Abstract
The influence of spindle air pressure and its direction on the properties of Polyester/Cotton vortex yarn was studied. The spindle air pressure direction was changed in both Z and S directions on the Z twist yarn of Ne 40s Polyester/Cotton vortex yarn (50:50 polyester: cotton) and these yarns were then tested for their properties such as tensile, unevenness, and hairiness. It was found that unevenness was lower with normal spinning condition and increased when the spindle air pressure increased in both directions. Imperfections were also found to be minimum with normal spinning condition and increased with increase in spindle air pressure. The yarn tenacity and elongation at break found to be lower at normal spinning condition. When the spindle air pressure increased yarn tenacity and elongation at break also increased with increase in spindle air pressure. At the same time spindle air pressure in the same direction of basic yarn twist gave less increase in tenacity and elongation than opposite direction of basic yarn twist. Hairiness index, H and hairiness in different length classes continuously increased as the spindle air pressure increased in opposite direction of basic yarn twist.