In traditional printing methods, such as pad or screen printing, ink is physically pressed into the surface. This pressure helps fill microscopic surface irregularities, creating partial mechanical bonding between the ink and the substrate.
In UV inkjet printing, ink is deposited as droplets that gently land on the surface without mechanical pressure. The ink first wets the surface and is then cured by UV light. Because there is no physical force pushing the ink into the material, adhesion depends mainly on:
- Surface energy
- Proper surface preparation
- Chemical bonding
- Use of primers or surface treatment
If the surface is not properly prepared, the ink may remain on top of the material instead of forming strong mechanical or chemical bonds, which can reduce scratch resistance.
For this reason, surface cleaning, plasma or flame treatment, and primer application are critical for achieving optimal durability in UV digital printing.
