US20050031232A1

US20050031232A1 - Package such as a bag with oriented tear opening

Info

Publication number: US20050031232A1
Application number: US10/495,436
Authority: US
Inventors: Jean-Claude Jammet; Stephane Mathieu
Original assignee: Soplaril SA
Current assignee: Soplaril SA
Priority date: 2001-11-28
Filing date: 2002-11-20
Publication date: 2005-02-10
Also published as: ATE359972T1; FR2832698A1; EP1458627B1; DE60219688D1; DE60219688T2; WO2003045816A3; FR2832698B1; WO2003045816A2; WO2003045816A8; AU2002364791A1; ES2286329T3; EP1458627A2

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.

Description

DOMAIN OF THE INVENTION

The invention relates to the domain of flexible packagings, typically bags. These bags are formed from single or multilayer strip materials, partly or entirely composed of plastic films.
It is particularly applicable to the opening of bags, when opening includes tearing of the strip material forming the bag, the strip material forming the bag being chosen from among hand tearable materials.

STATE OF THE ART

Commercially available bags are already known made from plastic films that can be torn during a first opening.
In general, these, bags have an opening zone typically near the top including a tear starting point or notch, typically in a “V” shape, so as to concentrate the tearing energy at a local point and thus start tearing the material from which the bag is made with a minimum manual force.
Opening of the bag requires experience in the use of a tear starting point, and such bags are usually difficult if not impossible to open by applying a manual force anywhere else than at the tear starting point, which guarantees the integrity of the bag throughout its life.
In the case of easily tearable materials, an opening method commonly called “Tircell” ®, typically composed of a striplet with mechanical properties stronger than the properties of the material to be torn, is fixed to the material to be torn, and comprising a free end at which the striplet can be pulled manually so that the said material can be torn.
Other preliminary cutting techniques are known that tend to locally weaken a material, for example by laser, in order to facilitate opening or tearing of a plastic film.
Problems that Arise
Firstly, in the case of tear-opening bags from a tear starting point, it is observed that the nature of the tear is often random.
Moreover, the tear can propagate in a given direction on one of the faces or walls of the bag, while it might propagate in a completely different direction on the other face or facing panel.
This is all very annoying, because a random propagation of the tear in the bag can purely and simply destroy the bag.
Moreover, in bag applications, there is no economic known tearable material in which the tear propagates in a predetermined manner or along a straight-line.
Furthermore, since the materials from which bags are made have increasingly high mechanical properties, a “Tircell”® type opening means would not be suitable, and in any case its production cost is relatively high. Moreover, since some existing bags may be sterilized, this opening means located outside the film to be torn would not be suitable for heat treatments such as sterilization.
Moreover, firstly the presence of a free end introduces a much greater risk of accidental opening than the presence of a tear starting point, and secondly it requires special and therefore expensive manufacturing means.
For formation of pre-cut lines, it is known firstly that they require expensive equipment, and secondly that they are difficult to use in that high precision and a uniform cut depth are necessary, and the final result may be that the material is mechanically weakened over a considerable width which can make it more difficult to maintain integrity of the packaging throughout its life.
Therefore, the applicant has attempted to find a more efficient and reliable means with greater industrial productivity to solve problems arising with the state of the art, particularly by the use of a laser.

DESCRIPTION OF THE INVENTION

According to the invention, packaging of a product, typically in the form of a bag, forms a container comprising two sidewalls, a bottom and a filling opening, that can be closed after the product has been packaged in the said packaging, the said container being formed from a hand tearable material typically made of a plastic strip, and comprising a first opening area containing a tear starting point typically formed on one edge of the said container in order to open the said packaging for the first time after it has been filled and sealed, the said edge typically being formed by sealing the edges of the two sidewalls.
This packaging is characterised in that, in the said first opening area:

- a) each side comprises at least one first stiffening element locally reinforcing the said side wall, typically facing each other and, with the associated said sidewall, forming a main barrier 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 forms a partition line in the said packaging, with a top part that will be completely or partly torn during the said first opening, and a lower part that will act as a container for the said product,
- b) the said tear starting point is wholly or partly located in the said upper part and at a distance from the said first stiffening element typically less than 10 mm,
- c) each sidewall comprises a means of guiding the said tear during the said first opening, such that the said tear cannot separate from the said first stiffening element by more than 20 mm.

