There are various dyeing methods for nylon yarn, and the following are some common methods:
1. Dyeing of tube yarn
Place the yarn to be dyed: Take a yarn cylinder with gaps wrapped around the nylon yarn to be dyed and place it on the yarn rack in the main cylinder of the cylinder dyeing machine.
Configure dyes and homogenizing agents: Add 0.1% to 2.8% of the weight of the nylon yarn to be dyed and water to the first dyeing cylinder of the yarn barrel dyeing machine, then add 1% to 3% of the weight of the nylon yarn to be dyed and water to the second dyeing cylinder, and raise the temperature in the first and second dyeing cylinders to 28-35 ℃ respectively.
Dyeing: After the completion of the dyeing process, turn on the feed pump switch of the second dyeing cylinder of the yarn tube dyeing machine to transfer the dyeing agent to the main cylinder. After the addition of the dyeing agent is completed, hold it for 8-13 minutes, and then turn on the feed pump switch of the first dyeing cylinder to transfer the dye to the main cylinder. During the process of transferring the dyeing agent and dye, the circulation pump in the main cylinder is turned on, with a speed of 1200-1350 revolutions per minute. The circulation pump reverses to allow the dyeing agent and dye to permeate and flow from the yarn to be dyed in the yarn tube to the inner wall of the yarn tube. After the addition of the dyeing agent and dye is completed, the circulation pump rotates forward while heating up to simultaneously transfer the dyeing agent and dye from the yarn tube. The inner wall flows towards the yarn to be dyed, and after heating to 55-65 ℃, it is kept for 6-15 minutes. Then, it is heated again to 95-99 ℃ and kept for 48-53 minutes. Finally, it is cooled down to 80-95 ℃ before drainage.
Cleaning: After dyeing is completed, add water to the main cylinder and clean it once at 42-55 ℃.
Post treatment: Add 0.5%~1% oil agent based on the weight of the nylon yarn to be dyed into the first chemical tank and add water for chemical treatment. After the chemical treatment is completed, raise the temperature to 28-35 ℃. Then turn on the feed pump of the first chemical tank to transport the oil agent into the main cylinder, and keep the circulation pump running forward. The oil agent will permeate and flow from the inner wall of the yarn cylinder towards the yarn to be dyed. Then raise the temperature in the main cylinder to 55-65 ℃ and maintain it for 15-30 minutes. Finally, drain the water to complete the dyeing process.
2. Online color matching and dyeing
Preparation of dye solution: Mix the dye, penetrant, organic solvent, and water, add acid to adjust the pH, and obtain the dye solution. For example, the dye used is the reactive dye Yanlilao y-r, which is dissolved in a mixed solution of ethanol, penetrant wa-m, and water. The mass ratio of ethanol, penetrant, dye, and water is 10:0.05:1:88.95 to prepare a yellow dye solution. 3g/l citric acid is added to adjust the pH of the solution to 3.5.
Nylon tube yarn online color matching dyeing: During dyeing, the stylus comes into contact with the yarn roller, and the yarn roller comes into contact with the tube yarn. By moving the stylus left and right to adjust the distance between adjacent two styluses, and adjusting the peristaltic pump to control the liquid supply speed, the width of the color bar on the bobbin yarn can be changed, so that the adjacent two different colors of dye gradually overlap on the bobbin yarn during the winding process, forming a transitional composite color, and ultimately achieving online color matching.
Post processing: After dyeing, the tube yarn is subjected to color fixation treatment, such as setting the temperature to 110 ℃, pressure to 0.06mpa, and time to 30 minutes.
3. Dyeing with reactive dyes
Refining treatment: Refine the undyed nylon yarn.
Dyeing treatment: Soak the refined nylon yarn in an aqueous solution of ERIOFAST reactive dye at 40 ° C to 45 ° C for a first dyeing treatment of no less than 15 minutes, then add calcium chloride for a second dyeing treatment of no less than 5 minutes, and add acetic acid and sodium acetate for a third dyeing treatment of no less than 5 minutes; Afterwards, heat up to 55 ℃ to 98 ℃ and continue the fourth staining treatment for no less than 50 minutes.
Soap washing treatment: Perform soap washing treatment to obtain dyed nylon yarn.
4. Batch dyeing, continuous dyeing, or solution dyeing
Recycled nylon yarn can be dyed using common dyeing techniques, such as batch dyeing, continuous dyeing, or solution dyeing. The choice of specific method depends on factors such as the expected use of the yarn and the required color fastness.