Fluid Dynamics & Acoustics
How inkjet printing really works
Monday 4 - Tuesday 5 July, 2022
Novotel Gent Centrum Hotel, Ghent, Belgium
COURSE FOCUS
Inkjet printing is a process of depositing small droplets with a specified volume onto a precise location on a substrate. During the course we follow the ink through the printhead, into droplet formation and onto landing on the substrate.
The course mainly covers piezo-driven printheads jetting Newtonian inks, although the issue of viscoelastic inks will be discussed. A piezo-driven printhead is modelled as a set of acoustic cavities, the characteristics of which will be presented in the time (response to waveforms) and frequency domain.
The course is based on precise descriptions of the physical phenomena involved and the derivation of the mathematical framework needed to solve the governing equations. Where possible the outcomes will be compared with experimental findings. Different mathematical methods will be presented to calculate the responses of different systems in the frequency and time domain. To describe correctly the behaviour of a printhead with a large number of narrow pitched nozzles, the long duct theory will be presented.
The aim of this course is to couple the characteristics of droplet formation and landing, spreading and permeation to the acoustics and microfluidics of the printhead. The knowledge conveyed during the course will enable the participants to analyse the behaviour of a wide variety of existing printheads and to support the development of new printheads and inks from a physics point of view.
COURSE OUTLINE
monday 4 July 2022
12:30 - 13:30 Registration
13:30 Course begins
General introduction
Overview of course
Different piezo printhead designs
Experimental methods and droplet formation movies
Waveforms
Fluid dynamics concepts and some mathematics
Single degree of freedom modelling of a single nozzle printhead (or one nozzle out of a multi-nozzle printhead)
Helmholtz theory of a single nozzle printhead (or one nozzle out of a multi-nozzle printhead)
17:00 Session ends
17:30 - 18:30 Reception
Join us for beers, wines, and good company!
Tuesday 5 July 2022
09:00 Session begins
Long duct analysis of a single nozzle printhead (or one nozzle of a multi-nozzle printhead)
Multi-nozzle printhead modelling
Droplet formation
12:30 - 13:30 Lunch
13:30 Session begins
Droplet impact
Electrostatic droplet generation
17:00 Course ends
Course Leader
Prof Dr J. Frits Dijksman
University of Twente, Faculty of Science and Technology, Netherlands
Prof Frits Dijksman is professor of biomedical applications of inkjet technology at the University of Twente, Netherlands. He has worked with Philips Research for more than 30 years and his main area of interest has been inkjet technology for consumer and non-consumer applications, such as PolyLED display manufacturing and the printing of biomolecules.