Why does the plastic seal change color during use?

The severe discoloration of plastic seals during the service cycle will directly affect product quality. For this reason, the discoloration of plastic seals will be discussed and dealt with. Through instrumental and visual methods, the plastic seals are exposed to natural weather and accelerated by artificial ultraviolet light. The light-aging resistance under the conditions is quantitatively characterized by the CIE standard colorimetric target. In-depth discussion with a lot of data and long-term tracking measurement. The research on plastic seal design has obtained the following primary results: The different parameters of the SP60 integrating sphere spectrophotometer have a greater influence on the value of the color measurement of the outer surface of the PVC plastic seal. The test has verified that the best measurement condition is the CIE L*a*b* system Color difference formula. Light source D65 (including specular reflection) and 10° field of view. The plastic seal is sealed under the sunlight of the window glass, and the light resistance of dark materials is better than that of light colors. The two changed relatively significantly in the initial 90 days, and the color of the light-colored edge banding was aggravated in the next 210 days; the dark color did not change significantly. In addition, the appearance of the edge banding strips showed different discoloration, some turned yellow, some faded and turned white. After 20 days of accelerated artificial ultraviolet light, the various parameter values u200bu200bof the white edge banding have changed significantly, and other color information has not changed significantly, which is definitely different from the change characteristics under natural exposure conditions.