introduction
In the paint industry, it is crucial to understand the scratch resistance of paint film. The GB/T 92798-2008 standard provides a scratch test method to determine the resistance of the paint film to scratches. This paper will deeply discuss the principle, operation, result expression, precautions and application importance of this method in coating industry.

The scratch test evaluates the scratch resistance of the film by determining the minimum load or work required to scratch the film under test. The basis of this method is to determine the minimum load required for the needle of the instrument to scratch through the paint film, usually to indicate the hardness of the paint film. In addition, it can also determine whether the paint film is scratched through by the needle under a certain load, to indicate the performance of the paint film in the way of passing and not passing.

Test method for scratches on paint film
In order to perform scratch tests, the following materials and instruments are required:

Scratch meter: Used to apply load and perform scratch tests.

Tinplate, sheet steel, duralumin plate: used as substrate, the template will be fixed to these plates for scratch testing.

When performing scratch tests, the following operating points need to be noted:

The template is fixed on the movable workbench of the instrument, and then the instrument is turned on, and the workbench begins to move at a constant speed.

The marker will move over the template and, depending on the scratch, gradually apply a load to the marker until the film is just broken.

Test method and application analysis of paint film scratch

The result shows:

The result of the scratch test is expressed as the minimum load required when the film is scratched, and this value is usually used to indicate the hardness of the film. The larger the value, the more difficult it is to scratch the film and the higher the scratch resistance.

When performing scratch tests, special attention should be paid to the following:

The selected substrate should be flat to ensure the accuracy of the test.

Electrical conductivity equipment is used, so the back of the sample under test should not be coated with any insulating material to ensure the consistency of electrical conductivity.

When brushing, ensure that the brush marks are parallel to the long side of the test plate to maintain the consistency and accuracy of the test.

Test method and application analysis of paint film scratch

Paint film scratch test application
Scratch test is widely used in coating industry. Understanding the scratch resistance of paint films helps manufacturers evaluate the quality and performance of their paint products. This is essential to ensure the durability of coatings under different environmental conditions, especially in applications that require higher wear resistance, such as automotive coatings and furniture coatings.

In addition, the scratch test can be used to research and develop new coating formulations to improve the scratch resistance of the paint film. By understanding the scratch performance of different coating materials under different loads, manufacturers can adjust formulations to meet the requirements of specific applications.

conclusion
GB/T 92798 scratch test for paints and varnishes is an important method for evaluating the scratch resistance of paint films. Key information about the hardness of the film can be obtained by determining the minimum load required for the film to be broken. The application of this test method in the coatings industry helps manufacturers to ensure the quality and performance of their products and provides basic data for product improvement. Therefore, the scratch test has an important position and wide application in the coating industry.