Package such as a bag with oriented tear opening

Abstract

A package forming a container with two side walls, a base and a top opening, the container being made from a hand tearable material, and having an incipient tear tab for first opening of the package once it is filled and sealed. Each side wall has at least a first stiffening element locally reinforcing the material, the stiffening element being selected such that the propagation energy of the incipient tear tab is lower than the rupture energy of the stiffening element. Each side wall includes means for guiding the incipient tear tab on first opening, with the incipient tear tab located between the first stiffening element and the guide means, so that the tear tab is guided.

1 . Packaging of a product ( 8 ), typically in the form of a bag, forming a container ( 1 ) comprising two sidewalls ( 2 ,  2 ′), a bottom ( 17 ) and a filling opening ( 13 ), that can be closed after the product ( 8 ) has been packaged in the said packaging, the said container ( 1 ) being formed from a hand tearable material ( 7 ) typically made of a plastic strip, and comprising a first opening area ( 15 ) containing a tear starting point ( 4 ) typically formed on one edge ( 3 ,  14 ) of the said container ( 1 ) in order to open the said packaging for the first time after it has been filled and sealed, the said edge ( 3 ,  14 ) typically being formed by sealing the edges of the two sidewalls ( 2 ,  2 ′), and characterised in that, in the said first opening area: 
 a) each sidewall ( 2 ,  2 ′) comprises at least one first stiffening element ( 5 ,  50 ,  51 ,  52 ,  53 ,  54 ) locally reinforcing the said side wall, typically facing the other and, with the associated said sidewall, forming a main barrier ( 5 ′) to the said typically continuous tear, the said stiffening element being chosen such that the propagation energy of the said tear is less than the rupture energy of the said main barrier, such that the said main barrier ( 5 ′) forms a partition line in the said package, with a top part ( 11 ) that will be completely or partly torn during the said first opening, and a lower part ( 12 ) that will act as a container for the said product ( 8 ),    b) the said tear starting point ( 4 ) is wholly or partly located in the said upper part ( 11 ) and at a distance from the said first stiffening element typically less than 10 mm,    c) each sidewall ( 2 ,  2 ′) comprises a means ( 6 ,  60 ,  61 ) of guiding the said tear during the said first opening, such that the said tear cannot separate from the said stiffening element by more than 20 mm,    d) the said guide means ( 6 ) is formed by: 
 d1) a choice of a strip material ( 7 ,  60 ) oriented in a direction symbolically denoted “O=>”, the propagation energy of the tear in the said direction typically being 1.5 times less than in a perpendicular direction,  
 d2) a relative orientation of the said “O=>” direction with respect to the orientation of the said partition line formed by the said first stiffening element, such that the tear propagates along the said partition line of the said package.  
   
     
     
         2 . Packaging according to  claim 1 , in which the said guide means of the said partition line and the said direction forms an angle α typically between 0 and 45°, and in which the said package includes one or two tear starting points ( 4 ), themselves possibly forming an acute angle oriented towards the said partition line.  
     
     
         3 . Packaging according to  claim 1  in which the said guide means ( 6 ) includes a second stiffening element ( 61 ) on each sidewall ( 2 ,  2 ′) and typically in parallel, forming a secondary barrier to the tear, typically parallel to the said first stiffening element forming the said main barrier, the said tear starting point being located between the said main and secondary barriers so as to maintain the said tear between the said first stiffening element and the said second stiffening element during the said first opening.  
     
     
         4 . Packaging according to  claim 3  in which the said main and secondary barriers are identical, continuous, parallel and separated by a distance typically varying from 1 to 20 mm, and preferably from 2 to 10 mm, the said main and secondary barriers possibly forming a thread ( 50 ), a striplet ( 52 ) or a label ( 55 ) fixed to the said face and having a line of weakness ( 520 ,  550 ) typically obtained by making a preliminary mechanical cut or a laser cut, the said striplet or label on one face ( 2 ) facing the said striplet on the other face ( 2 ′).  
     
     
         5 . Packaging according to  claim 1  in which the said partition line is a line forming a complete separation between the said upper part ( 11 ) and lower part ( 12 ).  
     
     
         6 . Packaging according to  claim 5  in which the said partition line is a transverse line, so as to ensure that the said bag can be fully opened.  
     
     
         7 . Packaging according to  claim 1  in which the nature, mechanical characteristics or thickness of the said first stiffening element ( 5 ,  50 ,  51 ,  52 ,  54 ,  55 ) forming the said barrier is chosen such that the propagation energy of the said tear is typically at least 20% higher at the crossing of the said main barrier ( 5 ′) than in the strip material ( 7 ) without the stiffening element.  
     
