Packaging machine and method for producing sealed packages

Abstract

There is described a packaging machine for producing sealed packages of a pourable product from a web of packaging material, the packaging machine comprises an isolation chamber having an inner environment and within which, in use, the web of packaging material is formed into a tube, a conduct assembly being in fluid connection with the inner environment; the conduct assembly defining and/or forming together with the inner environment at least a portion of a flow circuit of the packaging machine, a nitrogen distribution unit configured to inject and/or direct nitrogen into the flow circuit and a flow controlling device configured to create a flow of gas along a flow path within the flow circuit from the inner environment through at least a portion of the conduct assembly back into the inner environment.

1 . A packaging machine for producing sealed packages of a pourable product from a web of packaging material, the packaging machine comprising:
 an isolation chamber having an inner environment and within which, in use, the web of packaging material is formed into a tube;   a conduct assembly being in fluid connection with the inner environment; the conduct assembly defining and/or forming together with the inner environment at least a portion of a flow circuit of the packaging machine;   a nitrogen distribution unit configured to inject and/or direct nitrogen into the flow circuit; and   a flow controlling device configured to create a flow of gas along a flow path within the flow circuit from the inner environment through at least a portion of the conduct assembly back into the inner environment.   
     
     
         2 . Packaging machine according to  claim 1 , and further comprising a control valve connected to the conduct assembly and configured to control an evacuation and/or release of a portion of the gas flowing along the flow path from the flow circuit. 
     
     
         3 . The packaging machine according to  claim 2 , wherein the control valve is positioned upstream of an injection station at which, in use, the nitrogen distribution unit injects and/or directs the nitrogen into the flow circuit, along the flow path. 
     
     
         4 . The packaging machine according to  claim 1 , and further comprising a sterilization apparatus for sterilizing at least one face of the web of packaging material and comprising a sterilization chamber having an inner space, the inner space being in fluid connection with the inner environment;
 wherein the conduct assembly is in fluid connection with the inner environment and the inner space and the conduct assembly defines and/or forms together with the inner environment and the inner space the flow circuit;   wherein the flow controlling device is configured to create the flow of gas along the flow path within the flow circuit from the inner environment to the inner space and from the inner space to the inner environment through at least a portion of the conduct assembly.   
     
     
         5 . The packaging machine according to  claim 4 , and further comprising a control device configured to control the control valve so as to selectively open and close the control valve for respectively allowing or impeding the evacuation and/or release of gas from the flow circuit as a function of the nitrogen and/or oxygen content within the gas. 
     
     
         6 . The packaging machine according to  claim 4  or  5 , wherein the isolation chamber comprises an inlet opening configured to allow, in use, the web of packaging material to enter into the isolation chamber; and
 wherein the sterilization chamber comprises an outlet passage configured to allow, in use, the web of packaging material to exit from the sterilization chamber; 
 wherein the inlet opening and the outlet passage are adjacent to one another. 
 
     
     
         7 . Packaging machine according to  claim 4 , wherein the sterilization apparatus comprises an irradiation device positioned within the sterilization chamber and being configured to sterilize at least one face of the web of packaging material by means of a sterilization irradiation. 
     
     
         8 . Packaging machine according to  claim 1 , and further comprising a gas sterilization assembly configured to sterilize and/or purify the gas to be introduced and/or inserted into the inner environment;
 wherein the gas sterilization assembly is integrated into the conduct assembly and is arranged upstream of the isolation chamber and/or the inner environment along the flow path.   
     
     
         9 . Packaging machine according to  claim 8 , wherein the gas sterilization assembly comprises at least a main sterilization portion and a pre-sterilization portion arranged upstream of the main sterilization portion along the flow path. 
     
     
         10 . Packaging machine according  claim 9 , and further comprising a heating unit configured to heat the gas flowing along the flow path;
 wherein the heating unit is interposed between the main sterilization portion and the pre-sterilization portion.   
     
     
         11 . Packaging machine according to  claim 1 , and further comprising:
 a tube forming device at least partially arranged within the isolation chamber and being adapted to form a tube from the web of packaging material;   a sealing device at least partially arranged within the isolation chamber and being adapted to longitudinally seal the tube formed by the tube forming device;   a filling device for filling the tube with the pourable product;   a package forming unit adapted to form and to transversally seal the tube for forming the packages;   a conveying device for advancing the web of packaging material along a web advancement path to the tube forming device and for advancing the tube along a tube advancement path to the package forming unit.   
     
     
         12 . Method for producing sealed packages of a pourable product within a packaging machine, the packaging machine comprises at least:
 an isolation chamber having an inner environment and within which a web of packaging material is formed or can be formed into a tube;   a conduct assembly being in fluid connection with the inner environment; the conduct assembly defining and/or forming together with the inner environment at least a portion of a flow circuit;   the method comprises at least the steps of:   controlling a flow of gas along a flow path within the flow circuit and from the inner environment through at least a portion of the conduct assembly and back into the inner environment; and   controlling the gas content of the gas flowing within the flow circuit and/or of the inner environment and/or the inner space by introducing nitrogen into the flow circuit.   
     
     
         13 . Method according to  claim 12 , wherein the packaging machine further comprises a sterilization apparatus for sterilizing at least one face of the web of packaging material and comprising a sterilization chamber having an inner space, the inner space being in fluid connection with the inner environment;
 wherein the conduct assembly is in fluid connection with the inner environment and the inner space and the conduct assembly defines and/or forms together with the inner environment and the inner space the flow circuit;   wherein during the step of controlling a flow of gas, the gas flows from the inner environment into the inner space and from the inner space through at least a portion of the conduct assembly into the inner environment.   
     
     
         14 . Method according to  claim 13 , and further comprising the steps of:
 sterilizing the web of packaging material within the inner space; and   forming a tube from the web of packaging material within the inner environment;   wherein the step of forming the tube and the step of sterilizing are executed if the gas present within the inner environment and/or the inner space has a nitrogen content of at least 90 volume %.   
     
     
         15 . Method according to  claim 13 , wherein during the step of controlling the flow of gas, a flow controlling device creates a suction force within the inner space so as to extract gas from the inner space and to direct the gas extracted from the inner space together with the injected nitrogen into the inner environment. 
     
     
         16 . Method according to  claim 12 , and further comprising a step of evacuating and/or releasing gas from the flow circuit through a control valve. 
     
     
         17 . Method according to  claim 12 , and further comprising the step of determining and/or measuring the nitrogen and/or oxygen content within the gas flowing along the flow path;
 wherein the step of evacuating and/or releasing is executed as a function of the determined and/or measured nitrogen and/or oxygen content.   
     
     
         18 . Method according to  claim 12 , and further comprising the step of sterilizing the gas flowing along the flow path by means of a gas sterilization assembly arranged within the conduct assembly.