Flexographic Ink-Coating Interactions: Effects of Porous Structure Variations of Coated Paperboard
2013 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, no 4Article in journal (Refereed) Published
Ink transfer and ink penetration into a coated surface, and variations thereof, influences the print density, mottling and dot gain, which affects the achievable print quality and visual appearance. The pressure in the printing nip and the porosity of the substrate are conditions and properties that will regulate the amount of ink that penetrates into a porous coating structure. The purpose of this study was to relate print quality aspects to ink penetration of water-based flexographic ink into calcium carbonate based coatings of differently engineered structures. Pilot-coated paper-boards with different coating porosities were printed in a laboratory flexographic printer. Results indicate that ink transfer distribution is strongly affected by the roughness and the porosity of the substrate. A coating layer of broad pigment particle size distribution resulted in a lower print density, compared to coatings of narrowly distributed particle sizes. A structure characterized by larger pore volume and greater dominating pore radius, showed a higher amount of z-directional ink penetration, which was supported by estimating the penetration using a physical model accounting for both capillary- and pressure driven penetration. A coating with narrow particle size distribution also showed a lower dot gain.
Place, publisher, year, edition, pages
AB Svensk papperstidning , 2013. Vol. 28, no 4
Coating, Pigment, Calendering, Porosity, Flexographic Printing, Print quality
Research subject Chemical Engineering
IdentifiersURN: urn:nbn:se:kau:diva-30026ISI: 000328642400012OAI: oai:DiVA.org:kau-30026DiVA: diva2:664429