Dynamic Optical Displacement Calibration Protocols across Folding Boxboard Converting Lines
Dynamic blue-laser displacement calibration eliminates light-penetration drift, securing exact FBB crease metrics and stopping false sheet rejection.
Kaolin Top Coat
Mineral Formulation
Finely divided clay particles suspended in a synthetic binder create a smooth, highly white surface layer on paperboard designed for high-resolution graphics. This formulation, typically applied as a kaolin top coat, fills the microscopic voids between the surface fibres of the base sheet to improve ink holdout and brightness. The treatment establishes the foundation for excellent print gloss and uniform ink absorption during lithographic or flexographic printing.
Print Performance
Achieving a uniform barrier against ink vehicle penetration requires precise control over the clay slurry viscosity and the coat weight during the blade coating process. Lower coat weights can leave fibre tips exposed, which leads to mottled print or poor ink transfer on the press. Conversely, an excessively thick layer can become brittle, causing the coating to flake or crack when the board is folded along creasing lines.
By selecting a grade with an optimized coat weight, packaging converters ensure that both solid color blocks and fine halftone dots print with high fidelity.
Material Characteristic
Different clay grades offer varying levels of brightness and opacity depending on their particle size distribution. Sourcing clay with a narrow particle size ensures the most consistent surface finish across production runs.