GATE (TF) Textile 2015 Question Paper Solution | GATE/2015/TF/62

The drape of a fabric refers to how it hangs or falls when used in garments or other applications. It describes how the fabric flows, folds, and moves in response to gravity and body movements. Fabrics with good drape tend to hang smoothly and gracefully, while fabrics with poor drape may be stiff, rigid, or bulky. The drape of a fabric is determined by its weight, thickness, stiffness, and flexibility, as well as its inherent properties, such as fiber type, yarn construction, and fabric structure.

Drape is an important characteristic of fabric because it directly affects how a garment or textile product hangs, folds, and moves when worn or used. The drape of a fabric can significantly impact the overall aesthetics, comfort, and functionality of a garment or textile item. Here are some key reasons why drape is important in fabric:
Appearance: The drape of a fabric can greatly affect the visual appearance of a garment or textile product. Fabrics with good drape tend to hang smoothly and gracefully, creating an elegant and attractive look. On the other hand, fabrics with poor drape may hang stiffly or unevenly, resulting in a less appealing or distorted appearance. The drape of a fabric can contribute to the overall style, silhouette, and fit of a garment, which can greatly influence consumer perception and satisfaction.
Comfort: The drape of a fabric can impact the comfort of a garment or textile item. Fabrics with good drape tend to drape around the body naturally, allowing for ease of movement and a comfortable fit. In contrast, fabrics with poor drape may feel stiff, bulky, or restrictive, which can lead to discomfort and reduced wearability. The drape of a fabric can affect how a garment drapes against the skin, interacts with body movements, and regulates body temperature, all of which can impact comfort during wear.
Functionality: The drape of a fabric can affect the functionality of a garment or textile product. Different applications may require fabrics with specific drape characteristics. For example, garments such as dresses, skirts, or scarves typically require fabrics with good drape to achieve fluidity and movement, while fabrics used in upholstery or drapery may require a stiffer drape to maintain their shape and structure. The drape of a fabric can also impact how a textile product performs in terms of insulation, ventilation, moisture management, or other functional properties.
Design and garment construction: The drape of a fabric can influence the design and construction of a garment. Fabrics with specific drape characteristics may be preferred for certain garment styles, patterns, or construction techniques. For example, fabrics with good drape may be preferred for garments that require flowy or draped effects, while fabrics with stiffer drape may be preferred for garments that require structure or stability. Understanding the drape of a fabric can help designers make informed decisions on fabric selection, pattern making, and garment construction techniques to achieve the desired design and fit.
In summary, the drape of a fabric is important in textiles because it can impact the appearance, comfort, functionality, and design of garments and textile products. Careful consideration of fabric drape is essential in the textile industry to meet consumer expectations, achieve desired aesthetics and functionality, and ensure customer satisfaction.

