Determination of the surface tension
Test inks can be used to determine the surface energy / surface tension of solids made of plastics – metals – glass – ceramics. The adhesion possibility of the surfaces in particular for printing, bonding and painting should also be determined based on the wetting pattern .
The surface tension is determined by applying a stroke of ink measuring just a few centimetres in length to the surfaces to be evaluated and observing the behaviour of the stroke of ink.
If the stroke contracts within 2 or 4 seconds – depending on the ink specification – the surface tension of the test area is lower than that of the test ink.
Conversely, if the stroke spreads, this would show that the surface tension of the applied ink is lower than that of the surface.
If the stroke remains unchanged during the observation period, the value of the surface tension has been reached exactly or is slightly higher.