How many types of dye fastness are there for corduroy fabrics? How quickly does corduroy fabric dye? The dye fastness of corduroy fabrics refers to the ability of dyes or pigments to maintain their original color under the influence of various external factors during or after dyeing corduroy fabrics. This is also a quality requirement for dyed and printed fabrics. Because the dyed corduroy fabric will change color or change color due to light, sweat, friction, washing, ironing and other reasons during the wearing and storage process, thus affecting the appearance and beauty of the corduroy fabric or corduroy clothing. The nature or extent of changes in dyeing state can be expressed by color fastness. The color fastness of corduroy fabric is related to fiber type, yarn structure, fabric structure, printing and dyeing method, dye type and external force.
Dye fastness can be divided into: sun exposure Fastness, washing or soaping fastness, rubbing fastness, perspiration fastness, ironing fastness, sublimation fastness
1. Light fastness
Light fastness refers to the degree of discoloration of colored fabrics under sunlight. Test methods can be performed in sunlight or in a helium machine. The degree of fading of the sample after exposure is compared with the standard color sample. Grading standards include wool blue label and gray card, national standard and European standard. It is grade 8, grade 8 is the best and grade 1 is the worst; the American standard is divided into grade 5, grade 5 is the best and grade 1 is the worst. Fabrics with poor light fastness should not be exposed to the sun for a long time and should be placed in a ventilated and cool place to dry. Generally, a xenon lamp is used for 24 hours for testing.
2. Washing fastness
Washing fastness or soaping fastness refers to the color change of dyed fabrics after being washed with detergent. degree. Usually the gray scale sample card is used as the evaluation standard, that is, the color difference between the original sample and the faded sample is judged. Washing fastness is divided into 5 levels, with level 5 being the best and level 1 being the worst. Fabrics with poor wash fastness should be dry cleaned. If it is wet cleaning, you must pay more attention to the washing conditions. For example, the washing temperature cannot be too high and the washing time cannot be too long. Washing fastness is divided into two indicators: original change and white cloth staining. White cloth dyeing is divided into six types of fibers: cotton, nylon, polyester, wool, acrylic and acetate. The test temperature is 40/50/60/95 degrees, generally 40 degrees for silk and wool, and 60 degrees for cellulose fibers.
3. Rubbing fastness
Friction fastness refers to the degree of color fading of dyed corduroy fabrics after rubbing, which can be divided into dry rubbing and wet rubbing. friction. The rubbing fastness is evaluated based on the staining degree of white cloth, and is divided into 5 levels (1-5). The larger the value, the better the rubbing fastness.
4. Perspiration fastness
Perspiration fastness refers to the degree of discoloration of dyed fabrics after being soaked 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.
5. Ironing fastness
Ironing fastness refers to the discoloration or fading of dyed fabrics during ironing degree. 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 from 1 to 5, with level 5 being the best and level 1 being the worst. When testing the ironing fastness of different fabrics, the ironing temperature for the test should be selected.
6. Sublimation fastness
Sublimation fastness refers to the degree of sublimation phenomenon that occurs in dyed fabrics 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 the worst and level 5 being the best. This test is generally used for polyester fabrics dyed with disperse dyes.
7. Chlorine immersion fastness
Chlorine immersion fastness is generally aimed at some swimming suits, because seawater contains chlorine. Easily cause fabrics 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.
8. Perspiration fastness to light
Some fabrics have good perspiration fastness and light fastness after testing. However, in actual use, especially in summer, it is easy to fade due to sweat and sun exposure, which puts forward a new requirement, and at the same time, new standards are also produced.
9. Fastness to peroxide resistance
Most of the current washing powders are added with peroxides such as peracetic acid. Oxides and some activators cause textiles to fade due to oxidation during washing. Therefore, the color fastness of textiles must have a certain tolerance to peroxide.
The dye fastness of normal corduroy fabrics generally requires reaching level 2 to 3 to meet the needs of wearing.
Others include weather fastness, color fastness, saliva fastness, blister fastness, dry cleaning fastness, etc. These fastnesses are very important for The printing and dyeing processing of textiles puts forward increasingly higher requirements.
