A continuous packaging machine is comprised of two opposed pairs of conveyors arranged to define an elongated passage having a rectangular cross section for the passage of a hollow packaging tube. The four belts are synchronized and run in the same direction. A plurality of first forming devices and a plurality of complementary sealing and crimping devices are alternately disposed on a first pair of opposed conveyors and a plurality of second forming devices and a plurality of shaping plates are alternately disposed on a second pair of opposed conveyors. As the tube is fed downwardly through the passage, the tube is crimped and sealed, the first and second forming devices and the shaping plates engage the tube while it is being filled to define a rectilinear prismatic package and the tube is then crimped and sealed by the next pair of devices to define a closed filled package. Cutters may be provided with the sealing devices to separate the closed packages.