Abstract: The method is disclosed for checking the accuracy of folding a parallelepiped box made from a cardboard blank (1) comprising four adjacent panels (Pa, Pb, Pc, Pd), at least some edges of the panels being associated with flaps (Ra1, Ra2, Rb1, Rb2, Rc1, Rc2, Rd1, Rd2) for closing the top and bottom surfaces of the box. Slots (5, 6) with parallel edges are formed between the adjacent flaps. In the method, the spacing between the edges of the slots (5, 6), produced between the flaps (Ra1, Rd1 Ra2, Rd2) when the outer panels are folded together, is compared with a predetermined standard spacing between the edges of the slots (5, 6) to determine whether the folded box is defective.

Abstract: A method is disclosed for straightening a stack (P) of sheet material that has been deformed after conveyance on a roller conveyor (4), the rollers of which are mounted around parallel axes of rotation (5) extending transverse to the direction of conveyance of the stack (P), consists of putting the stack (P) in engagement with a stop surface (32) and driving the axes (5) of the rollers on which the stack (P) rests in a movement of translation in the direction of conveyance of the stack (P), allowing the rollers to rotate freely around their respective axes of rotation (5).