This webinar by the European Rotogravure Association (ERA) provides insight into how the rheological properties of inks and coatings are measured and how they affect the final product.
Rheology is the study of fluids and how they flow and thus effects every part of the printing process, from the ink development, transfer between rollers, and the interaction with the substrate.
Anzeige
Traditionally, on press viscometry maintained printed colour by ensuring a consistent amount of pigment in the carrier fluid by monitoring the ink properties. As demands increase in terms of quality, reduced environmental impact and functionality, inks and coatings have developed into a complex blend of various shaped solid functional micro and nano materials in a carrier fluid, made of complex polymers with various additives. The carrier fluid may also contain polymers which impact other properties when cured e.g., become an oxygen barrier for food packaging.
Off press characterisation of the rheological properties of the inks and coatings can be used to predict performance including ink release, spread and penetration into the substrate. These can then be used in conjunction with on press measurements maintain constancy.
