Textile Bleaching Process Objectives, Process Parameters

Textile Bleaching Process

Bleaching is the second step in the pretreatment of textile materials, as is wet processing technology. The bleaching process can be defined as the destruction of natural coloring matter from the textile materials in order to achieve a clean, white end product. Different types of bleaching agents are used during bleaching methods.

The whiteness of textile materials is liked by everybody. White fabric colored with dyes. Sometimes we want to get a white fabric, which is obtained by the bleaching process. After the scouring process, bleaching is done to get a white fabric. Bleaching is done to remove the natural color that is inherent in the fiber.

Objectives of Textile Bleaching Process

Different types of objectives are gained by the bleaching process. The following are the purposes of the bleaching process:

1. The main objectives of bleaching are to get a sufficiently high and uniform degree of whiteness in the textile materials.
2. To get a high and uniform absorptivity in the textile materials.
3. Bleaching agents cause some damage to the textile materials. So bleaching must be accompanied by minimal fiber damage.
4. To preserve the good user and technological properties of the textile materials.
5. The process must be ecologically and financially sensible.
6. To accelerate the next dyeing process.

The bleaching agent is alkaline in nature. Before using it, one should have deep knowledge about different types of bleaching agents. Different types of bleaching agents are available on the market. Some are strong, and some are weak in their alkaline nature. So, we have to have an idea about which bleaching agent is suitable for which type of fabric.

Process Parameters of Textile Bleaching Process

The following process parameters for bleaching must be considered:. Points are as follows:

• Bleaching agents have a chemical structure. During bleaching, the chemistry of bleaching.
• The concentration of bleaching agents and other chemicals used in the bleaching process.
• Bleaching is generally done in the alkaline medium of the bath. Bath pH determines the performance of bleaching. So the pH of the bath should be considered.
• The temperature of the bath should be considered during the process of bleaching.
• Bleaching performance is also affected by the duration of bleaching. So, time is an important factor.
• Materials and liquor ratios are also considered during the bleaching process.
• Scouring is done to remove impurities from fabric or fiber. If the scouring process is not successfully done, then the presence of impurities hampers the bleaching performance. So, the presence of impurities in the materials is an important point for the bleaching operation.
• Bleaching agents are sensitive to atmospheric conditions. So, the storage condition of the bleaching agent is important. The place of storage should be neat, clean, and dry. Otherwise, the working activities could be damaged.

Bleaching is done on different types of machines. Bleaching agents are manufactured by different types of chemical manufacturing companies. All of the bleaching agents do not have the same characteristics. In the bleaching process, H202 is widely used.

So, bleaching should be perfect for getting a better dyeing performance. After bleaching, materials need to be neutralized for the next process. After the neutralization process, materials get ready for dyeing. It is also called scouring, and bleaching is half of the dyeing.