Monitoring of Droplet Formation Behavior Across 1,024 Nozzles in an Industrial Inkjet Printhead

초록

Multi-nozzle inkjet printing technology has attracted extensive attention in various industrial fields owing to its high-throughput capabilities for mass production. However, a high defect rate caused by nozzle-to-nozzle variations in droplet jetting behavior remains a critical challenge for its widespread application. To address this jetting reliability issue, a fundamental understanding of droplet formation dynamics in multi-nozzle inkjet printing is essential; however, the absence of measurement platforms capable of monitoring the droplet formation behavior across numerous nozzles with high-temporal resolution has been a major obstacle. In this paper, we present a fully automated vision-based system that enables time-resolved monitoring of droplet formation behavior for all nozzles in an industrial multi-nozzle inkjet printhead with a temporal resolution of 1 & micro;s. Using the developed system, we analyzed the nozzle-to-nozzle droplet formation behavior for all 1,024 nozzles in an industrial printhead, capturing the entire evolution from liquid filament ejection and stretching, through nozzle pinch-off and filament contraction, to final spherical droplet formation. Our experimental results revealed a clear difference in liquid filament dynamics among nozzles: while the filament head behavior exhibited substantial nozzle-to-nozzle variation, the filament tail behavior maintained high consistency across all nozzles. These findings indicate that controlling filament head dynamics could be essential to improving jetting reliability in multi-nozzle inkjet printing. This study could offer fundamental insights into the droplet formation behavior in multi-nozzle printheads and help improve the jetting reliability of industrial printing systems.

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