Method for manufacturing liquid-trapping bag for use in vacuum packaging

Abstract

A method for manufacturing a bag for use in vacuum packaging comprises forming a first panel having a plurality of baffles for evacuating air and/or other gases from inside the bag using a suction source, while preventing liquids from being drawn into the suction source, and a second panel. Each panel comprises a gas-impermeable base layer and a heat-sealable inner layer molded from melt-extruded resin. The first panel is overlapped with the second panel, and three of four edges of the panels are heated such that the inner layers bond at the heated edges. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

1 . A method for forming a panel for use in a sealable bag, comprising: 
 flowing a material onto a backing film, such that the flowing material is molded to form a structure;    wherein the structure includes a plurality of protuberances;    cooling the flowing material such that the flowing material solidifies to form an inner layer having the structure; and    wherein the inner layer adheres to the backing film.    
     
     
         2 . A method for forming a bag adapted to receive an article, the bag being partially formed between a laminating roll and a cooling roll having a plurality of cavities for forming a structure, comprising: 
 feeding a gas-impermeable film to a nip formed by the cooling roll and the laminating roll;    extruding resin such that the resin fills the nip and the plurality of cavities exposed to the nip;    pressing the resin between the cooling roll and the laminating roll;    cooling the resin such that the resin forms the structure and adheres to the gas-impermeable film, forming a panel;    wherein the structure comprises a plurality of protuberances;    folding the panel such that a first portion of the panel overlaps a second portion of the panel; and    applying heat to a first, second, and third side of the first and second portions such that an envelope is formed.    
     
     
         3 . A method for manufacturing a bag adapted to receive an article, comprising: 
 feeding a first gas-impermeable film to a first nip between a first cooling roll and a first laminating roll, the first cooling roll having a plurality of cavities for forming a structure;    extruding molten resin to the first nip;    pressing the molten resin between the first cooling roll and the first gas-impermeable film such that the molten resin fills the plurality of cavities exposed to the first nip;    cooling the resin such that the resin forms the structure and adheres to the gas-impermeable film, forming a first panel;    wherein the structure comprises a plurality of protuberances;    feeding a second gas-impermeable film to a second nip between a second cooling roll and a second laminating roll;    extruding molten resin to the second nip;    pressing the molten resin between the second cooling roll and the second gas-impermeable film;    cooling the molten resin such that a second inner layer is formed;    wherein the second inner layer adheres to the second gas-impermeable film, thereby forming a second panel;    overlapping the first panel with the second panel; and    applying heat to a first, second, and third side of the first and second panels such that the first panel and the second panel form an envelope.    
     
     
         4 . A method for manufacturing a bag adapted to receive an article, comprising: 
 rotating a first cooling roll at a first rate, the first cooling roll including one or both of a plurality of cavities and a plurality of protuberances for forming a structure having a plurality of channels defined at least partially by a plurality of baffles;    rotating a first laminating roll at a second rate;    introducing a first gas-impermeable film having at least one layer to a first nip between the first cooling roll and the first laminating roll;    extruding molten resin to the first nip;    pressing the molten resin between the first cooling roll and the first gas-impermeable film such that the molten resin fills the plurality of cavities exposed to the first nip;    cooling the molten resin such that a first inner layer is formed;    wherein the first inner layer comprises the structure;    wherein the first inner layer adheres to the first gas-impermeable film, thereby forming a first panel;    rotating a second cooling roll at a third rate;    rotating a second laminating roll at a fourth rate;    introducing a second gas-impermeable film having at least one layer to a second nip between the second cooling roll and the second laminating roll;    extruding molten resin to the second nip;    pressing the molten resin between the second cooling roll and the second gas-impermeable film;    cooling the molten resin such that a second inner layer is formed;    wherein the second inner layer adheres to the second gas-impermeable film, thereby forming a second panel;    overlapping the first panel with the second panel; and    applying heat to a portion of a periphery the first and second panels such that the first panel and the second panel form an envelope.    
     
     
         5 . The method of  claim 4 , wherein the second rate is an integer multiple of the first rate and the fourth rate is an integer multiple of the third rate.  
     
     
         6 . The method of  claim 4 , wherein the first gas-impermeable film and the second gas-impermeable film comprise at least one layer.  
     
     
         7 . The method of  claim 6 , wherein the at least on layer is one of polyester, polyamide, ethylene vinyl alcohol, and nylon.  
     
     
         8 . The method of  claim 4 , wherein the molten resin is polyethylene.  
     
     
         9 . The method of  claim 4 , wherein a thickness of the first inner layer is determined by the size of the first nip and the thickness of the second inner layer is determined by the size of the second nip.  
     
     
         10 . The method of  claim 4 , wherein the plurality of protuberances are a plurality of baffles.  
     
     
         11 . The method of  claim 4 , wherein the plurality of protuberances are a plurality of vessels.  
     
     
         12 . The method of  claim 4 , wherein the plurality of protuberances are a plurality of catches.  
     
     
         13 . A method of manufacturing a bag adapted to receive an article, comprising: 
 rotating a first roller having a plurality of recesses that can define a plurality of receptacles;    rotating a second roller adjacent to the first roller, said second roller can feed a first film adjacent to the first roller;    applying a molten material between the first roller and the film;    said molten material filling the recesses of the first roller, and said molten material and film moving between the first roller and the second roller forming a first panel with a plurality of receptacles;    forming a second panel; and    mating the first panel to the second panel in order to form a bag.    
     
     
         14 . The method of  claim 13  including: 
 using a gas impermeable material for the film; and    using a heat sealable material for the molten material.    
     
     
         15 . The method of  claim 13 , wherein forming the plurality of receptacles forms a plurality of baffles.  
     
     
         16 . The method of  claim 13 , wherein forming the plurality of receptacles forms a plurality of vessels.  
     
     
         17 . The method of  claim 13 , wherein forming the plurality of receptacles forms a plurality of catches.  
     
     
         18 . The method of  claim 13 , wherein said second panel is formed with the first roller and the second roller.  
     
     
         19 . The method of  claim 13 , wherein said second panel is formed with the first roller and the second roller, and the mating step includes folding the first panel over the second panel.  
     
     
         20 . The method of  claim 13 , wherein said first roller includes a peripheral surface having a first portion including the plurality of recesses for defining a plurality of receptacles and a second portion without a plurality of recesses.  
     
     
         21 . The method of  claim 13 , wherein the first roller includes another plurality of recesses that can be filled with the molten material to form channels that run the length of the film.  
     
     
         22 . The method of  claim 13  including forming the receptacles in part with walls that run parallel to the length of the film and in part with walls that run across the length of the firm.  
     
     
         23 . The method of  claim 13  including forming the receptacle from the plurality of recesses with some of the plurality of recesses running the parallel to the length of the film and some of the plurality of recesses running across the length of the firm.  
     
     
         24 . The method of  claim 13  including forming the receptacles from the plurality of recesses with some of the plurality of recesses running in about the direction of rotation of a peripheral surface of the first roller and some of the recesses running in about a direction across the direction of rotation of the peripheral surface.  
     
     
         25 . The method of  claim 13 , wherein forming the plurality of receptacles forms U shaped receptacles.  
     
     
         26 . The method of  claim 13 , wherein forming the plurality of receptacles forms V shaped receptacles.  
     
     
         27 . The method of  claim 13 , wherein forming the plurality of receptacles forms L shaped receptacles.  
     
     
         28 . The method of  claim 13 , wherein forming the plurality of receptacles forms a plurality of liquid trapping shapes.  
     
     
         29 . The method of  claim 13 , wherein a passage is formed the plurality of receptacles such that gas flows through the passage.