Effect of nitrogen in denim dyeing:

1. Block air, reduce oxidation and save materials:

The use of nitrogen to seal the dye cylinder can block the touch between the dye solution and the air, and reduce the evaporation and consumption of sodium hydrosulfite in the practical dyeing process. According to the statistical data of our company, compared with the use of nitrogen, every 10000 meters of yarn can save 10kg~15kg of sodium hydrosulfite and 20kg~30kg of caustic soda.

2. Extend the soaking time of soaking solution and improve the dye uptake:

The upper part of the dye cylinder is sealed with nitrogen, which can extend the impregnation time of the yarn in the dye solution. After the impregnation, a impregnation zone is also set, and the top is connected with the dye cylinder, which is filled with nitrogen, so as to prolong the impregnation time of the dye into the yarn and improve the dye uptake rate of the dye solution. Take the yarn count (10+705+806) and the first 4062 ultra-deep blue of our company as an example. If nitrogen is not used in the general sizing and dyeing machine, the dye uptake rate should be planned to be 3.1%, while if nitrogen is used in the sealed sizing and dyeing machine, only 2.7% of the dye uptake rate can reach the depth of 3.1% without nitrogen. In this way, the utilization rate of dyes can be improved by about 10%~15%+

3. Accelerate the rate of dye uptake and improve the production power of labor:

Due to the sealing of nitrogen, it is equivalent to increasing the touch time between the dye and the yarn. The reduced leucophore of indigo dye can fully touch and soak with the yarn, and the time when the same dye uptake, i.e. the depth requirement, is reached compared with the time when nitrogen is not used, will be correspondingly reduced. The dyeing speed of the sizing and dyeing machine without nitrogen is generally (22~25) meters/minute, which can be improved by (3~8) meters/minute after application. The value of the invention of labor per unit time has improved. Take our company's yarn count (10+7+705) and the first 425 ultra-deep blue varieties as examples, the vehicle speed is 23 meters/minute without nitrogen, and the vehicle speed can be improved to 28 meters/minute after use.

4. Improve the washing fastness and increase the brightness of color:

With nitrogen sealed dyeing, the dye can fully penetrate into the inside of the yarn, so that the dye and the yarn can be combined more closely. From the cross-section of the dyed yarn, the white core of the yarn with nitrogen assisted dyeing is relatively small, and the white core of the yarn without nitrogen assisted dyeing is obvious, and the fastness of the combination of the dye and the yarn is also poor. There are many floating colors, which will soon become lighter after washing, However, the cloth surface with the same depth of nitrogen assisted dyeing will be about 15% deeper after washing. From the perspective of color light, the denim with nitrogen assisted dyeing will be pure and bright after washing, while the denim without nitrogen assisted dyeing will feel dull and less shiny after washing.

Article source: elastic denim manufacturerhttp://www.in-it.com.cn/