EP1394060A1 - Packaging bag - Google Patents

Abstract

The packaging sachet for chocolate has a flexible film which packaged by rolling longitudinally on a reel and divided transversely to form packaging film sections (10,20,30,40,50). The bag has a front face (14) and a rear face (12) connected by a closed base and each having a transverse cold sealing strip (20,22) along each edge. One of the faces has a tongue extension (18).

Description

The present invention relates to a packaging bag for packaging an article, this sachet being produced from at least one film flexible and flexible can be conditioned, by winding in the direction longitudinal, on a roll and sectionable transversely in films separated, the bag comprising a front face and a rear face connected by a closed bottom and each comprising, on the inside of the bag, the along each transverse edge, a strip of cold sealing plaster showing little or no adhesion to the smooth surface of the film but, applied one on the other have sufficient adhesion to close the bag along the transverse edges.

Although not limited thereto, the invention relates more particularly the packaging of products where heat is to be avoided and / or is desirable that the packaging facility operates at high speed. A typical example is the packaging of chocolate industry products.

It is known to use sachets for packaging such products. of the kind described above. These sachets include, in addition to the bands transverse adhesives, on the side opposite the bottom, on the inside of the front and rear sides two longitudinal adhesive strips to ensure closing the bag. These bags have the disadvantage that it is difficult to open them along the longitudinal adhesive strips due to a lack of access to capture the film with two fingers. We tried to go there remedy by shifting the longitudinal adhesive strips a little inside to leave a smooth strip along the edge longitudinal, but practice has shown that this measure does not resolve the problem to satisfaction.

The object of the present invention is to provide a new sachet of the kind described in the preamble which is easily openable and which also has other advantages over known sachets, such as the possibility of reclosing.

To achieve this objective, the present invention provides a sachet of the genre described in the preamble which is characterized in that one of the sides of the bag is, on the side opposite the bottom, extended by a tongue which is folded around the corresponding edge of the other side and in that both sides have, on said side, at least two bands longitudinal cold seals which are mutually stackable to ensure the closure of the bag.

Cold sealing coatings intended to form the sachet, although being designated by bands may, depending on the shape of the product to wrap, take different forms around the space reserved for this product. In this way, any contamination problem between the product to be packaged and sealant and, if applicable, it is possible to save sealing compound.

Said areas of sealing plaster may therefore, depending on the form and the size of the product to be packaged, take different forms. These strips of cold sealing plaster can also be surfaces continuous or discontinuous surfaces, for example points or lines. In short, in this context the designation of "band" is to be interpreted as "model".

By cold sealing, according to the present invention, is meant a sealing which is carried out instantly by simple contact, at a temperature between 0 and 50 ° C approximately. In reality, the temperature is not a critical parameter for obtaining an average seal of a cold sealing coating and had practically no influence on the quality of the seal obtained. We therefore carry out the sealing without a additional heat is not required; at temperature the space in which the packaging unit is located.

The qualification of longitudinal and transverse is made with reference at the winding of the film which provides the films for forming the sachet, the longitudinal direction being this direction of the winding and the direction of film running through its manufacturing and printing machine and that of the film running through the packaging station.

The designation for the front and rear sides are also interpret relatively. In practice, these designations are determined by printing and, in the context of this description, by the figures to which the text refers.

The front and back sides of the bag can be part of a single film which is folded around a fold line forming the bottom from the sachet.

The front and rear faces can also be part of separate films obtained by two films wound on rolls separated. In this case, the films have bands additional longitudinal so that they can be welded together to form the bottom of the bag. In addition, the two rollers with the films for film formation do not have the same width, the more wide being intended for the formation of the face of the sachet which is prolonged by a tab.

The tongue that extends one side is an important element of the sachet according to the present invention. The user can indeed easily grasp this tab between your thumb and forefinger and open the bag, without tear, releasing the adhesion between the two longitudinal strips sealing plaster on the front and back of the bag.

