EP0677377B1 - Process for packaging deformable products in a container made of semi-rigid material - Google Patents

Abstract

The method comprises several operating steps. Firstly blanks (21) are cut from a band of semi rigid material. The two parts of the pairs of zones (2,2A - 9,9A) which are to be stuck together are then pre-pasted with a contact glue. This is followed by drying which causes the glue to partially lose its adhesive ability. The blank is then folded around the product and the pairs of glued zones are turned down against each other to obtain contact. On the packets thus made is placed an enveloping film and the packets are placed against each other inside packaging. The packaged packets are held for a day to obtain an increase in the quality of gluing. <IMAGE>

Description

The present invention relates to a method for the packaging of deformable products in a packaging made of semi-rigid material.

It applies more particularly, but not exclusively for the packaging of cigarettes, cigars or similar products in packaging made from a blank of semi-rigid material such as cardboard or even a flexible material such as paper.

In general, we know that to achieve such packaging, we first of all carry out the blanks by continuously cutting and creasing a strip of paper or cardboard. We then transfer the blanks, a by one at a packing station in which, just before the folding operation, is carried out a coating of glue on the areas of gluing the blank, in general on the flaps.

This gluing takes place on one side of the blank to be using an adhesive, for example of the "PVA" type, or "HOTMELT", by glueers provided in the machine packaging. European patent application No. 0 492 950 A1 describes a glue of this type.

Usually the position of these glueers just before the folding station is imperative due to the presence of liquid or pasty glue on the blanks: This presence makes certain manipulations impossible if you want to avoid glue stains. In addition for the same reason, it requires a conception special blanks and folding station.

The bonding process that takes place at the level of the zones of glue on which come to apply, during the folding, corresponding areas to be glued are of the type classic.

In the two parts in contact, the adhesive solvent, water, for example, migrates inside the carton or paper. Bonding then occurs during drying.

Therefore, to ensure good bonding, it is necessary to keep these two parts in contact with one on the other during the drying time and plan at the packaging station, a plurality of external heat sources whose effects may to be harmful to the organoleptic qualities of food, for example cigarettes, contained in the package.

Another disadvantage of glues of this type consists in what they cannot be applied to areas bonding of large dimensions, due to risk of glue overflow that occurs during bringing the areas to be bonded under pressure, as well as possible degradations resulting from the absorption by paper or cardboard of quantities of important solvent.

By patents GB-A-2,173,423 and DE-C-826,815 it has already has been proposed to make packaging from blanks wavy, folded and glued with latex glue or similar which, once dried, has the particularity to be able to adhere only to itself.

Such a solution turns out to be interesting in the case where pre-glued blanks are delivered to end users themselves manually folding, bonding obtained spontaneously upon contact with areas pre-glued against each other.

However, a disadvantage of such glues is in that they do not provide good resistance to tearing off the glued parts.

To take this disadvantage into account, we have therefore proposed increase the surface of the glued parts, and to apply pressure on these two parts important in order to improve the quality of bonding.

It is clear that these two measures are not suitable in the case of a cigarette packaging operation which does not not allow to exert pressure on the package that the machine folds around cigarettes and that would risk therefore to deteriorate them. Likewise, in such package, it is not possible to increase the areas glued together which always remain very small.

In any case, the resistance measurements carried out on these glues and which usually consist of wrenching measures have always resulted in the conclusion that the quality of the collage was insufficient so that we can use it in a process packaging such as cigarette packaging. It is the reason why so far it has never been proposed pack of cigarettes using for glued parts of such glues.

The invention is based on two observations which make it possible to overcome this prejudice.

The first finding is that in a packet of cigarettes classic type, the greatest efforts exerted on the glued parts are shearing forces and not tearing forces: this results the specific design of cigarette packs and their fashion of use and in particular the fact that, unlike many packaging, the constraints on cigarette packages do not result not from the weight of the contents of the package, but from external actions exerted on these outer faces, for example when the package is in a pocket or in a bag. These external actions manifest themselves in level of bonding by shear stresses and not tearing. So far, no one had thought of using the resistance of adhesives to shearing and not tearing.

The second finding shows that the quality of the fixation obtained using this type of glue improves over time, during the first days after bonding. This manifests itself particularly in the case where, after packaging, the packages are overwrapped and / or arranged one on top of the other against others, in folders or cartridges. In this case, we assume that the slight pressure exerted on the packages contributes to increasing the quality gluing.

