Structural and mechanical characteristics of polyester dref-3 yarns in relation to fibre profile and annealing treatment

27-32The influence of process parameters and annealing treatment on structural parameters, tensile properties, flexural rigidity and abrasion resistance of polyester dref-3 yarns has been studied. Annealing leads to a marked increase in helix angle and helix diameter, and a decrease in mean fibre extent. The results show significant improvement in breaking extension, work of rupture and abrasion resistance, and an appreciable decrease in tenacity, hairiness and flexural rigidity on annealing. The degree of change in these characteristics is more marked in the yarns made from a circular polyester fibre and the coarse fibre denier, thicker core and higher production speed facilitate it. Compared to the yarns made from a trilobal fibre, the yarns spun from a circular fibre exhibit higher thermal shrinkage which further increases with the increase in spinning speed