Color fastness is the quality requirement to dyeing and printing. Because dyeing fabric will cause fading or discoloration during wearing and keeping which getting through light/sweat/friction/washing and iron that will affect the appearance of the fabric or clothing. Its can use color fastness to express that the dyeing state variant. Textile’s color fastness is related to yarn structure/ texture/ dyeing method/ kind of dye stuff and external forces. It divided light fastness/ washing fastness and soaping fastness/ friction fastness/perspiration fastness/ironing and sublimation fastness etc.
Light fastness is referring to extent of the colored fabric subjected to sun discoloration. Its test method can be used both sun basked and sun machine basked, comparing fading degree between sunning sample and standard sample, it divided into 8 class, no.8 is the best, no.1 is the worst. The fabric with worst light color fastness should be avoid from long time solarization, better place in the shade to dry.
Washing and soaping fastness is dyeing fabric’s color changing process through washing liquid washing. Generally it adopt grey grading sample as evaluation standard, i.e. comparing the color difference between original sample and test sample to judge it, washing color fastness is divided into 5 class, no.5 is the best, no.1 is the worst. The fabric with worst washing color fastness should dry cleaning, if getting through wet cleaning, it need notice washing conditions, such as washing temperature cannot be higher, and washing time cannot be too long etc.
3.Rubbing color fastness
Rubbing color fastness is refer to the degree of fading for dyeing fabric after rubbing, it divided into dry rubbing and wet rubbing. Rubbing fastness is evaluated by white cloth staining degree, totally divided into 5 class (1~5), the larger in the value, the better in rubbing color fastness. The fabric with worse rubbing color fastness will have a limit in using.
Perspiration fastness is referring to the fade degree after textile stained with sweat. Regarding to perspiration fastness because human’s sweat composition is not the same, generally except single test, it should be tested along with other color fastness. Perspiration fastness is divided into 1~5 class, the larger in class no., the better in perspiration fastness.
Ironing fastness is the degree for dyeing fabric color having fading or color changing during ironing. This discoloration or fading degree is based on ironing and other textile’s staining to judge. Ironing fastness is divided into 1~5 class, no.5 is the best, no.1 is the worst. While testing different textile, it should choose suitable ironing temperature.
Sublimation fastness is referring to the degree to sublimation during keeping the dyeing fabric. Sublimation fastness is using grey grading sample card to judge the stain degree of color changing/ fading/ white cloth after dry hot pressure, it divided into 5 classes, 1 class is the worst, 5 classes is the best.
Normal textile’s stain fastness, generally it required 3~4 class, which can fit for wearing.