Vortex Yarn Properties

Vortex Yarn Structure-Property Relationships. The value of correlation coefficient between the yarn structural parameters and physical properties was calculated. No correlation between these values was present. One might anticipate that a high mean migration intensity value should result in a higher tenacity. Once again relatively small differences between the levels of process parameter made impossible to see the expected effects of the process parameters.

Conclusion
The current work attempted to investigate the effects of five different process parameters: the distance between front roller to spindle, nozzle angle, nozzle pressure, spindle diameter, and yarn speed on the properties and structures of vortex yarns. Among these parameters the distance between the front roller and the spindle affected mainly yarn evenness, imperfection and hairiness values. They were better if this distance was short. The high nozzle angle, the high nozzle pressure, the low yarn delivery speed and the small spindle diameter reduced hairiness. In 100% cotton yarn the high nozzle angle and in polyester cotton blended yarn the low speed improved yarn evenness. In blended yarn the low nozzle angle and the large spindle diameter reduced the number of imperfections.
Among migration and yarn parameters the mean fiber position, r.m.s. deviation, helix angle and helix diameter were not affected by any of process parameters. The mean migration intensity and equivalent migration frequency, on the other hand, were mainly affected by the nozzle angle and yarn speed. These values were greater at the high nozzle angle and the low speed. It is possible that the yarn receives more twist at those conditions. The mean migration intensity was also influenced by the nozzle pressure. It was higher at the high nozzle pressure. The yarn diameter was mainly affected by the yarn speed. The low speed caused the smaller diameter.
Trials were run in Cotton Incorporated‘ s fiber processing laboratory. This restricted the experimental design to use only two levels for each parameter due to the unavailability of machine parts and the fact that previous experience indicated that spinning was not possible outside a narrow range of parameters. Differences between levels were very small for some parameters. If the differences were bigger results could be different. In addition due to the time constraint it was not possible to conduct more replications. Clearly more experiments are required to reach a solid conclusion and attain a “process-structure property” model for vortex yarns. Moreover, drafting conditions were not included to this study. Thus further work with more levels for each parameter and the addition of drafting conditions would be valuable.
As mentioned in vortex yarn the number of wrapper fibers is higher compared to that of air jet yarn. However the ratio of wrapper fibers to core fibers is still unaddressed. In preliminary study vortex yarn was untwisted and photographed under the SEM. It is likely that a similar technique can be utilized to investigate the wrapper fiber to core fiber ratio.