Snježana Brnada

Analysis of Size Pick-up and Mechanical and Surface Properties of Multicolored Warps

The impact of various colors in a multi-colored warp on size pick-up was tested. Likewise, the change of physical-mechanical properties of yarn by sizing multi-colored warps was examined. Tests were performed on various multicolored warps for each color. Based on the obtained results, we concluded whether there was a difference in the size pick-up among various colors of the warp, as well as a difference in physical-mechanical yarn properties under the same sizing and dyeing conditions.

Analysis of the Mechanical Properties of Woven Fabrics from Glass and Basalt Yarns

Among many other materials for the reinforcement of composites, technical fabrics are increasingly being used for the same purpose, especially from glass and basalt tows, which have good mechanical properties.. During tensile stress these fabrics are elongated in the direction of tensile force, and at the same time they contract crosswise in relation to the action of the tensile force. In this paper the tensile properties of woven fabrics made from glass and basalt yarns were investigated. Measurements were focused on the lateral contraction, according to which Poisson’s ratio can be calculated. For these purposes, an innovative device as an upgrade of the strength tester and samples of fabrics of non-standard shapes (cross and square) were used. Mechanical properties of the yarns from which the fabrics were made were analysed before and after weaving in order to define the impact of weaving on them.