Improving Inkjet Print Performance of Plain Sized Paper with Nanostructured Pigments

Abstract

Following the industry trends, it is clear that commercial inkjet printing will compete increasingly with traditional printing processes in the coming years. While special paper is already available for traditional impact printing processes, papers that meet the requirements of high speed inkjet printing are just in the infancy of their development. Standard papers, like those found in the office, still exhibit significant weaknesses in such important properties as optical density, gamut and water resistance.A very thin layer of a fumed silica based coating (0.5-2.0 g/m2) applied to plain paper at the size press improves inkjet printing performance. The silica coating behaves as an inorganic sponge with a well defined void and channel structure to absorb ink rapidly for enhancing color qualities, print uniformity and image resolution. In the presentation we show results of a paper machine trial and compare nano-structured silica based pigments with traditional coating pigments, e.g. calcium carbonate. Comparisons are made to other approaches, such as the incorporation of multivalent metal ions into the paper.