Calculating Counter Die Relief Depth across Laminated Substrate Thickness Variances
Counter die relief depth calculation requires adjusting nominal board caliper for dynamic fiber compression, film stiffness, and moisture regain clearance.
Lamination Delamination Failure
Structural Separation
Internal bond failure between layered materials occurs when the adhesive or thermal bond cannot withstand the mechanical or chemical stresses applied to the composite. Lamination delamination failure appears as bubbles or total detachment of films from a paperboard base. This breakdown compromises the barrier properties and structural integrity of the package, often leading to product spoilage or loss of shelf appeal.
Root Cause
Weakness usually stems from inadequate surface preparation or the presence of contaminants like waxes and oils on the substrate. If the surface energy of the paperboard is too low, the liquid adhesive will not wet the surface properly, resulting in a poor physical bond. Testing the dyne level of the board before lamination helps prevent these issues on the production line.
Environmental Stress
Environmental factors such as high humidity or temperature fluctuations during transport can stress the interface between materials with different expansion coefficients. Some aggressive food contents like fats or acids migrate through the layers and chemically degrade the bonding agent. The failure becomes critical when the protective function of the inner lining is lost, exposing the underlying board to moisture or grease, which quickly leads to a total loss of structural rigidity in the box.
This deterioration often results in a complete collapse of the secondary packaging during warehouse stacking, creating safety hazards and resulting in total loss of the contained product.