Color fastness
The color fastness of textiles (referred to as color fastness) means that the dyed or printed fabric is subjected to external factors (squeeze, friction, water washing, rain, exposure, light, seawater impregnation, saliva impregnation, etc. during use or processing). The degree of fading under the action of water stains, sweat stains, etc. is an important indicator of fabrics. The color fastness is good, the textile is not easy to fade in the process of post-processing or use; if the color fastness is poor, the color may be discolored or stained, which causes a lot of trouble.
The most common textile color fastness problem
Insufficient light fastness: when the outerwear is wearing, the color of the part exposed to sunlight is lighter or discolored (generally the back and shoulder parts), and the color is not changed or changed when the illumination is not applied or the illumination is small. Light, the original color of the product is different in color, can not continue to use.
Color fastness to washing, soaping and dry cleaning is unacceptable: the clothing fades after washing. Silk clothing, wool clothing, and cotton clothing are the most prone to such problems.
Unsatisfactory color fastness to rubbing: During the use of textiles, the degree of discoloration is different because different parts of the product are subjected to different degrees of friction. For example, the tops of the shirt, the elbows of the sleeves, the collar and the underarms are most likely to fade. In addition, the hips and knees of the pants are also easy to fade.
Unsatisfactory color fastness to perspiration: mainly in summer clothes or close-fitting underwear, when worn, it is faded by the impregnation of sweat.
Factors affecting the color fastness of textiles
There are many factors affecting the color fastness of dyed products, but mainly depends on the chemical structure of the dye, the physical state of the dye on the fiber (the dispersion of the dye, the combination with the fiber), the dye concentration, the dyeing method and the process conditions, etc.; The nature of the relationship is also very large.
Factors affecting the color fastness to rubbing
The color fastness to rubbing is also called the rubbing color fastness. The main influencing factors are the structure and properties of dyes, the structure of different fibers and fabrics, and the dyeing process.
The reactive dye contains a hydrophilic group such as a sulfonic acid group. If the dye on the textile is not sufficiently washed, there are many unfixed dyes on the fiber. At this time, the dye with high water solubility is easily faded and contaminated on the friction fabric. The dye with high directness is difficult to diffuse into the interior of the fiber, causing the surface of the textile to float and easily fade.
The morphological structure of the fibers is different, and the fixing rate of the dyes is different. The fixing rate is high, the amount of hydrolyzed dye is small, the floating color is easy to be washed off, and the rubbing color fastness is good; the fiber surface is smooth, the structure is flat and the friction coefficient is low, and the rubbing color fastness is good. In general, the color fastness to rubbing of regenerated cellulose fibers (Modal, Tencel, and viscose) textiles, especially wet rubbing, is better than natural fiber cotton. The texture of the fabric also has a great influence on the color fastness of rubbing: the order of friction coefficient is: plain weave > twill fabric > Woven Fabric.
Factors affecting soap fastness
The color fastness to soaping refers to the degree of fading of the dyed product after soaping in the soapy liquid under the specified conditions. Factors affecting the color fastness to soaping include the chemical structure of the dye, the strength of the dye-fiber bond, the different types of fibers, and the dyeing process.
The color fastness of the water-soluble dye containing a hydrophilic group is lower than that of the dye without a hydrophilic group, and the color fastness to soaping is caused by the affinity of the water-soluble dye containing a hydrophilic group with water. Poor.
The same dye has different soap fastness on different kinds of fibers. For example, the color fastness of disperse dye on polyester is higher than that on nylon. This is because the structure of polyester is tighter than nylon and has strong hydrophobicity.
Factors affecting light fastness
Light fastness is also known as light fastness or light fastness. The main factors affecting the fading of the sun, including the light, the molecular structure of the dye, the dye aggregation state and dyeing depth, and fiber properties.
Light is the most important factor leading to the fading of the dye. The chromophoric group of the dye undergoes photo-oxidation or photoreduction under the irradiation of ultraviolet light and visible light, which causes the fabric to fade.
The light fastness of the dye is also related to its molecular structure. 70%~75% of the molecular structure of the reactive dye is azo type, and the rest are 蒽醌 type and phthalocyanine type. The azo type light fastness is generally poor, and the 蒽醌 type and the phthalocyanine type have better light fastness.
The aggregate structure of the dye also has an effect on its light fastness. The state of existence of the dye on the fiber is mainly in the form of a molecule, an aggregate form, and a mixture of the two forms. The dyes in the form of molecules fade faster, and the aggregates of the dyes are more likely to transfer energy due to the stronger internal molecules, and the light fading mainly occurs on the surface, so the dyed fabric fades faster at the initial stage. Then basically unchanged.
Cotton Fabric,Cotton Material,Jersey Material,Organic Cotton Fabric
Shaoxing Yuezan Textile Co.,Ltd , https://www.yuezantextile.com