Due to the increasing use of polypropylene fibers in various industries, especially in the field of producing machine-made carpets, researchers have felt the need for extensive study on the microstructure, physical properties and resiliency of these fibers. In this study, the effect of the temperature of the drawing rollers (130, 140 and 150 °C) and fineness of the filaments on the microstructure and physical properties of polypropylene yarn, as well as the degree of resilincy of the fibers under constand load on the carpets (woven from the prodeced fibers), were eva‎luated., Wide-angle X-ray diffraction, DSC, and birefrinegence measurements were performed ALso the resilincy after static loading under constant load on the carpets were measured. The results of the tensile strength test showed that the fine yarn samples had significantly higher tensile strength. Also, the percentage of crimp of the finer filament Yarns was lower than that of the that of thicker filament yarns. The amount of resilincy after static loading of the woven carpets was 20% higher than those of the national standard No. 895. The results of X-ray diffraction and DSC tests and birefringence measurements showed that the degree of crystallinity and molecular orientation of the finer fibers is higher than that ofthe thicker fibers drawn under similar conditions. In general, it seems that the finer fibers have shown greater mechanical properties and resiliency from constant load than the thicker fibers due to greater crystallinity and orientation under similar production conditions. Keywords: machine made carpet, polypropylene, polypropylene fiber resiliency, physical properties

مصطفي يوسفي

محمد قانع , حسين فشندي