Test method for aging of synthetic resin tile

For the samples with special decoration (such as non-single color, wood grain, embossing, etc.), the color change of the samples before and after aging shall be evaluated with gray scale card, and the gray scale shall not be less than 3. The aging test shall be conducted according to the provisions of Method A in GB/T 16422.2-1999. The blackboard temperature is (65 ± 3) ℃, the relative humidity is (65 ± 5)%, the water spraying period is (18 ± 0.5) min, the water spraying time between two times is (102 ± 0.5) min, there is no dark cycle, and the aging surface is the surface of synthetic resin tile. Appearance: Conduct visual inspection at a distance of 0.3m under natural light or equivalent light source. Color difference: the length and width of the sample shall be 50mm × 40mm, and the number shall not be less than 2. Spectrophotometer using CIE D65 standard light source (including specular reflection) to determine condition 8/d or d/8 (both without filters). The measurement shall be carried out according to the provisions of GB/T 11186.1, GB/T 11186.2 and GB/T 11186.3. One sample is the original sample, and the other sample shall be measured within 24h after taking out the aging sample. Each sample shall be measured at two points, and the average value shall be taken to calculate △ E *. The gray level shall be tested according to the provisions of GB/T 250.