Correlation between xenon lamp aging and pigment weather resistance from natural exposure testing (2)

2.3 Model preparation and evaluation methodwill be to be tested colorTREND 1, 2, 3, 4, 5, 6 , a total of 6 different architectural coatings with color paste, according to a certain proportion to join the standard detection of flat light exterior paint, so that it reaches 1/25 color standard depth. Shake 3 min mix well on the shock machine and apply 2 channels with 100 μ m rod on a pre-coated aluminum plate. The exposure test is carried out after placing 5d at room temperature. Each color of the same test each preparation of 4 models, 3 input test, 1 as a standard board indoor placement. Natural outdoor exposure was carried out for a total of 24 months, assessed once in 6 months, 9 months, 12 months, 18 months and 24 months; The color is detected with the standard plate under the D65 standard light source with the d65 d photon meter to record the color difference D E value. Visually, the surface of the coating film is affected by loss of light, powdering, cracking, shedding and spots. In this test, a high weather-resistant flat-light exterior coating was used, and after 2,000 h xenon lamps and 24 months of natural exposure, the surface of the coating film was free of loss of light, powdering, cracking, shedding and spots, etc., without affecting color evaluation.3 Comparison between outdoor exposure and xenon laboratory acceleration testingBased on the data obtained from the evaluation results, the correlation coefficient between natural outdoor exposure and xenon laboratory acceleration test methods was calculated r s (s p e a r m a n). This correlation coefficient refers to the correlation between the results of a test using two different test methods to test a group of samples.the correlation coefficient rs is:where n is the number of samples and d i is the difference between each set of rows in the two columns of sorting. The closer rs is to 1, the better the correlation. Through the above methods to find out the correlation coefficient between natural outdoor exposure and xenon lamp laboratory accelerated aging test results, and the test data are evaluated to solve the common concerns - for different pigment types, if the laboratory accelerated test and outdoor exposure results are good enough, then the test in xenon test chamber how many hours is equivalent to how many months of outdoor exposure results.of color change (D E) for outdoor exposure to six samples is shown in Figure 4.The value of the color change (D E) of the xenon laboratory acceleration test is shown in Figure 5.the data in Figures 4 and 5, it can be seen that the color of each sample changes, whether it is outdoor exposure or xenon lamp acceleration testing, and the value of DE increases as the test time increases. Before calculating how many months the xenon lamp test 2,000 h is equivalent to outdoor exposure, we need to know the correlation between them. It makes sense to calculate how many months of exposure to the xenon lamp test of 2,000 h is equivalent to outdoor exposure only if the correlation is good.calculated , the correlation coefficient between A l l u n g a natural outdoor exposure and the accelerated testing of the xenon lamp laboratory is derived. Taking the correlation between 500 h xenon lamp and 6 months of natural exposure as an example, the correlation coefficient r s is calculated as table 3.
The value of all the relevant coefficientsis shown in Table 4.can be seen from Table 4, A l l u n g a outdoor exposure of 6 months, 9 months, 12 months, 18 months, 24 months results and xenon test box 500 h, 1,000 h, 1,500 h, 2,000 h of the correlation between the various time periods are better.according to the color change data of Figure 4 and Figure 5, 2,000 h was tested in the xenon arc lamp test box, and the color change of the sample did not change significantly after 24 months of outdoor exposure. Based on the color changes that occurred in 1,000 h, 1,500 h and 2,000 h samples tested in the xenon arc lamp test box, we calculated how many months each sample was tested in the xenon arc lamp test box for 1,000 h, 1,500 h, and 2,000 h, respectively, and then took their arithmetic average. By calculation, its correspondence is shown in Table 5.4 Conclusion:test is the basis of laboratory accelerated aging testing. Through this paper, we think that there is a certain correlation between the two experimental data. We also further recognize the importance of active outdoor aging testing and to guide laboratory accelerated testing. Of course, the correspondence between the two will vary depending on the geographical location of the outdoor test, climate change, changes in substrate types, etc. More importantly, pigments and coatings are tested as a whole. Different coating systems get different results. If any of these changes in the coating system, pigment type, or pigment content, we can only speculate on the final result. Because these changes may have a greater impact on the end result.