Date of Award
Doctor of Philosophy
Paper Engineering, Chemical Engineering and Imaging
Product development activity in the area of inkjet printing papers has accelerated greatly to meet the rapidly growing market for inkjet papers. Advancements in inkjet printing technology have also placed new demands on the paper substrate due to faster printing rates, greater resolution through increased drop volumes, and colorants added to the ink. To meet these requirements, papermakers are turning to pigmented size press formulations or pigmented coating systems. For inkjet coating applications, both the internal porosity of the pigment particles as well as the packing porosity of the coating affect print quality and dry time. Pores between the pigment particles allow for rapid diffusion of ink fluids into the coating structure, while also providing capacity for ink fluid uptake.
Past research has shown the presence of coating cracks to increase the microroughness of the papers, consequently reducing the gloss of the silica/polyvinyl alcohol based coating colors. Coating cracks were not observed, at the same level of magnification, in the scanning electron microscopy images of alumina/polyvinyl alcohol coated papers. Studies are therefore needed to understand the influence of coating cracking on the microroughening of silica/polyvinyl alcohol based coatings and consequences to coating and ink gloss. Since micro roughening is known to be linked to shrinkage of the coating layer, studies are needed to determine if composite pigments can be formulated, which would enable the coating solids of the formulations to be increased to minimize the shrinkage of coating layer during drying. Coating solids greater than 55% solids are needed to reduce the difference between application solids and the coating's immobilization solids point in order to reduce shrinkage. The aim of this research was to address the above mentioned needed studies. Studies were performed to understand the influence of particle packing on gloss and ink jet print quality. Composite pigment structures were built using well-characterized pigments to determine the influence of particle size and particle size distribution on coating application solids, coatings immobilization solids on coating gloss and print attributes.
This research consists of five articles which have all been accepted for publication: (1) Influence of Pigment Particles on the Gloss and Printability of InkjetCoated Papers, (2) Influence of Silica and Alumina Oxide Pigments on Coating Structure and Print Quality of Inkjet Papers, (3) Production of a Single CoatedGlossy Inkjet Paper Using Conventional Coating and Calendering Methods, (4) Influence of Pigment Particle Size and Packing Volume on the Printability ofGlossy Inkjet Paper Coatings-Part I, and (5) Influence of Pigment Selection on Printability of Glossy Inkjet Paper Coatings-Part II.
Lee, Hyunkook, "Fumed Metallic Oxides and Conventional Pigments for Glossy Inkjet Paper" (2004). Dissertations. 1120.