Method for preparing air channel-equipped film for use in vacuum package

Abstract

Disclosed is a method for preparing an air channel-equipped film for use in vacuum packages, which comprises the step of providing a gas-impermeable base, along with a melt-extruded heat-sealable resin, to a laminating unit consisting of a laminating roll and a cooling roll, to form a heat-sealable resin layer on the gas-impermeable base, characterized in that the heat-sealable resin is molded and quenched in such a way that a plurality of protrusions, corresponding to a plurality of grooves formed in a predetermined pattern on the circumferential surface of the cooling roll, are formed on the molded heat-sealable resin layer, defining channels for the evacuation of air therebetween. The method is simple because of its ability to form air channels without the aid of additional embossing-techniques, as well as being economically favorable owing to the employment of no embossing molds.

1 - 8 . (canceled)  
   
   
       9 . An apparatus for manufacturing a multi-layer film for use in vacuum packaging applications, said multi-layer film including an inner layer having a plurality of grooves which operate to form channels suitable for evacuation of gas when said multi-layer film is used in the creation of a vacuum packaging bag, said apparatus comprising: 
 an extruder for extruding a first material suitable for forming said inner layer of said multi-layer film, said first material capable of forming a substantially vacuum safe seal under sealing conditions present in typical vacuum packaging applications; and    a cooling roll positioned with respect to said extruder such that said extruder applies said first material onto a circumferential surface of said cooling roll, said cooling roll formed having a pattern on said circumferential surface of said cooling roll which gives shape to said plurality of grooves on said inner layer, said plurality of grooves tending to improve over a substantially flat surface an evacuation of gas in typical vacuum packaging applications.    
   
   
       10 . An apparatus as recited in  claim 9 , wherein said extruder is a melt-extrusion extruder.  
   
   
       11 . An apparatus as recited in  claim 9 , wherein said extruder further includes a nozzle arranged to apply said first material onto said circumferential surface of said cooling roll.  
   
   
       12 . An apparatus as recited in  claim 9 , wherein said extruder is a single layer extruder.  
   
   
       13 . An apparatus as recited in  claim 9 , wherein said first material is a heat-sealable resin and said apparatus further includes a source of said heat-sealable resin coupled to said extruder.  
   
   
       14 . An apparatus as recited in  claim 9 , wherein said pattern on said circumferential surface of said cooling roll is an uneven pattern.  
   
   
       15 . An apparatus as recited in  claim 9 , wherein said pattern on said circumferential surface of said cooling roll is a wave pattern.  
   
   
       16 . An apparatus as recited in  claim 9 , wherein said pattern on said circumferential surface of said cooling roll is a striped pattern.  
   
   
       17 . An apparatus as recited in  claim 9 , wherein said cooling roll includes steel.  
   
   
       18 . An apparatus as recited in  claim 9 , said apparatus further comprising a temperature controller for controlling a temperature of said cooling roll in order to properly effectuate cooling and formation of said first material into said patterned inner layer.  
   
   
       19 . An apparatus as recited in  claim 9  further comprising a laminating roll arranged to assist in holding said first material onto said cooling roll.  
   
   
       20 . An apparatus as recited in  claim 19 , wherein said laminating roll includes rubber.  
   
   
       21 . An apparatus as recited in  claim 19 , wherein a cooling roll diameter is about 1.5 to 3 times larger than a laminating roll diameter.  
   
   
       22 . An apparatus as recited in  claim 19  wherein said extruder, cooling roll, and laminating roll are arranged to accept an outer layer in conjunction with said extruded first material, such that said inner layer and said outer layer are laminated in between the cooling roll and the laminating roll to form said multi-layer film.  
   
   
       23 . An apparatus for manufacturing a multi-layer film for use in vacuum packaging applications, said multi-layer film including an inner layer having a plurality of grooves which operate to form channels suitable for evacuation of gas when said multi-layer film is used in the creation of a vacuum packaging bag, said apparatus comprising: 
 a single layer heat-extruder having a nozzle for melt extruding a heat-sealable resin suitable for forming said inner layer of said multi-layer film;    a cooling roll positioned with respect to said extruder nozzle such that said extruder applies said heat-sealable resin onto a circumferential surface of said cooling roll, said cooling roll formed having a pattern on said circumferential surface of said cooling roll which gives shape to said plurality of grooves on said inner layer, said cooling roll including steel;    a temperature controller for controlling a temperature of said cooling roll in order to properly effectuate cooling and formation of said heat-sealable resin into said grooved inner layer;    a laminating roll arranged to assist in holding said first material onto said cooling roll, said laminating roll having a diameter smaller than a diameter of said cooling roll; and    wherein said extruder, cooling roll, and laminating roll are arranged to accept an outer layer in conjunction with said extruded first material, such that said inner layer and said outer layer are laminated in between the cooling roll and the laminating roll to form said multi-layer film.    
   
   
       24 . An apparatus for manufacturing vacuum packaging bag material, said apparatus comprising: 
 at least one apparatus for manufacturing a multi-layer film, said multi-layer film including an inner layer having a plurality of grooves which operate to form channels suitable for evacuation of gas when said multi-layer film is used in the creation of a vacuum packaging bag, said at least one apparatus including: 
 an extruder for extruding a first material suitable for forming said inner layer of said multi-layer film, said first material capable of forming a substantially vacuum safe seal under sealing conditions present in typical vacuum packaging applications;  
 a cooling roll positioned with respect to said extruder such that said extruder applies said first material onto a circumferential surface of said cooling roll, said cooling roll formed having a pattern on said circumferential surface of said cooling roll which gives shape to said plurality of grooves on said inner layer, said plurality of grooves tending to improve over a substantially flat surface an evacuation of gas in typical vacuum packaging applications;  
   a device for merging two sheets of said multi-layer film into said vacuum packaging bag material by heat-sealing heat sealing opposing outer edges of said two sheets of said multi-layer film.    
   
   
       25 . An apparatus as recited in  claim 24 , further comprising a device for cutting said vacuum packaging bag material into multiple blanks each sealed on opposing outer edges.  
   
   
       26 . An apparatus as recited in  claim 25 , further comprising a device for sealing a third edge of each of said multiple blanks, whereby each blank becomes a vacuum packaging bag sealed on three sides with an opening for insertion of product and for evacuation.  
   
   
       27 . An apparatus as recited in  claim 24 , further comprising a device for forming a roll of bag material from said vacuum packaging bag material.