In the course of the measurement, we establish the surface tension of the parts.
From the test liquid with a specified surface tension manufactured by TANTEC, we can draw conclusions on the appropriateness of the preliminary treatment of the parts, and the expected binding of the powder coating and workpiece to be prepared. In all cases, we perform the measurement before dusting and we assess whether the given part is suitable for an appropriate coating or further treatment is necessary.
Using a brush, we apply liquids with different surface tensions to the surface to be tested (we draw a liquid film strip of about 5 to 10 cm). We begin the test with a liquid of 38 mN/m. If the testing liquid does not shrink into drops for more than 2 seconds after application, we continue the test using a liquid with a grade higher by one until the liquid film remains spread for less than 2 seconds before it shrinks into drops.
If the testing liquid of 38 mN/m shrinks into drops within 2 seconds after application, we continue the test using a liquid with a grade lower by one until the testing liquid film remains spread for more than 2 seconds before it shrinks into drops.
We perform the test on 3 different points on the given surface. In the event we receive different surface tension values, wee consider the lowest one as authoritative.
Recommended application:
It is a series of procedures applied at the determination of the surface tension of metallic parts and workpieces. It is practical to perform the procedure in all cases where the binding of the coating to the base metal is doubtful. Also, in cases where a new and unknown metallic raw material is used.
The results inform powder lacquering plants about the efficiency of their preliminary treatments (degreasing, phosphating, chromating). We use the tests to check the effectiveness of the chemical used for preliminary treatment. From the surface tension of the part tested, we draw conclusions on the appropriateness of the preliminary treatment. In the event the surface tension is below the limit value, the coating is expected to bind to the base surface appropriately. In all cases, tests are performed on unpainted surface. The parts to be tested can be workpieces and sample plates alike, the composition and degree of treatment of which are optional.
We perform measurements typically within 1 business day on our site, or within 5 business days on the clients' sites, depending on the availability of the measuring instrument.