     
         8 . Packaging according to  claim 7  in which the said stiffening element is formed by the incorporation of an add-on element, typically a thread or wire ( 50 ) or a striplet ( 51 ) fixed to the said sidewalls ( 2 ,  2 ′).  
     
     
         9 . Packaging according to  claim 8  in which the said thread or wire ( 50 ) is a textile thread made of a natural, artificial or synthetic material, or a metallic wire, the said thread or wire having a breaking strength equal to at least 0.5 N.  
     
     
         10 . Packaging according to  claim 8  in which the said striplet ( 51 ) is a paper or metal striplet, or a single layer or multilayer plastic striplet, possibly printed.  
     
     
         11 . Packaging according to  claim 1  in which the said first stiffening element forming the said barrier is composed of a pattern in relief ( 53 ) typically obtained by local deposition of material, for example by printing, so as to form a relief with a thickness typically between 20 and 200 μm, and thus locally increase the thickness of the said strip material by at least 20%.  
     
     
         12 . Packaging according to  claim 1  in which the said first stiffening element is composed of an overthickness ( 54 ) of the material forming the said face ( 2 ,  2 ′) typically formed by punching or extrusion of the said material.  
     
     
         13 . Packaging according to  claim 1  in which the said strip material ( 7 ) is a multilayer material, the said first stiffening element ( 5 ,  50 ,  51 ) being inserted between two layers ( 70 ) of the said multilayer material, the two layers possibly being different or identical.  
     
     
         14 . Packaging according to  claim 13  in which the said strip material ( 7 ) comprises at least one extruded thermoplastic layer ( 70 ) or at least two coextruded thermoplastic layers ( 70 ), or at least two layers ( 70 ) made of a complexed strip material, the said stiffening element typically being oriented in the “machine” direction MD of the strip material ( 70 ).  
     
     
         15 . Packaging according to  claim 1  formed either from two strip materials ( 7 ) that may be identical or different, by cutting the two materials into strips, each forming a sidewall ( 2 ,  2 ′) of the said packaging, and sealing of the edges to form an edge ( 3 ), or from a single strip material by folding, sealing and cutting, one side of the said packaging forming a fold ( 15 ).  
     
     
         16 . Packaging according to  claim 13  in which the said sealing is typically heat sealing consisting of compression of the edges, particularly such that each end of the said stiffening element ( 5 ,  50 ,  51 ) is coated by the said strip material ( 7 ) by local creep of the said strip material.  
     
     
         17 . Packaging according to  claim 1  in which the said strip material ( 7 ) is chosen from among, or includes, one or several of the following materials: paper, metallic sheet typically made of aluminium, film or a layer of PET, PA, PP, PE in one or two directions, possibly metallised, the said material being between 20 and 200 μm thick, the said strip material being a material with 1 to 5 layers ( 70 ).  
     
     
         18 . Packaging according to  claim 1  comprising an add-on bottom ( 18 ), so that a package can be obtained with an upright station.  
     
     
         19 . Packaging according to  claim 1  in which the said first stiffening element ( 5 ) is typically metallic, and its characteristics are chosen to enable detection of the said packaging, or reclosing it after the said first opening.  
     
     
         20 . Packaging according to  claim 1  composed of a bag, typically with rectangular faces ( 2 ,  2 ′) made from a multi-layer material typically with 2 to 4 layers, the said first stiffening element of each face ( 2 ,  2 ′) facing the other element and being composed of a textile thread, typically made of PET or PA parallel to the said opening ( 13 ), and typically at a distance from this said edge equal to between 1 and 50 mm, and preferably between 5 mm and 30 mm, so that the said upper part ( 11 ) has a relatively small surface area compared with the lower part, typically less than 0.2 times the surface area of the said lower part.  
     
     
         21 . Packaging according to  claim 1  in which the said first stiffening element is located on the inner and/or outer face of the said wall ( 2 ,  2 ′).  
     
     
         22 . Packaging according to  claim 1  in which the said first stiffening element consists of or includes a striplet ( 51 ,  52 ) forming a typically extruded profile.  
     
     
         23 . Packaging according to  claim 22  in which the said striplet ( 51 ,  52 ) also includes a closing means, the striplet on one face typically comprising a closing element cooperating with a complementary closing element facing it on the other side, the said closing means typically being of the “ZIP” type located below the said first stiffening element in the said lower part ( 12 ).  
     
