Color Fastness to Light of Textiles
2016-08-26 09:19 | writer: admin
1. Testing methods on color fastness to light of textiles
Color fastness to light testing refers to the textile samples together with a series of standard samples shall be simultaneously exposed to the artificial light according to the specified conditions. Then there will be a color contrast to evaluate color fastness.
2. The approach to improve the color fastness to light
Photobleaching mechanism is very complex. Mainly when dye has intensified after absorbing photons, and structure was destroyed because of series of photochemical reactions, so that lead to discoloration and fading. Color fastness to light of textiles depends on the chemical structure of the dye, as well as its state of aggregation, binding states and mixed-color matched status. Therefore, it is very important to choose the reasonable dyes.
3. Choose dye on the basis of the nature of fiber and use of textiles
Cellulose fiber textiles should be used superior inoxidizability dye; Protein fiber should be used with good reducibility or containing weakly oxidative dye additives; other fibers should be based on the influence of fading to choose dye.
4. Choose dye according to the color depth
A large number of tests show that light fastness of reactive dyes on cellulose fiber is proportional to the shade of dyed color, that is to say, the deeper color, the better the color fastness to light. On the contrary, the dye on the fiber was mostly a highly dispersed state, the lighter color will lead to the higher light intensity, so that the color fastness to light eventually decreased. Thus, light-colored dye should be used in high light fastness dyes. In addition, a lot of finishing agents such as softeners and anti-wrinkle finishing agent added in the fabric also will reduce the light fastness. Therefore, some dye which is not sensitive to those finishing agent should be chosen.