This combination of means a) to c) provides a means of solving all problems arising with the state of the art.
The applicant has observed firstly that the presence of a first stiffening element can form a sort of barrier delimiting two zones (the so-called upper part and the so-called lower part) such that a tear initiated in one zone will not propagate to the other zone, while choosing higher mechanical characteristics for the stiffening element than for the material forming the packaging, particularly its resistance to tearing. Thus, since the tear is typically initiated in the upper part rather than in the lower part forming the part of the packaging containing the packaged product, this means guarantees integrity of the lower part, thus eliminating the risk of the product been spilled when the bag is opened.
Secondly, the applicant has observed that problems that arise when the bag is opened can be restricted by also using a guide means in order to “direct” the tear—the tear being formed starting from a tear starting point close to the said first stiffening element in the upper part or at the limit between the upper and lower parts—without it being necessary to assign a precisely predetermined or determined trajectory to the tear, the purpose being that the final consumer can open the bag in a single gesture and without the need for any accessory whatsoever, so as to obtain the simply required result.
As will become clear in the reminder of the description of the invention, the combination of means a) to c) may be applicable to all types of bags including sterilisable bags, the extra cost for its application being negligible or very low depending on the precise nature of the chosen stiffening element and the guide means.

DESCRIPTION OF THE FIGURES

FIGS. 1 a to 15 c relate to the invention.
FIGS. 1 a, 1 c, 1 d, 2 a, 2 c, 3 a, 4 a, 6, 9, 10 and 12 a are diagrammatic views of rectangular bags (1) with a side view of a wall (2)—to illustrate the relative position of the said stiffening element (5), the said tear starting point (4), and the presence of the said guide means (6).
FIGS. 1 a, 1 d, 2 a, 3 a, 4 a and 5 relate to bags (1) with an unsealed filling opening (13) and therefore ready to be filled, while FIGS. 1 c, 2 c, 5 and 6 relate to bags that are closed after filling, with the filling edge being sealed (14).
FIGS. 1 b, 2 b, 3 b, 3 c and 4 b show sections through sidewalls (2, 2′) of bags (1) at the said first stiffening element (5) and possibly at the said guide means (6).
FIGS. 1 a to 1 c relate to a first embodiment of the invention in which the stiffening element (5) is a thread (50), and in which the said guide means (6) is formed by the use of an oriented material (60)—symbolized by “O=>” and by the sealed edge (14).
FIG. 1 a represents the bag (1) before being filled.
FIG. 1 b is a section along A-A in FIG. 1 a.
FIG. 1 c shows the bag (1) after it has been filled and closed.
FIG. 1 d, corresponding to FIG. 1 a, shows the bag (1) in which the filling opening (13) is perpendicular to the side (15) of the first opening of the bag.
FIGS. 2 a to 2 c relate to another embodiment of the invention in which the stiffening element (5) is a (50) and in which the said guide means (6) is composed of a thread forming the said second stiffening element (61).
FIG. 2 a shows the bag (1) before being filled.
FIG. 2 b is a section along A-A in FIG. 1 a.
FIG. 2 c shows the bag (1) after it has been filled and closed.
FIGS. 3 a to 3 c relate to other embodiments of the invention.
FIG. 3 a shows a bag (1) in which the filling opening (13) covers the entire section of the bag, while the said top part (11) corresponding to the part of the bag torn the first time that it is opened is only in the right corner of the bag.
According to FIG. 3 b, the stiffening element (5) and the said second stiffening element (61) are formed by local deposits (53).
According to FIG. 3 c, the stiffening element (5) and the said second stiffening element (61) are formed by overthicknesses (54) of the material forming the walls (2, 2′).
FIG. 4 a is similar to FIG. 3 a, but the stiffening element (5) and the said second stiffening element (61) are formed by a single striplet (52) fixed to the surface of each wall (2, 2′) in which a central line of weakness (520) is formed.
FIG. 4 b is a section along A-A in FIG. 4 a.
FIG. 5 shows a bag (1) in which the stiffening element (5) is formed by a thread (50) and in which the said second stiffening element (61) is formed by the sealing edge (14) typically reinforced (62) by pleating.
