First of all, pay attention to whether the yarn used is the same batch, because the "oil" content of different batches of yarn is different. At the same time, if mixed, it will become a factor in the dyeing process; Second, whether the original billet is pretreated and whether the refined original billet is dyed is very good, because the "oil" on the yarn is removed after treatment, and the dye can be dyed directly in contact with the fiber. Protect the cylinder pressure at both ends of the dyeing tank (or pad car, dyeing tank, dyeing machine), the continuous hot melt dyeing machine pad car is generally the use of air pressure, and each side of the roller has a cylinder. When the mill runs for a period of time, due to the role of water in the compressed air, the pressure at both ends of the cylinder will be different, resulting in uneven flow rate of the green belt liquid, resulting in edge to edge color difference.

In addition, both ends of the roll of the rolling car are pressurized, causing a certain deflection, resulting in the inconsistency of the edge margin will also lead to the color difference between left, middle and right. The pressure, concentricity and hardness coefficients of the dyeing groove rollers are under production. If the influence of roller pressure on the left, middle and right color difference is reduced to a low level, the general roller pressure should be controlled above 0.2MPa when the ribbon is dyed. Pressure, concentricity and hardness coefficient of the dyeing groove roller. In production, if you want to reduce the impact of roller pressure on the left, middle and right color difference to a low level, the general roller pressure should be controlled above 0.2MPa when the ribbon is dyed. Due to the wear and tear of the rolls during the production process, it is necessary to check the rolls regularly. Carry out calibration and maintenance, otherwise it is easy to cause inconsistent pressure zones due to inconsistent rolls, resulting in inconsistent design and color. The rolling ratio obtained by different hardness rollers is different, too hard may lead to insufficient dye absorption, too soft may lead to excessive gross profit margin, resulting in a large number of dye migration and color, how much hardness should be determined according to the strip.