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.
Polyethylene Wax Disperse Phase
Coating Dispersion
Substituted polyolefin particles suspended within an aqueous carrier form the polyethylene wax disperse phase during high-shear emulsification prior to web application. This microscopic solid suspension modifies surface friction coefficients on paper substrates during barrier coating operations. Surfactant stabilization prevents agglomeration of nonpolar hydrocarbon molecules inside the polar liquid matrix.
Particle size distribution directly dictates downstream slip properties and scuff resistance on folding carton surfaces. Thermal drying drives off moisture while forcing coalescence into a continuous protective micro-film across the fibrous sheet.
Slip Regulation
Finished packaging converters rely on precise concentration controls of the polyethylene wax disperse phase to prevent high-speed printing press jamming. Dynamic friction drops rapidly as dispersed paraffin fractions migrate toward the air interface during consolidation. Excessive particle volumes compromise subsequent glueability and hot-foil stamping adhesion on coated cartonboard.
Roller coater shear rates must remain constant to maintain uniform particle distribution across wide web widths without destabilizing the liquid suspension.
Rheological Control
Viscosity profiles fluctuate significantly when adding the polyethylene wax disperse phase to water-based barrier formulations destined for corrugated linerboard production. Non-Newtonian thinning behavior occurs under mechanical stress inside high-speed metering systems. Formulators adjust surfactant chemistry and solids loading to prevent premature sedimentation inside storage tanks before application onto moving substrates.
Proper formulation geometry ensures reliable leveling across rough paper webs without causing pinhole defects in the dried film.