Crease recovery is an important characteristic in textiles, particularly in fabrics used for garments or other textile products that are subject to bending, folding, or wrinkling during use, transportation, or storage. Here are some key reasons why crease recovery is important in textile:
Appearance: Crease recovery refers to the ability of a fabric to bounce back to its original, wrinkle-free state after being subjected to bending or folding. Fabrics with good crease recovery tend to regain their smooth and unwrinkled appearance quickly after being folded, hung, or worn, while fabrics with poor crease recovery may retain wrinkles or creases for longer periods of time. Creased or wrinkled fabrics can look untidy, unkempt, or unprofessional, which can affect the overall appearance and aesthetics of a garment or textile product.
Comfort: Creased or wrinkled fabrics can be uncomfortable to wear, as they can create pressure points, chafing, or irritation against the skin. Fabrics with good crease recovery can help maintain a smooth and comfortable feel against the skin, as they quickly regain their original form and do not bunch up or retain wrinkles during movement or wear. Fabrics with poor crease recovery may result in discomfort, reduced mobility, or skin irritation, particularly in areas where the fabric folds or creases, such as at joints or waistbands.
Durability: Fabrics with good crease recovery tend to be more durable, as they can withstand repeated bending, folding, or wrinkling without permanent deformation or damage. Fabrics with poor crease recovery may develop permanent creases, cracks, or damage to the fibers or fabric structure over time, leading to reduced durability and lifespan. Fabrics used in garments or textile products that require frequent handling, transportation, or storage, such as suits, uniforms, or home textiles, can benefit from good crease recovery to maintain their appearance and performance over time.
Convenience: Fabrics with good crease recovery can offer convenience in terms of care and maintenance. They may require less ironing, steaming, or other treatments to remove wrinkles and restore their smooth appearance, which can save time, effort, and energy in garment care. Fabrics with poor crease recovery may require more frequent and extensive care to remove wrinkles or creases, which can be inconvenient and time-consuming for the end consumer.
Consumer satisfaction: Fabrics with good crease recovery can contribute to overall consumer satisfaction. Garments or textile products that maintain their smooth and unwrinkled appearance during wear, storage, or transportation are more likely to meet consumer expectations for comfort, appearance, and durability. Fabrics with poor crease recovery may result in dissatisfaction, customer complaints, or returns, which can negatively impact the reputation of the brand or manufacturer.
In conclusion, crease recovery is an important characteristic in textiles as it can affect the appearance, comfort, durability, convenience, and consumer satisfaction of garments and textile products. Fabrics with good crease recovery are desirable for applications that require a smooth and unwrinkled appearance, durability, and comfort during wear, while fabrics with poor crease recovery may lead to issues related to aesthetics, comfort, and durability. Textile manufacturers and designers carefully consider crease recovery as one of the important performance characteristics of fabrics to meet consumer expectations and ensure customer satisfaction.

The tear strength test, also known as the tear resistance test, is a mechanical test performed on materials to determine their ability to withstand tearing or propagating a tear. It is commonly used in various industries, including textiles, plastics, paper, films, and packaging, to evaluate the durability and performance of materials.
The tear strength test is typically conducted using a specialized testing machine, such as a universal testing machine, equipped with a tear resistance testing fixture. The sample material is usually in the form of a rectangular shape with a predefined notch or slit, which serves as the starting point for the tear to propagate. The test involves applying a controlled force to the sample along the direction perpendicular to the notch or slit, causing the tear to propagate through the material until it reaches a specified endpoint or until the material fails.
The tear strength of a material is usually expressed in units of force per unit thickness, such as Newtons per millimeter (N/mm) or pounds per inch (lb/in). Higher tear strength values indicate greater resistance to tearing, while lower values suggest lower tear resistance. The tear strength test is important in determining the suitability of materials for various applications, such as packaging films, automotive interiors, protective clothing, and industrial textiles, where tear resistance is a critical property for performance and durability.

Strength CV% in yarn refers to the coefficient of variation of strength, expressed as a percentage, and is a measure of the variation or inconsistency in strength among yarn samples. It is commonly used in the textile industry to assess the quality and uniformity of yarns.
The strength CV% is calculated using the following formula: Strength CV% = (Standard Deviation of Strength ÷ Mean Strength) × 100%
Where:
Standard Deviation of Strength: This is a measure of the dispersion or spread of strength values around the mean strength. A higher standard deviation indicates greater variation in strength among the yarn samples.
Mean Strength: This is the average strength of the yarn samples.

The strength CV% is typically expressed as a percentage. A lower strength CV% indicates less variability in yarn strength, which is desirable as it signifies more consistent yarn quality. Conversely, a higher strength CV% suggests greater variability in yarn strength, which may indicate lower quality yarn or inconsistencies in the yarn production process.
Yarns with low strength CV% are generally preferred in textile applications where consistent and uniform yarn strength is important, such as in high-performance technical textiles, critical safety applications, or when yarns are used in high-speed weaving or knitting processes where uniformity is crucial for efficient production. Monitoring and controlling the strength CV% during yarn production can help ensure consistent yarn quality and performance in end products.