ABSTRACT
Nowadays printing can be defined as the reproduction of patterns by transfer of matter to a surface by mechanical force or hydrodynamic stress. For this, functional materials need to be transformed to a physical condition in which they can be mechanically transported, subdivided, deformed, and deposited: the liquid state. This liquid state needs to fulfill specific requirements of the respective printing technique like inkjet, gravure, flexographic, or screen printing. Depending on the physical nature of these materials there are different methods that can be used: dissolving the material in a more or less volatile solvent or creating nano-or microparticulate dispersions. The formulation of these fluids has a vital impact on the printing or coating process, as well as on the drying process. This section concentrates on the description of the printing fluid during the printing process. Starting with aspects of formulating organic materials, properties of printing liquids as well as their influences on layer formation and drying are explained.
