EP0387171B1 - Method for producing a tubular packing body, packing made by this method and device for this method - Google Patents

Abstract

The method is characterised in that it consists in unrolling at least two strips intended to form the component parts (2, 3) of the first layer of the body (1), in shaping them and placing them in such a way that they are joining without overlapping, then in unrolling at least two strips intended to form the component parts (4, 5) of the second layer of the body (1), in shaping them and in positioning them in such way that they are also joining without overlapping, these operations to be continued, if necessary, depending on the number of layers provided, the joints, (6, 7) of the strips of each possible additional layer being substantially offset with respect to those of the strips of the preceding layer, and finally in cutting off and removing the packing body (1). <IMAGE>

Description

The present invention relates to the field of packaging, in particular tubular packaging, and relates to a method of manufacturing a body of a tubular packaging comprising at least two superimposed layers of a material such as paper, cardboard, metal foil. , synthetic material, or any other material, a packaging thus obtained and a device for implementing this process.

• un complexe interne, compatible avec le produit à conditionner. Ce complexe peut comporter deux couches ou plus. Très souvent, la couche présentant les propriétés barrières assurant une étanchéité parfaite est composée d'un film d'aluminium. Elle peut également être en tout autre film présentant les mêmes propriétés barrières et la même faible résistance physique que l'aluminium. Cette couche est d'une épaisseur aussi faible que possible, afin de réduire au maximum le coût de l'emballage à réaliser. Habituellement, une étanchéité optimale est obtenue avec une épaisseur de la couche d'aluminium de l'ordre de 9 à 18 µ. Cette couche d'aluminium est souvent recouverte, de chaque côté, d'une couche d'un matériau différent, par exemple d'un côté de papier et de l'autre d'un film en matière synthétique, ou d'un vernis.
• une ou plusieurs couches d'un matériau plus rigide que le complexe interne. En général, ces couches sont en carton, c'est-à-dire d'un grammage supérieur à environ 225g/m². Le nombre de couches dépend, bien entendu, de la rigidité souhaitée, un baril de poudre à laver nécessitant une rigidité bien supérieure à un emballage de biscuits, par exemple.
• une couche ou un complexe externe, imprimé ou non. Il peut s'agir d'une couche simple, par exemple une étiquette imprimée de la dénomination commerciale du produit ou d'autres indications. Il pourra également s'agir d'un complexe garantissant une étanchéité parfaite de l'extérieur vers l'intérieur, afin de protéger les différentes couches de carton d'une quelconque atteinte par un liquide extérieur.

The existing packaging of the box, container, barrel, barrel type is all composed of a tubular body, of round, polygonal section, or any other sections, of a cover and of a bottom. The structure of the tubular body, produced by spiral, straight, convolute or other winding, is generally as follows:

• an internal complex, compatible with the product to be packaged. This complex can have two or more layers. Very often, the layer having the barrier properties ensuring a perfect seal is composed of an aluminum film. It can also be made of any other film having the same barrier properties and the same low physical resistance as aluminum. This layer is as thin as possible, in order to minimize the cost of the packaging to be produced. Usually, an optimal seal is obtained with a thickness of the aluminum layer of the order of 9 to 18 μ. This layer of aluminum is often covered, on each side, with a layer of a different material, for example on one side of paper and on the other of a film of synthetic material, or of a varnish.
• one or more layers of a more rigid material than the internal complex. In general, these layers are in cardboard, that is to say a grammage greater than about 225g / m². The number of layers depends, of course, on the desired rigidity, a barrel of washing powder requiring a rigidity much higher than a package of cookies, for example.
• an outer layer or complex, printed or not. It can be a single layer, for example a label printed with the product's trade name or other indications. It could also be a complex guaranteeing a perfect seal from the outside to the inside, in order to protect the different layers of cardboard from any damage by an external liquid.

The connection of these different layers is ensured by sealing or gluing.

As for the bottoms or covers of these packages, they are composed either of a completely different structure from the body, or of a structure equivalent to that of the body. In the latter case, they may advantageously be composed, from the inside of the packaging towards the outside, by a complex identical to that internal to the body and in contact with the product to be packaged, by one or more sheets of a material. more rigid than the complex, such as corrugated paper, cardboard, wood, metal, synthetic material, expanded polystyrene or any other material, the number of sheets to be applied being a function of the rigidity of the bottom or of the cover the packaging to be obtained, and optionally by a layer or an external complex, whether or not printed. Such a structure is described in French patent application No. 8701510.

