Packaging an article with a packaging sheet including a longitudinal fin seal and a transverse tear strip

Abstract

In packaging of articles such as chocolate bars the articles are wrapped on a packaging line by a respective one of sheet portions of a continuous packaging sheet in turn such that the longitudinally extending side edges are brought together and are sealed by a cold seal material together to form a sealed longitudinal fin seal along the article and ends of the sheet portions at each end of the article are sealed to enclose the article. The sheet portions are than severed each from the next to separate the wrapped articles. An improved tear strip is disclosed extending transversely across the sheet portion from a position at or adjacent the first side edge to a position at or adjacent the second side edge for guiding the tearing action of the sheet portion transversely when pulled. The tear strip is formed by applying, during the printing of the wrapping material for supply to the line, a band of a hot melt liquid material and causing the liquid material to set or harden and to bond to the surface with sufficient strength to guide the tearing action of the sheet portion in the transverse direction. The tear strip is arranged on the sheet inwardly of the fin seal such that the tearing action is commenced by a tab formed between notches in the fin and is guided in the sheet by the tear strip.

I claim:  
     
         1 . A method of packaging articles comprising: 
 providing a plurality of the articles to be wrapped in a packaging line;    forming a supply roll containing an elongate sheet of packaging material for wrapping the articles, the sheet having first and second longitudinally extending transversely spaced side edges and being defined by sheet portions arranged end to end along the sheet;    providing the supply roll of the sheet at the packaging line;    withdrawing the sheet from the supply roll such that the sheet extends longitudinally of the packaging line;    wrapping each article in the packaging line by a respective one of the sheet portions of the packaging sheet in turn such that the longitudinally extending side edges are brought together and are sealed together to form a sealed longitudinal fin seal along the article;    sealing together ends of the sheet portions at each end of the article to enclose the article;    transversely severing the sheet portions each from the next to separate the wrapped articles;    and providing on each sheet portion a tear strip extending transversely across the sheet portion from a position at or adjacent the first side edge to a position at or adjacent the second side edge for guiding the tearing action of the sheet portion transversely when pulled;    wherein the tear strip is formed by applying onto a surface of each sheet portion a band of a liquid material and causing the liquid material to set or harden and to bond to the surface;    and wherein the tear strip when set or hardened is arranged to have sufficient strength to guide the tearing action of the sheet portion in the transverse direction.    
     
     
         2 . The method according to  claim 1  wherein the band of liquid material is applied on the inner surface.  
     
     
         3 . The method according to  claim 1  wherein the band of liquid material is applied by printing, for example by a gravure roller.  
     
     
         4 . The method according to  claim 1  wherein the band of liquid material is applied by spraying.  
     
     
         5 . The method according to  claim 1  wherein the liquid material is a hot melt.  
     
     
         6 . The method according to  claim 1  wherein the tear strip is applied prior to forming the sheet into the supply roll.  
     
     
         7 . The method according to  claim 1  wherein the outside surface of the sheet has printed thereon indicia relating to the article and wherein the liquid material is applied on a printing press with the printing on the outside surface of the package.  
     
     
         8 . The method according to  claim 1  wherein the inner surface at each of the first and second side edges carries a band of a sealing material and wherein the tear strip is applied between at least one of the bands of sealing material and the inner surface so as to be covered by the band of sealing material and so as to allow direct contact and sealing between the bands of sealing material when wrapped around the article.  
     
     
         9 . The method according to  claim 8  wherein the outside surface of the sheet has printed thereon indicia relating to the article and wherein the band of liquid material and the bands of sealing material are applied on a printing press with the printing on the outside surface.  
     
     
         10 . The method according to  claim 1  wherein the bands of sealing material are formed from a cold seal material.  
     
     
         11 . The method according to  claim 1  wherein the liquid material when set or hardened has a thickness less than 0.002 inch so as avoid interfering with forming the sheet into the supply roll.  
     
     
         12 . The method according to  claim 1  including providing tearing notches on each side of strip in each of the first and second side edges.  
     
     
         13 . The method according to  claim 12  wherein the notches are cut in the fin seal after it is formed.  
     
     
         14 . The method according to  claim 12  where the notches in each of the first and second side edges are formed in the sheet prior to forming the sheet into the supply roll and are arranged so that when wrapped around the article, the notches in the first and second side edges are aligned  
     
     
         15 . The method according to  claim 12  wherein the tear strip is arranged on the sheet inwardly of the fin seal such that the tearing action is commenced by a tab formed between the notches and is guided in the sheet by the tear strip.  
     
     
         16 . The method according to  claim 1  wherein the tear strip extends to the first side edge and terminates short of the second side edge.  
     
     
         17 . The method according to  claim 8  wherein the tear strip extends from the first side edge and terminates at the edge of or short of the band of sealing material at the second side edge.  
     
