How to improve the dyeing quality of overflow dyeing machine?

1. Influence of cloth capacity of overflow dyeing machine
Overflow dyeing machines have an extra large nominal capacity which is not suitable for any fabric. Therefore, in production, it is necessary to determine the actual capacity of the overflow dyeing machine according to the thickness, width and other conditions of the fabric. For the same width of fabric, the thinner it is, the smaller the capacity. This is because if light and thin fabrics are fed according to the nominal capacity, the length of the fabric will inevitably be too long, and the cycle of dyeing will be long, which will easily cause the fabric to be knotted due to disorder in the dyeing room, causing fabric mottling.

2. The influence of capstan speed and nozzle pressure
The fabric in the dyeing chamber is pulled by the winch and then enters the nozzle. The nozzle is a ring-shaped outlet, and the dye solution is sprayed out from the gap of the nozzle. With the pressure of the nozzle, the dye solution is sprayed on the rope-shaped fabric, changing the position of the fabric folded due to accumulation in the dyeing chamber. The speed of the fabric depends on the speed of the capstan. and nozzle pressure. In the temperature region where the fabric absorbs the dye, increasing the number of cycles of the fabric, that is, increasing the running speed of the fabric, is beneficial to the level dyeing of the fabric. When the amount of liquid is constant, by increasing the flow rate of the dye liquid (that is, increasing the nozzle pressure), the cycle times of the dye liquid can be increased, the temperature in the dyeing machine and the uniformity of the dye distribution can be increased, the number of contact times between the dye and the fabric can be increased, and the dyeing time can be shortened. shorten.
While increasing the speed of the fabric and the number of cycles of the dye solution, attention should be paid to the mutual cooperation between the capstan speed and the nozzle pressure, otherwise it will directly affect the product quality. For example, if the capstan speed is too slow and the nozzle pressure is too high, the cloth speed is greater than the capstan speed, which will easily cause fabric scratches; if the capstan speed is too fast, exceeding the nozzle's ability to pass through the fabric, the fabric will accumulate at the nozzle, Clogged nozzles stop the dyeing machine and cause mottled fabrics.

3. The influence of bath ratio
The bath ratio not only affects the color of the fabric, but also affects the normal operation of the fabric in the dyeing machine. If the liquor ratio is too small, it will be difficult for the fabric to run, and the winch cannot smoothly take the fabric out of the dyeing chamber, and the fabric will run slowly. If the bath ratio is too large, the fabric floats on the water surface, which is prone to disorder and knotting, causing the fabric to be dyed. Furthermore, if the bath ratio is too large, it will inevitably lead to an increase in the amount of dyes and auxiliaries, and will also increase the labor intensity of the batching operation. Therefore, the determination of bath ratio should be minimized without affecting the running of the fabric and ensuring the quality of dyeing.

4. The influence of dyeing process
(1) The main factors affecting the overflow dyeing quality of inclusive dyes are dye use and adding method, dyeing temperature, type, amount and adding method of salt and alkali agent, dyeing time, dye bath ratio, etc. Among the above influencing factors, except for the addition method of dyes, salts, and alkali agents and the bath ratio, the rest of the factors only affect the depth of the fabric color, that is, the factors that affect the color fixation rate of reactive dyes.
(2) For disperse dyes. When dyeing with disperse dyes at 90°C, the heating rate can be larger, and when it is above 90°C, especially close to 130°C, the heating rate should be controlled to make it approach the dyeing temperature slowly to avoid uneven dyeing. The dyeing of disperse dyes is strongly affected by temperature, so in the temperature zone where dyes are absorbed, increasing the number of cycles of fabrics and dyeing liquor can make the dyes and temperature in the dyeing room evenly distributed, which is conducive to the level dyeing of fabrics.
After the dyeing is finished, the temperature should be lowered slowly at the beginning to avoid wrinkles of the fabric caused by sudden cooling. When the temperature is lowered to 100°C, rapid cooling can be used, down to 80°C, and then overflow cleaning is carried out to further reduce the temperature in the dyeing chamber. If the discharge and water intake are carried out at a higher temperature, it is very easy to form creases in the fabric and affect the dyeing quality.