FIG. 6 is similar to FIG. 1 c, but the thread (50) is oriented at an angle α>0 with respect to the orientation O=>of the material forming the walls (2, 2′).
FIGS. 7 a to 8 diagrammatically illustrate two embodiments for manufacturing the strip material (7) in the form of a reel (72) designed to form the bags (1) with the insertion of the stiffening element (5) and the guide means (6) composed of a thread (50).
According to FIG. 7 a to 7 c, the strip (7) is formed by extrusion or assembly of two layers (70).
FIG. 7 a shows a perspective view of the strip material (7), the threads (50) being parallel to the machine direction MD of the material. As a simple example, the dashed lines (71) diagrammatically show the cutting out shape of the walls (2, 2′) in order to form the bags (1).
FIG. 7 b shows a cross-sectional view before the two layers (70) are brought together with the threads (50) placed between them to form a strip material (7), as shown diagrammatically in the sectional view in FIG. 7 c.
FIG. 8 is similar to FIG. 7 a, but the thread is no longer straight due to a transverse displacement of the thread (50) on the input side, synchronized with a longitudinal displacement along the MD direction.
FIG. 9 corresponds to FIG. 1 c, but the bag (1) is formed by folding along a folding line (16) corresponding to the bottom (17) of the bag.
FIG. 10 corresponds to FIG. 1 c, but the stiffening element (5) is composed of a label (51) that may be printed and/or metallic.
FIG. 11 shows a perspective view of the bag (1) in FIG. 10 after opening and separation of the top part (11), and manual pressure on the edges (19), so as to elastically separate the two labels (51) and thus open up the orifice of the first opening (15).
FIG. 12 a shows a bag (1) in which the said stiffening element (1) and the said second stiffening element (61) are formed by a label (55) that could be printed and/or metallic, comprising a line of weakness (550) forming the said partition line, and provided with tear starting points (4) at its ends.
FIG. 12 b shows a vertical cross-section through the bag according to FIG. 12 a, after opening and separating the top part (11), and after closing again by using a foldable label (55), typically metallic and printed, for example made of aluminium or including aluminium.
Unlike FIGS. 7 a to 8, FIGS. 12 to 14 show longitudinal sectional views along the MD direction, of the formation of the multilayer material (7) in reels (72) by complexing of different types of films between cylinders, the MD direction usually also being the direction of the orientation O=>of the material if this material is oriented, with incorporation of a thread (50) as the stiffening element (5) and as a second stiffening element (61) between the layers.
FIG. 12 relates to manufacturing of the PET/Al/PP strip material (7), with 6/6 PA threads being inserted between the PET/AJ and PP layers.
FIG. 13 corresponds to FIG. 12, but relates to manufacturing of the PET//Al/OPP/PP material, with a nylon thread being inserted between the PET and Al/OPP/PP layers.
FIG. 14 is similar to FIG. 13, but the thread is coated with glue (73) before being inserted between the PET and Al/OPP/PP layers.
FIGS. 15 a to 15 c illustrate manufacturing of a strip material (7) in which the stiffening element (5) is a thread (50) arranged in the transverse direction TD, perpendicular to the machine direction MD.
FIG. 15 a shows a diagrammatic view of a longitudinal section perpendicular to the strip material (7) to be made, showing a device for gluing two films (70) using an adhesive (73), a thread (50) being deposited over the entire width of the strip at regular intervals so as to obtain a material according to FIG. 15 b (top view), and then a material according to FIG. 15 c corresponding to FIG. 15 b after the parts of the thread external to the material have been eliminated.
FIG. 16 shows a section through two sidewalls (2) and (2′) facing each other before welding to form a bag, two upper striplets (51) forming the said guide means (6, 61), and two lower striplets forming the said stiffening element (5).

DETAILED DESCRIPTION OF THE INVENTION

According to a first embodiment of the invention, the said guide means (6) may be formed by:

- a) 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,
- b) 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 packaging, the said partition line and the said direction typically forming an angle α between 0 and 45°, the said packaging including one or two tear starting points (4), themselves possibly forming an acute angle oriented towards the said partition line.

