welder 16 is mounted on or adjacent mandrel 11 to effect a seaming operation which joins opposite edges of film 15 specifically film 16 after being paid out by feed roll 14 is wrapped about the mandrel so that opposite sides of the film may be overlapped the overlapped edges pass between the head of seam welder 16 and the surface of mandrel 11 so that a seam may be formed which configures the film as a tube 17 the pressurized air emitted from the downstream end of mandrel 11 inflates the thusly formed plastic tube tube 17 then proceeds to a series of bag forming and liquid filling stations to be described instead of being seam welded from flat film the inflated tube 17 may come directly from a conventional blown film extruder making seaming unnecessary the inflated plastic tube 17 first passes a bagforming station at which seaming apparatus such as conventional hot seaming bars 21 22 are located bars 21 and 22 are positioned on opposite sides of tube 17 and are actuable to move toward one another whereupon to apply the pressure and heat necessary to effect two closely spaced pressure sealing seams 23 24 across the tube each pair of seams 23 24 thusly formed defines adjacent ends of two inflated plastic bags in this manner a series of connected platic bags 25 are formed and are transported to the filling station described below the filling mechanism at the filling station includes a pair of large hypodermic nozzles 31 32 the nozzles are fed liquid from a supply tank not shown via a manifold 33 nozzles 31 32 extend radially downward toward bags 25 and are normally displaced therefrom the spacing between the nozzles is such that.