Surface Energy Shift and Gloss Drift under Friction Sled Cycles
Friction sled cycles strip migratory slip agents, elevating polar surface energy while generating micro-roughness that causes severe specular gloss drift.
Dyne Level Degradation
Decay Velocity
Surface treatment retention on plastic and extrusion-coated paperboard determines the long-term adhesion of printing inks and adhesives. The dyne level degradation process describes the gradual decrease in surface energy that occurs on treated films or polymers over time. This decline starts immediately after corona, flame or plasma treatment.
Chemical Alteration
Atmospheric exposure and migratory additives in the polymer accelerate this loss of surface activity. Slip agents and waxes migrate to the surface of the film, masking the oxidized polar groups created by the treatment. High ambient temperature and humidity during roll storage also quicken this decay, making the material less receptive to ink.
Prudent converters use the material within a specified timeframe to avoid bonding failures on the press.
Converting Hazard
Assessment of this decay is carried out using dyne test pens or contact angle measurements before the printing or lamination step. If the surface energy falls below a minimum threshold, inks will not wet the surface properly, leading to peeling, flaking, or poor ink adhesion during subsequent converting operations. Material specifications must dictate maximum storage times and temperature limits to minimize the rate of this loss.
Maintaining these controls ensures that extrusion-coated board retains sufficient polar surface activity to bond securely with water-based or ultraviolet-cured laminating adhesives.