The impact strength test is the ability of the coating film to resist instantaneous deformation without cracking or falling off under the action of high-speed gravity. It comprehensively reflects the flexibility of the coating film and the bonding force to the substrate.
According to GB/T1732-93, the mass of the hammer of the impact Tester is 1000g, the diameter of the groove is 15mm±0.3mm, the depth of the punch entering the groove is 2mm±0.1mm (subject to correction), and the maximum sliding height of the hammer is 50cm. Expressed in N·cm. The quality and height of the weight of the impact Tester vary from country to country. IS0 6272-1993 defines it as a drop weight test with a weight of 1kg and a height of 1m.
The quality assessment after the test generally uses a 4x magnifying glass to observe whether there are cracks and breakages, but it is difficult to observe very fine cracks, and some use CuSO4 aqueous solution to adjust the humidity for 15 minutes, and observe whether there is copper or rust color to determine the impact strength.
郑顺兴 - 《涂料与涂装科学技术基础》