Analysis of Droplet Permeation into Coated Paper for Inkjet Printing

Abstract

Theoretical models to integrate pores size distribution and to analyze permeation of a droplet into coated paper are proposed. Droplet permeation into porous media plays an important role in the image formation of inkjet printing. In this study, pores size distribution of porous media of different coated papers was investigated using nitrogen adsorption-desorption method. Based on the pores size distribution, theoretical model for estimating permeation amount into coated paper of pico-scale droplet was proposed, with the consideration of Lucas-Washburn equation. In order to verify the theoretical model, experiments of droplet observation with pure water and several propylene glycol (PG) aqueous solutions were conducted. For some paper samples, results of theoretical calculation and experiments generally agree well. However, there are cases where the theoretical predictions show discrepancy. Possible reasons are considered to be deviation of pores size distribution. Moreover, the accuracy of estimated evaporation volume by Hu and Larson's Equation, and the complex shape of the pores in coated layer also contribute to the errors. The effect of these factors still needs to be further explored.