An Overview of Bleach Wash Applied on Garments
What is Bleach?
Bleach is a chemical which removes colors from the garments during bleach washing or bleach wash. Common chemical bleaches include household chlorine bleach, a solution of approximately 4–6% sodium hypochlorite (NaClO), and oxygen bleach, which contains hydrogen peroxide or a peroxide-releasing compound such as sodium perborate, sodium percarbonate, sodium persulfate, tetrasodium pyrophosphate, or urea peroxide together with catalysts and activators. It should be noted that bleaching powder is calcium hypochlorite. Most of the bleaches contain strong bactericidal properties which are harmful for human health and should be used with care.
Bleach wash is one of the garments washing process which is done by using strong oxidative bleaching agent. Sodium hypochlorite and potassium per-manganate (KMnO4) are two bleaching agents. By applying bleaching agent, color can be removed uniformly from the garment and removal of color have done as per requirement (as buyer’s provided wash approval). It should be noted that, there are three categories of bleaching, such as light bleach (where maximum color is removed), medium bleach and bleach. By applying bleaching wash special types of fading effect can be produced in the garments. Bleach wash can be applied on all types of garments such as woven, knit etc.
Bleach washed jeans
Purpose of Bleaching Wash:
- To achieve fading effect on the garments.
- To remove the starch present on the garments.
- To remove the size material from the garments.
- To achieve soft effect on the garments.
- To increase color fastness.
- To increase rubbing fastness.
Different types of Bleaching Agent:
1. Oxidizing Agent:
- Sodium hypo chloride (NaOCl),
- Hydrogen per oxide (H2 O2),
- Potassium di-chromate (K2Cr2 O7),
- Sodium chlorite (NaClO2).
2. Reducing agent:
- Hydrogen sulphide (H2S),
- Zinc Dust (ZnO),
- Sodium hypo-sulphite (Na2S2O2 ).
Mechanism of Bleaching Action:
Chemical bleaches can be worked on garments fabric in two ways which have discussed in the below:
1. Oxidizing bleach works by breaking the chemical bonds that make up the chromospheres. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore, which also does not absorb visible light.
2. On the other hand, reducing bleach works by converting double bonds into single bonds in the chromophore. This vanish the ability of the chromophore to absorb visible light.
Speech from the Writer:
If anybody reads this article very attentively then he can easily answer the following questions in the interview:
- What is Bleach?
- What is Bleach Wash?
- What is the Purpose of Bleach Wash?
- What is the objects of Bleach Wash?
- Describe different types of Bleaching Agent.
- Describe the classification of Bleaching Agent.
- Describe mechanism of Bleaching Action.