Compression Displacement
Dimensional deviation occurs when vertical pressure causes the lower layers of a palletized substrate to lose their intended alignment. Stacking creep describes this gradual shift in position resulting from sustained weight on fibreboards or corrugated structures. Moisture content within the paper pulp often determines the threshold of such movement under load.
Physical Mechanism
Gravity pulls against the internal friction of the stacked sheets while external vibration accelerates the process. Vertical stress forces air out from between the fibre matrix, reducing total thickness over time. A tall pallet experiences higher cumulative pressure at the base compared to the top, creating non-uniform settling across the unit.
Converting machines require precise sheet edges for successful feeding, making this tendency toward uneven stacks a primary concern for long-term storage of heavy paper stock.
Load Tolerance
Rigidity in the containerboard construction limits how far the product drifts before the structural integrity of the entire stack reaches a critical failure state. Engineers calculate the maximum allowable vertical load based on the humidity of the environment and the specific grammage of the material. Excess moisture significantly lowers the mechanical resistance of the boards, causing the stack to lean even under moderate storage conditions.
High humidity shifts the internal bond strength, rendering the paper vulnerable to deformation regardless of the initial pallet stability. Careful control of the warehouse environment prevents this reduction in load-bearing capacity.
