Bead mills grind the pigment in printing inks to the fineness each printing process needs: paste inks for offset need full color strength at high viscosity, liquid inks for gravure and flexo need high throughput, and inkjet inks need sub-micron particles with no oversize that could block print-head nozzles. INFOR supplies disc, disc-pin, pin-rod and screen-free vertical bead mills and complete coating and ink lines.
What the process needs
| Requirement | Why it matters | How the bead mill meets it |
|---|---|---|
| Fineness matched to the process | Color strength, gloss and print quality | Bead size and energy chosen per ink type |
| No oversize particles (inkjet) | Oversize blocks nozzles | Narrow distribution, circulation mode, final filtration |
| Viscosity control (paste inks) | Offset pastes are very viscous | Rotor and separator for high viscosity |
| Temperature control | Resins and solvents are heat-sensitive | Chamber cooling and suitable rotor |
| Solvent safety | Many liquid inks use flammable solvents | Explosion-proof versions |
Offset and paste inks
Paste inks combine high pigment content with high viscosity. The mill must keep the paste moving and cool while developing full color strength.
Gravure and flexo inks
Liquid solvent- and water-based inks are lower in viscosity and produced in large volumes, so throughput and explosion protection for solvent systems are the main concerns.
Inkjet and digital inks
Inkjet inks need sub-micron pigment with a narrow distribution, because a few oversize particles can block a nozzle. Small beads, circulation grinding and screen-free separation help, followed by fine filtration. The same applies to ceramic inkjet inks.
Recommended INFOR equipment
| Stage or need | INFOR equipment | Why |
|---|---|---|
| Premix | Dispersion tank | Wetting and pre-dispersion |
| Liquid inks | Disc bead mill | Versatile; explosion-proof versions for solvent systems |
| Heat-sensitive inks | Disc-pin bead mill | Efficient grinding at low temperature |
| Inkjet inks | LPM vertical bead mill or dual-power mill | Micro-beads, screen-free separation, narrow distribution |
| Complete plant | Automated production line | Dosing to storage as one line |
See the coatings and inks dispersion line case and bead mills for pigments and color paste. INFOR runs free material tests at its Dongguan and Hubei test bases; send your material, target fineness and output through the contact page.