Laser-induced functionalization and engraving capabilities of elastomer-based flexographic printing forms to control its flow and transfer behavior

• Applicant: Professor Dr.-Ing. Stefan Kaierle
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Coating and Surface Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 536009453

In this project, a basis for a technology evaluation of advanced pulsed laser beam sources in the production process of elastomer-based flexographic printing forms is to be created. The studies are to be carried out in cooperation with the industrial partner ContiTech Elastomer-Beschichtungen GmbH. The focus will be on functionalizing flexographic printing forms with laser-induced microstructures that optimize flow and transfer behavior and thus improve printing results in newspaper, label, and packaging printing (ZEV). Based on the results from the previous project, extensive tests will be carried out on both small table-top printing machines and large-format industrial printing machines. Based on this, the technology of elastomer-based functional flexographic printing forms will be evaluated. Functionalization is to be achieved by using (ultra-short) pulsed laser beam sources. Since CO2 lasers, diode lasers or high-power fiber lasers are already being used for engraving in the production of elastomer-based flexographic printing forms (which are not suitable for microstructure processes), it will also be examined whether the engraving process can be also carried out by the pulsed laser beam sources with similar process times and without any loss of quality. Thus, the high-power CW laser used so far could be substituted by a pulsed system. Finally, an economic analysis is to be carried out which takes into account aspects such as process and tooling times, lifetime of the printing form, in general costs for introducing the new technology of functionalized printing form and its production process, as well as environmental aspects. Since industrial ZEV printing uses printing forms in the sqm range, another focus of this project will be on the processing strategy and process scaling to apply the microstructures to large areas. This is to be achieved, for example, by multispot processing and fast beam deflection systems. In addition, it is important to verify if the manufactured microstructures are also mechanically stable and whether they influence the lifetime of the flexographic printing forms. Furthermore, the process understanding in flexographic printing will be extended, especially with regard to the factors microstructures, wetting behavior, surface topography and -energies. It is expected that additional conclusions about the optimal microstructure geometries can be drawn from the printing results and the ink separation investigations. Since the optimum microstructure geometry presumably also depends on the ink systems used, the printing form and substrate materials, the development of the theoretical process understanding is also an important part of the project.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: ContiTech Elastomer-Beschichtungen GmbH