This embodiment has been illustrated in FIGS. 1 a to 1 d, 6, 9, 10 and 12 a.
According to a second embodiment of the invention, the said guide means (6) may include 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.
The said first and second stiffening elements forming the said main and secondary barriers are preferably identical, continuous, parallel and separated by a distance typically varying from 1 to 20 mm, and preferably from 2 to 10 mm; they may possibly form 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′).
This embodiment has been illustrated in FIGS. 2 a to 2 c, 3 a to 3 c, 4 a to 4 b, 5, 12 a to 12 b, and 16.
Note also that the two types of guide means can be combined, as illustrated in FIG. 12 a, such that packaging can be torn during the first opening along a completely predetermined line.
As illustrated in all the figures, the said partition line, which generally runs along or is coincident with the line formed by the first stiffening element (5), may be a line forming a complete separation between the said upper part (11) and lower part (12). This arrangement is usually more practical or aesthetic, but it is absolutely not compulsory.
It is often advantageous if this partition line is a transverse line, so as to ensure that the said bag can be fully opened, as illustrated for example on FIGS. 1 a to 2 c. But partial opening would also be possible as illustrated in FIGS. 3 a to 4 b.
The nature, mechanical characteristics or thickness of the said first stiffening element (5, 50, 51, 52, 53, 54, 55) forming the said barrier should be 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. But in particular, when the first stiffening element (5) or the second stiffening element (61) are formed by the incorporation of an add-on element (thread, striplet, etc.), the propagation energy of the tear at the crossing of the said main barrier (5′) including the said first stiffening element (5) or the secondary barrier comprising the said second stiffening element (61), may be much higher, at least twice as high, or even five times as high or even more in some cases, than the propagation energy of the tear in the strip material itself, such that it becomes almost impossible for the tear to deviate from the “track” assigned to it in the design of the said packaging, the first time that it is opened.
All figures except for FIG. 3 c illustrate the case in which the said first stiffening element is composed of an add on element, typically a thread (50) or a striplet (51) fixed to the said sidewalls (2, 2′).
The said thread (50) may be a textile thread made of a natural, artificial or synthetic material, or a metallic wire, the said thread or wire having a fracture strength equal to at least 0.5 N.
Similarly, the said striplet (51) may be a paper or metal striplet, or a single layer or multilayer plastic striplet, possibly printed.
As illustrated in FIG. 3 b, the said first stiffening element (5) forming the said barrier may be 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%. It may thus be advantageous to form the said first stiffening element (5) and the said second stiffening element (61) at the same time as the strip material (7) that will form the container (1) is printed.
But as illustrated in FIG. 3 c, the said first stiffening element may be composed of an overthickness (54) of the material forming the said face (2, 2′) typically formed by punching or extrusion of the said typically plastic material. In this case, it may be advantageous to form two material rims (54) forming the said stiffening element (5) and the second stiffening element (61) with central thinning, typically during formation of the sealed edges (3) using a tool hot enough to make the plastic material creep, however cold enough so as not to seal the two faces (2, 2′).
Advantageously, particularly aesthetically, the said strip material (7) may be 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.
The said strip material (7) may comprise 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) as illustrated in FIGS. 7 a to 8 and 12 to 14 in which the stiffening element is a thread, but possibly in the “transverse” direction TD, as illustrated in FIG. 15 c. But it would also be possible according to the invention to insert a striplet between the layers, or even discontinuous elements placed on a very thin continuous thread type support (either a typically single-dimensional product with a very long length L (L>>0), or of the striplet type consisting of a two-dimensional product with a relatively narrow width l (L>>l>0).
The packaging according to the invention may typically be 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 a sealed edge (3), or from a single strip material by folding, sealing and cutting, one side of the said packaging forming a fold (15).
The said sealing may typically be 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, so as not to damage the leak tightness of the packaging.
According to the invention, the said strip material (7) may be chosen from among, or may include, 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).
When PE is used, a tearable PE preferably at least 60 μm thick will be used.
According to one variant of the invention, the packaging may comprise an add-on bottom (18), so that a package can be obtained with an upright station.
As also shown in FIGS. 12 a and 12 b, the said first stiffening element (5) may have characteristics chosen based on foldability/unfoldability so that the said packaging can be closed again after the said opening for the first time. This can be achieved using a metallic striplet, typically made of aluminium, that can also be printed.
One particular purpose of the invention is a bag, typically with rectangular sides (2, 2′) made of a multilayer material, typically including 2 to 4 layers, the said first stiffening element of each face (2, 2′) facing the other 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 edge equal to between 5 mm and 30 mm such that the said upper part (11) has a relatively small surface area compared with the said lower part, typically less than 0.2 times the surface area of the said lower part.
Depending on the case, this type of bag may have its filling opening (13) in the said upper part, as illustrated on most of the bags shown in the figures or in the said lower part (12) as illustrated in FIG. 5, or on the side as illustrated in FIG. 1 d in which the filling opening is perpendicular to the partition line formed by the said main barrier.
Like the second stiffening element (61), the said first stiffening element (5) may also be located on the inner and/or outer face of the said wall (2, 2′). Thus, the invention can also be used to obtain all sorts of combinations depending on which of the two faces is considered, the first stiffening element (5) or the second stiffening element (61). If necessary, it is also possible to accumulate several embodiments for the first stiffening element (5) and for the guide means (6) as a function of technical, aesthetic, production and usage requirements.
The first stiffening element (5), and possibly the said guide means, may be composed of or may include a striplet (51, 52), for example in the form of a typically extruded profile like that illustrated in FIGS. 10, 11, 16.
In this case, it may be advantageous for the said striplet (51, 52) to also include 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).
But moreover, and independently of the stiffening element, the packaging according to the invention may include 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).
Another purpose of the invention consists of a process for manufacturing a package according to the invention 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.

