Classification of wet processing in Textile dyeing industry
Different types of wet processing :
In the textile industry, wet processing is very important. The product that we get from loom needs some process to make it as usable for a human being. The processes are: Desizing, scouring, bleaching, dyeing, printing, and finishing. To fulfill this reaction need water and chemical. Water is the most usable chemical to complete this reaction. Without water these reactions are impossible.
Importance of wet processing:
Textile materials like fiber, yarn, and fabrics are treated by de-sizing, scouring, bleaching, dyeing, printing, and finishing all are the most important processes. The designing process helps to remove starch from these materials and helps to make preparations for the next process. The scouring process helps to remove oil, protein, wax, pectin, and other impurities from textile materials. To make more absorbency of textile fiber scouring is very necessary. The next process is bleaching this process is much necessary to remove natural color matter from textile fiber, yarn, or fabric. In this stage, the fabric is fully white and it has more affinity to absorb dyes.
Wet processing flow chart:
Grey fabric inspection
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fabric joining by sewing machine
↓
Brushing
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Searing/ Croping
↓
Singeing
↓
Desizing
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Scouring
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Bleaching
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Mercerising
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Dyeing
↓
Finishing
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Folding
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Packing & bailing
An elaborate discussion on above mentioned points is given below:
Fabric checking: After making fabric in the loom machine w need to check the fabric in an inspection table. Here need to cut the problematic fabric and be ready for the process.
Fabric stitching: Generally loom fabric does have not much length that's why we need to do fabric stitching widthwise.
Brushing: The fabric that we get from the loom may have dust on it so we need to clean it by brushing.
Searing and cropping: On the surface of the fabric there may be some loose ends, and tears of weft yarn, these need to be cut by the blade. This process is called searing and cropping.
Singeing: All projecting fibers are removed by this process and making a smoother surface. Sometimes we do both sides singeing to make both sides more smooth.
Desizing: Before the looming process we need to size in warp thread to make yarn strength so after complete weaving we need to remove size materials from fabrics. Size material must be removed before printing.
Scouring: By this process, we can remove oil, wax, protein, pectin, and other impurities from textile materials. The surface of the fabric becomes smooth and bright through this process.
Bleaching: By the bleaching process, we can remove natural color matter from the textile materials and it makes the fabric fully white. Due to this process fabric be more hydrophilic and also increase dyes and chemical absorbency. There are two kinds of bleaching agents. They are oxidizing and reducing bleaching agents.
Mercerizing: To improve smoothness and brighter surface we can do mercerizing process. It also increases hygroscopic quality and increases dye affinity. 55-65 TW caustic soda need to do the mercerizing process. The fabric needs to be passed through this chemical for 2-3 minutes and needs treatment. This is the process that applies only to cotton fabrics.
Washing: After complete mercerizing, we need to wash the fabric with water and then need to dry it well.
Steering: By this process, we can give the fabric a confirmation with and gsm. Here also one quality of the fabric is improved like the warp and weft yarn being 90° angle with each other.
Dyeing: Textile fabric is dyed with dyes or any other chemicals.
Printing: Fabrics are printed in textiles with various chemicals and processes. There are various types of printing.
Finishing: Some finishing processes on textile fabric need to do. For example Calendaring, optical whitening, and Resin finishing.
Folding: After that, we need to fold them well.
Packing and baling: To transmit fabric from a certain area needs packing and bailing.