Question 50 (Textile Engineering & Fibre Science)
In the context of Kawabata Evaluation System, match the fabric properties from Group I with the units from Group II.
|Group I||Group II|
|P||Tensile energy||1||gf . cm2 / cm|
|Q||Linearity of load-elongation curve||2||percentage|
|R||Bending rigidity||3||gf. cm / cm2|
|(A)||P-3, Q-4, R-1, S-2|
|(B)||P-3, Q-1, R-4, S-2|
|(C)||P-2, Q-4, R-1, S-3|
|(D)||P-1, Q-4, R-3, S-2|
Frequently Asked Questions | FAQs
What is the formula for tensile energy?
Tensile energy, also known as tensile work or tensile strain energy, is a measure of the amount of energy required to stretch or deform a material under tensile load. It is calculated using the following formula:
Tensile Energy = (1/2) x Stress x Strain x Volume
Stress (σ) is the applied force per unit area (typically in N/m^2 or Pa) acting on the material.
Strain (ε) is the deformation of the material expressed as a ratio of the change in length (or displacement) to the original length (or size) of the material. It is a unitless quantity.
Volume (V) is the volume of the material undergoing deformation (typically in m^3).
The (1/2) factor in the formula arises from the integration of the stress-strain curve, which represents the area under the stress-strain curve up to the point of failure. This integration accounts for the varying stress and strain values throughout the deformation process.
Tensile energy is an important parameter in materials science and engineering, as it quantifies the ability of a material to withstand deformation or elongation without fracture or failure. It is used to characterize the mechanical properties and performance of materials, and is often used in the design and analysis of structural components, such as in the automotive, aerospace, and civil engineering industries.
What is bending regidity of fabric?
Bending rigidity, also known as bending stiffness or flexural rigidity, is a measure of the resistance of a fabric to bending or flexing. It quantifies the ability of a fabric to resist deformation when subjected to bending forces or applied stresses. Fabrics with higher bending rigidity are less prone to bending or flexing, while fabrics with lower bending rigidity are more flexible and easier to bend.
Bending rigidity is typically measured using standard test methods that involve subjecting a fabric sample to a controlled bending force and measuring the resulting deformation or curvature. The most commonly used test methods for measuring bending rigidity of fabrics include the Cantilever or 3-Point Bending Test and the Circular Bending Test.
The bending rigidity of a fabric depends on various factors, including the type of fiber used, the weave or knit pattern, the yarn count, the fabric thickness, and the finishing treatments applied to the fabric. Fabrics with stiffer or more rigid fibers, tighter weaves or knits, higher yarn counts, thicker fabrics, and less flexible finishing treatments tend to have higher bending rigidity.
Bending rigidity is an important property in textiles, as it affects the drape, hand (feel), and performance of fabrics in various applications. Fabrics with higher bending rigidity are often used in applications where stiffness, stability, and shape retention are desired, such as in upholstery, automotive interiors, and industrial textiles. Fabrics with lower bending rigidity are used in applications where flexibility, drapeability, and conformability are required, such as in apparel, sportswear, and soft furnishings.
What is resilience in textile?
Compressional resilience in textiles refers to the ability of a fabric or textile material to recover its original shape and thickness after being subjected to compression or pressure. It is a measure of the fabric’s ability to bounce back or spring back to its original form after being compressed or deformed.
Compressional resilience is an important property in textiles, as it affects the comfort, durability, and performance of fabrics in various applications. Fabrics with higher compressional resilience are able to maintain their thickness, loft, and shape after being compressed, which can contribute to their durability, cushioning, and insulation properties. Fabrics with lower compressional resilience may suffer from reduced thickness, loft, and shape recovery, which can lead to decreased performance and comfort.
Compressional resilience is typically measured using standard test methods that involve subjecting a fabric sample to a controlled compression force and measuring the resulting deformation and recovery. One common test method used to measure compressional resilience is the ASTM D3574-17 Standard Test Methods for Flexible Cellular Materials – Slab, Bonded, and Molded Urethane Foams, which measures the recovery of a foam material after compression.
The compressional resilience of a fabric can be influenced by various factors, including the type of fiber used, the fabric construction, the finishing treatments applied, and the thickness or density of the fabric. Fabrics with resilient fibers, such as polyester or polyurethane, or fabrics with special treatments, such as foam laminations or quilted constructions, may exhibit higher compressional resilience compared to fabrics with less resilient fibers or constructions.
Fabrics with good compressional resilience are often used in applications where cushioning, padding, or insulation properties are desired, such as in mattresses, pillows, upholstery, and protective gear. Fabrics with lower compressional resilience may be more suitable for applications where flexibility, conformability, or drapeability are required, such as in apparel, sportswear, or lightweight fabrics.