Influence of sheath-core fibre characteristics on the properties of dref-3 friction yarns

The effect of sheath fibre fineness and length on the tensile and bending properties of dref-3 friction yarn has been studied using polyester and acrylic fibres. Sheath fibre fineness influences the tenacity of polyester yarns significantly but not of acrylic yarns. With the decrease in fibre fineness the polyester yarn tenacity decreases as the number of sheath fibres declines and the corresponding wrappings become loose. For acrylic yarn,,the effect is less pronounced as the fibre fineness was limited to only 2.22 die. x. The sheath fibre length mainly affects tenacity and extension of polyester yarns by changing the sheath fibre extent. However, the acrylic yarns remain unaffected as the sheath fibre extent does not change much with change in sheath fibre length.