Product packaging method and machine

Abstract

According to one embodiment a packaging method is provided in which a film is fed to a vertical forming tube, whereby the film is formed into a tubular shape, the ends of the tubular-shaped film are longitudinally sealed to one another by applying pressure on said ends, the product to be packaged is introduced into the forming tube and the film formed downstream of the forming tube is transversely sealed and cut. Furthermore, in the method, the ends of the film are pressed to one another with a force that keeps both ends static, the drop of the product upstream of the transverse seal is stopped or limited, and by maintaining said pressure and said stop or limitation, an airflow is generated inside the forming tube.

What is claimed is: 
     
         1 . A method for packaging a product comprising:
 applying a film onto an outer surface of a elongate vertical forming tube such that the film surrounds the vertical forming tube, when applied on the outer surface of the vertical forming tube the film includes a first longitudinal end and a second longitudinal end, the forming tube having a top end and a bottom end, the forming tube having an internal through opening that extends between the top and bottom ends;   sealing to one another the first and second longitudinal ends of the film by use of a longitudinal sealing tool that presses on the first and second longitudinal ends;   transversely sealing the film located below the bottom end of the forming tube so that a film tube having a transversely sealed bottom end and an open top end is produced;   generating a descending air flow in the through opening of the forming tube while pressing together the first and second longitudinal ends of the film;   from the top end of the forming tube introducing a product into the through opening, the descending air flow preceding the product inside the forming tube;   stopping or restricting an advancement of the product toward the transversely sealed bottom end of the film tube at a location below the bottom end of the forming tube and above the transversely sealed bottom end of the film tube,   wherein the generating of the descending air flow comprises injecting air into a first portion of the forming tube to cause a negative pressure upstream of the first portion to cause the product to be drawn through the forming tube by the descending airflow.   
     
     
         2 . The method for packaging a product according to  claim 1 , wherein the stopping or restricting the advancement of the product toward the transversely sealed bottom end of the film tube is accomplished by the use of a transverse sealing tool that presses against on one or more sides of the film tube, the method further comprising transversely sealing a part of the film located below the bottom end of the forming tube by use of the transverse sealing tool so that a film tube having a transversely sealed bottom end and an open top end is produced. 
     
     
         3 . The method for packaging a product according to  claim 1 , wherein the stopping or restricting the advancement of the product toward the transversely sealed bottom end of the film tube is accomplished by the use of a protective element pressing on one or more sides of the film tube. 
     
     
         4 . The method for packaging a product according to  claim 1 , wherein at least one partial cut is generated in an area of the film. 
     
     
         5 . The method for packaging a product according to  claim 1 , further comprising extracting air from the film tube during the generating of the descending airflow. 
     
     
         6 . The method for packaging a product according to  claim 4 , wherein the at least one partial cut is generated in the area of the film prior to the film being applied to the outer surface of the forming tube. 
     
     
         7 . The method for packaging a product according to  claim 4 , wherein the at least one partial cut is generated in the area of the film after applying the film to the outer surface of the forming tube. 
     
     
         8 . The method for packaging a product according to  claim 4 , wherein the part of the film located below the bottom end of the forming tube that is transversely sealed to form the transversely sealed bottom end of the film tube is also transversely cut to separate the film tube from a previously formed film tube, the transverse cut and the at least one partial cut generated in the area of the film being made by a one and the same cutting tool. 
     
     
         9 . The method for packaging a product according to  claim 8 , wherein the transverse cut is made with the one and the same cutting tool being in a first position with respect to the film tube and the partial cut of the part of the film is made with the one and the same cutting tool being in a second position with respect to the film tube, the second position being different from the first position. 
     
     
         10 . The method for packaging a product according to  claim 4 , further comprising generating a vacuum about an outer surface of the film tube in the area of the film tube possessing the partial cut. 
     
     
         11 . The method for packaging a product according to  claim 10 , wherein the generating of the vacuum occurs concurrently with the generating of the descending air flow. 
     
     
         12 . The method for packaging a product according to  claim 10 , wherein the vacuum is generated inside a suction chamber closed around the outer surface of film tube, the suction chamber being formed by first and second actuators, at least one of the first and second actuators being moveable towards and away from the other. 
     
     
         13 . The method for packaging a product according to  claim 10 , wherein the vacuum is generated inside a suction chamber closed around the outer surface of the film tube, the suction chamber being in fluid communication with the through opening of the forming tube. 
     
     
         14 . The method for packaging a product according to  claim 12 , further comprising moving one or both of the first and second actuators relative to one another for the purpose of stopping or restricting the advancement of the product toward the transversely sealed bottom end of the film tube. 
     
     
         15 . The method for packaging a product according to  claim 8 , wherein the cutting tool comprises a first cutting profile that generates the partial cut and a second cutting profile different from the first cutting profile that generates the complete transverse cut of the film tube. 
     
     
         16 . The method for packaging a product according to  claim 4 , wherein the partial cut is made by a cutting tool, the method further comprising generating a vacuum about an outer surface of the film tube in the area of the film tube possessing the partial cut, wherein the vacuum is generated inside a suction chamber closed around the outer surface of the film tube, the suction chamber being formed by first and second actuators, at least one of the first and second actuators being moveable towards and away from the other, the cutting tool being affixed to at least one of the first and second actuators and producing the partial cut on a portion of the film located inside the suction chamber. 
     
     
         17 . The method for packaging a product according to  claim 4 , further comprising generating a vacuum about an outer surface of the film tube in the area of the film tube possessing the partial cut, the vacuum being generated inside a suction chamber closed around the outer surface of the film tube, the suction chamber being formed by first and second actuators, at least one of the first and second actuators being moveable towards and away from the other, wherein an upper portion of the hollow conduit is positioned inside the forming tube and a lower portion of the hollow tube is positioned inside a part of the packaging film tube residing in the suction chamber, the hollow tube communicating the suction chamber with the inside of the forming tube via the partial cut.