Textiles - Test method for colour fastness to artificial light
The color fastness to light is an important index to evaluate the color fastness of textiles. In order to accurately detect the color fastness to light, many methods have been developed at home and abroad. All of these methods can reflect the color fastness to light of textiles to some extent, but there are some differences among them, and all have some limitations, especially some methods are not suitable for practical application due to the long detection cycle.
Test method
Five test methods for color fastness to light are listed in GB/T8427-2008, among which blue wool standard samples are used as reference for methods 1, 2 and 3.
Method 1, to check the exposure degree of the sample to control the exposure cycle, which is considered to be the most accurate. This method requires a set of blue wool standard samples for each test sample. If multiple samples are to be done in one experiment, a lot of blue wool standard samples will be consumed. And we should always pay attention to whether the discoloration of each sample reaches the 4 and 3 levels of the discoloration gray card, which is very time-consuming and energy, if a sample has 6 or 7 levels of color fastness to light, the detection cycle is longer.
Method 2, suitable for simultaneous detection of a large number of samples, its characteristic is to check the blue wool standard sample to control the exposure cycle. However, the operation process of this method is relatively tedious, and when reaching the end of exposure (blue wool standard sample 7 to achieve discoloration gray card level 4), it needs a long enough time.
Method three is to use two blue wool standard samples and the sample together to check the blue wool standard sample to control the exposure cycle. Rating results as good or worse than a specified level. This method is simple to operate, but the light resistance level needs to be specified, and the application scope is small.