Delivery unit for an aseptic packaging machine, aseptic packaging machine and sterilization method

A method to sterilize a tubular wrapping in a packaging machine during its normal functioning, said packaging machine comprising a delivery unit provided with at least one nozzle configured to feed a product to be packaged, a sterilizing mean and a sterile gas, said method comprising:

• feeding a film of packaging material along the at least one nozzle of said delivery unit,
• making longitudinal welds which join the films forming the tubular wrapping around said at least one nozzle and containing the latter, the tubular wrapping being closed at its lower part by a transverse weld and open at its upper aperture;
• feeding a sterilizing mean into said tubular wrapping using the at least one nozzle, the at least one nozzle comprising a sterilant delivery duct which has a respective outlet end and which is configured to deliver the sterilizing mean;
• deflecting the sterilizing mean at exit from the tubular wrapping in a transverse direction with respect to the development axis of the at least one nozzle using a deflector disposed around the at least one nozzle and upstream of both the upper aperture of the tubular wrapping and of the outlet end of the sterilant delivery duct so as to remain outside the tubular wrapping;
• making said sterilizing mean flow outside said tubular wrapping through said upper aperture, wherein the deflector is configured to protect the upper aperture from external agents and to interfere with the flow of said sterilizing mean exiting from said tubular wrapping to allow said sterilizing mean to flow outside of the tubular wrapping without being diluted by said external agents;
• and
• wherein the longitudinal welds are made upstream of the outlet end of the sterilant delivery duct and the transverse welds are made downstream of the at least one nozzle.