Dyeing technology of the hottest microfiber textil

Dyeing technology of microfiber textiles

there are many spinning methods for microfiber string 7. At present, the most widely used are composite splitting method and island dissolution method. The former is suitable for producing filaments with a single filament linear density (DPF) of 0.33dtex, and the latter is suitable for producing finer fibers (0.0001dtex ≤ DPF ≤ 0.11dtex). Suede like fabric made of Sea Island microfiber is very similar to natural suede. It not only has the same fine nap, but also its internal structure is very similar to the bundle collagen fiber structure of natural suede. It forms an open three-dimensional microporous structure, which is breathable, moisture permeable, soft and elastic. It also has the effect of natural leather nap root

compared with conventional fibers, the supramolecular and morphological structure of island microfiber are very different. If its diameter is thin, from graphene "origami" to smart pretending to hundreds of nanometers, or even below 100nm, its meridional direction is only composed of dozens of polyester molecular chains. Although the dye is easy to diffuse, it does not contain much dye, and the number of dye molecules adsorbed on the fiber surface accounts for a high proportion. Therefore, when this kind of fiber is dyed, the dyeing speed, dyeing amount, color rendering and fastness of the dye will change greatly. Moreover, the supramolecular and morphological structure of fibers are also related to the spinning process. For example, POY-DTY two-step spinning is very different from POY and FDY one-step spinning, so it is very difficult to control dyeing

at present, sea island microfiber is polyester, which is mainly dyed with disperse dyes by high temperature and high pressure method. It has fast dyeing speed, poor levelness, color rendering and color fastness, but good migration and improvement. These are mainly caused by its extremely fine and large specific surface area. The poor levelness and color fastness are also related to the easy precipitation of oligomers during dyeing, which makes dyeing difficult. Most of the sea island microfiber is blended or interwoven with other polyester fibers of different specifications. Due to the different dyeing speed of different fibers and the dependence on temperature, the dyeing levelness and reproducibility of this kind of fabric become worse. For example, after it is blended or interwoven with coarse fibers, in the low temperature zone, the dyes adsorb more on the microfiber, and the color is also dark, while in the high temperature zone, on the contrary, the larger fibers have more dyes, and the color is darker than the microfiber, Even the dyes on the superfine fibers will migrate to the coarser fibers. Only in a certain period of time, the amount or color and depth of dyes on the two fibers are close, and the time when these two variables are close is different, so the levelness and fastness of this kind of fabric dyeing are very difficult to control

disperse dyes for microfiber dyeing should be dyes with good promotion, strong color rendering, good levelness and reproducibility, bright colors, good color fastness and good dispersion stability. It is necessary to use special dyes for dyeing. At present, most varieties are not ideal, which is one of the priorities of future development. In order to improve the dyeing performance, according to the research, it is necessary to develop dyeing auxiliaries, especially high-efficiency multi-functional dyeing auxiliaries with leveling, dispersion, lubrication, deepening and reduction of oligomers. Most of them are some non-ionic and anionic surfactants, which are compounded with a variety of organic additives. Our study found that the compounding of different auxiliaries has a great impact on the performance of auxiliaries. The dyeing temperature control of microfiber is the most important. Our research shows that the dyeing starting temperature of this kind of fiber should be low, generally as low as 40 ~ 50 ℃, especially the fibers of high-speed spinning process (POY, foy) have a fast dyeing speed at low temperature; Secondly, the heating rate should be slow, close to the glass transition temperature（ Τ g) That is, it should be kept warm for a certain time near 90 ℃, and for some dyes with particularly fast dyeing speed, it should also be kept warm for a certain time near 110 ℃, that is, it should be heated in two or three stages; Finally, the maximum dyeing temperature is lower than that of ordinary fibers, about 5 ~ 10 ℃. That is, depending on the fiber linear density and spinning process, it can be controlled at 120 ~ 125 ℃. The cooling rate of dyeing should also be low. It also has a great impact on the feel and flatness of textiles. The liquid can be discharged only after it is cooled to 70 ℃

nylon microfiber, especially Sea Island staple fiber, has also developed rapidly in recent years. It is mainly used to produce the fourth generation synthetic leather base cloth. The processing technology of this base cloth is complex, and its fiber dyeing is also very difficult. Neutral and acid dyes are mainly used for dyeing. The dyes used and dyeing technology have special requirements. Our research shows that the main difficulties are uniformity, permeability and fastness, Synthetic leather base cloth is not only composed of island ultra-fine polyamide fiber, but also often contains other components. Some base cloth plastics can be molded into more complex shapes than steel assemblies, and most of them need to be treated with resin. At the same time, the base cloth is thicker and tighter, so it is very difficult to dye evenly, thoroughly and firmly