Nylon 6,6 Fiber Tensile Properties as a Function of Morphology

Nylon 6,6 amorphous and crystalline orientation and content data are reported herein for a fiber series produced by varying the degree of stretch in conventional spinning and drawing operations. Tensile elongation and tenacity are correlated exponentially with the amorphous orientation function. Crystalline orientation values were observed to be consistently high, varying only slightly with significant tensile property changes. In addition, crystalline and amorphous contents varied by no more than 12% and did not consistently correlate with tensile properties. Extrapolation of the tensile property/amorphous orientation correlations to perfect amorphous chain orientation in the fiber direction implies that, in principle, a nylon 6,6 fiber having 20 gpd (1765 kN.m/kg) tenacity and 5.4% elongation is attainable.