For these various reasons, it turns out that despite the prejudices previously mentioned, the quality of the assemblies obtained using this type of glue during packaging of deformable products such as cigarettes acceptable.

The invention therefore provides a method taking advantage of the peculiarities of this glue for packaging cigarettes then packets of cigarettes in a packaging made of a semi-rigid material, like a packet of cigarettes, this process comprising for each packet, so known per se, making blanks by cutting a strip of semi-rigid material and a pre-gluing of one of the two parts of each pair of zones to stick to each other, using glue.

• le préencollage puis le séchage des deux parties de chaque couple de zones à coller, ces deux parties étant situées sur les deux faces du flan,
• le pliage du flan autour des produits à empaqueter en rabattant les deux parties préencollées de chaque couple les unes contre les autres de manière à obtenir un collage par contact desdites parties,
• la mise en place sur les paquets ainsi réalisés d'un film de surenveloppement et/ou la disposition de ces paquets les uns contre les autres à l'intérieur d'emballages tels que des fardes, des cartouches ou des cartons, et le maintien des paquets ainsi conditionnés pendant au moins une journée de manière à exercer sur eux une légère pression et à obtenir aussi un accroissement de la qualité du collage.

According to the invention, this method is characterized in that said adhesive is a cold contact adhesive comprising a dispersion of latex in water, this adhesive losing after drying its adhesive power vis-à-vis any other material than itself, and in that said method comprises the following sequence of operating phases:

• pre-gluing then drying of the two parts of each pair of zones to be bonded, these two parts being located on the two faces of the blank,
• folding the blank around the products to be packaged by folding down the two pre-glued parts of each pair against each other so as to obtain bonding by contact of said parts,
• the placing on the packages thus produced of an overwrapping film and / or the arrangement of these packages against each other inside packages such as folders, cartridges or cartons, and the maintenance of the packages thus conditioned for at least one day so as to exert a slight pressure on them and also to obtain an increase in the quality of the bonding.

Advantageously, this pre-gluing operation can be carried out at during the printing and blank cutting operation. Thanks to the properties glue, the pre-glued and dried blank can be handled by means without risking contaminating the installation and, consequently, the blanks following. Likewise, there is no longer any fear of overflow of glue or deterioration of paper or cardboard.

On the contrary, it will be possible to provide larger bonding areas dimensions. The pre-gluing zones may, for their part, exceed the dimensions of the bonding zones, these then being limited to the intersections pre-glued areas.

Another advantage of the process according to the invention consists in that it allows a pre-gluing of areas located on both sides of the blank, which was not possible with the usual adhesives, due to the problems of subsequent handling of the blank.

• la Société CRODA FRANCE S.A. à Trappes,
• la Société NATIONAL STARCH & CHEMICAL ADHESIVES à Villefranche Sur Saône.

The adhesive used in accordance with the process according to the invention may consist, for example, of a cold adhesive composed of a dispersion of latex in water and offered by several companies, in particular:

• CRODA FRANCE SA in Trappes,
• NATIONAL STARCH & CHEMICAL ADHESIVES in Villefranche Sur Saône.

These adhesives are easily applied when printing the cutouts on rotogravure machines, for example in aqueous dispersion with syneresis water later in the manufacturing process. They allow to realize films which, once dried, remain translucent.

Of course, the invention also relates to a method comprising in combination of bonding using contact glue and type bonding traditional.

• une simplification importante du matériel d'empaquetage avec une suppression des colleurs, des barillets ou dispositifs équivalents pour le maintien des paquets pendant la prise de la colle, du chauffage et des "chemins de transfert" des découpes nécessités par la technique actuelle d'encollage (avant, pendant et après le collage, et avant même le contact des parties encollées),
• la possibilité d'augmenter la vitesse de paquetage du fait de la simplification de la machine,
• la suppression des risques de détérioration des produits due à la disparition de l'obligation de chauffer les côtés du paquet pour accélérer la prise de la colle,
• l'amélioration possible de l'étanchéité par dépôt de colle sur des zones plus larges et/ou différentes et/ou réparties différemment du fait de la possibilté d'encoller plus facilement les deux faces de la découpe,
• la diminution des rejets (pas de perte de découpes par séchage des points de colle sur arrêt prolongé, possibilité de reprise des paquets mal encollés sans être obligé de les détruire par application d'une nouvelle pression sur les zones ayant reçu une pression insuffisante),
• la diminution des temps d'entretien machine avec suppression des coûts liés aux colleurs et concernant ces derniers, des opérations de nettoyage, de préparation, de réglage et des contraintes liées à l'utilisation de colles,
• la conception de nouveaux emballages et de machines moins complexes grâce au nouveau concept d'encollage,
• la possibilité d'utiliser sur des machines existantes conçues pour travailler le carton, de nouveaux matériaux tels que de la matière plastique, du métal... qui ne pouvaient pas être collés par des colles liquides et sur lesquels on peut utiliser des colles à froid.

