How to solve the poor whiteness and wool effect of knitted fabric？

Regarding pretreatment: poor whiteness includes impure whiteness, unevenness and gross effect less than 8-10cm/30min, which is related to the quality of knitted fabrics, such as low-grade cotton content, often whiteness and gross effect are not easy To do a good job, of course, the most critical is the process formulation and the selection of additives. In process formulation:

① The amount of H202 and NaOH must be sufficient

H202: After pretreatment, it not only plays the role of bleaching pigment, but also has the effect of removing impurities (including removing cottonseed husks). The amount of H202 is insufficient (including decomposition too fast), and the whiteness cannot be guaranteed. NaOH not only provides the required bleaching effect of H202 Alkalinity (PH), and in combination with scouring agent, it has the greatest effect of removing impurities. If the amount of NaOH is insufficient, the removal of impurities will be poor. The gross effect cannot meet the requirements first, and of course the whiteness can not meet the requirements, so the amount of H2O2 and NaOH It can be said to be the primary factor to ensure whiteness and gross effect;

② Select high-quality scouring agent:

The comprehensive effect of scouring agent such as cleaning, emulsification, dispersion and penetration must be excellent to ensure the removal of impurities and ensure whiteness and gross effect. However, the quality of scouring agents on the market is uneven, we must choose products with excellent comprehensive effects Not only the penetration force and solid content are measured, but the penetration force is only one aspect to be considered;

③ Oxygen bleach stabilizer and chelating dispersant:

These two additives are mainly to improve water quality, adsorb and complex metal ions such as Fe3+ in water, and prevent the rapid and ineffective decomposition of H2O2 catalyzed by metal ions. If H202 is decomposed quickly and ineffectively, its whiteness and gross effect will not reach At the same time, it will cause brittleness and even holes in the fabric, so to achieve whiteness and wool efficiency, the oxygen bleaching stabilizer should be selected with excellent varieties, and the decomposition rate of H202 should be considered in the selection. The addition of the chelating dispersant not only chelates iron, but also can chelate various impurities in the dispersed water, so that these impurities will not re-contaminate the fabric and cause the whiteness to turn dark and gray. Therefore, the chelating dispersant not only To consider its chelating power to metal ions and also consider its dispersing power;

④ Process conditions:

It takes a certain amount of time and temperature to react the auxiliaries with impurities. If the conditions are not met, the pigments and impurities will not be removed cleanly, and the whiteness and gross effect cannot be achieved:

⑤ Washing:

Washing after training and bleaching is very important. It is necessary to clean and remove impurities to ensure whiteness and hair effect.