B. Antic’s research while affiliated with University of Nis and other places

The article presents an analysis of the influence between relative yarn density and breaking properties of woven fabrics with different structure and construction (weaves). The obtained results show that woven fabrics, with relative density higher than one, have the breaking force of smaller valve than predicted one. Therefore, a method is proposed for prediction the right value for maximum density in woven fabrics, without distorting the yarn quality.

The influence of the sizing agent application on the warp threads breaks during the weaving process was analysed in this paper. The threads breaks were observed on the pneumatic looms during the cotton warp weaving as well as during the weaving those warps, they were made from mixture of polyester and cotton fibres. The results manifest that to much sizing agent applications on the cotton warps cause increased number of threads breaks during the weaving. Also, to much sizing agent applications, by the sizing of the warps they were made from polyester and cotton fibres, do not contribute to the threads breaks decreasing, so they should be avoided because of unnecessary weaving cost increasing.

In the twisting, three different tension force intensities were used for each type of winded and doubled yarns. On the basis of F-ε curve, elasticity limits were defined of the analyzed twisted yarns. Also determined were values of breaking forces and relative breaking elongation for all registered tension forces, as well as force action to the elasticity limit and breaking.

In twisting, three different tension force intensities were used for each type of wound and doubled yarns. On the basis of the F-ε curve, elasticity limits were defined, as well as the yield point of the analysed twisted yarns assessed. Breaking forces and elongation at break for all registered tension forces, as well as the work to the elasticity limit and the work to the yield and breaking point were also determined.

In the twisting process yarn was exposed to various influences that caused various tensions in various sectors. All that influenced the resulting tension with which yarn was twisted onto the bobbin. Yarn tensions were defined under various twisting conditions. Afterwards, poly-cyclic mechanicalproperties of these yarns were examined. Fastness of twisted yarns to poly-cyclic extensions was examined by the method of repeated extensions to the constant elongation, on INSTRON-tester. Elongation of 4 %, corresponding to the warp elongation on the loom, was taken. As experimental material, worsted wool yarn spun from T-63 wool fibres was chosen.

In this paper work methods of weaving warp yarn hairiness reduction and mechanism of hairiness reduction have been described depending on the starch mass silts on warp yarn and relative warp density during the starching process. Besides, on the basis of the results given the empiric equation by which the diminuation of hairiness can be projected is given depending on the dressing size silts and warp relative density in sizing process.

In the winding process, on its way from the spinning tube to the bobbin, yarn was exposed to various influences that caused various tension in various sectors. All that influenced the resulting tension with which yarn was winded onto the bobbin. Yarn tensions were defined under various winding conditions. Afterwards, breaking properties of these yarns were examined. On the basis of F-ε curve, elasticity limits were defined of the analyzed winded yarns. Also determined were values of breaking forces and relative breaking elongation for all registered tension forces, as well as force action to the elasticity limit and breaking. Examination results of breaking mechanical characteristics point to the fact that with the yarn tension force increase in winding, yarn values decrease which influences winded yarns behavior in the subsequent processing procedures. Therefore, their changed behavior must be taken into consideration in the process projecting.

The effect of weaving tension on the crimp in warp and weft yarns is studied. Modern methods of determining yarn crimp using geometrical models of woven constructions assume equal warp and weft tension in a fabric. This is usually not so in practice, and an analysis is made of the relationship between the crimp coefficient and yarn tension in undyed cotton fabrics. Results indicate that yarn tension is an important parameter which influences crimp and must not be disregarded when designing fabrics.

The paper has analysed the dependence force/relative elongation of woolen fabrics types of various structural solutions. On the basis of the modulus curve, the elasticity limits and crawl gear have been defined. Also, force values and relative fabrics elongations for given limits have been determined, as well as force action up to the elasticity limits, and action up to the crawl gear to breaking. Wire spacing and weaving in influence on the given mechanical characteristics been has analysed.