In view of the above, with respect to conventional packaging techniques, the method according to the invention allows the following advantages to be obtained:

• a significant simplification of the packaging material with the elimination of glueers, barrels or equivalent devices for holding the packages during the setting of the glue, heating and "transfer paths" of the cuts required by the current gluing technique (before, during and after bonding, and even before contact with the glued parts),
• the possibility of increasing the packing speed due to the simplification of the machine,
• the elimination of the risks of deterioration of the products due to the disappearance of the obligation to heat the sides of the package to accelerate the setting of the adhesive,
• possible improvement of the seal by depositing glue on wider and / or different and / or distributed areas differently due to the possibility of gluing the two sides of the cut more easily,
• the reduction of rejections (no loss of cuts by drying the glue dots on prolonged stoppage, possibility of resumption of badly glued packages without being obliged to destroy them by applying a new pressure on the areas having received insufficient pressure),
• the reduction of machine maintenance times with elimination of the costs linked to and relating to the adhesives, cleaning operations, preparation, adjustment and constraints linked to the use of adhesives,
• the design of new packaging and less complex machines thanks to the new sizing concept,
• the possibility of using on existing machines designed to work cardboard, new materials such as plastic, metal ... which could not be glued by liquid glues and on which cold glues can be used .

Les figures 1 et 2 sont des représentations d'un flan vu du côté de la face extérieure (figure 1) et vu du côté de la face intérieure (figure 2), sur lequel on a indiqué les zones de préencollage ;

Les figures 3 et 4 représentent une variante d'exécution d'un flan pour paquet de cigarettes d'un type similaire à celui illustré figures 1 et 2 ;

Les figures 5 et 6 montrent une autre variante d'exécution d'un flan adapté à la mise en oeuvre du procédé selon l'invention ;

La figure 7 montre, en perspective, un paquet de cigarettes obtenu à l'aide des figures 1, 2, 3, 4 et 5, 6 ;

Les figures 8 et 9 montrent d'une façon similaire, le côté imprimé et le côté intérieur d'un flan de la coulisse d'un paquet tiroir/coulisse ;

La figure 10 est une vue schématique en perspective permettant d'illustrer le principe d'un paquet de cigarettes de type tiroir/coulisse.

Modes of execution of cigarette packets in accordance with the method according to the invention will be described below, by way of nonlimiting examples, with reference to the appended drawings in which:

Figures 1 and 2 are representations of a blank seen from the side of the outer face (Figure 1) and seen from the side of the inner face (Figure 2), on which the pre-gluing zones have been indicated;

Figures 3 and 4 show an alternative embodiment of a blank for a pack of cigarettes of a type similar to that illustrated in Figures 1 and 2;

Figures 5 and 6 show another alternative embodiment of a blank adapted to the implementation of the method according to the invention;

Figure 7 shows, in perspective, a packet of cigarettes obtained using Figures 1, 2, 3, 4 and 5, 6;

Figures 8 and 9 show similarly the printed side and the inner side of a blank of the slide of a drawer / slide package;

Figure 10 is a schematic perspective view for illustrating the principle of a pack of drawer / slide type cigarettes.

The blank 21 whose two faces 21 ', 21' 'are shown in Figures 1 and 2 is used to make a package cigarettes like the one shown in Figure 7.

This package, in closed state (solid lines), has a parallelepiped shape and has two parts trapezoidal rectangle, namely: a body 22 and a cover 23, these two parts being open at the level of their oblique face which constitutes the assembly face (plan P).

