Color fastness (Color fastness) is also called color fastness, dye fastness. It refers to the resistance of the color of textiles to various effects during processing and use.
The fastness grade is evaluated according to the discoloration of the sample and the staining of the undyed lining fabric. Textile color fastness test is a routine test item in the internal quality test of textiles.
During its use, textiles will be exposed to various external effects such as light, washing, ironing, perspiration, friction and chemical agents. Some printed and dyed textiles are also subjected to special finishing processes, such as resin finishing, flame retardant finishing, sand washing, and grinding. This requires that the color of printed and dyed textiles relatively maintain a certain fastness.
Color fastness is abbreviated as color fastness; the color of colored fibers, fabrics or other colored materials is resistant to sunlight, washing, friction, perspiration, etc. during processing and use.
The color abundance rating, except for lightfastness to old light), which is grade R, all others are grade 5. The higher the grade, the better the color fastness. Leather measurement methods include fading (change in the color of the leather itself) and staining of the contact material.
The fading test is the color difference between the leather sample and the untreated test sample after the leather sample is processed under the specified conditions, and is graded by comparison with the standard gray sample card. The staining test is to touch the sample and the standard white cloth according to the specified conditions, and the degree of the white cloth is determined by the color transfer of the sample. The gray staining sample card is used to measure the grade.
For garments composed of different colored parts, the dyes sometimes migrate from one area to another during storage, usually from dark parts to light parts. This phenomenon is different from sublimation because it is low It is carried out at sublimation temperature, and this phenomenon also occurs with non-sublimation dyes. Mainly reflected in the migration of polyester and other chemical fiber fabrics, as well as other raw materials.
The color transfer is mainly due to two reasons: one is the transfer of dyes, especially the floating color of disperse and reactive dyes and the dyes migrated and freed from the fiber, which may dye the fiber on the surface of another sample; especially The dark color dyes the light color and stays on the surface of another sample in a granular and embossed form. The second is that the fibers fall off under the action of friction and transfer from one sample to another.