Currently, the bodies of tubular packaging are normally manufactured in the following manner: the different strips are unwound on a reel, the width of each strip corresponding to the width of the profile to be produced, the width of each is increased next strip of the thickness of the previous strip, each strip is shifted laterally, the strips are assembled together to form the profile, the profile is folded so as to first form an open U, then a closed U , then an O, the joints, combined with the offset of the bands, thus also being offset, then the profile is dried and finally the cut is carried out, generally by means of circular knives guided by a format cam, profile thus obtained in different sections, the length of which corresponds to that desired of the packaging body, and the bodies thus obtained are removed. Such a manufacturing process is known from US Patent 2,256,263.

However, the packaging body obtained by application of such a method has the major characteristic of being provided with a weakening zone at the location of the various overlaps of the bands. It follows that the packaging body is not statically balanced. This static imbalance leads to various drawbacks, both at the level of the manufacturing process and at the level of the packaging body itself.

In fact, at the level of the manufacturing process, the static imbalance leads to difficulties in positioning and crimping the bottom and the cover. In addition, the interior complex is very difficult to set up by heat sealing, due to the overlap of the different strips, the latter resulting in particular in a lack of space for the heat sealing tool; therefore either the production rates are slowed down, or the interior complex is abandoned, which of course greatly affects the sealing of the packaging body.

On the other hand, at the level of the packaging body itself, it deforms under stress, for example when the final packaging is placed in containers for transport or in shelving during the sale, this coming from the fact that the joints are only slightly offset, the most important deformation arising, of course, always at the level of the overlap of the different bands and complexes.

Furthermore, cutting by circular knives guided by a format cam requires, on the one hand, a delicate adjustment due to the significant wear of the knives and, on the other hand, a change of the cam for each tube format to cut. In addition, it is not possible to cut tubes with sharp angles or having a section of complex shape.

Cutting with circular saws does not allow a clean cut, without burrs and precise, and produces a large amount of dust.

In addition, GB-A-2 000 105 discloses a multi-layer packaging box, as well as its manufacturing process.

The aforementioned method consists in producing the side walls of said box by the superposition by gluing of a plurality of layers each formed by strips of flexible material juxtaposed transversely.

Furthermore, document DE-B-1 227 772 also discloses a method for manufacturing a tubular packaging body, in particular a multilayer paper bag, comprising an internal complex and at least two superposed layers formed around said internal complex and made of a material such as paper, said method consisting in unrolling, first of all, a strip intended to constitute, after heat sealing, the sealed internal complex compatible with the product to be packaged, of the body to be produced.

This document also describes a device for implementing the aforementioned method, consisting of a continuous forming machine for the tubular packaging body, connected, on the one hand, to at least one reel, if necessary gluing, to the number of one per layer of the packaging body and, on the other hand, to a reel of the strip intended to form the internal complex of said packaging ccrps.

Nevertheless, the various constituent layers of this tubular body are not joined together and are each made up of a single strip of paper, respectively of waterproof complex, the lateral edges of which are folded back and assembled at the edge by mutual overlap and against bonding, so as to constitute a tubular body provided with a longitudinal allowance and having not undergone any particular shaping operation.

In addition, the different joining and overlapping areas of the different layers are not offset between them for two successive layers, which causes a structural imbalance of said packaging body, as already mentioned above.

The general problem to be solved by the object of the present invention therefore consists in designing, starting from document DE-B-1 227 772, a manufacturing process and a device for its implementation, making it possible to obtain a perfectly sealed, balanced packaging body, without causing deformations due to internal stresses, in particular by eliminating all weakened generators and all excess thicknesses due to overlapping of the bands and by joining the different layers together.

This process should also allow a significant rate of manufacture of the packaging bodies, an easy longitudinal heat-sealing of the interior complex as well as an equally easy installation of the bottoms and covers.

Finally, the cutting should be facilitated, eliminating any delicate adjustment and any abundant formation of dust, and be carried out in a clean and precise manner, whatever the section of the packaging bodies.

