Views: 0 Author: Site Editor Publish Time: 2021-05-13 Origin: Site
Rubbing fastness refers to the abrasion resistance or stain resistance of the color of textiles to other textiles. Generally, dark colors have lower abrasion resistance than light colors. Friction resistance plays an important role, especially when bright materials are in contact with dark textiles and there is concern about fouling of bright materials. Therefore, the wet rubbing fastness improver was born.
This passage is going to talk about the following questions of the wet rubbing fastness improver:
(1) Definition of color fastness
(2) Application areas of wet rubbing fastness
The color fastness is divided into 9 kinds. The dye fastness of normal fabrics generally requires 3~4 grades to meet the needs of wearing.
Light fastness refers to the degree of discoloration of colored fabrics by sunlight. The test method can use sunlight or sunlight machine.
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.
Rubbing fastness refers to the degree of discoloration of dyed fabrics after rubbing, which can be divided into dry rubbing and wet rubbing.
Perspiration fastness refers to the degree of fading 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. Perspiration fastness is divided into acid and sweat fastness and alkali sweat 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.
Sublimation fastness refers to the degree of sublimation of dyed fabrics in storage. The fastness to sublimation uses a gray graded sample card to evaluate the degree of discoloration, fading and staining of the white cloth after the fabric has been treated by dry hot pressing.
Chlorine immersion fastness is generally aligned with some swimming suits, because the seawater contains chlorine, which can easily fade the fabric. Nowadays, urban tap water also contains available chlorine. Some hospitals and hotel supplies need to be disinfected with chlorine-containing detergents, so higher and higher requirements are put forward for the fastness to chlorine bleaching.
Some fabrics are tested to have good perspiration fastness and light fastness, but in actual use, especially in summer, it is easy to fade with sweat and sunlight. This puts forward a new requirement, and at the same time , A new standard was born.
Most of the current laundry detergents are added with peroxides such as peracetic acid and some activators, causing textiles to be oxidized and faded during the washing process. Therefore, the color fastness of textiles must have a certain tolerance to peroxides.
The wet rubbing fastness improver can remove the disperse dye stains on the spandex, and obviously improve the dry cleaning, washing and rubbing fastness of the dyed fabric. Printing and dyeing auxiliaries are a branch of the fine chemical industry, with rapid development, improving product quality and dyeing fastness, and taking the road of technological innovation.
Nylon dyed fabrics are often cut and assembled in garment factories to produce multi-colored striped garments. The dye on the dark strips is required to not stain the white strips during soaping, and the color fastness of the white cloth must reach 4 to 5. Nylon fixing agent condensed with phenol formaldehyde does not meet the requirements, and there is a problem of free formaldehyde. Using commercially available formaldehyde-free fixing agent, the color fastness of white cloth can reach up to level 4, and tannin and tartar are used now. The fixing agent is still unsatisfactory many times. There is an urgent need to develop a fixing agent with good color fastness to white cloth. According to the information, the use of suitable polymers can meet this requirement.
When using wet rubbing fastness improver and when the printed fabric is heat-set, the edge of the pattern migrates and permeates to the white ground. The reason is the sublimation of the dye, even the dye with good sublimation fastness has this phenomenon. The other is the migration of dyes at high temperatures. Sublimation only vaporizes the dyes first, and then transfers to the white cloth in a single molecule state, while thermal migration is the transfer of dye aggregates (including single molecules) to surrounding fibers. This is the same as pad dyeing and drying. Dye migration when dry is similar. To prevent disperse dyes from migrating or migrating, it is to make the dyes form larger aggregates and make them difficult to move.