In the fabric dyeing process, uneven color is a common defect. And dyeing defect is a general problem.
Reason One: Pretreatment is not clean
Solution: Adjust the pretreatment process to ensure that the pretreatment is even, clean and thorough. Choose and use excellent performance wetting agents and emulsifying agent to avoid foaming resulting in dyeing defects.
Reason Two: Residual of hydrogen peroxide after pretreatment
Solution: Measure the residual hydrogen before dyeing. Enhance washing process after pretreatment or use an excellent deoxidant after neutralization. If use a reducing agent, please pay attention to the influence of the residual reducing agent on dyeing when deoxidizing.
Reason Three: The bad compatibility of dyes
Solution: Change the dyes. Choose dyes with low initial dye-update and good migration property. Choose a group of dyes with similar dye-update to match the color.
Reason Four: The dosage and adding order of anhydrous sodium sulphate/ sodium carbonate
Solution: Choose suitable dosage of anhydrous sodium sulphate/ sodium carbonate according to different dyes. Anhydrous sodium sulphate can be added before or after dyes. If anhydrous sodium sulphate is added before dyes, please add it one time. If anhydrous sodium sulphate is added after dyes, it needs to add it slowly.
Reason Five: Bad quality of production water and too high hardness of added auxiliaries
Solution: Monitor and detect pH value and hardness regularly every day. Use pH buffering agent and chelating dispersing agent to neutralize the water quality.
Reason Six: Dyeing condition
Solution: Adjust and optimize dyeing process. Control the dyeing bath ratio, heating speed, dye-uptake of dyes, dyeing time and operating condition of equipment, etc.
In dyeing process, there are many factors influencing the dyeing effect. In a word, there are three kinds: pretreatment, dyes and dyeing condition. Therefore, mastering and controlling the influence of these three factors and their mutual influence is the fundamental way to prevent dyeing defects.
Post time: Jun-27-2022