Quantifying Surface Energy Values on Polyolefin Packaging Materials
Polyolefin surface energy quantification relies on standardized liquid titration or goniometry to secure ink adhesion and lamination bond strength across runs.
Dyne Fluid Titration
Surface Evaluation
Surface energy measurement on polymer films determines the wetting behavior of liquid coatings and printing inks. Applying dyne fluid titration involves using a series of liquid mixtures with known surface tensions to find the point where the liquid does not bead on the material surface. When the surface energy matches or exceeds the liquid’s surface tension, the drop spreads into a continuous film.
Ink Receptivity
Converting operations use this value to predict how well a substrate will accept aqueous or solvent-based printing inks. Substrates with low energy values suffer from pinholes and poor ink adhesion because the ink cannot spread out over the film. Correcting the surface through treatment raises the dyne level, allowing the ink to anchor securely to the polymer substrate.
Testing Procedure
Performing the test requires applying drops of fluid across the surface of the film and observing the time it takes for the liquid to break into droplets. A mixture of formamide and ethyl cellosolve is typically used to prepare the fluids at specific concentration increments. If the liquid does not rupture within two seconds, the operator moves to the next highest fluid level in the series.
The highest level that remains continuous for the duration of the test defines the surface energy of the substrate.