LAUSR

This paper presents a comparative analysis of three batches of wool yarns with different fineness, twists and compositions and the way in which these characteristics influence the tensile properties of the yarns. We performed the tensile strength tests and the values for the following tensile characteristics were determined: breaking force, elongation at break, tenacity and the mechanical breaking work and were made the diagrams. Stroke for strength and elongation at break – the diagrams give us an idea on the distribution of weak sections along the yarn tested. In order to make this analysis we used the machine USTER® TENSOJET 4. The main conclusions drawn from this analysis are following: the breaking force of the yarns is mainly determined by the value of length density and only after that by the percentage of polyamide and the twisting value, elongation at break is primarily influenced by the percentage of polyamide from the yarns composition and only then by the yarns twisting degree, the toughest yarns are the ones with the smallest fineness, the mechanical work created when stretching the yarns depends mainly by the percentage of polyamide from the yarns composition, by the yarns fineness and only then by their twisting.