Yarn Structure and Fabric Geometry — Summer 2022

With neat diagram discuss the two effects governing Strength-twist relationship.

Write short note on Schwarz Constant.

With the help of coaxial-helix model explain Idealized Helical yarn structure.

Enlist the pertinent physical characteristics that are influenced by twist.

Enlist the fibre properties that are expected to influence fibre compactness.

With the help of neat diagram explain in detail Twist Contraction.

Describe Coil winding method for measuring yarn dimensions.

Calculate out Contraction factor, Cy for Twist angle (α) :20o

Define the tems: i. Fibre Modular length ii.Packing fraction.

Hamilton geometry gave the following data: • Major diameter = 230μ = a • Minor diameter = 162 μ = b • Ne = 29.5 Tex • Fibre specific volume = 0.66 cm3/g Estimate φ.

Calculate out Retraction factor, Ry for Twist angle(α) :30o

With the help of neat figure explain Migration.

Discuss the parameters used for characterization of migration behavior of fibre.

What is meant by Elastica model of fabric?

Explain Orthotropic& Isotropy.

Derive the equations for the Peirce’s geometry of Special case when “Weft yarn is straight and warp is not jammed”.

Explain Poisson's ratio.

Explain crimp interchange phenomena.

Derive all the equations of fabric cover.

Write the formula to find out warp and weft cover factor in direct and indirect system.

Explain fabric density and specific volume.

Derive and discussed cover factor of square jammed fabric.1

Explain any two Tensile properties of fabric.

Derive necessary equation of fabric model for Race-track cross- section.

Derive all the equations related to fabric Porosity.