Polyester is an important variety of synthetic fiber, is the trade name of polyester fiber in China. Polyethylene terephthalate (PET) is a kind of fiber-forming polymer, which is made from PTA, DMT and MEG by esterification, transesterification and polycondensation. It is a kind of fiber-forming polymer, which is produced by spinning and post-treatment.
For customers with high requirements for color fastness of polyester, the dyeing plant, after dyeing at high temperature and high pressure, through reduction cleaning and high temperature setting, still can not achieve the ideal color fastness.
The reasons are as follows:
1. Thermal migration of polyester dyed with disperse dyes is the key to the above problems. Thermal mobility is a common property of disperse dyes. It means that some dyes migrate from the inside of the fiber to the surface of the fiber through the fiber capillary, resulting in the accumulation and redistribution of dyes on the surface of the fiber. The existence of auxiliaries and surfactants, including the residue on the cloth surface, will aggravate the production.
2. Because this kind of heat transfer is mainly related to the structure of the dye itself, and the thermal mobility of disperse dyes with different structures is also different from each other. Therefore, when finishing at high temperature, especially when using silicone oil and antistatic agent, it contains a certain amount of surfactant, and when these auxiliaries adsorb unevenly on the cloth surface, including uneven pH on the cloth surface, it will produce There are a series of problems, such as frictions, washing, staining, etc., which bring the hidden danger and harm to the dyeing quality.
Treatment method:
1. First of all, disperse dyes with low thermal mobility and similar properties should be selected. Because these dyes have large molecular weight and high affinity with polyester fiber, it is difficult to transfer from the inside of the fiber to the surface. For example, XX's lxf, XX's XF, XX's big Enix XF / SF and XX's MS series all have good heat transfer fastness.
2. The selection of color matching dyes should be the same type or high temperature dyes as far as possible. Because different types of dyes have different heat transfer ratio and different sublimation fastness, high-temperature dyes have higher sublimation fastness. Although the heat transfer fastness and sublimation fastness of dyes are not consistent, the high-temperature dyes have less sublimation under higher temperature setting, and the corresponding color stability is also good.
3. The softer the finishing process is, the deeper the color is, the more migration of dyes will be. The higher the temperature is, the greater the impact on migration will be. Under the condition of ensuring the setting effect, 150 ℃ or lower temperature can be selected according to the variety to avoid or reduce the migration of dyes.
ENGLISH
España