In the industrial coating field, adhesion is a core indicator for measuring coating quality. In addition to the three widely used standard testing methods, various non-standard testing methods are increasingly emerging to meet the growing customized market demands. These highly targeted testing methods not only assess coating adhesion but also place higher requirements on their comprehensive quality such as strength and toughness. The collision paint chipping test is a common non-standard detection method in metal substrate coating. During the test, two metal workpieces are collided forcefully with each other, and the quality is evaluated by observing whether the paint chips off. There are no fixed standards for the force applied or the collision angle. This test not only checks adhesion but also assesses the strength and toughness of the coating, and is widely used in baking paint systems and two-component systems. The knife scratch test is mainly used for special substrates and elastic coating systems. For special substrates such as PP material and PPS material, even if the cross-hatch test passes, customers still require scratching with a knife and then scraping forcefully, not allowing any paint chipping. As elastic coatings (feel coatings) are soft on the surface, conventional cross-hatch tests are difficult to detect, so customers will focus on testing the scratch resistance of edges and damaged areas. In addition, impact resistance testing and bending testing have also become important non-standard detection items. The impact resistance test requires the coating to not crack or chip after impact; the bending test evaluates whether the coating cracks by bending the substrate to a specific angle, thereby comprehensively assessing the toughness and adhesion of the coating. Insiders in the industry stated that different fields formulate non-standard tests according to their own needs. Although this increases technical thresholds, it can effectively promote the performance upgrading of coating products, better meet the quality requirements of diversified application scenarios, and inject impetus into the high-quality development of the industry. For more information, you can click: https://www.tiktok.com/@mia_iota