Effects of Yarn Twist on the Mechanical Properties of Plied Yarn Fabrics

Twisting effect is an important factor determining the mechanical properties and structure of fabrics. An investigation was made of the relation between yarn and fabrics properties in terms of their tensile and bending properties when the resultant count of the plied yarn was varied. 1) A high correlation was found between yarn and fabric properties such as tensile, bending, and physical properties (thickness, and weight). 2) Surface roughness increases with increasing resultant count of piled yarn. Superficial crepe effect was obtained in coarse yarn fabrics when the constituent single yarns differed greatly in count. 3) The bending rigidity of gray and finished fabrics of coarse yarns were greater than those of fine yarn fabrics. The constant (R) indicating the degree of correlation between yarn and fabric in their bending rigidities is expressed as: R=Xf; /N•Xy; where, Xf; : bending rigidity of fabrics, Xy; : bending rigidity of yarns, and bending rigidity of fabrics, N: number of yarns per unit width of fabric. The value of R for cotton/cotton plied yarn fabrics is larger than those for cotton/polyester multi-filament plied yarn fabrics irrespective of the resultant yarn count.