Fineness is an index that indicates the size of pigments and other solid raw material particles in the ink and the uniformity of the distribution of these particles in the binder. Use a Fineness Meter to scrape the properly diluted oil from the deepest part of the groove of the Fineness Meter to the flat place, and immediately observe it at an angle of 15° to the light, and see that at least 15 particles in the ink are within a certain scale range, and other The value is the fineness of the ink.
The fineness of screen printing ink is generally between 15~45/μm. If the fineness is too coarse, a paste will be produced during printing, and the pattern cannot be printed. If the wire mesh is thicker, the fineness can also be thickened accordingly. Generally, the coarsest particles of ink should be less than 1/3 of the mesh area of the screen.
The fineness of the ink is different from that of the solid powder, the latter refers to the basic particle size of the powder, which is very small, see Table 7-7. Among them, the basic particle size of the general pigment is less than 1 μm . In fact, the pigment is added to the ink binder in the aggregated state (the size can reach 50 μm) of several basic particles sticking together. After grinding, the aggregate is dispersed and dispersed to obtain The better, the smaller the ink particles (fineness). The fineness of the general ink is about 5 μm , and the fineness of the ink can reach 1~2 μm . The fineness will affect the gloss of the ink film and the rheology of the ink.
| Pigment name | Particle size/μm | Pigment name | Particle size/μm |
| General pigment | <0.1 | fluorescent pigment | 1.2~50.0 |
| Titanium dioxide | 0.25 | Gold, silver powder | Thickness: 0.1~2.0 Diameter: 1~200 |
| carbon black | 0.01~0.1 | Foil paint | >200 |