     
         18 . A method of packaging articles comprising: 
 providing a plurality of the articles to be wrapped in a packaging line;    forming a supply roll containing an elongate sheet of packaging material for wrapping the articles, the sheet having first and second longitudinally extending transversely spaced side edges and being defined by sheet portions arranged end to end along the sheet;    providing the supply roll of the sheet at the packaging line;    withdrawing the sheet from the supply roll such that the sheet extends longitudinally of the packaging line;    wrapping each article in the packaging line by a respective one of the sheet portions of the packaging sheet in turn such that the longitudinally extending side edges are brought together and are sealed together to form a sealed longitudinal fin seal along the article;    sealing together ends of the sheet portions at each end of the article to enclose the article;    transversely severing the sheet portions each from the next to separate the wrapped articles;    and providing on each sheet portion a tear strip extending transversely across the sheet portion from a position at or adjacent the first side edge to a position at or adjacent the second side edge for guiding the tearing action of the sheet portion transversely when pulled;    wherein the tear strips for each of the sheet portions are applied to the sheet prior to forming the sheet into the supply roll so as to be carried by the supply roll for supplying to the packaging line.    
     
     
         19 . The method according to  claim 18  wherein the outside surface of the sheet has printed thereon indicia relating to the article and wherein the tear strip is applied on a printing press with the printing on the outside surface of the package.  
     
     
         20 . The method according to  claim 18  wherein the tear strip is applied on the inner surface.  
     
     
         21 . The method according to  claim 18  wherein the inner surface at each of the first and second side edges carries a band of a sealing material and wherein the tear strip is applied between at least one of the bands of sealing material and the inner surface so as to be covered by the band of sealing material and so as to allow direct contact and sealing between the bands of sealing material.  
     
     
         22 . The method according to  claim 21  wherein the outside surface of the sheet has printed thereon indicia relating to the article and wherein the tear strips and the bands are applied on a printing press with the printing on the outside surface of the package.  
     
     
         23 . The method according to  claim 21  wherein the bands of sealing material are formed from a cold seal material.  
     
     
         24 . The method according to  claim 18  wherein the tear strip has a thickness less than 0.002 inch so as avoid interfering with forming the sheet into the supply roll.  
     
     
         25 . The method according to  claim 18  including providing tearing notches on each side of strip in each of the first and second side edges.  
     
     
         26 . The method according to  claim 25  wherein the notches are cut in the fin seal after it is formed.  
     
     
         27 . The method according to  claim 25  wherein the notches in each of the first and second side edges are formed in the sheet prior to forming the sheet into the supply roll and are arranged so that when wrapped, the notches in the first and second side edges are aligned  
     
     
         28 . The method according to  claim 25  wherein the tear strip is arranged on the sheet inwardly of the fin seal such that the tearing action is commenced by a tab formed between the notches and is guided in the sheet by the tear strip.  
     
     
         29 . The method according to  claim 18  wherein the tear strip extends to the first side edge and terminates short of the second side edge.  
     
     
         30 . The method according to  claim 21  wherein the tear strip extends to the first side edge and terminates short of the band of sealing material at the second side edge.  
     
     
         31 . A method of packaging articles comprising: 
 providing a plurality of the articles to be wrapped in a packaging line;    forming a supply roll containing an elongate sheet of packaging material for wrapping the articles, the sheet having first and second longitudinally extending transversely spaced side edges and being defined by sheet portions arranged end to end along the sheet;    providing the supply roll of the sheet at the packaging line;    withdrawing the sheet from the supply roll such that the sheet extends longitudinally of the packaging line;    wrapping each article in the packaging line by a respective one of the sheet portions of the packaging sheet in turn such that the longitudinally extending side edges are brought together and are sealed together to form a sealed longitudinal fin seal along the article;    sealing together ends of the sheet portions at each end of the article to enclose the article;    transversely severing the sheet portions each from the next to separate the wrapped articles;    providing along each of the first and second side edges a band of sealing material for sealing the first and second side edges together to form the fin seal;    and providing on each sheet portion a tear strip extending transversely across the sheet portion from a position at or adjacent the first side edge to a position at or adjacent the second side edge for guiding the tearing action of the sheet portion transversely when pulled;    wherein the tear strip is applied to the inner surface of the sheet portion between the inner surface and the band of sealing material at least at the first edge so as to be covered by the band of sealing material and so as to allow direct contact and sealing between the bands of sealing material.    
     
     
         32 . The method according to  claim 31  wherein the bands of sealing material are formed from a cold seal material.  
     
     
         33 . The method according to  claim 31  wherein the tear strip extends to the first side edge and terminates short of the band of sealing material at the second side edge.