According to the present invention, this general problem is solved in that it relates to a method of manufacturing a body of a tubular package according to the preamble of claim 1, characterized in that it consists, all first, to shape and put in place, by continuous heat sealing, the sealed internal complex, the latter being composed either of a strip folded over on one side and heat sealed on each side, or of two strips which are heat sealed on each side , then to unroll at least two strips intended to form the constituent parts of the first layer of the body to be produced, to shape them and put them in place, by gluing or heat-sealing on the internal complex, in such a way that they are contiguous, without overlapping, the sum of the width of each strip corresponding to the perimeter of a packaging body, then unrolling at least two strips intended to form the constituent parts of the second layer of the co rps to be produced, shaped and put in place by gluing or heat sealing on the first layer so that they are also contiguous without overlapping, but the joints of the bands forming the constituent parts of the second layer being substantially offset by relative to the joints of the bands forming the constituent parts of the first layer, the sum of the width of each strip forming the second layer also corresponding to the perimeter of a packaging body, to continue, if necessary, these operations depending on the number of layers provided to form the packaging body, the joints of the strips of each possible additional layer being substantially offset from those of the strips of the previous layer, preferably 90 ° and, finally, to make the cut of the different layers thus superimposed according to the desired length of the packaging body, and to evacuate the packaging body obtained.

In fact, this method makes it possible to obtain a package whose body comprises an internal complex and at least two superimposed layers of a material such as paper, cardboard, metal foil, synthetic material or any other material, said body of packaging being advantageously constituted on the one hand, by a sealed internal complex compatible with the product to be packaged, this internal complex being composed either of a strip folded back on one side and heat-sealed on each side, or of two strips which are heat-sealed each side, and, on the other hand, by at least two additional layers superimposed by gluing or heat-sealing, each made up of two parts, joined without overlapping, the width of each part being exactly equal to half the perimeter of the body d the packaging and the joints of the two parts forming the second additional layer being offset by an angle of 90 ° relative to the joints of the two parts forming the first iere additional layer, said packaging further comprising an external label.

Finally, the invention also relates to a device for implementing the method, as described in the preamble of claim 6, characterized in that the forming machine comprises a mandrel of the desired shape of the packaging body. , shaping stations and in place of each layer around the mandrel by means of rollers or forming pads and rollers driving the layers thus formed towards a cutter, said forming machine having, in addition, a continuous heat-sealing station, upstream of the shaping stations and in place of the layers, constituted by four heat-sealing rollers and connected to the reel (s) of the strip (s) intended (s) to form the internal complex of the packaging body, the section of the mandrel to the right of the heat-sealing station of said complex on its banks being less than that to the right of the shaping stations and in place, in order to facilitate said heat sealing.

• la figure 1 (figures 1A, 1B, 1C et 1D) représente en plan et en coupe, les différentes étapes du procédé de fabrication d'un corps d'emballage de section circulaire, conforme à l'invention ;
• la figure 2 (figures 2A, 2B, 2C et 2D) représente en plan et en coupe, les différentes étapes du procédé de fabrication d'un corps d'emballage de section rectangulaire, conforme à l'invention ;
• la figure 3 représente une vue de face du dispositif pour la mise en oeuvre du procédé conforme à l'invention ;
• la figure 4 représente une vue en plan du dispositif représenté à la figure 3 ;
• la figure 5 représente une vue schématique à plus grande échelle et en coupe, de gauche, de la mise en forme et en place d'un complexe interne constitué par deux bandes, au poste de thermoscellage du dispositif conforme à l'invention ;
• la figure 6 représente une vue schématique à plus grande échelle et en coupe, de gauche, de la mise en forme et en place d'un complexe interne constitué par une bande, au poste de thermoscellage du dispositif conforme à l'invention ;
• la figure 7 représente une vue schématique à plus grande échelle et en coupe, de gauche, des parties constitutives d'une couche d'un corps d'emballage de section rectangulaire, au poste de mise en forme et en place pourvu, selon une variante de réalisation, uniquement de galets, du dispositif conforme à l'invention ;
• la figure 8 représente une vue schématique à plus grande échelle et en coupe, de gauche, des parties constitutives d'une autre couche d'un corps d'emballage de section rectangulaire, au poste de mise en forme et en place pourvu, selon la même variante de réalisation, uniquement de galets, du dispositif conforme à l'invention ;
• la figure 9 (figures 9A, 9B et 9C) représente une vue schématique à une échelle différente et en coupe, de gauche, des parties constitutives d'une couche d'un corps d'emballage de section rectangulaire, au poste de mise en forme et en place pourvu, selon une autre variante de réalisation, de galets et de patins, du dispositif conforme à l'invention ;
• la figure 10 représente une vue en plan du dispositif pour la mise en oeuvre du procédé conforme à l'invention, selon une variante de réalisation, et
• la figure 11 représente une vue en élévation latérale d'une unité de coupe faisant partie du dispositif représenté à la figure 3.

