Surface Energy Measurement Methods for Polyolefin Packaging Films
Polyolefin surface energy audits require OWRK polar component tracking and dyne fluid validation to prevent lamination delamination and slip agent masking.
Wet Tension Astm D2578
Surface Measurement
Standardized measurement procedures that determine the wetting limit of polyolefin films evaluate their receptivity to inks and adhesives. The execution of wet tension ASTM D2578 involves applying mixtures of formamide and ethyl cellosolve to the polymer surface to find the liquid that wets the film for exactly two seconds. This test provides a quantitative measure of the film’s surface energy, which must be high enough to ensure proper wetting and adhesion.
The measured value is expressed in dynes per centimeter or millinewtons per meter.
Testing Protocol
Draw-down cotton swabs are dipped in the test mixtures and drawn across the test film in a thin layer. The operator observes the wet line to see if it remains continuous or ruptures into droplets before the two-second mark. If the liquid layer remains intact, a mixture with a higher surface tension is tested next.
This iterative process identifies the surface energy level of the polymer substrate.
Quality Assurance
Low wet tension values indicate that the film requires additional treatment before printing or lamination can occur. If the film is processed with insufficient wet tension, the applied ink or adhesive will not bond properly, leading to package failure. Regular testing helps converters maintain consistent quality on the production line.