Quantifying Micro Surface Burnishing in Overprint Varnishes under Sled Shear
Surface burnishing under sled shear converts diffuse reflectance to specular gloss through silica displacement, controlled by matrix crosslinking and particle size.
UV Cured OPV
Protective Coating
Overprint varnishes formulated with photopolymerizable resins cure instantly under ultraviolet radiation to form a durable protective surface. Applying a uv cured opv onto printed paperboard provides high gloss and chemical resistance. The liquid varnish contains oligomers and photoinitiators that react when exposed to ultraviolet lamps on the printing press.
This instant curing allows immediate post-printing processes like die-cutting and folding. Utilizing this fast-drying technology increases production throughput and enables rapid turnaround times in high-speed converting facilities.
Surface Protection
The cured film provides an effective barrier against water, grease, and fingerprints, preserving the visual quality of premium packaging. Ink bleeding and dry-ink transfer are prevented during subsequent high-speed converting and packing operations. Precise adjustment of the formulation controls the coefficient of friction, ensuring the cartons slide smoothly through automatic packaging lines.
This customization prevents feeding jams and increases production efficiency.
Repulping Behavior
The high crosslink density of these varnishes can complicate the paper recycling process if the cured film does not separate from the fibers. Modern formulations are designed to break down into discrete particles during pulping, allowing them to be removed by screening and cleaning systems. Meeting these recyclability standards ensures that the gloss-coated packaging remains compatible with the circular economy.
This compatibility is checked through standardized laboratory deinking trials.