     
         24 . Packaging according to  claim 1  comprising a closing means, one face ( 2 ) typically including a closing element cooperating with a complementary closing element facing it on the other side ( 2 ′), the said closing means typically being of the “ZIP” type located below the said first stiffening element in the said lower part ( 12 ).  
     
     
         25 . Process for manufacturing a packaging according to  claim 1  in which: 
 a) all or part of the strip material ( 7 ) is formed by extrusion or coextrusion, complexing or gluing onto a backing, in which the said first stiffening element ( 5 ,  50 ,  51 ) and if applicable the said second stiffening element ( 61 ) is solidarised during the said extrusion or coextrusion, complexing or gluing onto a backing, to this material, the said first stiffening element and possibly the said second stiffening element typically being supplied and unwound along the machine direction MD of the material strip ( 7 ) and moved forwards by the forwards movement of the said extruded or coextruded, complexed or glued strip material ( 7 ),    b) the said container ( 1 ) is typically formed by forming a sealed edge ( 3 ) of the faces ( 2 ,  2 ′) formed from two material strips ( 7 )) or from a single strip forming a fold, and possibly forming the said tear starting point ( 4 ), and cutting out the said container.    
     
     
         26 . Process for manufacturing a packaging according to  claim 1  in which: 
 a) the said strip material ( 7 ) and the said first stiffening element ( 5 ), and possibly the said second stiffening element ( 6 ) are supplied,    b) and the said container ( 1 ) is then formed typically by forming a sealed edge ( 3 ) of the faces ( 2 ,  2 ′) formed starting from two material strips ( 7 ) or starting from a single strip forming a fold, possibly forming the said tear starting point ( 4 ) and cutting the said container, the said stiffening element and possibly the said second stiffening element being solidarised to the said container typically by welding or gluing, on the outside or inside of the said packaging, during formation of the said container.    
     
     
         27 . Process for manufacturing a package according to  claim 1  in which: 
 a) the said strip material ( 7 ) is supplied, and the said first stiffening element is applied or formed typically in a clearly marked manner on the said strip material,    b) the said container ( 1 ) is then formed, typically by forming a sealed edge ( 3 ) of the faces ( 2 ,  2 ′) formed starting from two material strips ( 7 ) or from a single strip by folding, possibly forming the said tear starting point ( 4 ) and cutting out the said container.    
     
     
         28 . Process according to  claim 25  in which the said first stiffening element ( 5 ), and possibly the said second stiffening element ( 61 ) is (are) coated typically with glue or adhesive such that it (they) is (are) inseparably fixed to the said strip material ( 7 ).  
     
     
         29 . Process according to  claim 25  in which the said first stiffening element ( 5 ) and the said second stiffening element ( 61 ) are identical and are formed simultaneously, in which case the strip material ( 7 ) may or may not be oriented.  
     
     
         30 . Process according to  claim 25  in which the said strip material ( 7 ) is chosen from among the following multilayer materials: PET/PP, PET/Al/PP, PET/Al/OPA/PP, PET/Al/PE, PET/Al/OPA/PE, PET/OPA/Al/PP, PET/OPA/Al/PE, PET/PE, OPP/PE, OPP/PP, OPP/OPP, OPA/PP, OPA/PE.  
     
     
         31 . Process according to  claim 25  in which the said strip material is supplied, and after the said container has been formed, the said product ( 8 ) is packaged in the said container and the said packaging can be closed, typically before forming the said tear starting point ( 4 ) and cutting out the said container, so as to use the so-called FFS (Form-Fill-Seal) process.  
     
     
         32 . Process according to  claim 31  in which the said supplied strip material includes the said first stiffening element ( 5 ) oriented along the transverse direction TD, perpendicular to the machine direction MD of unwinding of the said strip material.  
     
     
         33 . Process according to  claim 31  in which the said supplied strip material does not include the said first stiffening element ( 5 ), and in which the said first stiffening element ( 5 ) is formed or applied when using the said FFS process.  
     
     
         34 . Process according to  claim 26  in which the said first stiffening element ( 5 ) is a striplet applied to the inside of the said container.  
     
     
         35 . Strip material or film intended for use with the process according to  claim 25  comprising the said first stiffening element ( 5 ) and possibly the said guide means, the said first stiffening element ( 5 ) and possibly the said guide means being oriented in the machine direction MD or in the transverse direction TD.