Abstract
The theoretical orientation distribution functions were derived to predict the viscoelastic properties of the spun bonded nonwoven fabrics. The functions were obtained in terms of the process variables, such as feeding velocity of the filament, velocity of the moving conveyor belt, velocity and maximum angle of the oscillating adaptor, and the angle between the filaments from the adaptor and the axis of the moving conveyor belt. The theoretical results were compared and discussed with experimentals, and they were nearly conicident.