Coating Structure
Structural integrity of a sheet depends on the volumetric distribution of voids within the deposited mineral layer. The micro-porous matrix provides a network of interconnected capillary pathways that facilitate the controlled absorption of ink vehicles during the high-speed lithographic process. Proper configuration of these pores prevents the migration of pigments into the deep fibre structure, keeping the colorants at the surface for higher print density.
Void Geometry
Interstitial space determines the capillary pressure exerted on liquid carriers upon contact with the paper surface. Small pore diameters increase the rate of suction, ensuring the ink sets before the web reaches the next printing unit. Larger voids permit deeper penetration, which increases the likelihood of strike-through or ghosting in double-sided printing.
Manufacturers calibrate this void architecture by selecting specific particle size distributions for the pigment slurry.
Performance Threshold
Consistent print quality relies on the uniformity of this pore network across the entire width of the production run. Deviations in binder content or drying temperature alter the spatial distribution of the pores, leading to uneven drying times and mottling. Control systems monitor the permeability of the substrate to verify that the final web maintains the required ink acceptance rate for target gloss levels.
Substrate performance depends on the maintenance of a stable pore distribution under the mechanical stress of the transfer nip.
