The generation of drops at a piezo-based inkjet nozzle is an interaction between the geometry of the print head, the parameters of the liquid, such as surface tension and viscosity, and the waveform with which the piezo element is actuated. Here we present, by way of example, using the Drop Shape Analyzer – DSA Inkjet, how these quantities determine the jetting behavior based on a trapezoidal waveform and simple model liquids.
When measuring with the DSA Inkjet, the desired print parameters can first be defined, and then the trigger function of the measuring instrument synchronizes the generation of the drops with their image acquisition and analysis. For such image analyses, the DSA Inkjet is equipped with innovative optical technology. Relevant parameters such as volume and velocity of the drops, ligament length, and number of drop parts are available within a very short time, which simplifies the performance of studies such as this one or makes it possible in the first place. For some supported print head models, it is also possible to directly control the print head with integrated print electronics and an easy-to-use waveform editor. This option was used in this study.