A. A. Gharehaghaji - Textile Engineering, Isfahan University of Technology
Abdolrasool Moghassem - Faculty of Engineering, Islamic Azad University Qaemshahr Branch

Core yarn was spun by introducing a PVA multifilament as the core through the yarn forming zone of a ring spinning frame and viscose fibers as the sheath containing tracer fibers. The water soluble PVA multifilament was extracted from the yarn structure. Then internal structure and properties of the hollow ring yarn was assessed and compared with those of typical ring yarns. Also, two plain fabric samples with hollow and typical weft ring yarns were produced to investigate the effect of hollowness and fibers collapse on the structural parameters of the fabrics. Bending behavior and air permeability of these fabrics were consequently studied. The results showed the mean value of fiber spinning-in-coefficient (Kf) and strength of hollow and typical ring yarns were very close, but elongation at break, unevenness and hairiness of hollow ring yarn is more than those of typical ring yarn. Results indicated that the bending rigidity and air permeability of the fabrics constructed from hollow ring weft yarn were improved due to the collapse of the fibers in the center of yarn and better flattening.

Hollow Ring Yarn, Spinning, In, Coefficient, Tracer Fiber Technique, Fiber Collapse, bending rigidity, air permeability