1 The influence of semi-finished products
In the production process of dyed cloth, the performance of semi-finished products is crucial to the color consistency, color stability and color difference adjustment of the color cloth. The semi-finished product requires smooth treatment. If the processing conditions of the semi-finished product are slightly changed, it will be reflected in the dyeing color. In production, some orders are large in batches. Even if they are the same variety, the quality of semi-finished products may be different due to the different production location, sizing varieties, sizing rates, cotton quality, cotton mixing and textile production processes. Therefore, in production, each process must be strictly checked, and the process control indicators of each process of bleaching must be measured in a timely manner to keep the process conditions consistent. Large batches of samples should be produced, and prescriptions should be adjusted in time for large gaps to avoid large changes in color difference before and after production, resulting in increased re-repair and consumption. In order to reduce the impact of semi-finished products on dyeing and dyeing rate, reasonable bleaching techniques should be formulated. For the same variety of cloth, especially the order rebate, the machine must be set to be produced through mature processes to improve the dyeing reproducibility of the original order prescription.
2 Effect of dyeing process
2.1 Effect of the selection of dyes and additives on color difference
2.1.1 Dyes
When using Shilin dye to dye, some dyes are slow due to the dyeing rate. As deposited in the dyeing tank, the dye cloth color light gradually dyes the dyeing cloth with a slow dyeing rate approaching, causing the color difference between the front and back. Therefore, if you are producing olive green, Shilin yellow is often used. In order to stabilize the color, we use Shilin olive green or grass green. In addition, in order to prevent dye deposition, dispersant can also be added to the dye to make the dye liquid in the cylinder and trough more uniform, prevent aggregation, so as to effectively improve the color difference and reduce costs.
When using reactive dyes to dye, due to the high reactivity of reactive dyes, if the dye performance gap is large, the color light is difficult to control during continuous rolling and dyeing, and it is easy to produce color difference between the front and the back. Therefore, dyes with consistent or close compatibility should be selected during the production process.
2.1.2 Additives
Adjuvant has a great influence on the color difference and flower in the edges. Adding suitable additives can effectively improve the color difference and stripes caused by grey fabrics, equipment, etc. But sometimes the addition of a certain additive cannot solve many problems such as color difference and other problems. At this time, on the basis of re-selecting dyeing materials, use additives with better results to produce products that satisfy customers.
For example, adding anti-swimming agent to production can improve dye swinging caused by uneven drying temperatures in the air room and drying, which is conducive to the adjustment of color difference; but it cannot effectively improve fabric flaws and cotton on the surface Miscellaneous, neptun. Dead cotton. The dyed cotton is uneven and unfull due to defects such as weaving strips. Therefore, when the grey fabric is of poor quality, the use of uniform dyeing agent is better. However, the color difference is not easy to adjust when using uniform dyeing agent, and the color difference in the edge is heavier than using anti-swimming agent. For example, when producing gray polyester cotton, if an anti-swimming agent is added, the color difference is better controlled, but the cloth surface is uneven; when using a uniform dye, the cloth surface is better, but the color difference is not adjusted well. At this time, depending on the gray color, you can choose two prescriptions: dispersed black or dispersed gray, so that the color difference is controlled at level 4.5.
2.2 Base workerEffect of art on color difference, strips, and color strips
In production, due to different Rf values of dyes in the trough, their affinity for fibers is also different. The dyeing rate with high affinity is fast, and the dyeing rate with low affinity is low The rate is slow. When the dye is colored, the fibers will take away the dye components and it is very easy to form a head-tail color difference. If you keep thinking about replenishing dye in the material tank, the dye components in the material tank will gradually reach a dynamic balance, and the color difference will gradually stabilize at this time, which is the main reason for inaccurate color tests and unstable color at the beginning. , the lighter the color, the longer the time to reach equilibrium; the darker the color, the shorter the time to reach equilibrium. The capacity of the trench should be small, which will help the dye liquid to achieve balance in a short time and to facilitate color stability. For the color difference of the beginning car, dilution or color lake can be used to make up for it. For example, when producing light blue, the color becomes lighter and lighter as the dyeing progresses, and the red light increases. If the initial opening material trough is diluted, the color difference between the head and tail is reduced; and when producing dark blue, the color development liquid is used Add color lake to solve the color difference before and after.
The drying equipment on the base machine produced in our factory is divided into three parts: infrared ray and drying room dryer. The infrared effect is good, the dye is small in anti-swimming and moving, and the color difference is small; the air volume in the drying room should be moderate, the temperature is too high and it is easy to cause strips. If the temperature is too bottom, the drying load will be added. The first section should be 60 ~ 70℃, and the second section should be The distance between 90 and 100℃ is conducive to uniform dyeing.
The dryer is an auxiliary equipment and cannot directly dry fabrics. It is responsible for causing serious dye swirling, forming yin and yang surfaces, causing illusory color difference, which is not conducive to adjusting color difference by tying the vehicle. The dryer should be mainly dry and repaired, but not too hot. For example, when producing bright blue or gray, the color is sensitive. If the drying temperature is too high, the temperature in the middle of the drum is inconsistent, the temperature in the middle is high, the dye is colored and dark green is large; the temperature on both sides is not luminous, and the red is large, visual illusion chromatic aberration is formed on it. At this time, if pressure is added due to the deep middle and the pressure is reduced on both sides, the color difference will become heavier. At this time, the blocker must not only be experienced, but also have some understanding of the dye performance. For example, when producing light blue, due to the drying part of the color, when the color depth of the base is almost the same, the color difference between the machine is 2 to 3 levels; but when the color light of the base is adjusted to be close to the left, center and right, it looks deep in the middle. When the color difference is 4 to 5 levels after continuous operation.
