Definition of Textile Wet Processing:
Textile wet processing is a series of chemical and mechanical treatments that are used to alter the appearance, performance, and durability of textile materials after they have been woven or knitted, but before they are made into finished products. These techniques are performed using water or other liquids, which is why they are referred to as “wet processing”.
Flowchart of Textile Wet Processing:
Flowchart of textile wet processing is given below image.
Stages of Textile Wet Processing:
The various stages of wet processing are as follows:
1. Singeing: Actually singeing is not a textile wet processing process. But before starting wet processing, singeing operation is done to remove protruding and hairy fibers from fabric. Singeing is a process of passing an open-width fabric over a gas flame at such a distance and speed that it burns only the protruding fibers but does not damage the main fabric. The main objective of the singeing process is to produce a clean fabric surface and reduce fabric pilling tendency by removing the protruding fibers from the fabric surface.
2. Desizing: Desizing is a process in twet processing that is used to remove the sizing material (a starch-based or synthetic material) that is applied to yarn or fabric during the weaving process. This sizing material is used to make the yarn or fabric stronger and more stable, but it must be removed before the fabric can be dyed or printed.
3. Scouring: Actually pure wet processing operation starts from scouring, which is the process of removing natural oils, waxes, and impurities from raw cotton or other natural fibers. Scouring is done by using a combination of water and chemicals like soda ash, sodium hydroxide, and hydrogen peroxide.
4. Bleaching: The next stage is bleaching, which is the process of removing natural color from fibers or fabrics and making them whiter. Bleaching is done by using chemicals such as hydrogen peroxide or chlorine. The most common method is the use of hydrogen peroxide in the presence of catalysts like sodium silicate, sodium hydrosulfite or sodium formaldehyde sulfoxylate.
5. Mercerization: Mercerization is a process that increases the luster, strength, and dyeability of cotton fabrics. It is done by treating the fabric with a caustic soda solution, which causes the fibers to swell and become more receptive to dyes.
6. Dyeing: The process of dyeing is used to add color to fibers or fabrics. Dyeing can be done using a variety of techniques, such as immersion dyeing, yarn dyeing, and piece dyeing. Different types of dyes are used for different fibers, such as acid dyes for protein fibers, and disperse dyes for synthetic fibers.
7. Printing: Printing is a process that uses dyes or pigments to create patterns or designs on fabrics. There are various methods of printing such as screen printing, digital printing, roller printing, block printing and rotary printing.
8. Finishing: Finishing is the last stage of wet processing, which includes various mechanical and chemical treatments to improve the appearance, performance, and durability of the textile. Finishing techniques can include softening, stiffening, water repellent, wrinkle-free, anti-microbial, UV protection, flame resistant etc.
These processes are often used in combination to achieve the desired result. It’s important to note that the order of the stages may vary depending on the specific application, the type of textile and the desired final result.
Importance of Textile Wet Processing:
Textile wet processing is an essential part of the textile industry, as it is used to improve the appearance, performance, and durability of the textile. The importance of wet processing can be summarized as follows:
a) Improving the appearance of the textile: Textile wet processing is used to add color, patterns, and designs to textiles, which improves their overall appearance and makes them more attractive to customers.
b) Enhancing the performance of the textile: Wet processing can be used to add various properties to textiles such as wrinkle resistance, water repellency, and UV protection, which improves their performance and makes them more suitable for specific applications.
c) Increasing the durability of the textile: This process helps to increase strength, stability, and resistance to textiles, which increases their durability and makes them last longer.
d) Preparing the textile for further processing: Wet processing treatment is used to prepare textiles for further processing such as dyeing, printing, and finishing. Pretreatment process like scouring and desizing are essential to obtain pure fibers for further processing.
e) Environmental concerns: This process can have negative impacts on the environment if not properly managed, but with proper treatment of the wastewater and use of eco-friendly chemicals, the impact can be minimized.
References:
- Textile Engineering – An Introduction Edited by Yasir Nawab
- A Novel Green Treatment for Textiles: Plasma Treatment as a Sustainable Technology By Chi-wai Kan
- Textile Processing and Properties: Preparation, Dyeing, Finishing and Performance by Tyrone L. Vigo
- Water Recycling in Textile Wet Processing Edited By J Kenneth Skelly
