrate 405-nanometer sensors to eliminate sub-surface scattering errors during board crease verification.
Crease Symmetry
Folding Alignment
Physical equilibrium of a score line relative to the intended fold axis and the distribution of internal ply delamination. Precise crease symmetry ensures that when a board is folded, the material displaces equally on both sides of the central groove. This balance is critical for the squareness of the finished carton and the overall aesthetic of the package corners.
Conversion Accuracy
Variations in the alignment of the creasing rule with the matrix channel can cause one side of the fold to have more resistance than the other. When crease symmetry is poor, the carton may develop a leaning profile or fish tail effect during the gluing stage. High speed filling lines are sensitive to these deviations because they rely on the carton edges being perfectly parallel for proper closure.
Adjusting the lateral position of the tooling is the primary method for correcting these imbalances.
Internal Mechanism
Paperboard is designed to delaminate internally when it is creased, forming a hinge that reduces the stress on the outer liners. If the crease symmetry is off, the delamination occurs unevenly, which often leads to the surface coating cracking on the side with the higher stress. Visual inspection and cross-sectional analysis are used to verify that the internal break is centered.
Maintaining this property protects the barrier coatings and ensures the package remains intact through the retail supply chain.