Explore the method and application of Coating sagging test

In the application of Coating, sag property is an important performance indicator, which is directly related to the effect and quality of Coating in the construction process. Sag property refers to the degree to which part of the wet-film falls down due to the influence of gravity after the Coating is Spreader on the vertical surface and before the wet-film drying. The purpose of the sag property test is to evaluate whether the upper part of the Coating will become thinner, the lower part will become thicker, or even spherical and corrugated during the Spreader process. The method and application of the sag property test will be introduced in detail below.

Instruments and Materials

The main instrument for sag testing is the Sag Tester, which consists of multiple groove scrapers, a base and a test plate placement rack. The scraper can scrape the Coating into parallel wet-films of different thicknesses, and the base is used to support the test plate. The test plate requires a glass plate with a flat and smooth surface, with a size of 200mm × 120mm × 2~ 3mm. The application of these instruments and materials ensures the accuracy and Reliability of the test.

Test method

At the beginning of the test, place the test plate on the base of the Sag Tester. One end of the scraper is in close contact with the guide edge, and then place the Coating in the opening in front of the scraper. Hold both ends of the scraper with both hands and scrape from top to bottom smoothly and continuously, ensuring that the operation is straight and free of ups and downs. Immediately after the scraping is completed, place the test plate vertically to allow the film to form a sag phenomenon before the wet-film drying. Observe the sag condition of the wet-film and record it.

Result representation

A complete test usually uses three test plates for parallel testing to obtain more accurate results. For the same sample, the sag performance of Coating can be obtained by observing whether wet-films of different thicknesses produce sag after vertical placement. The test results are expressed in the maximum wet film thickness without sagging, measured in microns (μm). This value can reflect the sag nature of the Coating, and can also be compared with the product standard regulations to judge the quality of the Coating.

Application and meaning

The sag property test is mainly suitable for the relative sag property determination of Paints, but not for testing the sag property of varnishes and powder coatings. The sag performance of Coating directly affects the surface effect and mass after Spreader. If the sag property of Coating is not good, it will lead to uneven phenomenon of film during construction, which will affect the Appearance and performance of Coating. Through the sag property test, manufacturers can evaluate the sag property of Coating, ensure that the Spreader performance and mass of the product meet the expected standards, and improve the user experience.

Summarize

Sagging test is one of the important means of Coating performance evaluation, which is related to the performance of Coating in practical application. By understanding the methods and applications of sagging test in detail, we can better grasp the performance characteristics of Coating, so as to provide a scientific basis for the research and development, production and application of Coating, and contribute to the development of the Coating industry. An important force.