2.3 The impact of roasting dryer on color difference and color flowers
The existing domestic equipment is mostly old models in the 1980s. The circulation fan equipment is prone to uneven air volume, and the box volume is large. This makes the temperature difference between the roasted chicken edges large, resulting in color difference.
The air volume and orientation of the air nozzle, or the base rolling pressure can be adjusted to make up for the middle-color tea caused by the baking temperature difference. The temperature during the production process should be stable and consistent to prevent color difference before and after.
2.4 Effect of color development soap cooking on color difference
In production, the temperature of the reduction steamer must be above 100℃, and the pressure should be consistent and uniform, otherwise strips will be produced. By installing a U-shaped pressure gauge in the box, the pressure in the steamer can be controlled intuitively and accurately, and it can also prevent the inconsistency of the material tank and liquid volume.The batch difference is caused by different liquid immersion time and unstable liquid loading volume. In normal production, the rolling trough and the liquid sealing trough should be added with an appropriate amount of color lake according to the fabric, hue and depth to prevent the dye concentration in the trough from changing during the beginning and normal production. Because the dye that is poured onto the fabric during production will continue to dissolve into the sealing liquid, and then re-dyeed from the sealing liquid mouth to the fabric. Only the amount of dye dissolved and dyed onto the fabric will be the same as the amount of dyed onto the fabric after being dyed onto the fabric after being dyed onto the fabric after being dyed. Only when the trough can dynamic balance be achieved. When the vehicle speed, temperature and steam pressure change, this balance will fluctuate, resulting in front and back chromatic aberration.
Table 1 Ratio of color lake addition to dye usage
|———————————————————————————————– ——–|
|Pure cotton fabric| Add color lake/L |% of dye usage |
|——-|—- ——-|——————————————————————————————————————————————————————————————————————————————————– —|—————————————————————————————————————————-
|——–|———————————————————————————————————– Color | 4-6 | 1-1.5% |
|——————————————————————————————————– —|
|Dark| 6-10 | 1.5-2.5% |
|——-|—————-| —————-|
|Extra dark color| 10-15 | 2.5-4% |
|———— ————————–|
|Thin fabrics generally add more color lake than thick fabrics|
|– ——————————————————————————————————————————– L | accounts for % of dyes |
|————————————————————————————————————- -|
|Special light color| 0 | — |
|——————————————————————————————– ———-|
|Light color| 1-2 | 0.25-0.5% |
|——-|—— —–|—————-|
|Medium color| 2-4 | 0.5-1% |
|——–|– —————————————————————————————————————————————————————————————————————————————————————- ——–|——————————————————————————————————————————————————————————————————————————————————- | 2-3.5% |
|———————————————————————————————————————————————————————————————————————————————-
|Thick fabrics generally add more color lake than thin fabrics|
|——————————————————————————————————————————————————————————————————————————— ——–|
In production, the amount of water washing, overflow and spraying also has a very great impact on the color light stability. Especially for reactive dyes, due to poor dyeing fastness, the water flow size, pH value and dye content will change the color light in continuous production.
In addition, the soap cooking conditions have a great impact on certain colors. The dyed cloth of these colors should pay special attention to the consistency of the soap cooking conditions. For example, the fastness of dye soaps in blue series such as bright blue and dark blue is generally poor, so dyeing materials with good fastness should be selected in production, which is very important for color and light stability. For example, when dyeing lotus purple, it is compared and selected after multiple prescriptions. Although the prescription with normal color test and small color changes are used, the color light still fluctuates greatly during the actual production process.
The influencing factors of lotus purple in production are:
Car speed: The faster the car speed, the greater the red light; the slower the car speed, the greater the blue light.
Baking temperature: chromatic aberration, ideal color light and stable at 195℃. The higher the temperature, the greater the blue light; the lower the temperature, the greater the red light.
Spraying and overflow: Continuous overflow is large, with light hair color and large blue light; spraying and overflow are small, with dark hair color and large red light.
Soap boiling: The temperature of the flat wash grid has a great influence on color light. When the temperature is 90℃, the color light will be small and the color light will be stable. When the temperature is lower than 80℃, the machine will be dark blue continuously. When the soap boiling changes color, the soap boiling changes color twice. After boiling, the redness is bright; when the temperature is higher than 96℃, the color head is light and red, the soap will change color less, and the soap will not change color after boiling twice.
Vapor solid: The materials and techniques used during steam solid should be consistent, and the concentration, temperature and alkali content should be consistent.
2.5 The impact of post-organization on color difference and color flowers
2.5.1 Choose a finishing additive that has a small impact on color light
The greater the impact on color light, the greater the influence of conditions in production , the production process is unstable, which will affect the color consistency between front and back and the color difference between the edges and the color difference between the edges.
2.5.2 Parking of finishing equipment and unstable speed
There is a great impact on the color head changes, and sometimes it also affects the color difference between the edges and the middle; tentering and pre-dryingLater, the inconsistent tide of the left, middle and right dry tides may also cause color difference in the edges.
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