Limitations of Current Formulations when Decreasing the Coating Layer Thickness of Papers for Inkjet Printing

The porous network structure of a coating layer has a major effect on how quickly inkjet ink penetrates into the coated paper, and how large the pore volume is determines the capacity for ink volume uptake within the coating layer. If the penetration rate and/or pore volume are insufficient, the ink colors stay too long on the surface, resulting in undesirable mixing (intercolor bleeding) and trans-surface wicking (feathering). The aim of this work was to clarify whether it is possible to decrease the coating layer thickness of the specialty inkjet layer and still produce an inkjet printed surface using dye-based inks with low bleeding and, thereby, to define the reasons for limitations with respect to coat weight reduction. The online study of printed figures following printing nozzles on a high-speed inkjet printing press, by means of optical image capture, showed that the tendency for intercolor bleeding depends strongly on the coating layer thickness. As the printing speed increases, the pore network ...