Meaning
High-voltage electrical discharge components raise polymer surface energy relative to the surface tension of water-based inks and adhesives. A generator electrode delivers high-frequency electrical potential across air gaps to create localized corona discharge on polyolefin films. Non-polar resins like polyethylene require oxidation to permit wet-out during printing or laminating operations.
Datasheet dyne levels establish laboratory baselines, but actual surface activation depends on air gap distance, treat rate, and humidity.
Electrical Discharge
Alternating current at high frequency ionizes atmospheric air between the conductive element and a grounded backing roll. Hydroxyl and carbonyl chemical groups graft onto the polymer surface as electrons impact the moving film web. Gap spacing must remain constant across the width of the treater station to prevent uneven surface energy.
Thermal expansion of the electrode bar during continuous operation alters the discharge gap, requiring rigid mounting assemblies.
Dielectric Boundary
Excessive voltage levels cause dielectric breakdown of the backing roll sleeve, puncturing thin polyolefin films with pinholes. Over-treatment oxidizes low molecular weight fractions, forming a weak boundary layer that degrades heat seal strength. Contaminated films carrying slip additives require higher treatment power due to additive migration to the web surface.
Regrind content alters dielectric properties, demanding real-time power adjustment.
Adhesion Performance
Properly surface-treated films retain print quality and lamination bond strength during long-term storage. Uniform treatment across the web prevents ink flaking and coating defects during downstream converting operations. Monitoring dyne levels ensures consistent ink adhesion without damaging substrate mechanical properties.
