A bending moment induced by differential length changes is the physical basis for crimp in conjugate fibers. There fore, effects of cross-sectional shapes and component distributions on crimp can be estimated from considerations of mechanical principles governing the bending of rods or beams. Indices of these effects are defined as (a) stiffness of components relative to an axis perpendicular to the line between component area centroids and (b) angular deviation of this line from the cross-section principal moment of inertia axis. Regression analysis of experimental data shows these indices are statistically significant factors in bicomponent fiber crimp.