According to another embodiment, the tongue is provided, on the inner side, an additional longitudinal strip of plaster cold sealing. The folding of the tongue on the outside of the front face is made along a fold line which changes substantially at across the middle region of this longitudinal strip so that when the tab is folded down, this adhesive strip is folded over itself and ensures, by its adhesion on itself, the maintenance of the folded position of the tongue.

According to a third embodiment, the tongue has, along from its longitudinal edge, on the inside, a strip of plaster of cold sealing which cooperates with a longitudinal strip of plaster of cold sealing provided on the outside of the front panel. membership mutual between these two bands allows to close, on several occasions, the bag once it has been opened.

Finally the fourth embodiment is analogous to the third embodiment except that it is deprived of the tapes longitudinal adhesive on the inside of the front and on the front back. Here the longitudinal strips of cold sealing plaster ensure, therefore the initial closure of the sachet and offer the possibility reclosing after use.

Finally, the various embodiments may include security means allowing the consumer to check whether the sachet has already opened before use or before purchase.

la figure 1A une vue en plan d'un premier mode de réalisation d'une pellicule pour la fabrication d'un sachet;

la figue 1B une vue en plan d'un sachet réalisé avec la pellicule de la figure 1A;

la figure 1C une coupe transversale à travers le sachet de la figure 1B;

les figures 2A, 2B et 2C des vues correspondant à celles des figures 1A, 1B et 1C d'un deuxième mode de réalisation,

les figures 3A, 3B et 3C des vues correspondantes à celles des figures 1A, 1B et 1C d'un troisième mode de réalisation et

les figures 4A, 4B et 4C des vues correspondant à celles des figures 1A, 1B et 1C d'un quatrième mode de réalisation.

Other particularities and characteristics of the invention will emerge from the detailed description of several embodiments presented below, by way of illustration, with reference to the appended drawings in which the same references have been used to designate corresponding elements and that represent:

FIG. 1A a plan view of a first embodiment of a film for the manufacture of a sachet;

Fig 1B a plan view of a bag made with the film of Figure 1A;

Figure 1C a cross section through the bag of Figure 1B;

FIGS. 2A, 2B and 2C of the views corresponding to those of FIGS. 1A, 1B and 1C of a second embodiment,

FIGS. 3A, 3B and 3C of the views corresponding to those of FIGS. 1A, 1B and 1C of a third embodiment and

Figures 4A, 4B and 4C views corresponding to those of Figures 1A, 1B and 1C of a fourth embodiment.

FIG. 1A shows a rectangular film 10 cut from a film unwound from a roll and which runs in the longitudinal direction represented by the arrow MD (machine direction) through the machine packaging. The film 10 has two parts 12, 14 of height A symmetrical about a fold line 16, the upper part being extended by a tongue 18 of height B. Parts 12 and 14 have, along their edge, two transverse bands 20 and 22 cold sealing plaster and two longitudinal strips 24, 26 of plaster cold sealing that extend between the cross strips for form a symmetrical rectangular frame around the fold line 16. If the transverse bands 20, 22 extend along the edges, the longitudinal strips 24, 26 can be slightly set back, up to 1 cm.

A typical example of a usable cold sealing coating is product IP 7905 or IP 7936 from Sun Chemical Swale. The substrate of the film can be a Vifan OPP-CY metallized bioriented copolymer.

For the packaging of a product, it is placed in the center of Part 12, taking care to avoid contact with the adhesive tapes. The part 14 is then folded around the fold line 16 on the part 12 until the longitudinal and transverse bands cold sealing plaster adhering to each other. Then tab 18 is folded, in turn, to form the bag shown in Figures 1B and 1C and whose front face is formed by part 14 and the rear face by part 12.

The bag thus formed is hermetically sealed on the four sides which allows a good conservation of the packaged product. Furthermore, the tongue which is free over the entire height B provides a excellent possibility for the user to take the sachet for separation adhesive strips, in particular longitudinal strips 24 and 26. It note that the thickness of these has been exaggerated in Figure 1C for the needs of illustration.