The small base 24 of the cover 23 consists of a extension of the large base 25 of the body 22, the separation between these two bases being materialized by a folding line 26 which allows the cover 23 to switch between an open position (broken lines) and a closed position (solid lines).

The blank 21 making this package is obtained by cutting and creasing a strip of semi-rigid cardboard the same width as the blank, the cut, at the anterior end of the blank, defining a shape re-entrant trapezoidal while that performed at level of the posterior end delimits a shape truncated triangular.

In the example shown in Figures 1 and 2, the small base of the re-entrant trapezoidal shape is extended by an appendage 28 of the same width but of short length.

The blank comprises two longitudinal fold lines 29, 30 whose spacing corresponds to the width of the packet cigarettes that we want to obtain, these two lines of folding 29, 30, delimiting a central strip, bordered by two side strips of width equal to the thickness of the package.

It also includes six transverse fold lines T ₁ to T ₆ which extend over the entire width of the central strip 31 of the blank 21 and are extended at the side strips by cutouts D ₁ to D ₅ - D ' ₁ to D' ₅ .

The first fold line T ₁ , starting from the left, defines with the front edge of the central strip 31, a rectangular area P ₁ corresponding to the front face of the cover 23 and, with the oblique front edges of the two lateral strips, two flaps R ₁ , R ' ₁ of trapezoidal shape.

The second fold line T ₂ defines with the first, in the central strip 31, a rectangular area P ₂ corresponding to the upper face of the cover 23 and of width equal to that of the package and, at the level of the lateral strips 1 ′, 1 '', two rectangular flaps R ₂ , R ' ₂ .

The third fold line T ₃ is extended by two oblique cutouts D ₃ , D ' ₃ which extend parallel to the oblique edges of the re-entrant trapezoidal shape and the truncated triangular shape. It delimits with the second line T ₂ a relatively narrow rectangular area P ₃ which constitutes the rear face of the cover 23 and, at the level of the lateral strips 1 '', 1 ', two trapezoidal areas R ₃ , R' ₃ which constitute the faces side of the cover.

The fourth fold line T ₄ defines with the third line a rectangular area P ₄ which corresponds to the rear face of the body of the package, bordered by two lateral areas R ₄ , R ′ ₄ of trapezoidal shape which partially constitute the side walls of said body .

The fifth fold line T ₅ defines with the fourth, a rectangular area P ₅ constituting the bottom of the body, this area P ₅ being bordered by two rectangular areas serving as flaps R ₅ , R ′ ₅ .

This fifth fold line also delimits, with the front edge of the blank, a rectangular area P ₆ constituting the rear face of the body of the package. This area P ₆ is bordered by two lateral areas R ₆ , R ′ ₆ , which constitute the lateral faces of the body, and by the appendage 28. The latter is preferably connected to the area P ₆ by means of d 'A creasing or embossing line T ₆ of large dimensions, so as to obtain a good mutual positioning, facing the front face of the cover 23 when the latter is in the closed position.

The mode of folding the blank 21, in order to obtain the package shown in Figure 5, is of conventional type and does will therefore not be shown in detail. To facilitate the understanding, we have indicated by arrows the meaning folds.

According to the process according to the invention, before the phase folding and, preferably, during the cutting phase, we pre-glue and then dry the different areas that need to be pasted, using a contact adhesive as defined above.

In this example, this pre-gluing is carried out on the two sides of the blank in areas indicated by geometric figures such as rectangles or numbered triangles. According to the numbering, an area bearing a number is intended to be pasted on a area with the same number but affected by the letter AT.

Thus, the outer face of the blank comprises zones 4A, 5A - 2A, 3A - 6A, 7A - 8A, 9A respectively distributed over the flaps R ' ₂ , R ₂ , the flaps R' ₃ , R ₃ , the areas R ₄ , R ' ₄ , and the flaps R' ₅ , R ₅ .

The inner face of the blank comprises, for its part, zones 2, 3 and 6, 7 distributed over the flaps R ' ₁ , R ₁ and the lateral areas R ₆ , R' ₆ . It further comprises two rectangular zones 4, 5 made on the area P ₂ facing the flaps R ₂ , R ' ₂ and two rectangular areas 8, 9 made on the area P ₅ facing the flaps R' ₅ , R ₅ .

For the reasons indicated above, the bonding is obtained at the end of folding when the zones correspond to each other other.

