The effects of nozzle plate defects on droplet jetting behavior and directionality are studied numerically and experimentally. In particular, we examine the mechanism responsible for the phenomenon of tail-hooking, where break-up occurs at a point on the side of the nozzle, rather than on the central axis. We investigate how nozzle defects lead to this breaking of jet axisymmetry. Fully three-dimensional simulations through nozzle geometry were performed using Flow3D software are compared with experiments performed on a large scale model of a drop on demand inkjet print-head. For nozzles plates in which the outer surface is not perfectly aligned with the nozzle axis, we observe asymmetric break-off. The directionality of main droplets is not greatly affected by the nozzle angle but the behavior and directionality of the satellite droplets is dramatically altered.
Oliver G. Harlen, J. Rafael Castrejón-Pita, Arturo Castrejon-Pita, "Asymmetric Detachment from Angled Nozzles Plates in Drop-on Demand Inkjet Printing" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP29), 2013, pp 277 - 280, https://doi.org/10.2352/ISSN.2169-4451.2013.29.1.art00006_2