According to another variant embodiment of the invention:

- 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 package, during formation of the said container.

According to another variant embodiment of the invention:

- 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.

Regardless of which variant embodiment of the invention is used, the said first stiffening element (5) and possibly the said second stiffening element (61) may be coated typically with glue or adhesive such that they are absolutely fixed to the said strip material (7) and that there is no risk of delamination and no risk of the package losing its seal or the permeability of the package being increased.
Usually, the materials used to make the first stiffening element (5) and the second stiffening element (61) are compatible with the materials forming the said strip material (7), but if an appropriate choice of the glue or adhesive is made, it is virtually possible to make any type of first stiffening element (5) and second stiffening element (61) bond to the said strip material (7).
Depending on the case, and particularly when the said first stiffening element (5) and the second stiffening element (61) are inserted between the layers of strip material (7), the thickness ER of the said first stiffening element (5) and/or second stiffening element (61) will be chosen to be typically thin compared with the thickness of the strip material (7) E_B—for example four times thinner or even 8 times thinner (10 μM vs 80 μm).
On the other hand, for example when a striplet (51, 52) or a label (55) is used, its thickness may be approximately equal to the thickness of the strip material, if necessary.
Advantageously, the said first stiffening element (5) and the said second stiffening element (61) may advantageously be identical and be formed simultaneously, in which case the strip material (7) may or may not be oriented.
Usually, the said strip material (7) may be 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, where “Al” (also denoted “alu” or “ALU” in the figures) denotes a thin aluminium sheet, typically thinner than 20 μm, in which OPP and OPA denote oriented PP and oriented PA respectively, and “/” symbolically denotes separation between distinct layers.
According to the invention, the said strip material can also be supplied, and after the said container has been formed, the said product (8) can be packaged in the said container and the said package can be closed, typically before forming the said thinner tear starting point (4) and cutting out the said container, so as to use the so-called FFS (Form-Fill-Seal) process.
In this case, the said supplied strip material may include 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. FIGS. 15 a to 15 c illustrate one industrial means of making a strip material comprising a thread oriented in the transverse direction, rather than in the machine direction as shown in FIG. 7 a. The possibility of having a second thread forming the second stiffening element (61) is shown in dashed lines in FIGS. 15 b and 15 c.
According to one variant of the process, the said supplied strip material does not include the said first stiffening element (5), the said first stiffening element (5) and the said guide means (6) may be formed or applied onto the faces (2) and (2′) if necessary when using the said FFS process.
According to the invention, the said first stiffening element (5)—and possibly the said guide means (6) if necessary—may be a striplet applied to the inside of the said container such that nothing is visible from the outside, and/or such that the external surface of the bag is smooth. FIG. 16 illustrates this possible type of bag, in which the two sidewalls (2) and (2′) are represented before welding face to face, the two upper striplets (51) forming the said guide means (6, 61), the two lower striplets forming the said stiffening element (5). All these striplets can be fixed to the sidewalls either during manufacture of the said strip material, or during manufacture of the said container.
Another purpose of the invention consists of the strip material or the film (7) that will implement the process according to the invention. This material or film that will be used on automatic FFS type filling machines includes 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.
As already mentioned, this film can be obtained using different technologies including complexing. The stiffening element (5) and the guide means are typically introduced during lamination, preferably between the two films forming the layers (70). According to one method, their positioning within the width of the strip material is adjustable, and the function will be obtained in the longitudinal direction or the machine direction MD. Obviously, as many stiffening elements or guide means as are necessary can be introduced over the width of the strip material (7) in order to:

