1. Comparison of test methods for color fastness to rubbing
The test of color fastness to rubbing refers to the test of rubbing the colored sample with a dry rubbing cloth and a wet rubbing cloth, and then evaluating the degree of staining of the rubbing cloth. The test results are divided into 5 grades, with 5 being the best and 1 the worst. Although the test process is simple, it is the most basic color fastness assessment index for textile products, and it is almost one of the items that must be assessed when buyers from all over the world place orders. The technical conditions of the rubbing fastness test standards in various countries are very similar, but there are some differences.
2. Main factors affecting color fastness to rubbing and its control measures
In the process of friction between textiles and other objects, the color shedding or the degree of staining to the object being rubbed is affected by many factors. There are two ways of color shedding and staining: one is that the dyes on the textiles fall off or fade, and are stained on the surface of the friction object; the other is that the dyed fibers fall off and adhere to the surface of the friction object.
3. The main reason for staining
Although there are some differences in the covalent bond strength and adhesion between reactive dyes with different chemical structures and cellulose fibers, the effects on the wet rubbing color fastness of dyed fabrics are basically the same. When the dyed fabric is wet rubbed, the covalent bond formed between the dye and the fiber will not break and cause floating color. The transferred dyes usually do not form covalent bonds with the fibers, but only rely on van der Waals forces to produce adsorption, that is, float.