What is the use of Hydrosulfite?

Hydrosulfite is widely used in reductive dyeing, reductive cleaning, printing and decolorization in the textile industry and for bleaching of silk, wool, nylon and other fabrics. Because it does not contain heavy metals, the bleached fabrics are bright in color and not easy to fade. But hydrosulfite is destructive to most dyes except vat dyes.

Sulfur powder can be used to remove color stains on clothing. When dyeing colored flowers or peeling off part of the color in the printing and dyeing factory, it needs to be treated with insurance powder, and it can also renew the color of some old gray-yellow clothes. It can also be used to neutralize white fabrics bleached by sodium hypochlorite or potassium permanganate.

In the field of washing:

(1) Fibers suitable for hydrosulfites Hydrosulfites are suitable for all kinds of textile fiber fabrics, so they are called "hydrosulfites". When the hydrosulfite is bleached at high temperature and bleached to remove color stains, the fibers of the bleached clothes must be able to withstand high temperature without damage.

(2) The use of hydrosulfite is bleaching and stripping. The use of hydrosulfite in the laundry is mainly bleaching and stripping. Because insurance powder has no damage to any fibers, it is one of the important chemicals for laundry. Sulfurite can bleach the colors of various natural pigments and most dyestuffs. Bleachable, strippable, and hydrosulfite bleaching is called reduction bleaching.

(3) Decolorization ability and limitations of hydrosulfite The hydrosulfite has a strong ability to restore and decolorize. It can remove many colors and stains, and can also change the dyeing of many dyes, but it cannot work on all colors. The hydrosulfite is effective for dyeing and bleaching of natural pigments, and has no effect on paint printing, paint dyeing and polyester disperse dyeing. Dyeing vat dyes can make it achromatic or discolored, but it will restore the original color when exposed to air.

(4) The alkalinity of hydrosulfite is restored. Some colored clothes are stained with hydrosulfite or accidentally stained with hydrosulfite. The color of the clothes will change or disappear, and then it will appear or restore the original color when exposed to alkali. If this happens, soak it in an aqueous solution of alkali or alkaline washing powder (the pH value should be kept at around 11) to restore the original color of the clothes. The best effect is soda ash, followed by heavy-duty washing powder or industrial washing powder.

(5) When the hydrosulfite is used, the hydrosulfite should be added to the water and mixed well. Do not add water to the hydrosulfite, otherwise the hydrosulfite will decompose quickly and lose its effect.