Abstract: A rotary heat sealing system heat seals top and bottom webs to each other around discrete articles held in predetermined alignments and spacings between the webs. The rotary heat sealing system comprises a sealing station at which the heat sealing occurs, and a tensioning station upstream of the sealing station. The tensioning station produces a tension in the top and bottom webs and the articles by wrapping them in a reverse bend so as to maintain the predetermined alignments and spacings of the articles as they enter the sealing station. The sealing station includes an anvil and a heating die with a heat sealing grid and pockets between circumferential rails. The articles enter the pockets, and the webs are sealed to each other at areas corresponding to the heat sealing grid. A force mechanism applies a predetermined force between the heating die rails and the anvil.