Hennig G.,DI Projekt AG |
Baldermann T.,DI Projekt AG |
Nussbaum C.,DI Projekt AG |
Rossier M.,DI Projekt AG |
And 3 more authors.
Journal of Laser Micro Nanoengineering | Year: 2012
The currently used digital printing methods e.g. Inkjet or Xerography are very costly on an in-dustrial scale, because they use expensive consumables, specific inks and specially-coated sub-strates for the printing process. The laser-induced forward transfer of inks from a donor ribbon or roller to substrates allows for the use of inexpensive inks and paper as they are commonly used in today's industrial rotogravure or offset printing. The challenge of this approach is to develop a fast direct laser writing unit which can cover an area of more than 1 m2/min with a screen resolution of 300 dpi to 600 dpi and which allows for laser spot pointing accuracy of less than 4 μm and for a fine (8 bit) reproduction of each grey tone value of the printed image pixels. Due to the large area and the desired high printing speed, the laser power (mean) needs to be within a range of a few hundred Watts. At 20 to 25 MHz modulation rate of the high power laser beam and at a laser spot scanning speed of 800 to 2116 m/s over a scan field length of 530 mm, we demonstrated reproducible print-ing of commonly used, water-based environment-friendly and inexpensive inks.
Patrascioiu A.,University of Barcelona |
Florian C.,University of Barcelona |
Fernandez-Pradas J.M.,University of Barcelona |
Morenza J.L.,University of Barcelona |
And 3 more authors.
Applied Physics Letters | Year: 2014
Simultaneous two-beam laser-induced forward transfer (LIFT) was carried out for various inter-beam separations, analyzing both the resulting printing outcomes and the corresponding liquid transfer dynamics. In a first experiment, droplets of an aqueous solution were printed onto a substrate at different inter-beam distances, which proved that a significant departure from the single-beam LIFT dynamics takes places at specific separations. In the second experiment, time-resolved imaging analysis revealed the existence of significant jet-jet interactions at those separations; such interactions proceed through a dynamics that results in remarkable jet deflection for which a possible onset mechanism is proposed. © 2014 AIP Publishing LLC.