ASTM  D6279-15 Test for Rub Abrasion Mar Resistance of High Gloss Coatings

Scope:

High gloss coatings on automobiles, boats, and toys face various conditions during manufacturing and service that can mar their surface. The coating should be able to maintain its appearance in the face of these conditions. ASTM D6279-15 test method is a way to predict the ability of a high gloss coating to resist mar damage. This ability of materials is called mar resistance. Mar resistance is evaluated by measuring the gloss of the abraded and unabraded areas. The abraded area is the area on the coating that is marred during the test, while the non-abraded area is left untouched. Mar resistance is directly related to the coating’s ability to retain gloss in abraded areas.

Test Procedure:

In ASTM D6279-15 test method The coatings are applied uniformly to panels of uniform surface texture. The panels are left to dry. After drying or curing, or both, panels are marred by dry abrasion media or wet abrasion media, or both, over a certain area. The abraded area is the area on the coating that is marred during the test, while the non-abraded area is left untouched. A gloss meter is used to measure the coating gloss within the abraded and unabraded areas of test panels. Mar resistance is directly related to the coating’s ability to retain gloss in abraded areas.

Specimen Size: 

A minimum of two panels are prepared for every coating to be tested. The panels should be 101.6 by 152.4 mm. But if the abrasion apparatus can accommodate them, 101.6 by 304.8-mm (4 by 12-in.) panels can be used as well. Gloss measurements are color-dependent. Abraded areas on dark-colored panels tend to give lower gloss readings than similarly abraded areas on light-colored panels. For consistent results, testing is done using black coatings. 

Data: 

The percent gloss retention mar resistance values that were obtained for each coating in the series will be reported.