Viscoelastic Creep Compliance and Interfacial Fracture Energy in Paperboard Laminates
Creep compliance dictates long-term carton deformation, while interfacial fracture energy governs delamination under score bending and pallet loads.
Dyne Surface Energy
Wetting Behavior
Surface treatment levels of plastic films and coated paperboard are measured by the wetting tension of specified liquid mixtures. Packaging converters utilize dyne surface energy to determine if a substrate will accept ink or adhesive. The property represents the surface tension required to prevent a liquid from bead forming on the board.
Measurement Method
Liquid mixtures of known surface tension are applied to the test surface with a cotton swab or pen. Technicians observe the liquid film for exactly two seconds to see if it ruptures or remains continuous. Achieving a continuous film indicates that the dyne surface energy of the substrate is equal to or greater than the tension of the liquid.
This binary determination allows for rapid quality checks on the production floor.
Coating Reception
Low energy levels lead to poor adhesion of printed inks and laminating films. Inadequate dyne surface energy causes ink to bead up or peel away during subsequent handling or shipping of the packaging. Treatment methods like corona discharge increase this property by creating polar groups on the board surface.
The treatment degrades over time, making immediate printing or conversion necessary for optimal adhesion, meaning that storage conditions must be monitored closely to prevent premature aging of the treated substrate.