Test ink

for surface tension measurement

A prerequisite for the adhesion of an adhesive or coating to a surface is wetting. For wetting to take place, the surface energy of the substrate must be greater than that of the coating. In particular, very many plastics have a very small surface energy and are correspondingly difficult to bond. Often the aim of a plasma treatment is to make a surface wettable and bondable. The wettability can easily be tested with test inks. Diener electronic supplies a test ink set with 8 liquids with surface tensions between 30 and 73 (105) mN/m suitable for most practical applications. There is also a set of 23 test inks, with additional gradations between 30 and 73 (105) mN/m.