Abstract: The apparatus for aligning two plys of limp material being fed into a work station employs a pair of bi-directional motor driven belts operating in electrical circuit relationship with closed loop servo control and a pair of photo-diodes with light source sensing beams employed in retro-reflective configuration for generation of a bi-polar signal in response to the movement of the belts. A pair of pressure plates mounted in proximity to said belts, provide a nip between the belts and the plates for material gripping. The belts being movable in response to dark/light bi-polar signals generated by the presence or absence of material at the center line of each of said photo-diodes and the closed loop servo control is actuated to govern the movement of said belts with respect to any deviation from said center lines.