Effect of ink solvent modification on printing quality

• Main Authors: Jeng-Lung Lin, 林正隆
• Other Authors: Ying-Chih Liao
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/19559768463943243841

碩士 === 國立臺灣大學 === 化學工程學研究所 === 101 === For printed micro-patterns on plastic substrates, the decreasing volume due to solvent evaporation frequently leads to contact line receding and changes the original printed pattern. To prevent printing quality deterioration caused by contact line motions, an ink formulation method was developed in this study. A nearly non-volatile solvent (ethylene glycol, EG；polyethylene glycol, PEG) with low receding angle on polyethylene terephthalate (PET) sheets was added in water to hold the contact line. To obtain fundamental information about the contact line motion when water evaporated, the geometrical evolution of circular liquid films under evaporation was recorded and analyzed. The results showed at low EG/PEG concentrations, the contact line receded as water evaporated, but remain pinned at high EG/PEG concentration (~10 wt%). A model was proposed to explain the dewetting phenomena and can successfully predict the critical PEG concentration, beyond which the contact lines will be unconditionally pinned. After water evaporation, PEG was then removed by thermal evaporation. Uniform thin films of remaining nanoparticles were then deposited with the original shapes. This method can be directly applied to many pattern coating applications, such as inkjet printing, gravure, and offset printing.