Method and apparatus for packaging articles with a film of plastic material and a package thus obtained

Abstract

According to a method for packaging articles with a film of plastic material, a band of plastic film ( 6 ) is supplied to conveying means ( 5 ), while a strip of glue ( 18 ) is applied along a longitudinal edge of the band of plastic film ( 6 ) and zones of glue ( 19 ), regularly spaced apart, are applied crosswise to the band of plastic film ( 6 ). A series of articles ( 2 ) to be packaged are supplied to the conveying means ( 5 ), above the band of plastic film ( 6 ) in positions between the transversal zones of glue ( 19 ) and then the longitudinal edges of the band of plastic film ( 6 ) are folded to form a tube around the articles ( 2 ), so as to overlap the edges of the band of plastic film ( 6 ). The edges of the band of plastic film ( 6 ) are pressed to stabilize joining and the transversal zones of glue ( 19 ) are also pressed while cutting at the same time the band of plastic film ( 6 ) crosswise in portions located between the transversal zones of glue ( 19 ), in order to obtain single packages of articles ( 2 ).

1 . A method for packaging articles with a film of plastic material, characterized in that it includes the following steps: 
 continuous feeding of a band of plastic film ( 6 ) to conveying means ( 5 ),    application of at least one strip of glue ( 18 ) along a longitudinal edge of said band of plastic film ( 6 );    application of at least one series of zones of glue ( 19 ), regularly spaced apart, crosswise to said band of plastic film ( 6 );    orderly transferring of a series of articles ( 2 ) to be packaged to said conveying means ( 5 ), above said band of plastic film ( 6 ) supplied to the same conveying means ( 5 ), respectively in positions delimited between said transversal zones of glue ( 19 );    folding of longitudinal edges of said band of plastic film ( 6 ) over said articles to assume a tubular form around the articles ( 2 ) being packaged overlapping said longitudinal edges of said band of plastic film ( 6 ), with said longitudinal strip of glue ( 18 ) remaining between said opposite edges of the band ( 6 );    joining said edges of the band of plastic film ( 6 ) along said longitudinal strip of glue ( 18 ) and said transversal zones of glue ( 19 );    crosswise cutting of said band of plastic film ( 6 ) at the portions situated between said transversal zones of glue ( 19 ), in order to obtain single packages of articles ( 2 ).    
   
   
       2 . A method as claimed in  claim 1 , characterized in that said longitudinal strip of glue ( 18 ) and said transversal zones of glue ( 19 ) are applied to the same side of said band of plastic film ( 6 ).  
   
   
       3 . A method as claimed in  claim 2 , characterized in that said longitudinal strip of glue ( 18 ) and said transversal zones of glue ( 19 ) are applied to this side of said band of plastic film ( 6 ), which is to be turned to the inside of the package of articles ( 2 ).  
   
   
       4 . A method as claimed in  claim 1 , characterized in that said longitudinal strip of glue ( 18 ) is applied continuously along one of said longitudinal edges of said band of plastic film ( 6 ).  
   
   
       5 . A method as claimed in  claim 1 , characterized in that said longitudinal strip of glue ( 18 ) and said transversal zones of glue ( 19 ) are applied to said band of plastic film ( 6 ) in a station (C) situated upstream of an area, where the articles ( 2 ) to be packaged enter said conveying means ( 5 ).  
   
   
       6 . An apparatus for packaging articles with a film of plastic material, characterized in that it includes: 
 conveying means ( 5 ), on which a band of plastic film ( 6 ) is fed continuously;    a glue application station (C), where a suitable glue is applied;    first glue applying means ( 8 ), located at said glue application station for applying at least one strip of glue ( 18 ) along a longitudinal edge of said band of plastic film ( 6 );    second glue applying means ( 9 ), located at said glue application station for applying at least one series of crosswise zones of glue ( 19 ), regularly spaced apart to the band of plastic film ( 6 );    stationary folding means ( 10 ) for folding longitudinal edges of said band of plastic film ( 6 ) over said articles to assume tubular form around the articles ( 2 ) being packaged and moving along the conveying means ( 5 ), with the longitudinal edges of said band of plastic film ( 6 ) overlapped so that said longitudinal strip of glue ( 18 ) remains between said opposite longitudinal edges of the band ( 6 );    means ( 11 , 13 ) for stabilizing a joining of said longitudinal edges of said band of plastic film ( 6 ) along said longitudinal strip of glue ( 18 ) and said transversal zones of glue ( 19 );    means ( 12 ) for cutting crosswise said band of plastic film ( 6 ) at portions located between said transversal zones of glue ( 19 ), in order to obtain single packages of articles ( 2 ).    
   
   
       7 . An apparatus as claimed in  claim 6 , characterized in that said means for crosswise cutting said band of plastic film ( 6 ) include a pair of counter-rotating rollers ( 13 A,  13 B), at least one of which carries a radial blade ( 50 ), and two presser elements ( 60 A,  60 B), situated on both sides of the blade ( 50 ) for compressing adjacent portions ( 19 A,  19 B) of a transversal zone of glue ( 19 ) in step relation to cutting, by said blade ( 50 ), of the transversal strip ( 19 ) in order to separate the two portions ( 19 A,  19 B).  
   
   
       8 . A package obtained by the method of  claim 1 , including an article wrapped in a sheet ( 6 ) of plastic material having crosswise ends ( 19 A,  19 B) closed by strips of glue ( 19 ) and longitudinal edges of the sheet also joined to each other by means of a strip of glue ( 18 ).  
   
   
       9 . A package as in  claim 8 , wherein a strip of glue ( 19 ) is present at each crosswise end ( 19 A,  19 B) between the upper and lower portions of the sheet ( 6 ) wrapped in tubular form around the article.  
   
   
       10 . A package as in  claim 8 , wherein a strip of glue ( 18 ) is present between longitudinal overlapped edges of sheet ( 6 ) wrapped in tubular form around the article.