During the polyester dyeing process, the heating rate, holding temperature and dye bath pH value have a great impact on the dyeing quality. Theoretically, the shorter the dyeing process and the lower the dyeing cost, the higher the control requirements for the dyeing process while ensuring that the fabric does not appear colored. The dyeing process when a large amount of dye is applied to the fiber (generally 30% to 90% of the dye is applied) will be shortened due to the increase in cloth speed, and it is easy to produce color flowers if not properly controlled. During the heat preservation stage, the dye is easy to level dye on the fiber, and this period of time will not be shortened due to the increased cloth speed in the dye vat. When cooling down, the cooling rate should be slow, otherwise the polyester will shrink sharply and easily produce creases. Therefore, the key to controlling the rationalization of the dyeing process lies in the stage of mass dyeing.
This experiment analyzes the dyeing rules of E-type, SE-type and S-type disperse dyes, and explores the effects of heating rate and holding temperature on the color and light of fabrics.
Test
1. Materials and instruments
Fabric: 100% polyester single-sided fabric
Dye: E type (dispersed yellow ACE, dispersed blue ACE, dispersed red ACE), SE type ( Disperse yellow UNSE, disperse blue UNSE, disperse red UNSE), S-type (disperse yellow SW, disperse blue HSD, disperse red SPW) auxiliary glacial acetic acid, disperse leveling agent RDT-27
Equipment: high-temperature glycerin dyeing machine, Datacolor color measurement and matching instrument
2. Test method
2.1 Stage heating dyeing
Prepare 10 cups of dye solution using the cup-dividing method, and discard the last 1 cup of dye solution. Put 9 cups of dye solution into the dyeing machine. Starting from 80℃, take 1 cup every 10℃ to keep warm at 130℃. Take one cup every 10 minutes, a total of 9 cups, see Figure 1.
After the temperature rises to the target temperature, immediately take out the label, wash it with cooling water, and take the residual liquid for dyeing. Afterwards, the force score of the stained sample at each stage was measured, and a coordinate graph of temperature, time and force score was drawn.
2.2 Dyeing process curves of different types of dyes
In order to explore the influence of different dyeing process curves (different heating rates and holding temperatures) on the color yield of different types of dyes, three dye combinations of E type, SE type and S type were dyed according to the three process curves in Figure 2. The whole process lasts for 80 minutes, and then the dyed sample is dried for testing.
3. Test
3.1 Dyeing intensity
Fold the fabric into four layers , measure the force score on a Datacolor colorimeter. Set the force score of the color sample obtained after incubation at 130°C for 30 minutes to 100%. Measure each cloth sample three times and take the average.
3.2 Color Difference
Fold the fabric into four layers and place it under the D65 light source Below, use the Datacolor Color Tester to measure the color difference of fabrics dyed with different dyeing process curves, including DL, Da and Db. Measure each cloth sample 3 times and take the average value.
Results and discussion
1. Effect of staged temperature-increasing dyeing on dyeing intensity The influence of
The absorption and residual liquid dyeing curves of light three-primary colors (E-type dyes), middle three-primary colors (SE-type dyes) and deep three-primary colors (S-type dyes) are shown in Table 1.
In Table 1, the dyeing intensity of E-type dye has reached 49.99% at 80℃; it rises to At 90℃, the strength soared to 62.77%. During this period, the dye is absorbed quickly, and insulation measures need to be taken to prevent the fabric from producing color blooms. In production practice, it can be kept at 85°C for 10 minutes, and the temperature can be raised normally at other temperatures.
The dyeing intensity of SE-type dye reaches 35.28% at 80℃, which is much smaller than 49.99% of E-type dye; when the temperature rises from 110℃ to 120℃, the dyeing strength The strength increased from 49.34% to 60.87%. During this period, the dye is absorbed quickly, and insulation measures need to be taken to prevent the fabric from producing color blooms. During production, it can be kept at 110°C for 10 minutes, and the rest of the temperature can be raised normally.
The dyeing intensity of S-type dye at 80℃ is only 5.74%, which is much smaller than the 49.99% of E-type dye and 35.28% of SE-type dye; the temperature ranges from When the temperature rises from 110℃ to 120℃, the dyeing intensity increases from 19.82% to 34.13%; when the temperature rises from 120℃ to 130℃, the dyeing intensity increases from 34.13% to 53.34%. During this period, the dye absorption is relatively high. Quickly, insulation measures need to be taken. It can be kept at 110℃ and 120℃ for 10 minutes each, and can be heated normally at other temperatures.
2. The impact of staged heating dyeing on color light
According to 1.2 In this process, E-type dyes, SE-type dyes and S-type dyes are used to dye polyester fabrics. The staged heating dyeing samples and residual liquid dyeing samples are shown in Figures 3 to 5.
In Figure 3, the E-type dye has been completely absorbed at a lower temperature, which can be seen through the residual liquid dyeing sample It turns out that the dye has been completely absorbed at 100℃; after incubating it for 30 minutes from 80℃ to 130℃, a sample is taken. The color sample is basically from light to dark, indicating that the three dyes areBetter compatibility.
In Figure 4, the SE type dye begins to absorb completely at medium temperature. It can be seen from the residual liquid sampling that at 110 ℃ has been completely absorbed; after incubating from 80 ℃ to 130 ℃ for 30 minutes, the color samples were basically from light to dark, indicating that the compatibility of the three SE-type dyes is better.
In Figure 5, the S-type dye is completely absorbed only at a higher temperature. It can be seen from the residual liquid sampling that the dye is basically completely absorbed only after the temperature is raised to 130°C and kept for 10 minutes. Samples were taken after being incubated from 80°C to 130°C for 30 minutes. The color of the color sample basically ranged from light gray to dark gray, indicating that the three S-type dyes have better compatibility.
When choosing a dye combination, try to choose the same type of dye and avoid cross-level combinations, such as the combination of E-type dyes and S-type dyes, otherwise the chance of color flowers will be very high. big.
3. The influence of different dyeing process curves on fabric shade
Using the 95°C insulated sample as the standard sample, measure the color difference between the 105°C and 115°C insulated dyed samples and the standard sample, see Table 2.
In Table 2, different insulation temperatures have little effect on the color of the dyed samples. The differences are all within a reasonable error range. It can be seen that using appropriate heating rates and heat preservation points can reduce the possibility of color blooming to a great extent. In addition, controlling the cloth speed in the vat and the dyeing rate so that the dye can be dyed at a uniform speed can also effectively avoid the occurrence of color flowers.
Conclusion
1. The key to polyester disperse dye dyeing is the dyeing temperature , control of time and pH value, E, SE and S type disperse dyes have different dyeing characteristics.
2. The exhaustion temperature point of E-type dye is lower, the exhaustion temperature point of SE-type dye is in the middle, and the exhaustion temperature point of S-type dye is higher.
3. When choosing a dye combination, try to choose the same type of dye to avoid cross-level combinations.
4. Using stage dyeing, choosing the appropriate heating rate and heat preservation point is the key to preventing color blooming.
</p