The invention will be better understood thanks to the description below, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the appended schematic drawings, in which:

• Figure 1 (Figures 1A, 1B, 1C and 1D) shows in plan and in section, the different steps of the manufacturing process of a packaging body of circular section, according to the invention;
• Figure 2 (Figures 2A, 2B, 2C and 2D) represents in plan and in section, the different stages of the process for manufacturing a packaging body of rectangular section, in accordance with the invention;
• FIG. 3 represents a front view of the device for implementing the method according to the invention;
• Figure 4 shows a plan view of the device shown in Figure 3;
• FIG. 5 represents a diagrammatic view on a larger scale and in section, from the left, of the shaping and installation of an internal complex constituted by two strips, at the heat-sealing station of the device according to the invention;
• FIG. 6 represents a diagrammatic view on a larger scale and in section, from the left, of the shaping and installation of an internal complex constituted by a strip, at the heat-sealing station of the device according to the invention;
• FIG. 7 represents a diagrammatic view on a larger scale and in section, from the left, of the constituent parts of a layer of a packaging body of rectangular section, at the shaping station and in place provided, according to a variant production, only of rollers, of the device according to the invention;
• 8 shows a schematic view on a larger scale and in section, from the left, of the constituent parts of another layer of a packaging body of rectangular section, at the shaping station and in place provided, according to the same variant embodiment, solely of rollers, of the device according to the invention;
• FIG. 9 (FIGS. 9A, 9B and 9C) represents a schematic view on a different scale and in section, from the left, of the constituent parts of a layer of a packaging body of rectangular section, at the shaping station and in place provided, according to another alternative embodiment, rollers and pads, the device according to the invention;
• FIG. 10 represents a plan view of the device for implementing the method according to the invention, according to an alternative embodiment, and
• FIG. 11 represents a side elevation view of a cutting unit forming part of the device represented in FIG. 3.

According to the invention, the manufacturing process is characterized in that it consists, first of all, in shaping and in place by continuous heat sealing, said sealed internal complex 8, the latter being composed of either strip 8 folded over on one side 9 and heat-sealed on each side 9, 10, or two strips which are heat-sealed on each side 9, 10, then unroll at least two strips intended to form the parts 2, 3 constituting the first layer of the body 1 to be produced, to put them into shape and in place, by gluing and heat sealing on the internal complex, in such a way that they are contiguous, without overlapping, the sum of the width of each strip corresponding to the perimeter d 'a body 1 of packaging, then to unroll at least two strips intended to form the parts 4, 5 constituting the second layer of the body 1 to be produced, to shape them and put them in place by gluing or heat-sealing on the first c ouche in such a way that they are also contiguous without overlapping, but the joints 7 of the bands forming the parts 4, 5 constituting the second layer being substantially offset with respect to the joints 6 of the bands forming the parts 2, 3 constituting the first layer, the sum of the width of each strip forming the second layer also corresponding to the perimeter of a packaging body 1, to continue, if necessary, these operations depending on the number of layers provided to form the packaging body 1, the joints of the bands 6,7 of each additional possible layer being substantially offset with respect to those of the bands of the previous layer, preferably by 90 °, and finally to cut the different layers as well superimposed as a function of the desired length of the packaging body 1, and to evacuate the packaging body 1 obtained (see FIGS. 1A, 1B, 1C, 2A, 2B, 2C, 5 and 6 of the attached drawings). In addition, the joints of the strips 6, 7 are advantageously arranged along the medians of the lateral faces of the packaging body 1.

According to a first embodiment of an alternative embodiment of the invention, the manufacturing process consists, after the shaping and in place of the last layer of the body 1 to be produced before cutting, to unroll at least one strip 11 printed intended to constitute the external label, of bodies 1 to be produced, then to form it and in place by heat sealing or bonding on the last layer (Figures 1D and 2D).

