A closure device including a closure assembly for closing the flaps of a box. The closure assembly includes a T-shaped structure having a first horizontal surface upon which a box can move during a closure process and a guide positioned on each side of the T-shaped structure, each guide being angled relative to the T-shaped structure and adapted to close the major flaps of the box as the box is moved proximally across the T-shaped structure. The horizontal portion can be positioned vertically higher than a support surface to allow a portion of the box to move therebetween. The closure device can further include a minor flap closure device for closing the minor flaps of the box prior to closing the major flaps of the box. The closure device can also include a sealing device, such as a taping head, for sealing the box closed.