A surface can be wetted by a liquid if its surface energy is greater than the surface tension of the liquid. Plasma technology offers a wide range of possibilities for increasing the wettability:
- With all substrates, the prerequisite for wettability is removing all layers of grease, wax, and oil. Plasma cleaning removes these layers without any residue.
- Metals have very high surface energies, but these energies may be significantly reduced by oxidised surfaces.
Oxide reduction in the hydrogen plasma may expose the pure metal surface.
- Non-polar surfaces, primarily in plastics, can be activated in the oxygen plasma, which significantly increases the surface energy
- By means of plasma polymerisation, hydrophilic vinyl acetate coats with a high surface tension can be applied.