Development of a Diffusion Model within Paper Fibers for the Paper Expansion Phenomenon during the Fusing Process

Abstract

Changes in moisture content inside paper significantly affect image quality during printing. In inkjet and electrophotographic printing, heating and cooling processes alter the paper’s moisture, leading to dimensional changes that impact image positioning accuracy. Various paper types are used in commercial printing, but differences in post-printing dimensional changes require image positioning adjustments, posing a practical challenge. Paper expansion occurs in two stages: first, moisture concentration changes in paper voids; second, moisture diffuses into fibers, altering their diameter and expanding the paper. This study measured surface temperature and paper width immediately after the fusing process for papers with different layer structures. By comparing experimental data with simulations, we clarified how temperature-driven moisture changes in fibers affect overall paper dimensions.