The types of cold sealing plaster provided by the invention are not not a critical factor and can generally be considered like pressure sensitive adhesives. They can join permanently under the simple effect of pressure on the surface of many substrates.

Generally, pressure sensitive adhesives are compositions based on natural and / or synthetic rubber associated with modified cellophanes, phenol-formaldehyde resins or hydrocarbon resins (waxes). Besides rubbers, we use largely polymers based on styrene, (metha) crylic acid or vinyl ether alone, or in admixture, also in combination with resins. Finally, silicone resins can be used. We use, preferably compositions comprising rubber mixtures natural and synthetic and copolymers of (metha) crylic acid and styrene.

There are different types of cold sealing plasters that lie between plasters of the "dry" type with limited adhesive power and the plasters of "soft" type with strong adhesive power. The right choice depends on many criteria including the packaging of the film, as well as the structures sealant on the film.

As already mentioned above, the film is packaged under roll or coil form. When one side of the film is provided of an adhesive structure, it is therefore necessary to ensure that there is no adhesion between it and the other face of the neighboring turn on the roller so that the film can be unwound. One possibility is to apply on this other side of the film a coating with non-stick properties.

However, some "dry" type adhesives, when used on well-defined substrates such as oriented polypropylene films, do not need such a non-stick coating. These films are of the type called "Plain OPP" with a side treated with corona or chemically which is the printing or laminating side and an untreated side which has good non-stick properties on contact with adhesive structures when the film is wound on a roll. In other words, this type of adhesive allows good adhesion on an adhesive coating of the same type but a insufficient adhesion on a smooth surface of the film to disturb the unwinding of the film from its roll. This is the principle of adhesion controlled described in detail in document WO 00/21852.

Regarding the choice of substrate, it is dictated basically by treatment practice criteria like by example thickness or stiffness, provided that the problem above mentioned blocking in roll is avoided. For example, substrates between 15 and 150 microns thick comprising one, two, three or more layers of polypropylene, polyester, polyethylene, polyamide, different types of paper, sheets aluminum are suitable. In general any substrate used in the field flexible packaging can be used. Therefore, the invention allows, at will, the use of films, papers, sheets having optimal properties (aesthetics, rigidity, printability) for a specific application.

FIG. 2A shows a film 30 similar to film 10 of the Figure 1A for the production of a bag as shown in the figures 2B and 2C. The difference between the two embodiments is that the one of Figure 2A has on the tongue 18, near the rear face 12, an additional longitudinal strip 32 of sealing plaster cold which is arranged so that when the tongue 18 is folded down on the front face 14 in order to close the bag, the line of folding of the tongue 18 is located substantially in the middle zone longitudinal of this strip of sealing plaster 32. This strip 32 ensures, therefore, by adhesion on itself a good maintenance of the tongue in its closed position of the bag according to Figures 2B and 2C.

FIG. 3A shows a film 40, also analogous to the film 10 of the embodiment of FIG. 1A for the production of a bag as shown in Figures 3B and 3C. The difference, this times, is that the film 40 has two longitudinal strips additional cold sealing plaster. One 42 of these bands is arranged on the outside of the front face 14 at a certain distance of its free edge and the other 44 on the inner side of the tongue 18 has a sufficient distance from the free edge of the tongue to allow the user, when opening the bag, to be able to easily grasp the tongue 18, the positions of the bands 42 and 44 must however be coordinates so that they come into mutual adhesive contact when closing the bag as shown in Figure 3C.

These two bands 42 and 44 therefore ensure the maintenance of the tongue 18 and closed position, so that the adhesive strip 32 of the previous embodiment is no longer required.

