In the coating industry, the flexibility of the paint film is a key performance indicator, which reflects the elasticity and resistance of the coating under external effects. The GB/T 1731 standard provides a method to measure the flexibility of paint films. This article will introduce the testing principle, required materials and equipment, operating points and precautions of this standard, and analyze the significance of this method in practical applications. and advantages and disadvantages.
Determination of paint film flexibility
The testing principle of the GB/T 1731 standard is to deform the paint film and the substrate together to check its rupture elongation, which also includes the role of the interface between the paint film and the substrate. This test method simulates the deformation of the coating under external forces to evaluate its flexibility and resistance.
The flexibility Tester is the key equipment for testing. The QTX paint film elasticity Tester mentioned in the GB/T 1731 standard consists of 6 steel shaft rods with different thicknesses. The length of each shaft rod is 35mm, and the radius of curvature is 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 5mm, 7.5mm. In addition, the test also requires tinplate as the substrate. To perform the test, the painted sample needs to be pointed upwards and pressed firmly against the shaft rod of the required diameter with both hands. Then, bend around the shaft within 2 to 3 seconds. After bending, the two thumbs should be symmetrical to the center line of the shaft. This process simulates the bending deformation of the coating under external forces to evaluate its flexibility. Use visual inspection or a magnifying glass to observe whether the paint film appears reticulation, cracks, peeling or other damage during the test process. The flexibility of the paint film is expressed by bending the sample on mandrels of different diameters without causing damage to the paint film. The smaller the result, the better the flexibility of the paint film.
Note: When performing the test, it is necessary to pay attention to the sample being pressed tightly on the shaft rod, the bending action should be completed quickly, and the force of the two thumbs should be even to ensure the accuracy and consistency of the test.
The significance and application of paint film flexibility determination
GB/T 1731 paint film flexibility determination method is one of the important methods to evaluate the elasticity and resistance of coatings. In practical applications, this method can help manufacturers understand the deformation of the coating under the action of external forces, thereby optimizing the coating process and material selection, and improving the quality and performance of the coating. In addition, the flexibility of the paint film is also closely related to the service life of the coating, so this method is particularly important for long-term use of coating products.
Summarize
The GB/T 1731 paint film flexibility determination method is an important means of evaluating coating performance. By simulating the deformation of the coating under the action of external forces, its elasticity and resistance can be evaluated. The operation of this method is relatively simple, but it has important application value in the coating industry, helping to improve the quality and performance of the coating and meet the coating needs of different fields.
