The influence of the variation of texturing process parameters on structural characteristics of polyamide textured yarns in the false twist

Abstract

The variation of texturing process parameters within the limits of the industrial texturing machine brings about substantial structural changes of yarn characteristics. To obtain required characteristics of textured PA6.6 yarns for specific purposes, it is necessary to adjust the optimum process parameters. For that reason, in addition to modification of the quality of textured polyamide yarns, the aim of this work is to define the limit values of the texturing process. In this work, the influence of technical-technological parameters in the false twist texturing process on structural characteristics of polyamide yarns was studied. Partially oriented POY multifilament of 22f07*l dtex fineness was textured under production conditions on the friction texturing machine ICBT, model FT 15 E3. Using low temperature long heaters, the influence of variations of the heater temperature, texturing speed and D/Y ratio on the properties of the textured yarn (filament density, the crystallinity degree, the orientation degree of individual filaments, end -NH2 group content, -COOH group content and the total content of end groups) was investigated. Thereby, the values for the tension in the texturing zone (stretching) of 1.305 and in the winding zone of 0.954 were kept constant. The studied texturing parameters affect the change of above mentioned characteristics to a varying degree. For heater temperatures of 200, 210 and 220 °C, and D/Y ratio of 1.7, 1.9, 2.1 and 2.3, negative linear correlations were found between the speed of texturing - filament density, the speed of texturing - the degree of crystallinity and the speed of texturing - the degree of orientation of individual filaments. The correlation factor between the texturing process parameters and the analyzed properties of the yarn was determined. Based on the analysis of the obtained results, it can be concluded that with the established correlation between the speed of texturing and the investigated properties of the yarn, the correlation factor generally increases with the increase of D/Y ratio to 1.9 and 2.1, for the heater temperature up to 210 °C. However, in most cases the correlation factor decreases at the temperatures above 220 °C and higher values of the D/Y ratio. Therefore, in this study, the optimum temperature of the heater is 210 °C and D/Y ratio from 1.9 to 2.1, taking into account the selection of other values of texturing speed parameters and stretching.