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.
Anilox Volume
Carrying Capacity
Fluid delivery on a flexographic printing press relies on the precise micro-cavity capacity of the ceramic roller. Engineers define anilox volume as the total fluid capacity held within the engraved cells per unit of surface area. In European metrics, this value is specified in cubic centimetres per square metre.
The measurement determines the wet ink film transferred directly to the printing plate.
Transfer Efficiency
The release of fluid from the cells during the impression cycle depends on cell geometry and surface finish. A shallow cell profile releases ink more readily than a deep, narrow structure of the same anilox volume. Modern lasers engrave these cells in hexagonal patterns or continuous waves to minimize aeration and ink spitting.
Highly fluid coatings and varnishes require a lower overall capacity than dense water-based inks. Proper blade setting ensures the excess ink is wiped clean, leaving only the measured amount. If the blade is worn, the transfer becomes uneven across the web.
Operational Limit
Rollers must undergo regular volumetric checks to account for wear and dried pigment buildup. Over time, the effective anilox volume decreases due to cell plugging, which reduces the colour density of the printed board. Regular ultrasonic cleaning maintains the target delivery rate.
When the volume drops below the tolerance threshold, the operator must replace or re-engrave the ceramic sleeve to prevent unacceptable print drift.