The color fastness requirement of textiles is different because of their different use and process. For example, the curtain which is less washed requires low colorfastness, but due to exposure to the sun for a long time, it needs high lightfastness. Summer clothing fabrics should have higher light fastness, washing fastness and perspiration fastness for the reason that they always expose to sun and human body always sweats.
Colour fastness is assessed generally by comparing any staining of specified adjacent fabrics during the test with a set of standard ‘grey scales’. A numerical grading is given on a scale of 1–5, where 1 is very poor and 5 is excellent. Generally, a grade of 4 or above is deemed acceptable for commercial use.
Badly dye, easy to fall off the fiber, soaping fastness is poor, washed after washing is not clean, floating color residue, will lead to decreased soaping fastness, soap liquid temperature, pH and stirring Have a great impact on soaping fastness. But if the dye concentration is high, the combination of dye and fiber is supersaturated, and the dye by external force is easy to fall off, which also affects soaping fastness.
Selection of high light fastness of the three primary colors, blue chromatography to use anthraquinonoid type, Phthalocyanine and other light color fastness of the dye better, poor light fastness will affect the whole color of light fastness. The relatively small amount of dye in the mixed color component can select the dye with high fastness to light, thus ensuring the overall color fastness of the fabric.
Full soaping, washing, minimizing the amount of hydrolyzed dyes and floating color to improve the fabric’s fastness to light, the choice of fixing agent. At present, there are three kinds of fixing agent, cationic, non-surface active quaternary ammonium type, and reactive type, which cationic fixing agent and dye in the fiber to generate lakes, although the washing fastness is good, but often will reduce the dye the original light fastness, light-colored fabrics should be used with little or not use at all.
Soap blowing fastness of the factors that affect the color fastness of dyeing products, many factors, but mainly depends on the chemical structure of the dye, the physical state of the dye on the fiber, the degree of dye dispersion, the combination with the fiber, dye concentration, dyeing methods and process conditions on the color fastness also has a great impact. The nature of the fiber and the color fastness is also a great affect, and the same dyes tend to have different fastness on different fibers.
Different countries have set different standards for the different colorfastness requirements of different textiles. The main standards for colorfastness are as follows
1. AATCC (American Association of Textile Chemists and Colorists) technical manual:
Describes 66 numbers of different colorfastness tests.
2. SDC (Society of Dyers and Colorists):
In 1927, SDC (Europe) made fastness test committee.
3. ISO(International Organization for Standardization):
In 1947, ISO made color sub committee. ISO also grades the fastness:
For light fastness: 1~8
For other fastness: 1~5
Color Fastness types about Textile
Color fastness of rubbing: rubbing fastness is said to be the fading degree that dyeing textile goes through, it can be divided as dry friction and wet friction. Rubbing fastness is based on dyeing degree of white cloth the as evaluation criterion, which is 5 levels. The bigger value is the better the rubbing friction is.( a series of products of wet friction in our company)
Color fastness of lightening: lightening fastening means the degree of discoloration that dyeing textile is influenced by daylight effect. Its testing method is to compare the fading degree of samples with standard color swatch by means of modeling the process of daylight. It can be divided into 8 levels, among which the eighth degree is the best while the first one is the worst. The textile with poor lightning friction should be avoided exposing under the sun for a long time, and it should be placed in the ventilation where will help to dry in the shade.( our company’s light fastness improver)
Sublimating fastness: it points to the degree of sublimation of dyeing textile when being placed. The common dyeing fastness of textile should reach 3 to 4 levels to meet the requirements of wearing generally. ( our company’s heat sublimation fastness improving agent)
Washing fastness: fastness to washing or soaping means the degree of the variation of color after the dyeing textile going through detergent washing. It is generally adopted grey classification card as evaluation criterion, that is to say, to depend on the difference of color between the fading color of original sample and the one of trial sample. Washing to fastness is classified as 5 levels. The fifth level is the best but the first one is the worst. The textile with poor washing fastness should be dry—clean. If it is wet—clean, we should be doubly careful about the washing conditions, like the washing temperature can not be too high and the time can not be too long, etc.( our company’ s wet rubbing fastness improver)
Perspiration of fastness: perspiration of fastness is the fading degree when dyeing textile soaks the sweat lightly.
Ironing fastness: it means the variation of color or fading degree when the dyeing textile is being
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