Fraunhofer Institute for Manufacturing Engineering and Automation IPA
Systematic Evaluation of Rheology and Waveform Data for Jet-Ability Prediction Using Seiko RC1536 Printhead
In short
In collaboration with Seiko Instruments GmbH, the potential of piezo inkjet technology was investigated, taking into account the rheological properties and the behavior of the fluid after pulse excitation. The methodology improved the assessment of the drop formation behavior of new fluids and shortened the process development time for new pressure parameters.
In detail
Piezo inkjet technology enables the precise, contactless placement of tiny drops of material and can therefore be used for applications ranging from functional coatings to 3D printing. However, the process development for this is time-consuming and cost-intensive, as the waveform for controlling the print head in particular is determined iteratively using dropwatching. This involves analyzing the drop discharge in terms of speed and stability.
In collaboration with Seiko Instruments GmbH, Fraunhofer IPA aimed to shorten this process and to be able to narrow down the waveform parameters more precisely in advance.
In the project, the ink composition was varied, and rheological properties were characterized in order to analyze their influence on the printing behavior. In addition, the impulse response behavior of the inks was analyzed, and process parameters were validated using dropwatching. By comparing the inks with reference inks in dropwatching, differences and similarities in drop formation behavior could be identified and the process parameters validated accordingly.
The analysis of the impulse response behavior enabled a better assessment of the printability and comparability of unknown fluids. In combination with rheological characterization, this allows companies to select inks and process parameters more efficiently.
A deeper understanding of the influence of ink composition and impulse response behavior will enable the targeted development of optimized ink formulations and process parameters in the future. The knowledge gained can also serve as a basis for the development of models that predict the drop formation behavior of new fluids.