Water-based flexo and gravure inks use acrylic resins that dissolve only when neutralised with a base. The amine chosen for that job decides much of how the ink behaves on press.
Why the amine matters
As the ink dries, the amine evaporates and the resin becomes insoluble again, which gives the print its water resistance. A volatile amine leaves fast; a less volatile one stays longer and keeps the ink open.
| Ammonia (FLYRON FD) | MEA (FLYRON MD) | TEA (FLYRON SD) | |
|---|---|---|---|
| Drying on press | Fastest | Medium | Slowest |
| Open time and re-solubility | Shortest | Good | Longest |
| Odour | Noticeable ammonia odour | Low | Very low |
| Early water resistance | Best | Good | Slower to develop |
| Typical use | High-speed flexo, corrugated, absorbent papers | General flexo, lower odour pressrooms | Fine anilox, gravure, long runs, hot climates |
| Food packaging | Compliant grades | Compliant grades | Check per application |
Keep the system consistent
Mixing concentrates on different amines changes pH balance and drying. Build each ink from one line, and adjust pH with the same amine during the run. Ammonia is lost from open ink ducts over time, so FD inks need regular pH checks and top-ups.
Climate and press speed
In hot, dry pressrooms fast-drying inks can dry on the anilox and plate, causing dot gain and dirty print. A slower line, or blending in an SD ink based on the same pigment, can help. On cold, humid days or with non-absorbent films, FD gives the fastest drying.
