GATE (TF) Textile 2009 Question Paper Solution | GATE/2009/TF/11

In textile manufacturing, desizing is the process of removing the sizing agent from the fabric that was applied during the sizing process. Sizing is the process of applying a protective coating on the surface of the warp yarns before they are woven into fabric, which helps to improve their strength and other properties during the weaving process. However, this sizing agent needs to be removed from the fabric after weaving, as it can interfere with subsequent finishing processes such as dyeing or printing.
Desizing can be achieved through several methods, depending on the type of sizing agent used and the type of fabric being desized. Some of the common desizing methods include:

Enzymatic desizing: This method involves using enzymes to break down the starch or other sizing agents on the surface of the fabric. This is an eco-friendly and efficient method that can be used for a wide range of fabrics.
Chemical desizing: This method involves using chemicals such as acids, alkalis, or oxidants to dissolve or degrade the sizing agent. This method is effective for removing certain types of sizing agents, but it can also be harsh on the fabric and may require additional washing steps to remove the chemicals.
Hot water desizing: This method involves washing the fabric in hot water to dissolve the sizing agent. This method is effective for removing water-soluble sizing agents, but it may require a longer washing time and can be less efficient for certain types of fabrics.
After desizing, the fabric is thoroughly rinsed to remove any residual sizing agent or desizing chemicals. The fabric can then be subjected to additional finishing processes, such as dyeing or printing, to achieve the desired properties and appearance.