Topic: Test Inks - determination and measurmeant of surface tension, test liquids, define surface of materials

Test inks: Determination of surface tension with the aid of test liquids

Each surface of a material has a certain surface tension.

Each liquid, each paint, each adhesive has its own inherent tension. The secure and durable adhesion of a coating is conditional on the surface tension of the material being greater than that of the liquid. By means of selective pre-treatment with Plasmatreat’s Openair atmospheric-pressure plasma a distinct increase in surface tension is achieved so that the materials can be printed upon, adhesively bonded or coated in an optimum fashion in the next process step.

Test inks provide a simple method for measuring surface tension on materials such as plastics, metal or glass.

Most plastics have low surface tensions (frequently less than 28 mN/m). If printing is to be carried out on such materials solvent-based inks require that they have surface tensions of over 40 mN/m or over 56 mN/m in the case of UV-drying systems. If water-based ink systems are employed surface tensions of over 72 mN/m are needed.