Test methods and technical requirements of light fastness tester
The sunlight color fastness tester is used for light aging tests of various textiles, furs, plastics, and other materials. In the national standard system, GB/T8426-1998 ("Textile Color Fastness Test Color Fastness to Light: Sunlight") and GB/T8427-1998 ("Textile Color Fastness Test Color Fastness to Artificial Light: Xenon Arc") have 5 exposure methods for selecting.
Method 1 is to control the exposure cycle by checking the sample. Each sample needs to be equipped with a set of blue wool standards;
Method 2 is to control the exposure cycle by checking the blue wool standards. A batch of different samples only needs one set of blue wool standards;
Method 3 is used to check whether the sample is consistent with a certain performance specification. The sample only needs to be equipped with two blue wool standards according to the requirements. The exposure cycle is also controlled by checking the blue wool standards;
Method 4 is used to check whether the sample conforms to a certain agreed reference sample. It does not require a blue wool standard but controls the exposure cycle by checking the reference sample;
Method 5 is used to check whether the sample conforms to the recognized radiation energy. The sample can be exposed alone or equipped with a blue wool standard. The exposure time is determined based on whether the specified radiation energy is reached.
In the national standard system, GB/T8429-1998 "Textiles Color Fastness Test Weathering Color Fastness: Outdoor Exposure" and GB/T8430-1998 "Textiles Color Fastness Test Artificial Weathering Color Fastness: Xenon Arc" have only three methods for the selection of exposure methods, of which Method 1 and Method 2 are the same as above. Method 3 is the same as Method 5 above. However, the exposure method in GB/T843I-1998 "Textiles Color Fastness Test Photochromic Inspection and Evaluation" is specific, only low-level blue wool standard 1 or L2 is required, and the exposure time of the sample is determined according to the time needed for the blue wool standard to change color. GB/Tl6991-1997 "Textiles Color Fastness Test High-Temperature Light Fastness: Xenon Arc" also has three exposure methods, Method 1 and Method 3 are the same as above, and Method 2 is to control the exposure cycle by checking the specified minimum limit standard.
Technical requirements:
Because the climatic conditions in my country and the United States are not the same, there are certain differences in their standards. GB/T84271998 "Color fastness to artificial light: xenon arc" standard requires temperature and humidity control as follows: medium effective humidity is used under normal conditions (temperate zone), the humidity control standard is level 5, the high standard blackboard temperature is 50℃, and the radiometer measures the radiation energy per unit area (i.e. radiation amount) as 42W/m (wavelength is 300nm~4OOnm). The humidity control standard is cotton poplin fabric dyed with red insoluble azo dyes. The method is to expose the humidity control standard together with the blue wool standard fabric. When the humidity control standard changes color to gray sample level 4, the blue wool standard is used to assess its light fastness grade.
The technical conditions for indoor textile exposure in the American AATCCTM16-2003 "Colorfastness to sunlight" standard are: air temperature in the test chamber (43±2)℃, relative humidity in the chamber (30±5)%, blackboard thermometer (63±3)℃, and radiation amount (48±1)W/m2 (wavelength 300nm~4OOnm).