GAB Isotherm Calculations for Microfibril Barrier Sorption Qualification
GAB isotherm parameters determine microfibril moisture sorption capacity and establish precise water activity thresholds for barrier packaging compliance.
Paperboard Barrier Coating
Surface Treatment
Barrier treatment of a paper surface prevents the transmission of fluids or gases to protect the integrity and quality of the packaged contents. Engineers specify a paperboard barrier coating to protect the contents of a package from environmental degradation and to prevent leakage.
Protective Function
The coating is typically applied during the papermaking process or as a secondary converting step using blades or rods. Polyethylene and aqueous dispersions are common choices for creating a shield against water and moisture vapour. These layers must remain flexible enough to withstand the stress of creasing and folding without cracking.
Grease resistance is achieved by closing the surface pores or using materials that have low affinity for oils. The thickness of the layer is measured in grams per square metre and must be uniform across the entire web. High-performance barriers are necessary.
Recycling Capacity
Traditional plastic coatings can be difficult to remove in a standard hydrapulper and may require specialized separation equipment. Newer water-based dispersions are designed to break down more easily during the repulping process. The choice of coating involves a trade-off between the level of protection and the ease of recovery at the end of the product life.