Pigment inks are a special form of ink used in inkjet printing. In contrast to classic dye inks, pigment inks do not dissolve in the medium. Instead, a so-called dispersion is created.
The advantages of pigment inks are a strong color strength, high lightfastness and high water resistance (document-proof). They are also resistant to many chemicals.
The disadvantage of these inks is that the pigments settle comparatively quickly and often clump together. To prevent this effect, various additives are added to the ink to stabilize it.
The pigments used can be divided into earth pigments, mineral pigments, metal pigments, carbon pigments and ceramic pigments. The usual pigment sizes are in the range from 100 nm to 1 µm.
Ceramic inks are carriers of finely divided ceramic metal oxide pigments (no raw dyes, but prefired stain powders) that are used in automated application techniques. Ceramic inks must have a physical consistency that is suitable for creating fine details. This requires that they be suspended in a medium (water or solvent). Depending on the application, these media can flow like an ink or they can have a gel consistency that stays in place after application. Furthermore, nano-sized spots can be produced from particle colors, which remain in suspension in a highly fluid medium (for inkjet printing). They can be water or oil based and can be both quick and slow drying. The color of the ink can be adjusted via the particles used.
The adhesion of ceramic inks to the carrier medium is created by a baking process at high temperatures. Furthermore, these media require a carrier medium for adhesion, which is brought to melt in the stoving process and thus connects the ceramic color pigments with the carrier surface.
Especially in press hardening at temperatures above 900 ° C, such inks can be used for permanent individual marking of components, since ceramic inks are especially suitable for such applications and are not removed during the heating process.