How many types of textile dye fastness are there?

Sunlight fastness refers to color The extent to which a fabric changes color due to sunlight. The test method can be either sunlight exposure or insolation machine exposure. The fading degree of the sample after exposure is compared with the standard color sample. The rating standards include wool blue label and gray card, national standard and European standard. It is grade 8, with grade 8 being good and grade 1 being poor; the American standard is divided into grade 5, with grade 5 being good and grade 1 being poor. Fabrics with poor sun fastness should not be exposed to the sun for a long time and should be placed in a ventilated place to dry in the shade. Generally, a xenon lamp is used for 24 hours of testing.

Washing or soaping fastness refers to The degree of color change of dyed fabrics after being washed with detergent. The gray graded sample card is usually used as the evaluation standard, that is, the color difference between the original sample and the sample after fading is used for evaluation. Washing fastness is divided into 5 levels, level 5 is good and level 1 is poor. Fabrics with poor washing fastness should be dry cleaned. If wet cleaning is performed, extra attention should be paid to the washing conditions, such as the washing temperature should not be too high and the washing time should not be too long. Washing fastness is divided into two indicators, the original change and the staining of white cloth. The staining of white cloth is divided into six types of fibers: cotton, nylon, polyester, wool, acrylic, and acetate. The test temperature is 40/50/60/95 degrees. Generally, silk and wool use 40 degrees, and cellulose fibers use 60 degrees.

The rubbing fastness refers to the degree of discoloration of dyed fabrics after rubbing, and can be divided into dry rubbing and wet rubbing. The rubbing fastness is based on the degree of staining of white cloth as the evaluation principle, and is divided into 5 levels (1-5 ), the larger the value, the better the rubbing fastness.

Perspiration fastness refers to the resistance of dyed fabrics to stains Degree of discoloration after soaking in sweat. Since the composition of artificially prepared sweat is different, the perspiration fastness is generally not only measured separately, but also combined with other color fastnesses for assessment. Perspiration fastness is divided into levels 1 to 5, with the higher the level, the better. In European standards and national standards, perspiration fastness is divided into color fastness to acid perspiration and color fastness to alkali perspiration.

Ironing fastness refers to dyed fabrics The degree of discoloration or fading that occurs when ironing. The degree of discoloration and fading is evaluated by the staining of other fabrics by the iron at the same time. Ironing fastness is divided into levels 1 to 5, with level 5 being good and level 1 being poor. When testing the ironing fastness of different fabrics, the ironing temperature for the test should be selected.

Sublimation fastness refers to the The extent of sublimation phenomena that occur during storage. The sublimation fastness uses a gray grading sample card to evaluate the degree of discoloration, fading and white cloth staining of fabrics after dry heat pressing. It is divided into 5 levels, with level 1 being poor and level 5 being good. This test is generally used for polyester fabrics dyed with disperse dyes.

Chlorine immersion fastness is generally aligned Swimming suits, because seawater contains chlorine, can easily cause the fabric to fade. Nowadays, urban tap water also contains available chlorine, and some hospital and hotel supplies need to be disinfected with chlorine-containing detergents, so there are increasingly higher requirements for chlorine bleach fastness.

Some fabrics have good perspiration fastness and sun fastness after testing, but in actual use, especially in summer, they are easy to fade when soaked in sweat and sun exposure, which raises a new question. requirements, at the same time, new standards have emerged.

Most of the current washing powders are added with peracetic acid. Peroxides and some activators cause textiles to be oxidized and fade during the washing process, so the color fastness of textiles must have a certain tolerance to peroxides.