Appendix 28 can be pre-glued after folding using an infinite open time glue allowing repeated opening and closing of the package, ensuring a better seal.

The blank shown in Figures 3 and 4 is very similar from that shown in Figures 1 and 2. This is the reason we used references identical to designate similar parts.

However, unlike the previous version, the appendix 28 is extended by two trapezoidal tongues 28 ', 28''whose large base extends parallel and at a short distance and over the entire length of the oblique ends of the lateral pads R ₆ , R ' ₆ . These tabs 28 ', 28''are intended to be applied and glued to the lateral faces R ₁ , R' ₁ of the cover 23 and therefore have, on the outside of the blank 21, two pre-gluing zones 2 ' A, 3'A respectively, intended to be applied to two corresponding pre-gluing zones 2 ', 3' provided on the lateral faces R ₁ , R ' ₁ of the cover on the inside of the blank. The tongues 28 ', 28''are fixed by easy-break means, for example narrow links, at the oblique ends of the lateral areas R ₆ , R' ₆ , so as to allow the lid 23 to be opened by a consumer. Such an arrangement ensures the closure of the package and testifies to its integrity until it is opened by the consumer. In this example, the trapezoidal pads R ₃ , R ' ₃ have, at the cutouts, notches E ₁ , E ₂ of shapes complementary to those of the tongues 28, 28'.

Advantageously, the zones of a face of the blank located at the level of the pre-glued areas worn on the other side of the blank can be covered with a repellent varnish to avoid adhesion of the blanks to each other when these are stacked.

The use of the blank described above can be intended to the end user. In this case, it can be offered to client, separately, or be integrated into a cartridge from 5 to 10 packs.

For this, it can be placed on a large face of the cartridge or file by folding the two strips side on the central strip so that the blank does not protrude from the cartridge. In this case, the blank pre-gluing areas are not in contact with their counterparts and will not be active. They can therefore fulfill their role when formatting the product. This can be very easily done at hand by the consumer.

In the example shown in FIGS. 5 and 6, the blank has no appendage 28. On the other hand, it has a rectangular flap R ₈ connected to the front edge of the area P ₁ by a transverse fold line T ₈ . On the inside face of the blank, the flap R ₈ and the pad P ₁ carry two longitudinal pre-gluing zones 1, 1A - 1 ', 1'A, spaced from one another, which allow the flap R _{8 to be} fixed. against area P ₁ in the folded position. The lateral areas respectively carry two longitudinal pre-gluing zones 12 starting from the oblique cutouts D ₃ , D ' ₃ . Likewise, the rectangular area P ₆ carries two longitudinal pre-sizing zones 11.

On the side of the outer face of the blank, the flap R ₈ carries a transverse pre-gluing zone 10, while the pre-gluing zones 6A, 7A have two rectangular notches E ₃ , E ₄ making it possible to avoid any sticking with the pads 12 when the blanks are stacked.

In this example, the blank further comprises a separate collar 32, substantially C-shaped comprising a central core 33 and two lateral wings 34, 35. This collar 32, the width of which corresponds to that of the blank 21, comprises two lines of folding L ₁ , L ₂ corresponding to the longitudinal folding lines 29, 30. The central core 33 comprises two longitudinal pre-gluing zones 10A, 11A intended to be applied temporarily on the pad 10 and definitively on the pads 11. Similarly, the lateral wings 34, 35 comprise two longitudinal pre-gluing zones 12A intended to be applied and to stick permanently against the zones 12.

This arrangement ensures better closing the box thanks to the contacting of pre-glued areas 10 and 10A. It also improves the times the package before consumption and its appearance during consumption thanks to better holding the cover in the closed position after operation to extract cigarettes.

The pack of cigarettes shown in Figures 8, 9 and 10 includes a tubular case 76 in the form parallelepiped in which engages and can slide a drawer 36 containing the cigarettes.

The blank used to make the case 37 consists of a strip of rectangular cardboard provided with four transverse fold lines L ₃ to L ₆ which delimit the two main faces FP ₁ , FP ₂ of the case, its two lateral faces FT ₁ , FT ₂ and a PF mounting bracket. On the side of the outer face of the blank, the fixing tab PF carries a pre-gluing area 41, while on the inside, the edge of the blank opposite the tab PF, carries a corresponding pre-gluing area 41A. Once these zones 41, 41A are pre-glued, the folding and gluing operations are carried out in an extremely simple manner, without having to provide additional glue and without the risk of staining of glue.

