(Tianjin University of Technology, Tianjin 300160) has the disadvantage of poor dyeability. In order to solve this problem, the dyeing properties and dye polarity of the dyes dyed by disperse dyes were studied. Table 1 The optimum dyeing temperature of the disperse dyes and the corresponding molecular weight dye temperature 2.2.3 Temperatures for dyeing properties The influence of 10 disperse dyes was selected, and the dyeable polypropylene fibers were dyed at 100C, 110C, 120C and 130°C respectively, and the dyed fibers were measured by DATACOLOR color measurement system. 2.2.4 Effect of concentration on dyeing 2.2.5 Determination of color fastness The 3921.1-1997 standard was evaluated. The 3922-1995 standard is assessed. The 1997 standard was assessed. Evaluation of color fastness The evaluation of the dye fastness is generally carried out by comparing the fastness stained sample cards. The umbilical fastness determines that um2 is around 5 to ensure the stability of the dye in the dye bath. The size of the molecular weight also has a certain influence on the temperature of the dyeing. Because of the molecular weight increase port, the dye dyeing rate is often lowered, so that the dye needs to be dyed at a higher temperature. 3.2 Effect of dye concentration on dyeing depth (lifting force). Table 3 Disperse dye dyeing can be seen from Table 3, the fastness of the disperse dye dyeable polypropylene is basically lower than the fastness of the disperse dye dyed polyester, but the friction fastness is the most significant. The fastness of disperse dyes after dyeing polypropylene is lower than that of disperse dyes because the glass transition temperature of dyeable polypropylene is relatively low, around 0C, and the glass transition temperature of polyester is about 80 C. . Especially when the soaping fastness test is carried out, the temperature is higher than the glass transition temperature of the polypropylene, and the molecular segment activity in the dyeable polypropylene is intensified, so that the dye molecule is easily detached from the fiber, and the fastness thereof is lower than that of the polyester. degree. At the same time, when the dyeable polypropylene is dyed, the plastic effect of water is not large. Although its melting point is relatively low, it can still be dyed at a high temperature of 130 C, that is, it has a similar melting point under dry heat and hot and humid conditions. When polyester is dyed, the plastic effect of water is relatively large. Since the polarity of the dyeable polypropylene is relatively small compared to the polyester, the dyeable polypropylene is dyed with a disperse dye suitable for dyeing polyester, and the fastness is slightly worse. However, for dyeable polypropylene, the dye has a lower polarity and the soaping fastness of the dyed fiber is better. At the same time, the soaping fastness is also related to the selected detergent. This experiment uses standard detergent, which is anionic. If other detergents are used, it may have different results. The molecular weight also has an effect on the soaping fastness of the dyeable polypropylene. Most of the dyes with large molecular weight have better soaping fastness. Since the dye enters the inside of the fiber, it is difficult to be detached from the fiber during soaping because of its relatively large molecular weight. For example, disperse dark blue H-GL, which has a relatively large molecular weight and good soaping fastness. In addition, the perspiration fastness is mainly related to the molecular structure, and the influence of the glass transition temperature is not obvious. 4 Conclusions 4.1 Experiments have shown that the optimum temperature for the dyeing of dyeable polypropylene by disperse dyes is 120~130Q, but some dyes are special. Therefore, when the dyeing process is formulated, it should be treated specifically; the less polar of the disperse dyes, The dyeing rate is better. 4.2 The fastness of dyeable polypropylene after dyeing by disperse dye is lower than that of dyeing polyester; the disperse dye with small polarity or large molecular weight has good soaping fastness. 4.3. Different dyes have different lifting powers, so it is necessary to combine the lifting power of the dyes when formulating the process. The less polar disperse dye has better lifting power for dyeable polypropylene. shaoxing rongxi textile co.,ltd , https://www.rongxifabrics.com
June 02, 2023