Dyeing and finishing of dark black polyester-cotton stretch thin fabric
It is difficult to obtain black polyester-cotton interwoven stretch thin fabric To solve the problem of deep color, the disperse/reactive dye continuous pad dyeing process is used to dye the polyester-cotton interwoven elastic fabric. The influence of pre-treatment process, dye structure, dyeing method, dyeing conditions, finishing and other aspects on black depth was discussed, and solutions were proposed.
With the development of the market and people’s demand for color, especially the requirements for black color are getting higher and higher. Under normal circumstances, large-scale goods produced by printing and dyeing factories must follow the principle of “rather deep than shallow” in order to meet customer requirements. However, different customers provide different standard samples. Some are the same as the bulk fabrics, some are different from the bulk fabrics, and some have QTX file values. It is easy to solve the problem of the same depth of fabrics with the same specifications as the bulk fabrics, but it is not easy to solve the problem of different specifications of the same specifications of the same bulk fabrics, especially the polyester-cotton interwoven elastic thin fabrics are more difficult to solve.
This article introduces the dyeing and finishing process to obtain deep black polyester-cotton interwoven elastic thin fabric, through reasonable selection of pre-treatment process, dyes, dyeing methods, and dyeing conditions , post-finishing process to achieve the purpose of improving the dyeing depth.
Experimental part
1
Materials and instruments
Fabric: Cl4.5tex×T75D+40D, 206×221, 127 cm, polyester-cotton interwoven stretch fabric.
Dyeing materials: disperse black, reactive black, penetrating agent, pre-treatment auxiliary, salt, caustic soda, soda ash, finishing auxiliary, flat horse mineral.
Instruments: electronic balance, rolling car, oven, steam solidification prototype machine, glass rod, beaker, measuring cylinder, thermometer, electric iron, computer color measurement and matching instrument.
2
Pre-treatment process
The pre-treatment process is: turning seams → singeing → rolling → deboiling and bleaching → shaping → mercerizing.
①Singeing
Polyester-cotton intertwined elastic fabric is different from conventional polyester-cotton blended fabrics. The singeing requires a vehicle speed of 150 m /min, the flame temperature is 2200℃, the wind pressure is 22-13 MPa, and the cloth drop temperature is lower than 50℃.
② Rolling
The rolling process is: caustic soda l8-20 g/L, The vehicle speed is 60 m/min, the temperature is 30-35°C, and the rotation and stacking time is 3-4 hours.
③Deboiling and bleaching process
In order to obtain excellent pre-processed semi-finished products, two options are available: Different deboiling and bleaching processes are used to treat fabrics in order to provide conditions for improving the black depth of polyester-cotton interwoven elastic thin fabrics.
(1) Two-step pre-treatment process
Process flow: fabric → padding Deboiling liquid (remainder rate 100%) → steaming (100 → 102℃×50 min) → hot water washing → cold water washing → water padding (remainder rate 60%) → padding oxygen bleaching working fluid (remainder rate 95%) → steaming (98-100℃×30 min) → water washing → hot water washing → Wash → dry.
Recipe for reducing boiling: (g/L)
Caustic soda l8-20
Dispersing chelating agent 2-6
Wax remover 4-6
Bleach prescription: (g/L)
Hydrogen peroxide 10-l2
Sodium metasilicate pentahydrate 8-10
Refining agent 6-10
Chelating agent 3-5
(2) One-step pretreatment process
Process flow: Fabric→Padding, deboiling and bleaching liquid (padding rate 100%)→Steaming (98-100℃×30 min) → wash in hot water → wash in cold water → dry
Recipe for deboiling and bleaching: (g/L)
Hydrogen peroxide 10-12
Sodium metasilicate pentahydrate 8-10
Refining agent 9-l5
Chelating agent 3-5
④ Styling
Because it is polyester-cotton thin elastic fabric, the temperature of the setting machine cannot be too high. The temperature is preferably 195-200°C, the speed is 50 m/min, the drop width is the same as the customer’s requirement, and the drop temperature is lower than 50°C.
⑤ Mercerizing
Caustic soda 210 g/L, speed 60 m/min, the width of the drop cloth is the same as the customer’s requirement, and the pH value of the drop cloth surface is controlled at 7.5-8
3
Dyeing process
①Dyeing process (two-bath method)
Rolling dispersion material → drying → baking → reduction cleaning (caustic soda 30 g/L, insurance powder 30 g/L) → water washing → soaping → water washing → drying → rolling active material → drying → rolling solidification Color liquid → steaming → washing → soaping → washing → drying
②Dye selection
For thin polyester-cotton interwoven stretch fabrics when dyed black,For scattered dyes, medium-temperature and high-strength dyes should be selected. For reactive dyes, high-strength dyes with dual reactive groups and high solubility and good alkali resistance should be selected.
