1. Atmospheric aging test
During use, the coating film is affected by various factors, resulting in irreversible changes in its chemical and mechanical properties. This phenomenon is called "aging" of the coating film. The atmospheric aging test of the coating film is to study the destructive effects of various factors in the atmosphere (sunshine, wind, rain, snow, dew, temperature, humidity, oxygen and industrial waste gas, etc.) on the coating film under various climatic conditions.
The atmospheric aging test of the coating film can be measured according to the national standard GB1767-79 "Measurement of Weather Resistance of Coating Film", according to the guidance test of GB9276-88 "Guiding Document for Natural Aging Test of Paint and Varnish Coating Film", according to GB1766 -79 "Methods for Grading Weather Resistance of Paint Films" and GB/T1766-1995 "Evaluation of Aging of Paint Coatings" and other regulations require that the aging test of the coating film be determined. (Related instruments: aging Test Chamber)
Atmospheric aging test takes a long time and requires many inspections. It is quite complicated and difficult to test under complex climatic conditions, and it is difficult to draw accurate conclusions due to the influence of various factors such as region, season, and environment.
2. Artificial accelerated aging test
The artificial accelerated aging test is based on a large number of atmospheric aging tests, summarizing the key factors affecting the weather resistance of the coating film, such as sunlight, temperature, humidity, oxygen content, etc., and simulating these factors in the laboratory. A method of simulation test for coating film.
The light source is the main influencing factor, especially ultraviolet rays are extremely destructive to the coating film. Therefore, in the laboratory, an artificial climate environment is formed by changing the type and strength of the light source, as well as the temperature, humidity, and oxygen content under various climatic conditions.
After the aging test, the inspection and testing items that should be carried out: the degree of coating damage, loss of light, discoloration, powdering, cracking, blistering, rust, spots, peeling, mold growth, and coating pollution. The following set of tables is the rating index when checking the aging of the coating.
(1) Rating table of uniform damage change degree of coating (Table 8-9)
