Effect of fiber characteristics on cohesive and physical properties of cotton/polyester blended open-end yarns

The objective of this study was to determine the effect of fiber characteristics on cohesive and the physical properties of Polyester/cotton blended open-end spun yarns. High tenacity-low elongation and low tenacityhigh elongation polyester fibers were blended with two different types of cotton fibers using blend ratios of 100:0, 65:35, 50:50, 35:65, and 0:100. . Yarns were spun on the Rieter open-end spinning machine Model M 1/1.

The tensile properties of fibers determined included tenacity, elongation, uncrimping extension, and uncrimping toughness. Interfiber friction on carded laps was measured using an oscillating shear friction tester. The cohesive properties of first and fourth drawn slivers were determined by the Rotchild Cohesion Meter. The tensile properties of yarns such as tenacity, breaking elongation, initial modulus and breaking energy were measured using an Instron tensile tester.

Shear friction of carded laps was found to increase with increasing polyester content. Shear friction was found to positively correlate with cohesive force of first and fourth drawn slivers and also with tenacity, elongation, and energy to break of yarns. Correlation between shear friction and yarn modulus was found to be negative.

iv Cohesive force of fourth drawn slivers was found to increase with increasing polyester content. Cohesive force of first drawn slivers correlated positively with tenacity and modulus of yarns and in fourth drawn slivers, cohesive force positively correlated with tenacity, breaking elongation, and energy-to-break of yarns.

The stepwise regression analysis of data indicated that cohesive force and C.V. of cohesive force of fourth drawn slivers, and linear density (Tex) and tenacity of first drawn slivers were found to account for 58% of the variation in yarn tenacity. Shear friction, cohesive tenacity of first drawn slivers, C.V. and cohesive tenacity of fourth drawn slivers were found to explain 73% of the variation in breaking elongation. Shear friction, linear density (Tex), and cohesive force of first drawn slivers were found to account for 72% of the variation in yarn modulus. Finally, tenacity of first and fourth drawn slivers and C.V. of cohesive force of first drawn slivers were found to explain 79% of the variation in yarn energy.

The differences observed between cohesive force of a series of drawn slivers indicate that fiber characteristics such as surface roughness, crimp, and fiber length influence the frictional properties of fiber assemblies in various stages of textile processing. The interaction between similar and biconstituent blends in turn influences the physical properties of blended open-end spun yarns.