Résumé
In this paper we report what we believe is the first-time observation of femtolitre drop generation from a nozzle in an industrial inject printhead. While femtolitre drops have been observed and reported, it has been mostly in the context of jet ligament thinning and subsequent breakdown into drops by Rayleigh-Plateau instability. This communication will show jetting of femtolitre size drops directly from the ink meniscus formed on the nozzle exit of two different industrial printheads. The printheads are from different manufacturers, with different microchannel and piezoelectric structures, and the two inks used are very similar, one of them having one extra polymer component used to increase the ink viscosity. The jetting events happen at random times, from immediately after the ligament detachment from the nozzle up to several hundreds of microseconds later. While the physical mechanism underlying this jetting phenomena is not understood, we will analyse our results and compare with existing theories small drop formation, to try to build an understanding of how this jetting process work.