Analysis of webbing continuous dyeing process should pay attention to what matters?

1. Raw material factors for webbing wholesale The raw materials for webbing should first pay attention to whether the yarns used come from the same batch, because the "oil" of different batches of yarns is different, for example, blending will become the color in the dyeing process of factors; Secondly, regardless of whether the raw materials are pretreated or not, the dyeing and coloring effects of the raw materials after refining treatment are very good, because after treatment, the "oil" on the yarn is removed, dyes can be dyed directly with optical fiber, no protection.

2. Dyeing tank (or roller, dye vat, dyeing machine) The roller of continuous hot melt dyeing machine generally adopts air pressure and rollers with cylinders on both sides. After running for a period of time, due to the role of moisture in the compressed air, the pressure at both ends of the cylinder will be different, resulting in uneven empty liquid rate, edge color difference. In addition, the roller pressure at both ends of the rolling car produces a certain degree of deflection, resulting in inconsistent margin rate of the edge of the rolled piece, which will also cause left and right color difference.

3. In production, in order to minimize the influence of rolling on the left and right color difference, the rolling pressure should be controlled above 0.2mpa when dyeing the ribbon. In the production process, due to the wear of the rolls, it is necessary to calibrate and maintain the rolls regularly, otherwise it is easy to cause the roll inconsistency due to the different centers of the rolls.

The residual amount of rollers with different hardness is different. Too hard will lead to insufficient dye absorption, while too soft will lead to too large residual amount and large amount of dye swimming. The hardness should be determined according to the rubber strip.

4. Effect of Infrared Pre-drying Temperature on Ribbon After pretreatment and padding dyeing process, polyester webbing generally needs to undergo infrared (line) pre-drying treatment before entering the color box to prevent the occurrence of dye swimming in the drying process and to avoid defects such as color flowers and positive and negative color differences.

When the infrared pre-baking temperature is lower than 80 ℃, the positive and negative color difference of the ribbon is large, and it is difficult to meet customer requirements. When the infrared pre-drying temperature reaches above 100 ℃, the positive and negative color difference of the ribbon is greatly improved. This is because the pre-drying reaches above 100 ℃, the water of the ribbon is basically evaporated, which greatly reduces the possibility of dye swimming.

Considering the actual dyeing production and energy consumption, it is more appropriate to control the infrared pre-baking temperature at 100 ℃ ~ 150 ℃. Production is generally based on the thickness of the green belt and the liquid rate, the higher the green belt liquid rate, the higher the infrared pre-drying temperature. In actual production, we can not only rely on infrared pre-baking temperature to control the color difference between the positive and negative sides of the ribbon dyeing, especially sensitive colors such as coffee and dark green. We must use anti-swimming agents and other additives to achieve good dyeing effect.

5. The effect of oven fixing temperature on the color of hair dyeing. Roasting and dyeing is an important part of continuous thermal solution dyeing. The uniformity of oven fixing temperature plays a key role in controlling the left, middle and right color difference of webbing. Polyester ribbon after infrared pre-baked into the oven, the temperature must be consistent, otherwise it will produce obvious color difference. Experiments show that when the temperature difference between the left and right of the oven is greater than 2 ℃, the color of the ribbon changes significantly. Therefore, dyeing production must ensure uniform oven temperature.

The effect of moisture content on the left, middle and right color difference of the webbing polyester filament will add a certain amount of oil during the spinning process, so degreasing treatment should be carried out before dyeing. The pre-dyeing treatment of the webbing is generally drying, and the uneven surface temperature of the dryer will cause the difference in the moisture content of the blank belt, resulting in the color difference between the left and right of the webbing. In the dyeing process, in order to avoid the left, middle and right color difference caused by the different moisture content of the green belt, it is necessary to ensure that the green belt is thoroughly dried before the padding dyeing solution and the drying cylinder is regularly maintained.