According to a second embodiment of the alternative embodiment of the invention, the manufacturing process consists, after the shaping and in place of the last layer of the body 1 to be produced, and before cutting, to unstack a label in format 11, then to shape it and put it in place by heat sealing or gluing on the last layer (Figures 1D and 2D).

According to a characteristic of the invention, the cutting operation is triggered by a device for quantifying the movement of the packaging body 1 and consists, immediately after triggering, of moving, from its rest position, at least a cutting unit 19 parallel to the axis of travel of the body 1, then to rapidly synchronize its speed of movement with the speed of advance of said body 1, to cut off, after the synchronization of the speeds, the body 1 by actuation of knife holders 29 provided with knives 29 'and, finally, to quickly replace said cutting unit 19 in its rest position.

The subject of the invention is also a package obtained by application of this process, the body 1 of which comprises at least two overlapping layers made of a material such as paper, cardboard, metal foil, synthetic material or any other material, said body 1 d packaging being advantageously constituted, on the one hand, by a sealed internal complex 8 compatible with the product to be packaged and, on the other hand, by two additional layers each made up of two parts 2, 3 or 4, 5, contiguous without overlapping, the width of each part 2 to 5 being exactly equal to half the perimeter of the packaging body 1 and the joints 7 of the two parts 4, 5 forming the second additional layer being offset by an angle of 90 ° relative to seals 6 of the two parts forming the first additional layer, said packaging further comprising an external label 11.

Finally, and as shown in Figures 3, 4 and 10 of the accompanying drawings, the invention also relates to a device for the implementation of this process, characterized in that the continuous forming machine 12 of the body 1 of the packaging comprises a mandrel 14 of the desired shape of the packaging body 1 and stations 15, 16 for shaping and in place of each layer around the mandrel 14 by means of rollers 21 or 27 or pads 28 for forming , rollers 17 driving the layers thus formed towards a cutter 18, said forming machine 12 having, in addition, a continuous heat sealing station 22, upstream of the shaping stations 15 and 16 and in place of the layers, consisting by four heat-sealing rollers 23 and connected to the reel (s) 24 of the strip (s) intended to form the complex 8 of the body 1, the section of the mandrel 14 in line with the heat-sealing station 22 of said complex 8 on its banks being less than that at right es shaping stations and in place 15, 16, in order to facilitate said heat sealing.

Each layer of the body 1 of the packaging corresponds to a station 15 or 16 for shaping and in place consisting of four rollers 21 or 27 or four pads 28, a station 15 for shaping and in place bands arriving from the reels 13 horizontally and preceding a station 16 shaping and positioning strips arriving from the reels 13 vertically, therefore previously twisted, or vice versa (Figures 7, 8 and 9 of the accompanying drawings).

According to another characteristic of the invention, the forming machine 12 has, downstream of the last shaping station and in place 16, and upstream of the drive rollers 17 of the layers formed towards the cutter 18, a station 25 for positioning and in the form of labels 11 (see FIGS. 3, 4 and 10).

The station 25 for placing labels 11 is connected either to a reel 26, if necessary a glue dispenser, of the strip intended to form said labels, or to a feeder previously unstacking the labels 11 one after the other.

As also shown in Figures 3, 4 and 10 of the accompanying drawings, the cutter 18 comprises one or more cutting units 19, their number being a function of the desired length of the packaging body 1 and each comprising several knives 29 'arranged in opposition, two by two, one in relation to the other.

According to an additional characteristic of the invention, shown in Figure 11 of the accompanying drawings, each cutting unit 19 is constituted, on the one hand, by one or more knife holders 29 provided with knives 29 'interchangeable with one or more blades 20, along the profile of the body 1 to be cut, said knife holders 29 being slidably mounted on devices guide 30, and, on the other hand, by one or more actuating devices 31 of the knife holders 29, two by two, in the direction of the body 1 moving on the mandrel 14. The actuating device or devices 31 are advantageously in the form of toggle devices 32 connected to jacks 33 and further comprise means 34, 35 for adjusting the travel of the knife holders 29, the displacements of two opposite knife holders 29 being made simultaneous with the using a connection means 36, for example, in the form of a bar.