③Dyeing process prescription
The polyester-cotton interwoven elastic fabric used in the experiment is pure cotton in the warp direction Fiber, the weft direction is polyester fiber. The composition of cotton fiber accounts for a higher proportion than that of polyester fiber. Therefore, the depth of color can be improved by adjusting the amount of disperse and reactive dyes.
Prescription 1: (g/L)
Rolling dispersion: Disperse Black 40
p>
Pingmasu 15
Rolling activity: reactive black 55
Pingmasu 15
Prescription 2: (g/L)
Rolling dispersion: dispersion black 75
Pingmasu 15
Rolling activity: Reactive black 40
Pingmasu 15
Fabric rolling The residual rate should be controlled at 60-65%, the infrared pre-baking should be uniform, and the drying temperature in the drying chamber should be 80-85°C to ensure the stability of the color difference between the left, center and right and the migration of the cloth surface.
④Baking
On the premise of ensuring the elasticity of the fabric, the baking temperature should be selected as much as possible Higher temperature, baking temperature is 198-200℃, time is 60 S.
⑤ Steaming
Process prescription: (g/L)
Salt 200
Soda ash 20
Caustic soda 6
When steaming reactive dyes, the amount of alkali agent should be sufficient. The amount of caustic soda should be adjusted while the amount of salt and soda ash remains unchanged. Compare the amount of caustic soda with the color yield, and choose the one with the highest color yield. Excellent craftsmanship
Similarly, the steaming time is also under the condition that the fixing agent remains unchanged. Adjust the length of the steaming time, compare the dosage of the fixing agent and the color yield, and choose a process with a high color yield. According to the experimental results, the steaming temperature is 100-102°C, the steaming time is 60 S, and the caustic soda dosage is 6 g/L.
⑥Washing, soaping and drying
After the fabric comes out of the steamer, it must be washed with cold water first, and then soaped with a temperature above 95℃ Soap with liquid for 60 seconds, then wash with cold water and dry.
4
Finishing process
①Process flow:
Finishing additives after rolling → Tenting → Pre-shrinking
② Post-finishing process:
Prescription 1. (g/L)
Special finishing additive 30
Prescription 2: ( g/L)
General finishing additive 30
General finishing additives do not greatly improve the black depth of thin polyester-cotton interwoven elastic fabrics, but if you choose special finishing additives with better hydrophilicity, you can significantly increase the black depth. Tententer temperature Control at 130-132℃, vehicle speed 30 m/min
Results and Discussion
1
Previous The impact of treatment process on color depth
The quality indicators of semi-finished products after two pre-treatment processes and the impact on color depth are shown in Table 1 and Table 2 respectively.
It can be seen from Table 1 and Table 2 that the two-step method The one-step pre-treatment process has higher semi-finished product indexes than the pre-treatment process, the L value of the semi-finished product test is smaller, and the two-step pre-treatment process has a higher dyeing depth. The two-step pre-treatment process removes the sizing of the yarn after alkali desizing and reduces the pressure of scouring. Therefore, it is particularly important to improve the pre-treatment effect of thin polyester-cotton interwoven stretch fabrics.
2
The influence of dyeing process on color depth
The effects of the two dyeing processes on color depth are shown in Table 3.
It can be seen from Table 3 that the dyeing process is more efficient than dyeing. The L value of process two is small, so the dyeing depth of the previous dyeing process one is higher. Therefore, when the cloth surface is full, the smaller the amount of disperse dye used on polyester, the higher the color depth. When improving the black depth of thin polyester-cotton interwoven stretch fabrics, a reasonable selection of the proportion of polyester-cotton dye is an important factor affecting the color depth.
3
The impact of post-finishing process on color depth
The effects of the two finishing processes on color depth are shown in Table 4
It can be seen from Table 4 that the L value of post-finishing process one is smaller than that of post-finishing process two, so the post-finishing processYiyi’s dyeing depth is higher. Therefore, when the color depth is difficult to meet customer requirements, it is very critical to choose a reasonable finishing additive process. However, under normal circumstances, try to choose finishing additives with small color changes, because this will make it easier to control the changes in color and light during the production of large vehicles, and the product quality will be more stable.
In addition to the above three aspects, to improve the black depth of thin polyester-cotton interwoven stretch fabrics, we must also consider choosing high strength, good solubility, good diffusibility, and lifting properties. High dye content and optimal dyeing process conditions can improve the depth of color.
Conclusion
Using continuous pad dyeing process with disperse/reactive dyes to interweave polyester and cotton When dyeing elastic fabrics into dark black, the depth of the color can be improved by selecting a reasonable pre-treatment process, adjusting the dye dosage of cotton fiber and polyester fiber, and selecting reasonable finishing aids, dyes and dyeing process conditions.
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