Polymeric Paperboard Barrier Coating Test Methods and Compliance Documentation
Verify polymer barrier paperboard through creased Cobb testing, migration simulant suites, Cepi repulpability yields, and lot-matched Declarations of Compliance.
Aqueous Dispersion
Fluid Matrix
Liquid systems containing finely divided solid particles distributed throughout a water phase enable the application of functional layers without organic solvents. An aqueous dispersion acts as a carrier for polymers or pigments that are insoluble in water but must be spread evenly across a paper surface. Surfactants and stabilizers prevent the particles from settling or clumping during storage.
Environmental Profile
Compliance with modern sustainability targets often involves the replacement of plastic lamination with waterborne alternatives. Using an aqueous dispersion reduces the reliance on traditional extrusion methods and allows for easier repulping of the treated paper. The recovery of fibres during the recycling process is more efficient because the coating breaks down more readily in the hydrapulper.
This shift supports the circular economy by making grease-resistant and moisture-resistant packaging compatible with standard waste streams.
Film Formation
The transformation from a liquid state to a solid barrier involves the evaporation of water followed by the fusing of individual polymer spheres. Heat and airflow in the drying tunnel of a coating machine drive this aqueous dispersion toward its final film state. Achieving a pinhole-free surface is critical for maintaining barrier integrity against gases and liquids.
If the drying rate is too aggressive, the surface may skin over and trap moisture, leading to blistering or poor adhesion. Proper balance between the wetting characteristics of the substrate and the surface tension of the liquid ensures a uniform layer across the entire width of the web.