Phase Change
Temperature thresholds where air becomes saturated and water vapor condenses into liquid form create immediate risks for paper packaging. Crossing the dew point transition results in the formation of surface moisture on cold containers when they enter a warmer, humid environment. This liquid water is absorbed directly into the porous fibers of the paperboard, which leads to a rapid loss of structural rigidity and potentially causes the stack to lean.
Material Degradation
Liquid water acts as a lubricant between the cellulose fibers and interferes with the adhesive bonds at the flute tips. During a dew point transition, the compressive strength of a corrugated case can drop by over fifty percent in a matter of minutes as the paper reaches its saturation point. This effect is particularly dangerous for refrigerated goods being moved onto an unrefrigerated loading dock.
Protective Barrier
Preventing damage requires the use of functional coatings or waxes that limit the rate of water absorption. Barrier layers do not stop the dew point transition from occurring but they provide a temporal buffer that keeps the liquid on the surface of the board. This protection allows the package to survive the temperature shift until the moisture can evaporate.
