Systems and methods for folding a stack of substrate sheets

A system for folding substrate sheets comprising:

• a roller assembly including a first set of opposing rollers, a second set of opposing rollers juxtaposed with the first set of opposing rollers, and a third set of opposing rollers downstream from the second set of opposing rollers;
• a positioning mechanism including a sheet guide having an upper curved form and a lower curved form, the upper and lower curved forms forming an elongated aperture therebetween, the upper curved form including a first flange adjacent the elongated aperture and extending downwardly and toward the roller assembly, the lower curved form including a second flange adjacent the aperture and extending upwardly and toward the roller assembly,
• the positioning mechanism further including a slidable object slidably positioned to extend through the elongated aperture between the upper and lower curved forms to push a stack of substrate sheets in the curved position toward the roller assembly;
• and
• a controller coupled with the roller assembly to control rotation of the first and second sets of opposing rollers to draw at least a portion of the stack of substrate sheets through the first and second sets of opposing rollers, rotation of the second and third sets of rollers to draw at least a folded portion of the stack through the second and third sets of opposing rollers, reverse direction of rotation to draw at least the folded portion of the stack of substrate sheets back through the third set of opposing rollers, and thereafter reverse the direction of rotation to drive the folded portion of the stack again between the third set of opposing rollers.