میثم معزی

UV radiation is a major source of radiation in environmental conditions which affects many characteristics of the exposed fabrics. Toughness of polymeric materials and fabrics decreases when exposed to environmental conditions. Study of the changes in toughness has been a major attention for the researchers. The main aim of this work is to predict toughness of UV-degraded woven fabrics at different levels of exposure time and various directions. Samples of plain-woven fabrics that consist of nylon 66 as weft yarns and polyester as warp yarns are selected. A UV light source was used to induce controlled degradation at different exposure times. The samples were then tested with tensile tester machine and load–elongation curves were obtained. The toughness and the loss rate of toughness of the fabrics were determined. The areas under the curves are measured by the numerical method in Matlab 7.1 software. Regression method was used to find the correlation between the exposure times and the loss rate of toughness. For validating the regression model, a category of samples with an arbitrary exposed time were prepared. The experimental result of the validating sample was compared with the results form predicting regression model. Acceptable agreement was observed between experimental results and regression model.