Double bleaching process for woolen knitwear

Abstract

The invention relates to a double bleaching process for woolen knitwear. The bleaching process comprises a step of oxidation bleaching and a step of re-reduction brightening. According to the step of oxidation bleaching, hydrogen peroxide with a concentration of 15 mol/L and ammonia water with a concentration of 0.3 to 0.5% are used; the hydrogen peroxide is added when temperature is 30 DEG C; heating is carried out in 20 min so as to allow the temperature to rise to 50 DEG C, and heat preservation is carried out for 10 min; then the ammonia water is added, and heat preservation is carried out for 90 min; and after bleaching, cooling and flushing are carried out until no hydrogen peroxide is left. According to the step of re-reduction brightening, rinse powder with a concentration of 12 to 18% and a brightening agent WG with a concentration of 0.2 to 0.7% are used; the rinse powder and a solution of the brightening agent are added when temperature is 30 DEG C; heating is carried out so as to allow the temperature to rise to 75 to 80 DEG C within 45 to 50 min; bleaching is carried out for 60 while the temperature is maintained; and after bleaching, cooling and cleaning are carried out. A wool fabric produced by using the process has long-lasting whiteness, is not prone to yellowing, presents good hand feeling, suffers from little strength loss and is applicable to bleaching of worsted wool fabrics.

Description

technical field [0001] The invention relates to a wool fabric treatment process, in particular to a wool fabric double bleaching process. Background technique [0002] After the wool fabric is washed, most of the impurities are removed, but there is often a little natural pigment in the wool, even the very white wool is slightly yellow. To obtain pure white fabrics, these pigments must be removed by bleaching. After the fabric is bleached, it is required to have a certain degree of whiteness, and it is also required that it is not easy to yellow during storage, and the whiteness of the fabric must have a certain degree of stability. Hydrogen peroxide is commonly used for bleaching. Although the bleaching effect is good, it will damage wool to a certain extent. If the amount of hydrogen peroxide is too large, the fiber will be over-oxidized, which will easily make the fabric feel rough and reduce its strength. Wool bleaching powder is also commonly used in industry. Althoug...

AI Technical Summary

Problems solved by technology

Hydrogen peroxide is commonly used for bleaching. Although the bleaching effect is good, it will damage the wool. If the amount of hydrogen peroxide is too large, the fiber will be over-oxidized, which will easily make the fabric feel rough and reduce its strength.

Wool bleaching powder is also commonly used in industry. Although it has less damage to wool, its light fastness is poor.