03. Electronics Packaging and Thermal Management

The moisture content of paper greatly affects the image quality when printing on paper media. Especially in the drying process of inkjet printing and the fusing process of electrophotographic printing, the amount of moisture of the paper decrease in the heating process, and increase in the cooling process, which results in a change in paper dimension that is known to greatly affect the accuracy of image position. Various types of paper are used in the commercial printing filed according to the intended application, but it is not clear how changes in paper dimension occur due to differences in paper structure, and image positioning adjustments are currently made based on empirical rules. We assume that in the paper expansion phenomenon in the cooling process, in the first step, moisture diffuse into the paper voids, in the second step, moisture is absorbed into the paper fiber and diffuse, causing the fiber diameter to expand, and as a result, the paper dimension expands. Therefore, we show the results of simultaneous measurements of paper weight and dimension when the ambient temperature and relative humidity actually change, and the results of paper dimension prediction using the moisture diffusion model into the paper fiber obtained from the experimental results.