The feeding conveyor takes the round boxes and brings them aligned towards the layering zone. A pusher moves the boxes under the stacking unit, where they are piled up depending on the size pre-set. Then the plane goes up and the layered boxes move by a conveyor belt towards the grouping area. Here, a pusher moves the lot in the packing area where the operator puts manually the carton over the lot of boxes. The short flaps are folded through a movement of the operator from right to left, while the long flaps are closed by two folders during the exit of the box from the machine.