Apparatus for packaging products in vacuum or in a modified atmosphere

Abstract

An apparatus for packaging products in vacuum or in a modified atmosphere, comprising: a first conveyor belt, which is adapted to convey at least one product to be packaged; first transport rollers, which are arranged downstream of the first conveyor belt and are adapted to transport an upper film and a lower film which are separate and are adapted to form a packaging pouch for the at least one product; a first heat-sealing bar, which is arranged downstream of the first transport rollers and is adapted to heat-seal the packaging pouch at its leading and trailing ends; a vacuum generation bell, which has a plurality of second heat-sealing bars which are adapted to heat-seal the longer sides of the pouch for packaging the at least one product, and is further provided with a conveyor belt which is adapted to convey the at least one product through the bell; and a further conveyor belt, which is arranged at the output of the bell.

What is claimed is:  
     
         1 . An apparatus for packaging products in vacuum or in a modified atmosphere, comprising: 
 a first conveyor belt, which is adapted to convey at least one product to be packaged;    first transport rollers, which are arranged downstream of said first conveyor belt and are adapted to transport an upper film and a lower film which are separate and are adapted to form a packaging pouch for said at least one product;    a first heat-sealing bar, which is arranged downstream of said first transport rollers and is adapted to heat-seal said packaging pouch at the leading and trailing ends;    a vacuum generation bell, which has a plurality of second heat-sealing bars which are adapted to heat-seal the longer sides of the pouch for packaging said at least one product, and is further provided with a conveyor belt which is adapted to convey said at least one product through said bell; and    a further conveyor belt, which is arranged at the output of said bell.    
     
     
         2 . The apparatus according to    claim 1   , comprising an additional conveyor belt which is arranged downstream of said first heat-sealing bar and upstream of said bell.  
     
     
         3 . The apparatus according to    claim 2   , wherein said additional conveyor belt arranged between said first heat-sealing bar and said bell is driven by second transport rollers.  
     
     
         4 . The apparatus according to    claim 1   , wherein said first heat-sealing bar is contoured, with recesses which are adapted to form leading and trailing heat-seals for said pouch.  
     
     
         5 . The apparatus according to    claim 4   , wherein said recesses of said first heat-sealing bar have sharp edges.  
     
     
         6 . The apparatus according to    claim 4   , wherein said recesses of said first heat-sealing bar are rounded with curved blending portions.  
     
     
         7 . The apparatus according to    claim 1   , wherein said first heat-sealing bar is arranged transversely to an advancement direction of said at least one product to be packaged.  
     
     
         8 . The apparatus according to    claim 1   , wherein said second heat-sealing bars are arranged longitudinally along an advancement direction of said at least one product to be packaged.  
     
     
         9 . The apparatus according to    claim 1   , wherein third transport rollers are provided at the output of said bell.  
     
     
         10 . The apparatus according to    claim 1   , wherein said bell comprises an upper portion which is adapted to couple to a lower portion which is peripherally provided with gas injection nozzles adapted to inject gas into a partially formed pouch that passes through said bell.  
     
     
         11 . A method for packaging products in vacuum or in a modified atmosphere, comprising the steps of: 
 unwinding from respective reels an upper film and a lower film which are adapted to constitute at least one packaging pouch for at least one product;    inserting said at least one product between said upper film and said lower film, after heat-sealing a leading side of the pouch to be formed;    heat-sealing a trailing side of said pouch and inserting said pouch in a vacuum forming bell;    generating a vacuum in said bell and sealing longer sides of said pouch;    opening said bell and expelling a packaged product, eliminating the waste of said upper film and of said lower film.    
     
     
         12 . The method according to    claim 11   , wherein the steps of heat-sealing the leading and trailing sides of said pouch are provided by means of a first contoured heat-sealing bar.  
     
     
         13 . The method according to    claim 11   , further comprising the step of: 
 introducing gas in said pouch, when said pouch is inside said bell.    
     
     
         14 . The method according to    claim 13   , comprising the step of returning the pressure in said bell to an atmospheric value after said gas has been injected into said pouch.  
     
     
         15 . The method according to    claim 11   , wherein said steps of heat-sealing said leading and trailing sides of said pouch comprise cutting, simultaneously with the heat-sealing operation, excess portions of the upper and lower films.  
     
     
         16 . The method according to    claim 11   , wherein said upper film and said lower film are unwound from separate reels and are transported by first transport rollers, said at least one product to be packaged being inserted between said first transport rollers.