Dyeing of cheese yarn is to wind the yarn on a bobbin with holes, and then load many bobbins into the dyeing vat. The basic operation flow of the cheese dyeing machine is: loose tube – cage loading – dyeing – drying – rewinding.
Reactive dyes are generally used for pure cotton cheese dyeing. There are many factors that affect the difference in size of cheese dyeing, such as the performance of the dye directly to the difference in size, winding The process is closely related to the dyeing quality. The quality of the winding will also affect the quality of the dyeing. Color difference between the inner and outer layers is prone to occur. The quality of the stainless steel core will also affect the dyeing effect.
Due to the influence of these factors, there are differences in the large and small samples of cheese dyeing, including inconsistent color depth; inconsistent color light; large samples are prone to flower yarn phenomena, and even the inner and outer layers Color difference.
Differences in large and small samples of pure cotton cheese dyeing
1. Types of differences in large and small samples of cheese dyeing
1.1 The color and light are consistent but the depth is inconsistent
The large sample is darker or lighter than the small sample, which means that the color and light of the large sample and the small sample are the same, but the large sample is sometimes much darker than the small sample, but More often than not, the large sample will be shallower than the small sample. If the dyeing bath ratio of the large and small samples is different, the bath ratio of the small sample is larger and the bath ratio of the large sample is smaller. Then the color of the large sample will be darker than the small sample, otherwise the large sample will become lighter; the yarn cooking time will also affect the difference in depth between the large and small samples. If the time is short, the yarn will not be cooked thoroughly, and the color of the large sample will be lighter. On the contrary, if the time is too long, the color of the large sample will be lighter. , the yarn is cooked and the large sample is darker. Generally, yarn is boiled for 30 minutes; different dyeing times and temperatures for large and small samples will also affect the color depth.
1.2 Inconsistency in color and light
There is not much difference in depth between the large sample and the small sample, but there is a large deviation in color and light. This has a lot to do with the choice of color-matching dyes. If the dye selected for the sample is unreasonable and has poor compatibility, it may not have much impact on the color imitation of the sample, but it will be clearly reflected when the large sample is produced. ; The process operation specifications of large sample workers will cause differences in color and light; different yarn counts and batches will also cause large and small differences in color and light.
Dyeing of cheese yarn is to wind the yarn on a bobbin with holes, and then put many bobbins into the dyeing vat. The basic operation flow of the cheese dyeing machine is: loose tube – cage loading – dyeing – drying – rewinding. Pure cotton cheese dyeing generally uses reactive dyes. There are many factors that affect the difference in size of cheese dyeing, such as the performance of the dye directly to the difference in size, the winding process is closely related to the dyeing quality, and the winding quality is good or bad. It will also affect the quality of dyeing, and color difference between the inner and outer layers will easily occur. The quality of the stainless steel core will also affect the dyeing effect. Due to the influence of these factors, the differences between the large and small samples of bobbin dyeing include inconsistent color depth and inconsistent shades; large samples are prone to flower yarn phenomena, and even color differences between the inner and outer layers.
1.3 Flowers are easy to appear on large samples
There is no obvious color flower when dyeing small samples, but flowers will appear after dyeing large samples. There is color difference between the inner and outer layers; color difference between the two ends of the tube and the middle. The loose fibers must be caged evenly and tightly. Differences in tightness and uniformity will cause floral yarns to appear on the cylinder, and color differences will appear between the bobbin and the bobbin; the winding density of the rewinding package may be loose or tight, resulting in color differences between the inner and outer layers. This requires standardizing the operations of large-scale production personnel.
