Petra Jiraskova

Technical University of Liberec | TUL · Department of Textile Technologies

The main aim of this article is to extend piece of knowledge about a deviation rate function (DR(±5%, L)) as one of characteristics of yarn mass irregularity. The relation of deviation rate to other characteristic functions of yarn mass irregularity (in particular to a variance-length curve and also a spectrogram) is analysed. Based on ascertained...

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,...

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 g...

The paper is focused on the analysis of irregularity of combed yams made from various biending ratios of CO/PL. The level of irregularity (CV) is evaluated in reiation to the percentage representation of cotton in a yarn. Yarn irregularity is measured by a capacitive method (the apparatus Uster Tester IV-SX) and simultaneously by an optical method...

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 s...

Unevenness of woven fabric results from irregularity of the yarn used as well as from the process of its manufacture (weaving). A periodical and non-periodical yarn irregularity shows itself in the flat textile by known effects -the moiré effect, cloudiness, and stripiness. It is possible to predict the appearance of flat textiles from measured val...

Parameters and characteristic functions exist to description and denomination of the mass irregularity of linear textiles and they are usually used in practise. There are these parameters in practise limit irregular calculation of the additional irregularity that originate during of the production - production and mechanical irregularity. According...

Parameters and characteristic functions exist to description and denomination of the mass irregularity of linear textiles and they are usually used in practise. There are these parameters in practise limit irregular calculation of the additional irregularity that originate during of the production - production and mechanical irregularity. According...

Vyd. 1. Nad názvem: Technická univerzita v Liberci, Fakulta textilní, Katedra mechanických technologií