The Relationship between the Structural Geometry of a Textile Fabric and Its Physical Properties: Part V. The Interaction of Twist and Twill Direction as Related to Fabric Structure

This report examines the influence of the interaction between twist and twill direc tions in woven cloth. Consideration is given to the phenomena of nesting between warp and filling yarns, as affected by the local helix angles of bent yarns. Lateral dis placement of yarn segments is shown to follow from the asymmetric yarn pressures along the twill line. The effect of this displacement is to alter both the nesting angle and the local yarn twist. Changes in felting shrinkage, twill prominence, and yarn pull-out resistance occur with nesting and local tightening of yarn structure, and hence with selected combinations of twist and twill directions. Observations of the effect of twist-twill relationships are reported for worsted, rayon, and cotton fabrics.