Extreme shear flow hydrodynamics in rotary printing technology

What is it about?

We study the liquid flow under the ink meniscus in the nip between the rotating cylinders of a gravure printing press. Transport of the ink and wetting of surfaces is dominated by the extreme liquid compression and shear. The combination of hydrodynamical lubrication theory, numerical Galerkin simulation and experimental measurements on an industrial-scale printing press yield insight into the highly nonlinear fluid dynamics at the center point of the printing nip, and on the dynamical response and self-stabilizing ability of a printing process, operating under steady external perturbation.

Featured Image

Photo by Senad Palic on Unsplash

Photo by Senad Palic on Unsplash

Why is it important?

Rotary printing techniques, such as gravure, have developed from graphical to "functional" applications. They are the industrial backbone of liquid-based surface valorization and structuring. Example are food packaging technology or printed electronics, where printing enables the fast, cost- and resource-efficient production of not only colorful finishing. Packages also receive functional capabilities which protect the sensitive goods against chemical and microbial contamination, degradation by humidity and UV radiation, and endow them with logistical communication add-ons which enable fast and reliable product distribution and quality control. Our vision is that printing develops to a key technology for safe nutrition and supply of a growing human population under the conditions of restricted natural resources.

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