A. UV lamp accelerated weathering test of PPGI steel sheet
Exposed the samples into ultraviolet light and/ or condensation atmosphere, after the specified test period. Measure its luster, color difference and assess its discoloration, chalkiness, chalking and other coating surface aging phenomena. That test is called UV lamp accelerated aging test. This test is commonly used by CAMELSTEEL to test the resistance to accelerated aging ability of ppgi steel sheet.
The experiment is generally carried out by a dedicated UV lamp test chamber. The gloss and chroma coordinate value of the sample should be measured before and after test. And this also calculates its color difference. Finally, the discoloration, chalkiness, chalking grade of the coating shall be measured according to GB/T 1766-95 Paints and varnishes- Rating schemes of degradation of coats.
B. Atmospheric exposure test
After the natural atmospheric aging of color coated steel coil, the test to evaluate its coating loss. Including light, pale, chalking, foaming, rusting, cracking and other coatings aging performance. This is called the atmosphere exposure test. The test is usually carried out in the atmospheric exposure test site. The technical conditions of the test site have detailed rules in GB/T 12754.
Before the test, determine the samples’ luster, chromaticity coordinate value like other weatherability test. This also needs to assess the T-bend and impact performance, observe the appearance performance of crossed parts, drill parts, riveting parts and bend on the sample surface, and make the original record.
The original record shall include substrate information, coating information, original gloss, chromaticity coordinate value, T-bends, impacts, the appearance performance of crossed, drill, riveting and bend parts, and the date when sample began the atmospheric exposure test.
After the test, users should evaluate the chalkiness grade, discoloration grade, chalking grade, foaming grade, rust grade and cracking grade of the sample according to GB / T 1766-1995 standard, taking the worst value of the parallel test specimens for the test results.