Factors affecting the difference in sample sizes for cheese dyeing
1. Technical proficiency of the operators on the vat
Insufficient technical skills of the operator will increase the possibility of color difference in the sample. Control the temperature, neither too high nor too low; control the time; the length of time should be reasonable and consistent with the sample process; the influence of boiled yarn quality, the boiled yarn must be transparent and even, and the wool effect must reach 8-10cm/30min , otherwise it will cause the dyeing color of the cheese yarn and the difference between the inner and outer layers, which will affect the one-time sample rate. After boiling the yarn, it must be pickled and neutralized to neutrality, and then a deoxygenase is used to remove the residual hydrogen peroxide. Because the hydrogen peroxide is not completely removed, it will Causes light color and flowers; the influence of chemical materials, the chemical materials should be uniform. If the chemical materials are uneven or not melted, the dye particles will be adsorbed on the surface of the cheese, which will not only affect the dyeing and color fastness of the dye, but also directly affect the dyeing process. Such a sample rate. The temperature of the chemical material should not be too high and the time should not be too long, otherwise some dyes will be hydrolyzed, resulting in light colors and inconsistent shades, which will affect the one-time sample rate; post-dyeing treatment. Post-dyeing treatment needs to be adjusted according to the amount of dye and the type of dye.
2. The accuracy of the sample maker when making samples and the feasibility of the prescription
If the person who makes the small sample does not suck the material accurately, it will directly affect the large sample color light stability. If the prescription is unreasonable, it will affect the dyeing effect of the large sample. Only when the sample accuracy is high can it have high sample conformity.
a. The yarn must be weighed accurately when copying samples. If the yarn weight is high or low, even if the color is adjusted accurately, the color will be different during mass production. To measure yarn accurately, you must first control the moisture regain of the sample yarn. The moisture regain directly affects the weight of the yarn. Secondly, the yarn weighing for the sample must be accurate to 0.001g. It cannot be determined by the traditional number of turns, but must be based on the actual situation.
b. The dye measurement must be accurate. It is necessary to compare samples of each batch of dyes and obtain detailed information of each batch of dyes; weighing materials should be accurate; imitation dyes should be kept fresh, and the same batch of dyes used in large-scale production should be used for imitation colors to eliminate differences in batches. Secondary dyeDifferences in intensity and color.
3. Consistency of process operations between small samples and large samples
Dye bath ratio, water quality of dyeing water, pre-treatment, dyeing temperature, PH value etc. consistency. Cheese dyeing has strict requirements on pre-treatment and all aspects. Inconsistent process operations between large and small samples will seriously affect the differences between large and small samples.
a. The imitation color process for small samples and large-scale production must be unified. Try to use the same process flow and the same process conditions.
b. The imitation bath ratio of the sample should be as consistent as possible with the actual production of the dye vat. Most of the large-scale production of cheese yarn adopts a small liquor ratio, as low as 1:5-6. However, due to equipment limitations, the minimum liquor ratio of the normal temperature oscillating dyeing machine is 1:15. Then it must be considered based on actual conditions, and appropriate equipment must be selected when dithering.
4. Uniformity of cage loading operation and rewinding density
Uneven cage loading and different yarn rewinding densities will lead to large samples. Color flowers may even cause color difference between the inner and outer layers. That would require repairs, which is troublesome and costly.
Measures to reduce the differences in cheese dyeing samples
To reduce the differences in cheese dyeing samples, we must analyze their influencing factors to reduce Differences between large and small samples. Strengthen the technical proficiency level of large sample operators, strengthen the training of large sample operators on the proficiency of each process of the dye vat, and the operation of various precautions. The color imitation process of small samples should be unified with that of large-scale production, and the bath ratio of imitation colors of small samples should be the same as that of actual production in the dye vat. When copying samples, the yarn must be weighed accurately and the dye measurement must be accurate. Consistency of process operations between small samples and large samples. The dyeing conditions such as dye bath ratio, dyeing water quality, pre-treatment, dyeing temperature, dyeing time, pH value, etc. must be consistent. Strengthen the uniformity of cage loading operations and the consistency of rewinding density.
