High-speed forming of a series of partitioned tubular film packages, e.g., rock bolt resin cartridges, wherein different materials are maintained on opposite sides of a strip-like or tubular partition which is secured to the ends of the package, by forming and advancing a continuous tube of film and advancing a film barrier layer (a strip or smaller-diameter tube) within the advancing tube at substantially the same rate therewith; filling the tube with two different materials on opposite sides of the barrier layer; constricting the tube around the barrier layer at spaced intervals and applying a pair of encircling closure means thereto; and severing the tube between the pair of closure means. Apparatus for advancing and filling nested tubes to produce a tubular package having an inner tubular barrier layer secured to the ends thereof.