GATE (TF) Textile 2017 Question Paper Solution | GATE/2017/TF/52

Carbonizing is a process used to remove the natural impurities from plant-based fibers, such as cotton, linen, and jute. The process involves heating the fibers to a high temperature in the absence of air, which causes the impurities to be burned off and converted into carbon.
The process of carbonizing typically involves the following steps:

Preparation: The fibers to be carbonized are first cleaned and sorted to remove any debris or foreign matter.

Impregnation: The fibers are then soaked in a solution of concentrated sulfuric acid, which breaks down the impurities and makes them easier to remove.

Drying: The fibers are dried to remove any excess moisture and to prepare them for carbonization.

Carbonization: The dried fibers are then heated in a furnace to a temperature of around 800-900°C in the absence of air. This causes the impurities to be burned off and converted into carbon, leaving behind pure fibers.

Neutralization: The carbonized fibers are then treated with an alkaline solution to neutralize the acid and remove any remaining impurities.

Washing: The fibers are washed thoroughly to remove any residual chemicals and to prepare them for further processing.

Carbonizing is a complex and specialized process that requires careful control of temperature, time, and chemical concentrations to ensure that the fibers are not damaged during the process. The resulting carbonized fibers are pure and free of impurities, making them suitable for use in high-quality textiles and other applications.

Scouring is a process used in the textile industry to remove natural impurities, such as dirt, oil, and wax, from fibers, yarns, and fabrics. The process involves treating the material with a detergent or chemical solution to dissolve and remove the impurities, leaving behind clean fibers that are ready for further processing.
The scouring process typically involves the following steps:

Preparation: The fibers or fabrics are first cleaned and sorted to remove any debris or foreign matter.

Scouring: The material is then treated with a detergent or chemical solution that dissolves and removes the natural impurities. The solution is heated and agitated to ensure that the impurities are completely removed.

Rinsing: The material is then rinsed thoroughly with water to remove any remaining detergent or chemicals.

Neutralization: The material may be treated with an alkaline solution to neutralize any acidic residues from the scouring process.

Drying: The material is dried to remove any excess moisture and prepare it for further processing.

Scouring is an important step in the production of high-quality textiles because it ensures that the fibers are clean and free from impurities. The process can be performed on a variety of materials, including cotton, wool, silk, and synthetic fibers, and is often used as a pre-treatment before dyeing or finishing the material.

Bleaching is a process of treating textile materials with chemical agents to remove impurities, natural color, and to achieve a desired level of whiteness. This process is commonly used in the textile industry to prepare fabrics for further processing such as dyeing or printing.
There are various methods of bleaching textiles, but the most commonly used methods are:

Chlorine bleaching: This method uses chlorine gas or sodium hypochlorite to bleach textiles. Chlorine is highly effective at removing color, but it can also damage the textile fibers if not used properly.

Hydrogen peroxide bleaching: This method uses hydrogen peroxide to bleach textiles. It is less harsh than chlorine bleach and is commonly used for delicate fabrics.

Oxygen bleaching: This method uses a combination of hydrogen peroxide and sodium percarbonate to create a controlled release of oxygen, which helps to break down color and stains.

The uses of bleaching in textiles include:
Preparing textiles for dyeing: Bleaching is used to remove the natural color of fabrics so that they can be dyed to the desired color.

Whitening fabrics: Bleaching is used to achieve a uniform level of whiteness in textiles, which is important for products like bed sheets and towels.

Removing stains: Bleaching is used to remove stains and discoloration from textiles, making them appear cleaner and brighter.

Disinfecting textiles: Bleaching is also used to disinfect textiles, killing bacteria and other microorganisms that may be present on the fabric.

However, the use of bleaching agents in textiles should be done with caution, as excessive use or improper handling can damage the fabric and cause harm to the environment. Therefore, it is important to follow safety guidelines and regulations when using bleaching agents in the textile industry.

Mercerization is a chemical process used in the textile industry to increase the strength, luster, and affinity for dyes of cotton and other cellulosic fibers. The process involves treating the fibers with a solution of sodium hydroxide (NaOH) under tension, followed by a thorough washing.

During the mercerization process, the sodium hydroxide solution causes the fibers to swell and become more round in cross-section, which increases their surface area and makes them more receptive to dye. The solution also breaks down the cellulose in the fibers, resulting in an increase in their tensile strength and improved luster.
The process of mercerization can be carried out on yarns or fabrics. The yarns are usually mercerized before they are woven into fabrics. After mercerization, the yarns are usually washed thoroughly to remove any residual chemicals, and then they are dried and wound onto cones for weaving.

The benefits of mercerization include:

Improved strength: The mercerization process increases the tensile strength of the fibers, making them more durable and less likely to break or tear.

Enhanced luster: The process gives the fibers a more reflective surface, which makes them appear brighter and more lustrous.

Increased dye affinity: Mercerized fibers are more receptive to dyes, allowing for brighter and more vibrant colors.

Reduced shrinkage: Mercerized fabrics are less likely to shrink after washing, as the fibers have been stabilized during the mercerization process.

Improved hand feel: Mercerized fabrics have a smoother, softer hand feel, making them more comfortable to wear.

The mercerization process is an important step in the production of high-quality cotton and other cellulosic fiber textiles, and it is widely used in the textile industry.