As in the examples previously described, the invention eliminates the heating means which ensure bonding on traditional machines and therefore ensures better preservation of qualities organoleptics of cigarettes that are not subject to sources of heat during the manufacture of packages. It also brings a simplification of the materials and improving their efficiency. Because that it allows larger bonding areas dimensions, it increases the tightness of cigarette packs.

Claims (7)

1. Method for packing cigarettes and then cigarette packets in packaging made of a semi-rigid material, said method including for each packet the embodiment of a blank (21) by the cutting of a strip made of a semi-rigid material and a pre-glue spreading of one of the portions of each pair of zones (2, 2A-9, 9A) of this blank (21) to glue one to the other using a glue, characterised in that said glue is a cold contact glue including a dispersion of latex in water, this glue after drying losing its adhesive power in relation to any other material than itself, and in that said method includes the following sequence of operational phases :

   pre-glue spreading and then drying of the two portions of each pair of zones to be glued (2, 2A-9, 9A), these two portions being situated on the two opposing faces of the blank (21),

   the folding of the blank around the products to be packed by folding down the two pre-glue spread portions of each pair against each other so as to obtain a glueing via the contact of said portions,

   the placing on the embodied packets a wrapping film and/or the arrangement of these packets against one another inside the packages, such as folders, cartridges or cartons, and the keeping in position of the packed packets for at least one day so as to exert on them a slight pressure and thus obtain increased glueing quality.
2. Method according to claim 1, characterised in that the pre-glue spreading operation is carried out during the operation for cutting and printing the blanks (21).
3. Method according to one of the preceding claims, characterised in that said pre-glue spreading portions have different dimensions from those of the zones to be glued (2, 2A-9, 9A), the latter then being limited at the intersections of the pre-glue spread portions.
4. Method according to one of the preceding claims, characterised in that it includes the application of a repellent varnish on the zones of a face of the blank (21) situated at the level of the pre-glued portions borne by the other face of the blank (21) so as to avoid the adherence of blank spaces when these are stacked.
5. Method according to one of the preceding claims, characterised in that the folding and packaging operations and carried out in the factory.
6. Method according to one of the preceding claims, characterised in that it includes a pre-glue spreading of certain zones by using an infinite open time glue allowing repeated glueings and unglueings.
7. Method according to one of the preceding claims, characterised in that the blank (21) has an approximately rectangular shape, the front extremity of said blank having a re-entering trapezoidal shape, whereas its other extremity has a truncated triangular shape, and in that this blank (21) includes two longitudinal folding lines (29, 30) delimiting a central strip (31) ands two lateral strips and six transversal folding lines (T₁ - T₆) which extend over the entire width of the central strip (31) of the bottom and are extended at the level of the lateral strips (1, 1') by cuts (D₁ to D₅ and D'₁ to D'₅), these folding lines (T₁ to T₆) successively delimiting at the level of the central strip (31) the front upper and rear faces of a cover (23), then the rear face, bottom and front face of the body (22) of the packet, said cuts (D₁ to D₅, D'₁ to D'₅) delimiting at the level of the two lateral strips the lateral faces of the cover (R₃, R'₃) of the flap (R₁, R'₁), a lining of the lateral faces of the covers (R₂, R'₂), a lining (R₄, R'₄) of the lateral faces of the body (22) of the reinforcement areas of the bottom (R₅, R'₅) and the lateral faces (R₆, R'₆) of the body (22), the external face of the blank including pre-glue spreading zones at the level of the lining of the lateral face of the cover (4A, 5A), the lateral face of the cover (2A, 3A), the lining of the lateral face of the body (6A, 7A) and of the reinforcement area of the bottom (8A, 9A), the internal face of the blank including pre-glue spreading zones (2, 3 and 6, 7) distributed on the flaps (R₁, R'₁) and the lateral faces (R₆, R'₆), as well as two pre-glue spreading zones (4, 5) embodied on the upper face of the cover opposite the lateral faces of the covers (R₂, R'₂) and two pre-glue spreading zones (8, 9) embodied on the bottom opposite the reinforcement areas of the bottom (R₅, R'₅).

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