Redispersibility of ceramic ink characterized with SMLS

Introduction Printing inks used in ceramics are constituted of inorganic pigments dispersed in a serigraphic liquid. This liquid gives to the ink some rheological properties necessary for the printing process. A good stability of ink, at rest or in use, is essential because pigments tend to settle and to aggregate. This instability leads to evolutions of the rheological properties of the product, which can make the application difficult or even impossible, and provoke defects in the printing. For a given pigment, it is necessary to study the stability of the ink as a function of the different serigraphic liquids as the aggregation can be reversible or not due to chemical interactions between the pigment and the liquid. Depending on the stability behaviour, the ink redispersibility can be different. This note will show, on the example of three inks from the market, how SMLS technology permits to characterize pigment stability and redispersibility.