The sectioning of the body 1 is carried out in one or more operations depending on the number of knife holders 29 to be actuated and takes place during a synchronous movement of the cutting unit 19 with said body 1, the movement of the cutting unit section 19 parallel to the body 1 being produced either mechanically by a connecting rod-crank device, or electromechanically by a ball-screw motor provided with an electronic variator or even pneumatically by jack.

The cut made by the implementation of the device described above is clean and precise and allows the sectioning of body 1 of any section by simply changing the knives 29 ′, without requiring any additional adjustment. The coarse and fine adjustments of the knife holder 29, using, respectively, adjustment means 34 and 35, allow the cutting of bodies 1 of the same section, but of different dimensions, with the same set of knives 29 ′.

• déroulage d'une bande 8 destinée à former le complexe interne ;
• mise en forme et en place de ce complexe 8 au poste de thermoscellage 22 (figures 1A et 2A) ; le complexe intérieur 8 composé de deux bandes de même largeur (figure 5) ou d'une bande repliée (figure 6) est déroulé et thermoscellé en continu au poste de thermoscellage 22 constitué par quatre galets 23, sur ses rives autour de la queue du mandrin de forme 14, puis tiré sur celui-ci par l'intermédiaire des bandes destinées à former les parties 2 à 5 ; grâce à la section du mandrin 14 au droit du poste de thermoscellage 22, inférieure à la section du reste du mandrin 14, le thermoscellage est grandement facilité, puisqu'il existe un espace important entre le complexe 8 et le mandrin 14 ;
• déroulage des deux bandes destinées à former les parties 2, 3 constitutives de la première couche ;
• mise en forme et en place de ces bandes (figures 1B et 2B) suivant deux U opposés autour du mandrin 14 ; cette opération peut s'effectuer, par exemple, grâce à quatre galets 21 verticaux, deux supérieurs et deux inférieurs, le poste 15 mettant en forme et en place des bandes arrivant des dévidoirs 13 horizontalement (figure 7) ; elle peut également s'effectuer, par exemple, grâce à deux galets presseurs 27 disposés avant quatre patins de forme 28, précédant eux-mêmes deux nouveax galets presseurs 27 ; si les deux premiers galets 27 sont horizontaux, les deux derniers galets 27 sont verticaux (figure 9), ou inversement ;
• déroulage des deux bandes destinées à former les parties 4, 5 constitutives de la seconde couche ;
• mise en forme et en place de ces bandes (figures 1C et 2C) suivant deux U autour du mandrin 14, mais décalées de 90° par rapport à celles de la première couche ; cette opération peut s'effectuer de la même manière que pour les premières bandes (voir par exemple figure 8 des dessins annexés, les bandes arrivant des dévidoirs 13 verticalement, dont préalablement vrillés, et les galets 21 étant disposés horizontalement) ;
• le cas échéant, poursuite de ces opérations si plus de deux couches sont prévues ;
• déroulage d'une bande 11 imprimée, destinée à constituer l'étiquette externe ;
• mise en forme et en place de cette bande (figures 1D et 2D) au poste 25 de la machine de formage 12 ; l'étiquette 11 est déroulée et encollée en continu, puis appliquée et formée autour de la dernière couche précédemment réalisée, et tirée par celle-ci ; si l'étiquette 11 se présente non pas en bobine, mais en format, un margeur dépilera une étiquette 11 après l'autre ; elles seront alors encollées et plaquées sous le corps 1, puis formées autour ;
• coupage des différentes couches ainsi superposées aux différentes unités de coupe 19, ces dernières comportant chacune plusieurs couteaux 29′ disposés par paire en opposition l'un par rapport à l'autre ; il s'agit par conséquent d'une coupe "à la volée" ;
• évacuation des corps 1 d'emballage ainsi obtenus.

