Hydroxyethyl methyl cellulose controls the diffusion behavior of pico-liter scale ink droplets on silk to improve inkjet printing performance

In this study, a simple and effective coating method to improve printing quality and material utilization rate was proposed. The flow behavior of pico-liter scale ink droplets on the silk fabric surfaces which treated separately with Sodium alginate (SA), Hydroxyethyl cellulose (HEC) and Hydroxyethyl methyl cellulose (HEMC) was observed and measured. Indeed, based on the direct empirical results, the optimal pretreatment process on the fabrics, aiming to increase the ink utilization rate and further improve the surface printing clarity, has been obtained in the experiments. Studies on rheological property, surface activity, scanning electron microscope (SEM) and contact angle have shown that HEMC can form the densest and smoothest film on silk fabrics, where the most hydrophobic surface arises. X-ray photoelectron spectroscopy (XPS) results indicate that the surface of the fabric is covered with films of different properties formed by the treatment solution, and confirmed that the films formed by HEMC were more hydrophobic. The spreading motion of ink droplets revealed that although the hydrophobicity of HEC and HEMC effectively restrain the flow of ink droplet along the fiber, and the length and width of one-ink droplet deposition are minimum in HEMC treated fabric. Similarly, the findings on color performance suggest that HEMC has absolutely comparative advantage over HEC in improving the color effect of printing, with dye utilization rate of three different colors increasing by 68.7 %-80.0 %.