Laser Triangulation Topography Principles for Boxboard Surface Evaluation
Laser triangulation delivers uncompressed 3D areal topography data, isolating micro-roughness and void volumes that drive print quality across coated boxboard.
Dale Void Volume
Pore Architecture
Fiber network porosity defines how printing inks penetrate corrugated linerboards during high speed flexographic application. Dale void volume quantifies the total air space trapped between uncompressed cellulose fibrils within the paper matrix. This internal cavity structure dictates ink vehicle absorption rates and determines whether pigment remains on the surface for high optical density or drains too deeply into the substrate.
Refining mechanical stock preparation alters the interstitial spacing between bleached kraft fibers to restrict fluid migration. Excessive open volume leads to print show through on folding cartons while restricted spacing causes ink trapping failures and mottled solids.
Calendering Suppression
Heavy steel roll nip pressure flattens surface topographies to reduce caliper and close interior pathways before printing plates touch the paper. Press crews adjust loading schedules to compressDale void volume downward until liquid absorption matches the drying speed of water based flexographic inks. Excessive nip compression collapses internal capillaries entirely and prevents adequate anchor penetration for lamination adhesives.
Uncontrolled web moisture during rewinding exacerbates porosity fluctuations and causes inconsistent dot gain across large production runs.
Absorption Threshold
Finished packaging stock requires precise control over fluid uptake kinetics to prevent blistering during thermal drying stages. Laboratory Cobb testing measures water absorptiveness over defined time intervals to verify that Dale void volume remains within acceptable converter tolerances. Converters reject shipments failing these permeability limits because inadequate internal capacity ruins bond strengths during aqueous coating applications.
Accurate void calibration guarantees that corrugated containers maintain structural rigidity without sacrificing print fidelity.