Thanks to this device, it is therefore possible, for example, to carry out the manufacturing process as follows:

• unwinding of a strip 8 intended to form the internal complex;
• shaping and positioning of this complex 8 at the post of heat sealing 22 (Figures 1A and 2A); the inner complex 8 composed of two strips of the same width (FIG. 5) or of a folded strip (FIG. 6) is unrolled and heat-sealed continuously at the heat-sealing station 22 constituted by four rollers 23, on its banks around the tail of the form 14 mandrel, then pulled on it by means of the bands intended to form parts 2 to 5; thanks to the section of the mandrel 14 to the right of the heat sealing station 22, smaller than the section of the rest of the mandrel 14, the heat sealing is greatly facilitated, since there is a large space between the complex 8 and the mandrel 14;
• unwinding of the two strips intended to form the parts 2, 3 constituting the first layer;
• shaping and positioning of these strips (FIGS. 1B and 2B) along two opposite U's around the mandrel 14; this operation can be carried out, for example, by means of four vertical rollers 21, two upper and two lower, the station 15 shaping and positioning strips arriving from the reels 13 horizontally (FIG. 7); it can also be carried out, for example, by means of two pressure rollers 27 arranged before four shaped shoes 28, themselves preceding two new pressure rollers 27; if the first two rollers 27 are horizontal, the last two rollers 27 are vertical (Figure 9), or vice versa;
• unwinding of the two strips intended to form the parts 4, 5 constituting the second layer;
• shaping and positioning of these bands (FIGS. 1C and 2C) along two U around the mandrel 14, but offset by 90 ° with respect to those of the first layer; this operation can be carried out in the same way as for the first bands (see for example FIG. 8 of the appended drawings, the bands arriving from the reels 13 vertically, including previously twisted, and the rollers 21 being arranged horizontally);
• if necessary, continuation of these operations if more than two layers are planned;
• unwinding of a printed strip 11, intended to constitute the external label;
• shaping and positioning of this strip (FIGS. 1D and 2D) at station 25 of the forming machine 12; the label 11 is unrolled and glued continuously, then applied and formed around the last layer previously produced, and pulled by it; if the label 11 is not in reel, but in format, a feeder will unstack a label 11 after the other; they will then be glued and pressed under the body 1, then formed around;
• cutting the different layers thus superimposed on the different cutting units 19, the latter each comprising several knives 29 ′ arranged in pairs in opposition to each other; it is therefore a cut "on the fly";
• evacuation of the packaging bodies 1 thus obtained.

There is thus obtained, by virtue of this manufacturing process, a perfectly sealed packaging body 1 and without any particularly weakened generator, mainly due to the significant offset of the seals 6 and 7 relative to each other, these seals being somewhat so uniformly distributed over the entire perimeter of the packaging body 1.

Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (11)

