The impact test allows you to evaluate the results of impacts on painted surfaces, thus highlighting the flexibility of the paint and the potential for cracks to form.
Impact tests are extremely useful when coating because they measure the coating’s resistance to deformation when a certain load is rapidly applied.
The test is performed by dropping a hemispherical weight onto the coated surface. The weight, guided by a rail, is dropped from ever-increasing heights until it causes the film to crack; the result will be expressed by the ratio between the height at which the test started and the weight used to hit the surface.
The result is influenced by a number of characteristics, such as the thickness of the paint, the mechanical properties and the surface of the substrate.
The standard governing the test is ISO 6272, which specifies the standard method for assessing the resistance of paints to breakage or detachment from the substrate when subjected to a deformation caused by a falling mass with a spherical punch of 20 mm diameter.