TENSILE PROPERTIES OF TEXTURED POLYESTER WOVEN FABRICS - THEORETICAL-MODEL FOR PLAIN WEAVE FABRIC

A force-geometric model is developed to predict the stress-strain relationship of textured polyester woven fabrics for small strains. The model is based on yam parameters, fabric geometry, and force equilibrium principles. Strains due to removal of weave crimp, removal of textured yam crimp, and extension of textured yarn filaments are assumed to be in series and then summed to yield total predicted fabric strain as a function of stress. Only two strain components are considered: strain due to weave crimp removal and to textured yarn crimp removal. The analysis adopted by Johnson is used to derive the weave crimp component. Predicted stress-strain curves are compared to experimental curves for eight different fabrics representing two levels of feed yarns and four levels of textured yarns; the fabrics are in the dyed state, having been woven and hot water bulked prior to jet dyeing. In this state, these textured woven fabrics have maximum stretch potential resulting from yarn crimp in the woven fabric and textured filament crimp generated during wet finishing. There is good agreement between experimental and predicted stress-strain curves for low modulus fabrics, but agreement between predicted and experimental values is not good in all cases.