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Properties Of Viscose Vortex Yarns Depending On Technological Parameters Of Spinning

Moučková E., Mertová I., Jirásková P., Krupincová G., Křemenáková D.

Autex Research Journal

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2015

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Vol. 15, no. 2

138--147

EN

This paper analyzes the relationship between technological parameters of spinning of 100% CV Vortex yarns of different counts and its selected geometrical parameters (a lead of helix of wrapping fibre ribbon, yarn diameter) as well as yarn properties. The number of twist of wrapping fibre layer is determined. The effect of the yarn delivery speed, hollow spindle diameter, and the main draft on the hairiness, mass irregularity, tenacity, elongation, resistance to abrasion and bending rigidity of Vortex yarn is observed. The yarn properties are compared with the properties of open-end rotor spun yarns. Slivers of the same spinning lot were used for the production of both kinds of yarn. The results showed that the delivery speed in combination with spindle diameter affects yarn diameter, hairiness and abrasion resistance. Mass irregularity and imperfections of yarn is mainly affected by the main draft of drafting unit. Technological parameters of spinning do not affect the level of bending rigidity of the Vortex yarn. Tested rotor spun yarns had a larger diameter, higher hairiness, lower tenacity and higher elongation, lower mass irregularity and number of imperfections, higher abrasion resistance and lower bending rigidity compared to tested Vortex spun yarns.

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New possibility of objective evaluation of yarn appearance: part II

Moučková E., Jirásková P.

Autex Research Journal

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2013

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Vol. 13, no. 1

1--10

EN

In this article, the possibility of new objective evaluation of yarn appearance in area employing selected spatial statistical functions is presented. The yarns wound on the boards were used for the experiment. Appearance of standard yarn boards from the standard CSN 80 0704 and real yarn boards with faultless and faulty yarns were converted into grayscale images. Fluctuation in degrees of grayness was evaluated between square fields in the image using statistical function called the area variation curve. In addition, the method was applied to the simulated yarn board appearance generated by the Uster Tester apparatus. Behavior of area variation curves in dependence on the result of visual evaluation of yarn board appearance was discussed. The generated appearances from the Uster Tester device were also evaluated by other statistical function called semivariogram. It was found out that the area variation curve is not a suitable tool for evaluation of yarn board appearance. The semivariogram seems to be a more suitable tool. The paper extends the knowledge on the issue of objective evaluation of yarn appearance and directly follows the author’s work [1].

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New possibility of objective evaluation of yarn appearance

Moučková E., Jirásková P.

Autex Research Journal

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2012

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Vol. 12, no. 1

7--13

EN

The possibility of new and objective evaluation of yarn appearance wound on the board is described. A statistical method which has previously been used for the evaluation of surface unevenness of flat textile - semivariograms is used. The yarn board appearance is converted into a grey-scale image and the fluctuation in degrees of greyness between square fields in the image is evaluated by semivariogram. This method was applied on standard yarn boards from the standard CSN 80 0704 in addition to real yarn boards. The results of semivariograms constructed from a simulated ideal appearance of yarn on the board are discussed with the aim of introducing an ideal case behaviour of semivariograms. The possibility of using this function for the objective evaluation of yarn board appearance is also discussed.