Method and machine for packaging a product into flexible packages in a sterile environment

Abstract

A machine for packaging a product into flexible packages comprises one or more shaping and filling units for shaping and filling the packages; each shaping and filling unit extends along a longitudinal axis and comprises at least one nozzle, feeding means configured to make advance along the longitudinal axis a tubular casing of the material with which to make the packages and having an internal surface facing toward the nozzle, longitudinal welding means configured to form at least a first longitudinal weld that joins together at least two sides of the tubular casing and preliminary sterilization means, disposed in proximity to said longitudinal welding means for delivering a sterilizing agent.

1 . A method for packaging a product into flexible packages in a sterile environment in a machine that comprises one or more shaping and filling units for shaping and filling said packages, each of said shaping and filling units extending along a longitudinal axis and comprising at least one nozzle, wherein said method comprises at least:
 a feeding step in which a tubular casing, made of a material suitable to produce said packages, which has an internal surface facing toward said nozzle, is made to advance with respect to the nozzle and along said longitudinal axis;   a longitudinal welding step in which said tubular casing is welded along at least one longitudinal side thereof defining at least one longitudinal weld;   a preliminary sterilization step in which preliminary sterilization means deliver a preliminary sterilizing agent in the form of vapor onto portions of said internal surface which define, or are adjacent to, said longitudinal welds;   a sterilization step of said tubular casing in which a second duct comprised in said nozzle delivers a sterilizing agent into said tubular casing;   
       wherein said preliminary sterilization step is followed by a condensation step of the preliminary sterilizing agent and wherein said longitudinal welding step is further configured to cause re-evaporation of the preliminary sterilizing agent. 
     
     
         2 . The method as in  claim 1 , wherein said preliminary sterilization step occurs prior to said longitudinal welding step and said sterilization step of said tubular casing. 
     
     
         3 . The method as in  claim 1 , wherein preliminary sterilizing agent delivered in said preliminary sterilization step is hydrogen peroxide, which, during the delivery step, is preferably in the form of vapor. 
     
     
         4 . The method as in  claim 1 , also comprising a transverse welding step in which transverse welding means perform a transverse weld adapted to close a respective one of said packages at a lower part. 
     
     
         5 . The method as in  claim 1 , also comprising a filling step in which a first duct comprised in said nozzle delivers said product inside said tubular casing. 
     
     
         6 . The method as in  claim 5 , wherein said filling step occurs after said sterilization step. 
     
     
         7 . The method as in  claim 1 , also comprising both a transverse welding step in which transverse welding means perform a transverse weld adapted to close a respective one of said packages at a lower part and a filling step in which a first duct comprised in said nozzle delivers said product inside said tubular casing, wherein said filling step occurs after said transverse welding step. 
     
     
         8 . A machine for packaging a product into flexible packages in a sterile environment which comprises one or more shaping and filling units for shaping and filling said packages; each of said shaping and filling units extends along a longitudinal axis and comprises:
 at least one nozzle provided with a first duct configured to deliver said product and a second duct configured to deliver a sterilizing agent,   feeding mean configured to make one or more sheets advance in a direction of advance, said one or more sheets defining a tubular casing around said nozzle which has an internal surface facing toward said nozzle,   longitudinal welding means configured to form at least a first longitudinal weld which joins longitudinal sides of said one or more sheets,   
       the machine further comprising preliminary sterilization means configured to deliver a preliminary sterilizing agent, at a temperature and at a pressure such as to guarantee both the delivery thereof in the form of vapor, and the subsequent condensation thereof on portions of said internal surface which define, or are adjacent to, said longitudinal welds, wherein said preliminary sterilization means comprise at least one duct disposed in proximity to said longitudinal welding means. 
     
     
         9 . The machine as in  claim 8 , wherein said at least one duct of said preliminary sterilization means is disposed upstream of said longitudinal welding means with respect to said direction of advance. 
     
     
         10 . The machine as in  claim 8 , wherein said at least one duct of said preliminary sterilization means comprises a delivery aperture disposed in proximity to said longitudinal welding means and upstream thereof with respect to said direction of advance. 
     
     
         11 . The machine as in  claim 10 , wherein said delivery aperture is disposed directly above the point where said longitudinal welding means bring two portions of said one or more sheets in contact with each other to form said longitudinal weld. 
     
     
         12 . The machine as in  claim 8 , wherein said preliminary sterilizing agent is hydrogen peroxide.