There is, however, a fundamental difference between this third embodiment and the first two. In the embodiment of Figures 1 and 2 all the longitudinal strips of sealing plaster are found on the same side of the film 10 or 30, in this case on the side inside compared to the bag. In contrast, in the third mode of embodiment, the three longitudinal strips 24, 26, 44 are located on the inner side of the film, while the longitudinal strip 42 on the exterior side. The result is that when the film from which the film 40 is wound on a roll, the outer longitudinal strip 42 will inevitably be found, because of the increasing diameter of the roller, several times opposite the interior longitudinal strips 24, 26, 44. It it is therefore important to choose a cold sealing coating that meets the controlled membership criteria as described above.

Since, in this latter embodiment, the two longitudinal strips 42, 44 ensure a tight closure of the bag after the tongue has been folded down, we could, for simplification, do without the two interior longitudinal strips 24, 26. The figures 4A, 4B and 4C show, by way of illustration, such an embodiment. The film 50 of FIG. 4A therefore also has on its faces opposite, two longitudinal strips 52, 54 of cold sealing plaster. However, unlike the previous embodiment, the strip outer 52 is arranged along the free edge of the front face 14, which fact that the strip 54 disposed on the inside of the tongue 18 must be set further back from the free edge thereof, which facilitates taking tab for opening the bag.

Example of making a 40 or 50 film.

A double layer structure is produced, the outer layer of which comprises a transparent printed film of oriented polypropylene copolymer with a thickness of 25 microns. If necessary for the adhesion of the ink, a lacquer or "primer" (type 10-612 205 MX 41 from Siegwerk) can be applied. Printing can be carried out by various techniques well known in the field in question, such as gravure printing, flexography, offset or others. A lacquer having non-stick properties with regard to cold sealing coatings is applied to the entire outer surface of the film. Such a non-stick lacquer generally consists of a polyamide resin mixed with polyethylene resins (type 10-609 345 -3P from Siegwerk) at a rate of 1.5 g / m ² . A strip of "soft" type cold sealing plaster (for example IP 7985 from Sun Chemical Swale at a rate of 2.5 g / m ² ) is applied to the surface of this lacquer. This coating does not adhere to the outside of the laminated structure, that is to say of the film described below. This means that the laminated structure can be easily packaged in the form of a roll without unwinding problems. In addition, this sealant has a low COF (coefficient of friction between 0.2 and 0.6 which reduces the risk of adhesion to the metal and jamming in the packaging machine.

This film is laminated against a homopolymer oriented polypropylene metallized film with a thickness of 30 microns with an inner layer which has non-stick properties with regard to the "soft" sealing coating which is applied to the outside of the laminated structure. On the inner side of this film is provided, as described above, a strip of sealing plaster of the "dry" type (for example the product IP 7979 Sun Chemical Swale at a rate of 1.8 g / m ² . packaging in roll, this adhesive will come into contact with the non-stick lacquer on the outside but will not adhere to it. The cold sealing coating on the inside of the film will inevitably also come into contact with the 'cold sealing coating of the film in certain places of the reel, but thanks to the properties of controlled adhesion as described above, there will be no unwinding problems.

The different embodiments described above can also be provided with a means of security making it possible to verify whether the bag has already been opened. An advantageous means, for example in the embodiment of FIG. 1, consists in providing between one of the longitudinal strips of sealing plaster 24 or 26 and the film 10 a lacquer or "primer" which has the property of adhering to the coating strip of sealing when the bag is closed, however, this adhesion is a adhesion which is weaker than that between the two adhesive strips 24, 26 so that, when the bag is opened, the two strips adhesives 24 and 26 remain glued together and separation occurs between one of the strips 24 or 26 and its underlying lacquer. Now, once that the strip has been separated from its lacquer, it will no longer adhere to it.

The bag according to the present invention has, moreover, the advantage of being able, again, to be closed by the consumer a once it has been opened, for example when the contents of the sachet have not been consumed only partially.

There are several ways to do this. The simplest in the case of embodiment of Figures 3 and 4 is to take advantage of characteristics of the types of sealer with controlled adhesion which, as described above can adhere several times together after being separated.

