DIN 55660-5:2012-04

This standard specifies a test procedure with optical methods for the determination of the polar and dispersive fractions of the surface tensions of liquids. The procedure can be used for characterization of liquid coating materials. There may be limitations with regard to applicability in the case of liquids with non-Newtonian flow behaviour. This part of the standard assumes knowledge of the total surface tension of the liquid to be tested and the surface free energy of a disperse reference object surface. See DIN 55660-2 and DIN 55660-3 and also DIN EN 13470 and DIN ISO 1409, amongst others, for procedures with other methods. Principle: Step 1: The surface tension of the liquid to be tested is measured according to DIN 55660-3, DIN EN 14370 or DIN ISO 1409. Step 2: The surface free energy of a reference solid without polar fraction of the surface free energy is calculated in accordance with DIN 55660-2. Step 3: A contact angle measurement between the reference solid and the liquid to be tested is carried out in accordance with DIN 55660-2. Step 4: The disperse fraction of the surface tension of the liquid is calculated according to the Owens, Wendt, Rabel and Kaeble or Wu method. The polar fraction of the surface energy is calculated from the disperse fraction of the surface tension and the surface tension measured in step 1. The committee responsible for this standard is NA 002-00-07-15 AK "Kontaktwinkel/Benetzbarkeit" ("Contact angle/Wettability") at DIN.