- guide the tear,
- and/or satisfy the needs of several placements that will be cut out later,
- and/or integrate the required function on the front and/or the back.

The principle diagram in FIG. 7 a only shows two threads (50) in the strip material (7), for the purposes of illustration.
The invention is used for applications in packaging of all types of products, for example for food products, cosmetics and household cleaning products.
Example Embodiments
All figures show example embodiments of bags (1).
The strip materials (7) used in the manufacturing tests are 12 μm/9 μm/90 μm thick PET/Al/PP, PET/Al/OPA/PP as shown in FIGS. 12 to 14, and 80 μm thick PET/PE and PEBD.
The first stiffening element (50) and the second stiffening element (61) consist of a 13 strand PA6/6 nylon thread, the diameter of each strand being 10 μm.
When completing layers (70) according to FIGS. 7 a and 12 to 14, two threads (50, 61) were inserted at a distance of 7 mm from each other, without needing to modify the “standard” completing rate, so as to form the stiffening element (50) and the second stiffening element (51) simultaneously.
Sterilisable bags were also made.
Tests were carried out using a metal wire or an “anti-theft” striplet designed to provide an alert, typically by triggering a siren, in the case of a fraudulent crossing between the gateways associated with cash tills in shops, as the first stiffening element (50).
Reclosable bags were also made using a 40 μm thick and 20 mm wide aluminium striplet as the first stiffening element (5) on each face, by incorporating a “ZIP” type closure.
All the manufactured bags were tested by a panel of persons representing “average consumers” opening the bags normally without taking any special care as they would in everyday life at home.
The results clearly showed that the tear propagates in a controlled and direct manner using the means according to the invention.

ADVANTAGES OF THE INVENTION

The invention has very many advantages.
Firstly, it divulges a new type of packaging that maintains its integrity the first time it is opened.
It also divulges a large number of ways in which the invention can be implemented.
It also divulges possibilities of simultaneously incorporating other functions in the packaging (reclosing, detection, etc.).
Finally, it may be used at no significant extra cost, depending on the embodiment.
List of Marks

- Bag—Container . . . 1
  - Partition line . . . 10
  - Upper part . . . 11
  - Lower part . . . 12
  - Bag filling opening . . . 13
  - Sealed filling edge . . .
  - Area or side of the first opening . . . 15
    - First opening orifice . . . 150
  - Fold . . . 16
  - Bottom of bag . . . 17
  - Add on bottom for upright station . . . 18
  - Opening side edge . . . 19
- Sidewalls . . . 2, 2′
- Edge with weld of bag sidewalls 2 and 2′ . . . 3
- Tear starting point . . . 4
- Stiffening element . . . 5
- Main barrier=5+2/2′ . . . 5′
  - Thread . . . 50
  - Striplet, strip, label . . . 51
  - Striplet with line of weakness . . . 52
  - Line of weakness . . . 520
- Relief pattern—localized deposition of material . . . 53
- Material overthickness . . . 54
- Printed label (metallic) . . . 55, 55′
  - Line of weakness . . . 550
- Guide means . . . 6
  - Oriented material (O=>) . . . 60
  - Second type 5 stiffening element . . . 61
  - “Reinforced” sealing edge 14 . . . 62
- Strip material to form 2, 2′ and 1 . . . 7
  - Multilayer material layers . . . 70
  - Cut lines . . . 71
  - Reel . . . 72
  - Glue—adhesive . . . 73
- Product contained in the bag . . . 8

Claims

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.