Abstract: A machine for forming a variety of different sturdy, stackable three-part fiberboard containers having a depth dimension greater than their width dimension, and which are suitable for holding bags filled with liquid. The machine includes a slidable, removable mandrel which cycles between a fiberboard hopper area and a container forming compression area. Each of two side bins provides a fiberboard end panel to the mandrel. Just before the mandrel cycles forward, the suction cups remove two fiberboard end panels, one from each side bin, and pull them next to the mandrel. As the mandrel moves forward, the end panels are bent by the action of two folding elements. Meanwhile, a fiberboard body matt is brought into position in front of the retracted mandrel from an overhead feed unit. Adhesive material is sprayed onto selected parts of the body matt as it is placed into position in front of the mandrel.