The Introduction and Application of the Common Bleach in Laundry Shops

In the daily operation of the laundry shops, normal detergents normally cannot remove stubborn colorful stains like coffee, tea, juice, and so on. As a result, bleach becomes a very important auxiliary means. It is mainly composed of bleaching active ingredients (sodium hypochlorite, hydrogen peroxide...), stabilizers, surfactants, pH buffers, etc. Some products also add fluorescent brighteners or activators to enhance the effect.

By oxidizing and decomposing the stains’ large molecules into small molecules that are easily soluble in water, bleach can achieve a coloring removal and bleaching.

Categories

There are so many kinds of bleach on the market.

Form

They can be classified into liquids (bleach water, color-safe bleach liquid) and solids/powders (bleaching powder, sodium percarbonate, sodium perborate...).

Working principle

• Oxidizing bleaching agents

Destroy stains through oxidation reactions.

1. Chlorine-containing bleaching agents (chlorine bleach/bleach water): Their active ingredients are mainly sodium hypochlorite (liquid) or calcium hypochlorite (solid), with extremely strong oxidizing power.
2. Oxygen-containing bleaching agents (oxygen bleach/color-safe bleach): Their active ingredients are mainly hydrogen peroxide (liquid) or sodium percarbonate/sodium perborate (solid), with relatively mild effects.

• Reducing bleaching agents

These are less used in laundry shops.

In this article, we will introduce the commonly used chlorine-containing bleaching agents and oxygen-containing bleaching agents.

Oxygen-Containing Bleaching Agents

They are relatively mild and very safe. They have little damage to the textile and are not easy to cause color fading (apply to most colorful clothes). They have a wide application range. They apply to cotton, linen, silk, fur, chemical fibers, and other common fabrics. However, the real material of the clothes and the processing technology have a big difference. People must carefully check the laundry label of the clothes to confirm whether bleaching is allowed and what kind of bleach is permitted before washing. People should operate strictly in accordance with the product instructions.

• Application method

1. Prepare hot water (usually above 50℃, depending on the product instructions and the heat resistance of the fabric).
2. Add enough water into the washing machine.
3. Pour an appropriate amount of color-safe bleach liquid/powder into water according to the product instructions and stir thoroughly to dissolve evenly.
4. Thoroughly immerse the clothes in the bleach solution.
5. Immerse for a long enough time.
6. Completely rinse.

Even if the clothing label allows bleaching, it is recommended to do a little test first in an inconspicuous area to ensure there are no adverse reactions (fading or damage).

Chlorine-Containing Bleaching Agents

Their oxidizing is very strong and has vivid bleaching and stain removal effects. However, they are highly corrosive and irritating, which easily damages the fibers and makes the dye fade. They are mainly used for white, natural-color, and chlorine-resistant clothes. Colored clothes, clothes that are prone to fading, as well as silk, wool, cashmere, leather, feathers, nylon, spandex, coated fabrics, etc., cannot be treated with chlorine bleach. If the label of the clothes has a “Chlorine bleach not allowed” mark, chlorine bleach cannot be used either.

• Application method

1. Prepare an adequate amount of cold or warm water (avoid high temperatures) and add it to a container or washing machine.
2. According to the product instructions, pour an appropriate amount of bleach powder into water and stir thoroughly to dissolve evenly.
3. Immerse the clothes completely in the bleach solution.
4. The soaking time should not be too long (as per the product instructions, it is usually shorter).
5. Rinse thoroughly immediately after bleaching to remove residual chlorine.

Tips

1. Chlorine bleach solution must not be directly poured onto clothes or the inner walls of the washing machine because it can easily cause severe local fading or damage.
2. It must be used under low-temperature and alkaline conditions. High temperatures will accelerate the decomposition and failure of chlorine and increase its danger.
3. Do not mix with acidic substances! (Especially not with toilet cleaners, descaling agents...), as this will produce highly toxic chlorine gas, which is life-threatening! People should wear gloves to avoid contact with their skin and eyes during the operation.
4. After bleaching, rinse the fabric several times immediately to prevent residual chlorine from damaging it. For clothes of uncertain material or color, be sure to check the label first and do a concealed area test.

How to Choose

1. The choice between using oxygen-containing bleach or chlorine-containing bleach should be based on the material and color of the clothes.
2. Oxygen-containing bleach is suitable for a wider range of clothes' materials and colors. Chlorine-containing bleaching agents are generally suitable for bleaching white cotton fabrics. For clothes of uncertain material, it is advisable to test them on the hidden parts of the clothes first.
3. Commonly used chlorine-containing bleaching agents do not require high temperatures and can achieve good bleaching effects within a short period of contact with dirt. However, it can cause damage to fabrics, especially wool and silk, and also fade many dyes. Therefore, it cannot be used for bleaching wool, silk, and colored fabrics.
4. Oxygen-containing bleaching agents have a mild effect, but their bleaching effect is poor at low temperatures and requires high temperatures. Generally, they are effective only when used at temperatures above 50℃.

Conclusion

All in all, the oxygen-containing bleach is safer and has a wider application range. However, no matter which kind of bleach is used, people should strictly follow the product instructions.