1. Strengthen the technical proficiency level of large sample operators
If the large sample operators are not skilled enough, they will directly affect the dyeing effect of large samples. Increased color difference in large samples. In the same way, the technical level of the sample sampler is also very important. Whether the sample sampler is accurate in sucking the material and whether the prescription is reasonable will affect the inconsistency between the large sample and the sample. It is necessary to continuously strengthen the technical level of the large and small sample workers. When the small sample workers are color matching, improper selection of dyes can also cause uneven dyeing and color differences between the inner and outer layers. Because when two or more dyes are used for color matching, due to the different diffusivity and affinity properties of the dyes, the dyeing rate will be uneven during the dyeing process. So choose materials reasonably.
2. Yarn pre-treatment process
The requirements for yarn pre-treatment before package dyeing are very strict. Capillary effect, should be checked before dyeing. In addition, after the package yarn is scoured, the density of the package increases due to yarn shrinkage. Generally, ordinary yarn can shrink by 6 to 8%, and high-count yarn may shrink by about 8 to 10% (please test in advance). When the yarn shrinks during dyeing, it hinders the circulation of the dye liquor and can also cause color differences between the inner and outer layers of the package.
Therefore, the shrinkage of the yarn should be considered when winding the original yarn. Although the cotton wax in the yarn is removed after scouring the cheese, the fiber is full of water. This part of the water is put into the dyeing pot without being fully dehydrated before dyeing, which will inevitably cause the dye liquor circulation to reach equilibrium with this part of the water. For a long time, it is easy for the outer layer and the inner layer of the cheese to have different balances of dye liquor, which will affect leveling and increase the color difference between the inner and outer layers.
Dyeing of cheese yarn has high requirements on water quality. Generally, soft water (below 30ppm) should be used. If hard water is used, a large amount of flocculent sediment will stick to the surface of the cheese yarn layer. It is better to choose dyes with less impurities, and they can be ground if necessary. Reactive dyes should be used as needed to prevent hydrolysis and deterioration of dyes.
Try to use the same yarn, dyes and auxiliaries of the same batch. Because there are differences between different batches of raw cotton due to changes in cotton blending or cotton origin, it is difficult to eradicate these differences by relying only on pre-treatment, which will cause color and light differences after dyeing. Therefore, after changing cotton yarn batches, the laboratory must Repeat the sample before dyeing. If the color light changes, adjustments must be made in time.
3. Adjust the uniformity of the cage operation and the rewinding density
Similar to cage hank dyeing, yarn dyeing also It is easy for the dyeing water flow to short-circuit, which is an important factor in producing color flowers.
The cage must be evenly packed and tightly packed. The fiber loading capacity must be appropriate. If it is lower than the reasonable loading capacity, it is easy to form irregular water flow channels, that is, a “short circuit” phenomenon; once it occurs, it will become more and more obvious, and will gradually reduce the quality of the entire cage. Where the water penetration is large, it is larger, and where it is weak, it is weaker.
Since the dye molecules contact and exchange with the fibers in various parts along with the liquid flow, the color blooming phenomenon is inevitable due to uneven and inconsistent flow and intensity.
So, for dye vats with different loading capacity specifications, production planners must clearly understand their respective maximum and minimum loading capacities. When loading the cage, make sure that each tube is evenly and tightly distributed in the cage. Make the water flow evenly through each tube in the cage. In this way, the phenomenon of colored flowers can be reduced as much as possible.
The winding density also has a great influence on package dyeing. Different densities will cause the tube to become stained. If the winding is too tight, it will be difficult for the dye solution to penetrate the thick yarn layer, and the partial color will be lighter due to too little contact with the dye, resulting in dyeing defects such as color flowers or color circles. If the winding is too loose, the yarn will easily deform and fall off, causing mess. Yarn, difficult to get on the machine. Then we need to make the cage loading operation more uniform and the rewinding density consistent.
Only by minimizing the impact of these factors on the dyeing of large and small samples can the difference in dyeing of large and small samples of cheese yarn be truly reduced.
If it falls off, it will cause messy yarn and make it difficult to get on the machine. Then we need to make the cage loading operation more uniform and the rewinding density consistent.
Only by minimizing the impact of these factors on the dyeing of large and small samples can the difference in dyeing of large and small samples of cheese yarn be truly reduced. </p