This solution has the advantage of being provided during the production of the film and therefore does not require adaptation of the machine packaging. Another advantage is that these bands never come in contact with the packaged product, especially when it occurs in granular or powder form, which means that the properties adhesive cannot be disturbed by the product.

Another possibility is to provide under the inner edge of the tongue an adhesive strip which, until the first use, is neutralized by a silicone band. When the consumer wishes close the bag it will only have to remove this silicone band to make adhere the adhesive strip to the front of the bag. This band adhesive could of course also be provided on the front from the bag, below the tab.

Another solution is to provide, at the free end of the tongue 18 a longitudinal adhesive strip of which one half longitudinal adheres to the tongue and of which the other longitudinal half adheres to the outside of the bag.

This possibility of reclosing the sachet after use has significant advantages. There is no need for implementation of heat and the means which allow its realization can be provided in the printing or film manufacturing installation intended for making the bag. Another advantage is that these means are are found on the outside of the bag and are therefore never contaminated with content of it which is important when it comes to matter powder.

It remains finally to recall the relative character of the concepts "face front "and" rear side ". Indeed, the tongue 18 which has been presented as an extension of the rear face 12 can just as easily be the extension of the front face 14 and be folded down on the rear face 12.

Claims (10)

Sachet for packaging an article, this sachet being produced from at least one flexible and flexible film which can be conditioned by winding in the longitudinal direction, on a roll and sectionable transversely in separate films (10), (30) , (40), (50), the bag comprising a front face (14) and a rear face (12) connected by the closed bottom and each comprising on the inside of the bag, along each transverse edge a strip of plaster cold sealing (20), (22) having little or no adhesion with the smooth surface of the film, but, applied to one another have sufficient adhesion to ensure the closure of the sachet along the transverse edges, characterized in that one of the faces of the bag is, on the side opposite the bottom, extended by a tongue (18) which is folded around the corresponding edge of the other face and in that the two faces (12 ), (14) have, on said side, at least two lon bands gitudinal of cold sealing plaster which are mutually superimposable to ensure the closure of the bag. Bag according to claim 1, characterized in that the front and rear sides (14), (12) of the bag are part of a single film (10), (30), (40), (50) which is folded around a fold line (16) forming the bottom of the bag. Bag according to claim 1, characterized in that the front and rear faces (14), (12) of the bag form part of separate films obtained by two films wound around separate rolls of different width, said films each comprising an additional longitudinal strip intended to be welded together to form the bottom of the bag. Bag according to any one of Claims 1 to 3, characterized in that the two longitudinal strips of cold sealing plaster (26) (24) are located along the upper edge of the bag, respectively on the inner side of the front face (14) and on the inner side of the rear face (12) which is extended by said tongue (18). Bag according to any one of Claims 1 to 4, characterized in that the tongue (18) is provided, on the inner side, with an additional strip (32) of cold sealing plaster and in that the folding of the tongue (18) on the outside of the front face (14) is made along a fold line which evolves substantially through the middle region of this longitudinal strip of sealing plaster (32). Bag according to any one of Claims 1 to 3, characterized in that the tongue (18) has, along its longitudinal edge, on the inside, a strip of cold-sealing plaster (44), (54) which cooperates with a longitudinal strip of cold sealing plaster (42), (52) provided on the outside of the front face (14). Bag according to claim 6, characterized in that the mutual adhesion between the longitudinal strips (44), (42) and (54), (52) allows the bag to be closed several times once it has been open. Bag according to claim 6, characterized in that the tongue (18) has along its free edge on the inner side an adhesive strip which, until the first use, is neutralized by a removable silicone strip. Bag according to claim 6, characterized by a longitudinal adhesive strip adhering by a longitudinal half to the free end of the tongue and by the other longitudinal half to the outer face of the bag. Bag according to any one of claims 1 to 9, characterized by security means allowing the consumer to check whether the bag has already been opened before its use or before its purchase.

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