Prediction of the Exposure Endpoint of Textile Color Fastness to Light

The color fastness to light of textile in the product standard is always tested by method 3 in GB/T 8427, which determines the endpoint of exposure according to the discoloration of the blue wool standard sample. The aging of the xenon lamp for exposure resulted in the different sun exposure times of blue wool references required for the same color fastness level. As a result, the difficulty of testing increased, and the test accuracy was also affected. In this paper, the relationship between the exposure time and the service time of xenon lamps was studied through real-time monitoring to accurately predict the endpoint of textile light fastness. The exposure time for color fastness class 3 curve according to the service time of xenon lamp was fitted as: y1=10.4785+6.39539E−5x1+2.53603E−7x1 2; the exposure time of color fastness class 4 underexposure was fitted as: y2=38.17692-0.00131x2+2.78006E−6x2 2-4.81015E−10x2 3; the color fastness to light of textiles wetted with artificial perspiration was y3=13.78014-5.53089E−4x3+1.53274E−6x3 2-2.92228E−10x3 3+1.02685E−14x3 4. The method is practical and effective, has practical value for the light fastness testing of textiles, and has important guiding significance for daily light fastness testing in the future.