Whiteness and wool effect Poor whiteness includes impure whiteness, non-uniform whiteness and less than 8-10cm / 30min gross efficiency, which is related to the quality of grey knitted fabric. For example, the content of low-grade cotton is high, so it is difficult to do well in whiteness and gross efficiency. Of course, the key is the process formulation and the selection of auxiliaries. resolvent In the process development: ① Choose a good scouring agent: The comprehensive effects of scouring agent, such as cleaning, emulsifying, dispersing and penetrating, must be good to ensure the removal of impurities, whiteness and gross effect. However, the quality of scouring agents in the market is uneven. We must choose products with good comprehensive effects instead of only measuring the permeability and solid content. The permeability is only one aspect to be considered. ② Oxygen bleaching stabilizer and chelating dispersant: These two auxiliaries are mainly used to improve water quality, absorb and complex metal ions such as iron ions in water, so as to prevent metal ions from catalyzing the rapid and ineffective decomposition of hydrogen peroxide. If hydrogen peroxide is rapidly and effectively decomposed, its whiteness and wool effect can not meet the requirements, and at the same time, it will cause fabric brittleness and even holes. Therefore, to achieve whiteness and wool effect, the oxygen bleaching stabilizer should choose a good variety The decomposition rate of hydrogen peroxide should be considered in the selection. The addition of chelating dispersant can not only chelate iron, but also chelate various impurities in the water, so that these impurities will not contaminate the fabric again, resulting in whiteness, dark and gray. Therefore, chelating dispersant should not only consider its chelating force on metal ions, but also its dispersing force. ③ Process conditions: It takes a certain time and temperature for additives to react with impurities. If the conditions are not met, the pigment and impurities will not be removed completely, and the whiteness and wool effect will not be achieved. ④ Washing: Washing after scouring and bleaching is very important. The impurities removed should be cleaned to ensure whiteness and wool effect.

1、 After anodizing, it can only be cleaned with cold water, not hot water, and not touched with hands, so as to prevent the dyeing effect from being affected. In addition, in order to prevent the residual acid from being brought into the dyeing tank, neutralization treatment can be carried out in the solution containing 10-30 ml / L ammonia or 50 g / L sodium carbonate after anodization if necessary. 2、 Coloring should be carried out immediately after anodizing cleaning. If the time is too long, it should be soaked in 10% acetic acid (phosphoric acid, oxalic acid, tartaric acid or citric acid) for 10 minutes at room temperature before dyeing to improve the dyeing performance of organic dyes. 3、 When the dyeing solution is turbid, it should be filtered in time. Because the turbid dyeing solution will cause these solid particles to penetrate into the pores, the surface brightness of the dyed cloth will obviously decrease, and the beauty will be affected. 4、 The temperature of dyeing solution should not be too high (80-90 ℃), otherwise the dye molecules will not be able to penetrate completely, resulting in too light color, too low dyeing fastness and even surface blooming.

(1) Less than 100 ℃ stage In this stage, the pressure has not been raised yet. If there is a fault, the consequence will not be serious, and the treatment is more convenient and simple. After the fault is eliminated, the original process can still be used and the re dyeing can be started from 60 ℃. Under 100 ℃, the expansion of polyester fiber is not enough and the disperse dyes are not dyed in large quantity, so the problems of color blooming and wrinkle printing are not obvious. But in case, when the temperature reaches 130 ℃, the dyeing time can be extended to make up for the safety. In this way, the staining results are generally satisfactory. (2) 100 ℃ to 130 ℃ stage When the failure occurs in the stage of 100-130 ℃, due to the existing pressure in the dyeing machine, the first thing to pay attention to is safety. At this stage, due to the faster expansion speed of polyester fiber and the faster dye uptake, it is very difficult to avoid color stains. If it is not a big accident and the treatment time is not too long, the high temperature leveling agent can be added and the heat preservation dyeing time can be extended; if the accident treatment time is long and the fabric stays in the dyeing machine for too long, the high temperature carrier method must be used for strengthening treatment; if the problem is serious, the high temperature carrier method can be repeated. (3) 130 ℃ heat preservation dyeing stage The failure occurred in the stage of 130 ℃ heat preservation dyeing. When the accident was treated after lowering the pressure and temperature, the time of heat preservation should be ignored, and the insurance remedy should be made by extending the heat preservation time according to the process regulations. At this stage, the adsorption of disperse dyes is sufficient, so it is not enough to make them play the role of migration and penetration and fully enter into the fiber, so the risk of defects is greater than that before 100 ℃, but less than that at 100-130 ℃. However, if the fabric is stopped due to blockage, or the dyeing machine stays for a long time, high temperature leveling agent 0.5-1g/l should be added during re dyeing, and then the holding time should be appropriately extended. This can not only promote and strengthen the dye transfer, but also help to overcome the wrinkle.