There are six main color fastness for the common workwear fabrics as following:
Light color fastness refers to the degree of discoloration of colored fabrics by sunlight. The test method can be sun exposure or daylight machine exposure. The fading degree of the sample after exposure is compared with the standard color sample, and it is divided into 8 levels, 8 is the best, and 1 is the worst. Fabrics with poor light fastness should not be exposed to the sun for a long time, and should be dried in the shade in a ventilated condition.
2. Rubbing fastness
Rubbing fastness refers to the degree of discoloration of dyed fabrics after rubbing, which can be divided into dry rubbing and wet rubbing. The rubbing fastness is evaluated based on the degree of white cloth staining, and it is divided into 5 levels (1~5). The larger the value, the better the rubbing fastness. The life of fabrics with poor rubbing fastness is not longer.
3. Washing fastness
Washing or soaping fastness refers to the degree of color change of dyed fabrics after washing with washing liquid. Usually, the gray graded sample card is used as the evaluation standard, that is, the color difference between the original sample and the faded sample is used for judgment. The washing fastness is divided into 5 grades, grade 5 is the best and 1 is the worst. The fabrics with poor washing fastness should be dry-cleaned. If they are wet-washed, the washing conditions should be paid extra attention, such as the washing temperature should not be too high and the time should not be too long.
4. Ironing fastness
Ironing fastness refers to the degree of discoloration or fading of dyed fabrics during ironing. The degree of discoloration and fading is assessed by the iron's staining of other fabrics at the same time. Ironing fastness is divided into 1~5 grades, grade 5 is the best and grade 1 is the worst. When testing the ironing fastness of different fabrics, the temperature of the iron used for the test should be selected.
5. Perspiration fastness
Perspiration fastness refers to the degree of discoloration of dyed fabrics after being immersed in sweat. The perspiration fastness is not the same as the artificially prepared sweat composition, so it is generally evaluated in combination with other color fastnesses in addition to a separate measurement. The perspiration fastness is divided into 1 to 5 grades, the larger of the value, the better.
6. Sublimation fastness
Sublimation fastness refers to the degree of sublimation of dyed fabrics in storage. The sublimation fastness is evaluated by the gray graded sample card for the degree of discoloration, fading and staining of the white cloth after the dry hot pressing treatment. There are 5 grades, 1 is the worst, and 5 is the best.
The color fastness to ironing and sublimation is mainly used to determine the color resistance of various colored textiles to high temperature and the color of textiles to resist heat pressing and hot roller processing. So as to provide a basis for the reasonable selection of dyes to determine the printing and dyeing process parameters, and it can also be used to detect the quality of printed and dyed finished products.