Application of Mar Resistance Tester
What is "Mar"? It's a blemish on the surface of a coating, extending over a particular area and visible due to differences in light reflection compared to adjacent areas.
The Mar Resistance Tester from Qualitest for coatings operates similar to a scratch resistance tester. However, instead of a straight stylus, this Mar resistance tester uses an arc (loop-shaped or ring-shaped) stylus to assess the mar resistance of a single coating of paint, varnish, or related product, or the upper layer of a multi-coat system.
To conduct the test, the product or system under examination is applied at a uniform thickness to flat panels with uniform surface textures. After drying/curing, the mar resistance is evaluated by passing the panels beneath a curved (loop-shaped or ring-shaped) stylus mounted to press down on the test panel's surface at a 45° angle. The load on the test panel is gradually increased until the coating shows signs of marring.
This test is valuable for comparing the mar resistance of different coatings, especially for providing relative ratings for coated panels that display significant differences in mar resistance. It's important to note that this test does not specify a method using a pointed stylus, unlike the methods outlined in ISO 1518-1 and ISO 1518-2, respectively. The choice of method depends on the specific practical requirements.
The Qualitest QualiMar Mar Resistance Tester complies with the latest international standards ISO 12137-2011, ASTM D 2197, and ASTM D 5178. It offers a load range from 100g to 5,000g for testing panels.
