Influence of spinning conditions on structure and properties of polyester-viscose blended MJS yarns

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">The effects of first nozzle pressure, second nozzle pressure and spinning speed on the properties of polyester-viscose blended MJS yarns have been discussed in the light of the yarn surface structure. An alternative classification of fibre configurations in air-jet spun yarn is proposed. Fibres have been classified into five different categories; belt, short wrapper, long wrapper, migrated core fibre and core fibre. Belt, short wrapper and long wrapper have been further classified into tight and loose wrappers. It is observed that there is a majority of trailing hooks in air-jet yarn. Increase in first nozzle pressure increases the percentage of wrapper fibres and decreases the core fibre percentage, whereas the increase in second nozzle pressure increases the percentage of tight wrapper. Percentage of long wrappers and migrated core fibres increases with the increase in spinning speed. The average fibre extent increases with increase in second nozzle pressure and spinning speed but decreases with increase in first nozzle pressure. Tenacity and breaking elongation increase up to a certain point and then decrease with the increase in first nozzle pressure and spinning speed. An increase in second nozzle pressure increases the tenacity and breaking elongation. Flexural rigidity increases with increase in first nozzle pressure, second nozzle pressure and decrease in spinning speed. Unevenness and imperfections show no regular trend with first nozzle pressure, second nozzle pressure and spinning speed.</span>