Importance of Yarns:
Designing yarns for specific end-uses. Selection of fiber /filament, structure of fiber/filament, spun yarns, multifilament yarns, textured yarns and micro denier multi filament. Yarn diameter derivation of Pierce, Grosberg and Dickson formulae. Functional properties of end products.
Yarn Structure and yarn Regularity:
Geometrical properties of single and folded yarns. Derivations of related equations. Open & hexagonal packing and their merits and demerits. Twist contraction and retraction - practical applications. Twist migration and segment length in spun and filament yarns -Theoretical analysis of yarn irregularity - blend irregularity.
Transfer of Force:
Transmission of force from fiber to fiber in spun yarns - mechanism of yarn breakage.
Relationship:
Effect of fiber properties and their geometrical configuration on tensile properties of yarns. Concept of elongation.
Blends:
Effect of properties of constituent fibers and their composition on the behavior of blended Yarns.