Abstract
The prevention of nozzle clogging caused by moisture evaporation at inkjet nozzles is an important issue in ensuring printing reliability. Although comprehending the physical properties of flying ink droplets is effective in analyzing jetting behavior, direct measurement is difficult because droplets are minute and flying is transient. Accordingly, observations were attempted on droplet vibrations produced when satellite droplets collide with main droplets. In result, it became possible to predict the physical properties of droplets in flight, and relationship between increased viscosity due to evaporation and the phenomenon of the jetting degradation was evaluated. In addition, piezoelectric driving power requirements were evaluated with inks that have different initial viscosity conditions. Although the main cause of jetting degradation following non-jetting-time is due to the rise in ink viscosity, results indicate the possibility that a thin ink layer of solid content formed on the nozzle may have slightly contributed to the degradation.