1. Method for producing a body of a tubular package comprising an internal complex and at least two superimposed layers formed round said internal complex (8) and consisting of a material such as paper, cardboard, metal foil, synthetic material or any other materials, involving firstly unwinding at least one strip (8) intended to form, after heat sealing, the impermeable internal complex compatible with the product to be packaged, of the body (1) to be produced, characterised in that it involves shaping and positioning by continuous heat sealing said impermeable internal complex (8), the latter being composed either of one strip (8) folded back on one side (9) and heat sealed on each side (9, 10) or of two strips which are heat sealed on each side (9, 10), then unwinding at least two strips intended to form the constituent parts (2, 3) of the first layer of the body (1) to be produced, shaping and positioning them on the internal complex (8) by adhesion or heat sealing, such that they are joined together without overlapping, the sum of the width of each strip corresponding to the perimeter of a packaging body (1), then unwinding at least two strips intended to form the constituent parts (4, 5) of the second layer of the body (1) to be produced, shaping and positioning them on the first layer by adhesion or heat sealing such that they are also joined together without overlapping but with the joints (7) of the strips forming the constituent parts (4, 5) of the second layer being substantially offset from the joints (6) of the strips forming the constituent parts (2, 3) of the first layer, the sum of the width of each strip forming the second layer also corresponding to the perimeter of a packaging body (1), if necessary carrying out these operations as a function of the number of layers proposed to form the packaging body (1), the joints (6, 7) of the strips of each possible additional layer being substantially offset from those of the strips of the preceding layer, preferably by 90° and, finally, cutting the various superimposed layers as a function of the desired length of the packaging body (1) and emptying the packaging body (1) obtained.
2. Method of production according to claim 1, characterised in that it involves, after the shaping and positioning of the last layer of the body (1) to be produced and before cutting, unwinding a printed strip (11) intended to form the external label of the body (1) to be produced, then shaping and positioning it on the last layer by heat sealing or adhesion.
3. Method of production according to claim 1, characterised in that it involves, after the shaping and positioning of the last layer of the body (1) to be produced and before cutting, unpeeling a formatted label (11) then shaping and positioning it on the last layer by heat sealing or adhesion.
4. Method of production according to claim 1, characterised in that the cutting operation is triggered by a device which quantifies the travel of the packaging body (1) and involves, immediately after the triggering, displacing at least one cutting unit (19) from its rest position in parallel with the axis of travel of the body (1), then rapidly synchronising its speed of travel with the speed of advance of said body (1), dividing the body (1) by the actuation of knife holders (29) equipped with knives (29′) after speed synchronisation and, finally, rapidly returning said cutting unit (19) to its rest position.
5. Package obtained by application of the method according to any one of claims 1 to 4, of which the body (1) comprises an internal complex and at least two superimposed layers of a material such as paper, cardboard, metal foil, synthetic material or any other materials, said packaging body (1) consisting, on the one hand, of an impermeable internal complex (8) compatible with the product to be packaged, this internal complex being composed either of a strip folded back on one side and heat sealed on each side or of two strips which are heat sealed on each side, and, on the other hand, of two additional layers superimposed by adhesion or heat sealing each composed of two parts (2, 3 or 4, 5) which are joined without overlapping, the width of each part (2 to 5) being exactly equal to half of the perimeter of the packaging body (1) and the joints (7) of the two parts (4, 5) forming the second additional layer being offset by an angle of 90° from the joints (6) of the two parts (2, 3) forming the first additional layer, said package also comprising an external label (11).
6. Device for carrying out the method according to any one of claims 1 to 4, for producing a package according to claim 5, consisting of a machine (12) for the continuous shaping of the body (1) connected, on the one hand, to at least one unwinder (13), if applicable a glue-spreading unwinder, in a proportion of one per part (2 to 5) forming each layer of the packaging body (1) and, on the other hand, to at least one unwinder (24) of the strip(s) intended to form the internal complex (8) of the body (1), characterised in that said shaping machine (12) comprises a mandrel (14) having the shape desired of the packaging body (1) and stations (15, 16) for the shaping and positioning of each layer round the mandrel (14) by means of shaping wheels (21 or 27) or blocks (28), rollers (17) driving the layers thus formed towards a cutter (18), said shaping machine (12) also having a continuous heat sealing station (22) upstream of the layer shaping and positioning stations (15 and 16) consisting of four heat sealing wheels (23) and connected to the discharge device(s) (24) of the strip(s) intended to form the complex (8) of the body (1), the section of the mandrel (14) in line with the heat sealing station (22) of said complex on its edges being smaller than that in line with the shaping and positioning stations (15, 16) so as to facilitate said heat sealing.
7. Device according to claim 6, characterised in that each layer of the packing body (1) is allocated a shaping and positioning station (15 or 16) consisting of four wheels (21 or 27) or four blocks (28), one station (15) shaping and positioning strips arriving from the unwinders (13) horizontally and preceding a station (16) shaping and positioning strips arriving from the unwinders (13) vertically, therefore previously twisted and vice versa.
8. Device according to any one of claims 6 and 7, characterised in that the shaping machine (12) has, downstream of the last shaping and positioning station (16) and upstream of the rollers (17) driving layers formed towards the cutter (18), a station (25) for the positioning and shaping of labels (11).
9. Device according to any one of the preceding claims 6 to 8, characterised in that the cutter (18) comprises one or more cutting units (19), the number of which depends on the desired length of the packaging body (1) and each of which comprises several knives (29′) opposing one another in pairs.
10. Device according to claim 9, characterised in that each cutting unit (19) consists, on the one hand, of one or more knife holders (29) provided with interchangeable knives (29′) with one or more blades (20) according to the profile of the body (1) to be divided, said knife holders (29) being mounted slidably on guide devices (30) and, on the other hand, of one or more devices (31) for actuating the knife holders (29) in pairs in the direction of the body (1) travelling on the mandrel (14).
11. Device according to claim 10, characterised in that the actuating device or devices (31) are in the form of toggle-joint devices (32) connected to jacks (33) and also comprise means (34, 35) for adjusting the course of the knife holders (29), the displacements of two opposing knife holders (29) being rendered simultaneous by a connecting means (36).

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