GATE (TF) Textile 2013 Question Paper Solution | GATE/2013/TF/38

Question 38 (Textile Engineering & Fibre Science)

Consider the following assertion [a] and reason [r] and choose the most appropriate answer

[a] Heat setting increase the dimensional stability of synthetic fabrics
[r] The free energy reduced as a result of heating

(A)[a] is right [r] is wrong
(B)[a] is right [r] is right
(C)[a] is wrong [r] is wrong
(D)[a] is wrong [r] is right
Answer / Solution
[Show Answer]

Option B

Frequently Asked Questions | FAQs

Why is heat setting is used?

Heat setting is used in textiles for several reasons:
Dimensional stability: Heat setting helps stabilize the dimensions of textile fibers, yarns, and fabrics, preventing excessive shrinkage or stretching during subsequent processing or use. Synthetic fibers, such as polyester, nylon, and acrylic, have lower heat resistance compared to natural fibers like cotton or wool. Heat setting can improve the dimensional stability of synthetic textiles, ensuring that they maintain their intended shape and size even under heat, moisture, or mechanical stress.

Crease resistance: Heat setting can enhance the crease resistance of textiles, making them more resistant to wrinkling or permanent creasing. During the heat setting process, the textile is subjected to heat and pressure, which can relax the fibers and set them in a desired configuration. This can help prevent creasing and wrinkling, leading to fabrics that look smoother and more wrinkle-resistant, requiring less ironing or maintenance.

Shape retention: Heat setting can be used to impart specific shapes or configurations to textiles. For example, in applications such as automotive interiors, home furnishings, or garment linings, heat setting can be used to create fabrics with specific shapes, contours, or three-dimensional structures that are required for functional or aesthetic purposes. Heat setting can help the textile fabric retain its shape even after repeated use or exposure to environmental conditions.

Texture and hand feel: Heat setting can be used to create desired textures or hand feel in textiles. By subjecting textiles to controlled heat treatment, the fibers can be partially fused or rearranged, resulting in different surface textures or finishes, such as smooth, crinkled, or embossed. This can add visual interest, tactile sensation, or functional properties to the textiles, depending on the desired end use.

Dye fixation: Heat setting is commonly used in textile dyeing processes to improve the fixation of dyes onto the fibers. Heat can help accelerate the chemical reactions between the dye molecules and the fiber molecules, allowing the dye to penetrate and bond with the fibers more effectively. This can result in improved color fastness, wash fastness, and overall color durability of the textiles.

Overall, heat setting is used in textiles to improve dimensional stability, crease resistance, shape retention, texture, hand feel, and dye fixation, leading to textiles with enhanced performance, appearance, and functionality.

What is the heat setting process?

Heat setting is a process in textiles where heat is applied to synthetic fibers or fabrics to stabilize their shape and dimensions, and to enhance their physical properties. Heat setting is typically used for fabrics made from thermoplastic fibers, such as polyester, nylon, and acrylic.
The heat setting process typically involves the following steps:

Fabric Preparation: The fabric is cleaned and prepared for heat setting by removing any impurities, such as oils, dirt, or sizing agents, that may interfere with the process.

Tensioning: The fabric is stretched and tensioned to its desired dimensions using mechanical devices or equipment. This helps to ensure that the fabric retains its shape and size during the heat setting process.

Heat Application: The fabric is exposed to heat using various methods, such as hot air, steam, or infrared radiation. The temperature and duration of heat exposure are carefully controlled based on the type of fiber and the desired outcome.

Cooling: After the heat is applied, the fabric is allowed to cool slowly to room temperature while maintaining its stretched dimensions. This helps to set the fabric in its new shape and size.

Relaxation: Once the fabric has cooled, the tension is released, allowing the fabric to relax and return to its normal dimensions. This helps to prevent any residual stress in the fabric and ensures its stability.

The heat setting process helps to improve the dimensional stability, crease resistance, and durability of synthetic fabrics. It is commonly used in the production of textiles for various applications, including apparel, home textiles, automotive textiles, and industrial textiles.

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