How to improve the color fastness of fabrics? The color fastness of fabrics refers to the dyeing fastness of textiles, referred to as color fastness, which means that the dyed or printed fabric is subjected to external factors, such as extrusion, friction, washing, and rain during use or processing. The degree of fading under the action of showering, sun exposure, light, sea water immersion, saliva immersion, water stains, and sweat stains is an important indicator of fabrics.
Good color fastness, textiles are not easy to fade during post-processing or use, and poor color fastness will cause color loss, discoloration, or staining, causing a lot of trouble. Measures to improve color fastness to light, reasonable selection of dyes, the choice of dyes is the key to improving light fastness.
All dyes will leave floating dyes in the fiber after printing and dyeing. The more the amount of dye, the more floating dyes are bound to be. The fiber has a limit value for the adsorption of each dye, which is the saturation value of dyeing. Generally, the amount of dye cannot exceed About 10% of the saturation value. When the amount of dye greatly exceeds the saturation value, the excess dye cannot be dyed and fixed, and can only accumulate on the surface of the fabric, thereby affecting the friction color fastness of the fabric.
Dyes are poorly dyed and easily fall off from the fiber, and the soaping fastness is poor. After dyeing, the washing is not clean, and the floating color remains, which will also cause the drop of soaping fastness. The temperature, pH value and stirring of the soaping solution All have an effect on soaping fastness. The dye concentration generally has a small effect on soaping fastness. However, the dye concentration is high, the combination of dye and fiber is super saturated, and the dye is easy to fall off by external force, which also affects the soaping fastness.
Choose the three primary colors with high light fastness, and use dyes with good light fastness such as anthraquinone type and phthalocyanine type for blue color spectrum. Poor light fastness will affect the light fastness of the entire mixed color. The dyes with relatively small content in the mixed color components can choose the dyes with high light fastness grades, so as to ensure the sun light grade of the overall color fastness of the fabric.
Fully soap and water, minimize the amount of hydrolyzed dyes and floating colors to improve the light fastness of the fabric, the choice of fixing agent, there are currently three kinds of fixing agents, cationic, non-surface active quaternary ammonium salt, reaction type. Among them, cationic fixing agent and dyes form lakes on the fibers. Although the washing fastness is very good, they tend to reduce the original light fastness of the dyes. Light-colored fabrics should be used as little as possible or not.
There are many factors influencing the fastness of soaping and the color fastness of dyed products, but they mainly depend on the chemical structure of the dye, the physical state of the dye on the fiber, the degree of dispersion of the dye, the combination with the fiber, the concentration of the dye, and the dyeing. The method and process conditions also have a great influence on the color fastness. The properties of fibers are also closely related to the fastness of dyeing. The same dyes often have different fastnesses on different fibers.