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

A force-geometric model is developed to predict the stress-strain rela tionship of textured polyester woven fabrics for small strains. The mo del is based on yam parameters, fabric geometry, and force equilibrium principles. Strains due to removal of weave crimp, removal of texture d yam crimp, and extension of textured yarn filaments are assumed to b e in series and then summed to yield total predicted fabric strain as a function of stress. Only two strain components are considered: strai n due to weave crimp removal and to textured yarn crimp removal. The a nalysis adopted by Johnson is used to derive the weave crimp component . Predicted stress-strain curves are compared to experimental curves f or eight different fabrics representing two levels of feed yarns and f our levels of textured yarns; the fabrics are in the dyed state, havin g 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 genera ted during wet finishing. There is good agreement between experimental and predicted stress-strain curves for low modulus fabrics, but agree ment between predicted and experimental values is not good in all case s.