Analysis of the Process of Pulling a Thread Through a Friction Barrier Considering the Non-uniformity of Visco-Elastic Properties of Yarns and Their Random Changes
Research and development
Authors:
- Włodarczyk Bogdan
Department of Knitting Technology and Structure of Knitted Products, Faculty of Material Technologies and Textile Design, Technical University of Lodz, Łódź, Poland - Kowalski Krzysztof (j/w)
 Full text | Abstract: Textile technologies are characterised by zones in which threads are stretched between elements of different machines and working elements of the same machine on which the drawn threads are displaced. The length of these zones is from several millimetres to several metres. The variability of tensions in the displaced threads is caused by technological conditions and the factors connected with the non-uniformity of the mechanical properties of threads. The mathematical modelling of forces presented in literature does not often consider the mechanical non-uniformity of the raw material and therefore only presents average values of the force without informing about the parameters of the value dispersion which is observed in real processes. The aim of this article is to attempt to evaluate the influence of the non-uniformities of the mechanical properties of yarns on the generation of forces acting in threads pulled through friction barriers and on their character. Broad ranges of thread speed values and the curvature radii of the barriers were accepted in our computer simulations. The model described in this article is a development of solutions described earlier. |
Tags: visco-elastic thread, random irregularities, tensions, probalistic model, stretching, drawing zone, friction barrier.