Abstract
The role of meniscus motion and ink viscosity in the formation of a secondary tail and its breakup are studied experimentally during the picoliter-droplet formation process of a MEMS piezoacoustic inkjet print head using laser-induced 8-ns single-flash stroboscopic imaging with a temporal resolution of 100 ns. It is found that the formation of the secondary tail is driven by meniscus motion and that the secondary tail forms reproducibly between the primary tail and the meniscus in the final microseconds before pinchoff. We demonstrate that the stability of the secondary tail can be controlled through the motion of the meniscus after the primary tail has formed. A 4 times increase in stretching rate results in a 2.2 times increase in the secondary-tail length and a 3 times higher number of femtoliter satellites. Furthermore, as expected for Rayleigh breakup, a 43% increase in ink viscosity is found to increase the secondary-tail length by 50%. Finally, it is found that, during inkjet printing, the secondary tail cascades into tertiary and quaternary tails. We show that the formation of higher-order tails is irreproducible and therefore driven by noise. The formation of thicker secondary and thinner higher-order tails results in a bimodal satellite size distribution, where the secondary satellites with a volume greater than or equal to 4fL are located closer to the primary-tail droplet, while satellites with a volume less than 4fL are located closer to the nozzle. The main findings of the present work, that the stability of the secondary tail decreases with a decrease in stretching rate and ink viscosity, can be employed in the inkjet-printing community for waveform design to minimize internal contamination of inkjet printers.
Original language | English |
---|---|
Article number | 024075 |
Number of pages | 14 |
Journal | Physical Review Applied |
Volume | 13 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2020 |
Funding
Maaike Rump is kindly acknowledged for her assistance during the high-speed imaging experiments. This work is part of the “High Tech Systems and Materials” (HTSM) research program, Project No. 12802, and part of the Industrial Partnership Program No. i43, of the Dutch Technology Foundation (STW) and the Foundation for Fundamental Research on Matter (FOM), which are part of the Netherlands Organization for Scientific Research (NWO). The research is cofinanced by Océ Technologies B.V., the University of Twente, and Eindhoven University of Technology.
Funders | Funder number |
---|---|
Stichting voor de Technische Wetenschappen | |
Stichting voor Fundamenteel Onderzoek der Materie | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Stichting voor de Technische Wetenschappen | |
Stichting voor Fundamenteel Onderzoek der Materie |