The short fiber bundles separated from the machining waste of a printed circuit board (PCB) manufacturing plant were used in preparing functionally graded composites using polysulfide-modified epoxy resin. The graded material was developed using centrifugation technique. The centrifugation time was varied to obtain different gradient profiles. The concentration profile was then compared with the theoretical HD model (Hashmi-Dwivedi model), which was modified to accommodate the changes in the shape of suspending particles. A shape factor was introduced in terminal velocity estimation. The simulated results are in agreement with the experimental trends. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 3840-3846, 2009