Yarn Numbering Conversion Formulas for Fabric Cover Factor Analysis
Cover factor analysis requires direct conversion to Tex linear density and adjustment for fiber packing density before computing fractional surface area.
Wet Swell Expansion
Fiber Absorption
A physical transformation increases fiber cross-sectional area upon moisture absorption within aqueous processing baths. Hydrophilic materials undergo wet swell expansion when water molecules enter amorphous polymer regions and force cellulose chains apart. Transverse yarn growth alters fabric thickness and thread spacing in woven or knitted structures.
Natural fibers like cotton and viscose experience substantial lateral expansion, whereas synthetic filaments absorb minimal water and show little dimensional movement.
Crosswise Increase
Cotton fiber diameter increases up to fourteen percent when fully saturated. Transverse growth forces neighboring yarns tightly against each other.
Structural Displacement
Yarn swelling increases crimp angle in woven structures as warp and weft push against each other. As yarn diameter expands, internal geometry forces fabric length to contract, creating wet processing shrinkage. Processing equipment must accommodate high web tensions generated by structural tightening during continuous washing and dyeing operations.
Dimensional Stability
Finishing plants use mechanical preshrinking or resin crosslinking to stabilize fabrics prone to water absorption. Uncontrolled volume changes in wet processing cause severe fabric distortion and width loss during garment laundering. Testing laboratories measure dimensional changes after standardized wash cycles to verify that fabric structures resist progressive swelling.
Garment manufacturers specify maximum allowable expansion levels to prevent seam puckering and garment deformation.