Microscale droplet absorption into paper for inkjet printing

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The Lucas-Washburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper.