Dynamic Crease Stiffness Reduction Ratios under Ultra High Speed Packaging Line Strain Rates
Dynamic crease stiffness reduction ratios must be evaluated under operational strain rates of 1000°/s to 5000°/s to prevent high-speed cartoning line jams.
Side-Wall Bowing
Structural Deflection
Paperboard packaging containers experience outward or inward curvature of their vertical panels when subjected to axial stacking loads or ambient humidity shifts. During transport and storage, side-wall bowing reduces box compression strength and alters container dimensions beyond automated handling limits.
Moisture Gradient
Moisture absorption causes cellulose fibres to expand in diameter at a rate significantly higher than their axial length extension. When one face of a paperboard panel absorbs moisture faster than the opposing face, differential dimensional expansion creates internal stress gradients that force the panel to bow outward or inward. Compression forces applied during pallet stacking exacerbate this curvature, pushing vertical panel centers outward and shifting the vertical load onto unsupported box corners.
Severe panel deformation reduces top-to-bottom compression resistance by up to thirty percent, increasing the risk of stack collapse in humid warehouses. Balanced barrier coatings and symmetrical board construction minimize moisture gradients across the paperboard substrate.
Load Distribution
Package design adjustments incorporate vertical creases or corner bevels to redistribute compressive forces away from flat panel surfaces. Structural reinforcement increases panel flexural stiffness, preventing dimensional distortion under heavy stacking loads. Maintaining flat panel geometry preserves package appearance and stacking performance throughout supply chain distribution.