FR2981333A1 - METHOD FOR MANUFACTURING A PACKAGING BOX AND BOX OBTAINED ACCORDING TO SAID METHOD - Google Patents

Abstract

The subject of the present invention is a method of manufacturing a packaging box in which a cap (15) is cut out and shaped in a material having sealing and heat-sealing properties. cup-shaped lid (15) in one of the ends of a tubular box body (10) previously made of a material having sealing and heat-sealing properties, said raised edge of the seal (15) is sealed with ) at the inner face of said body, along a first peripheral sealing zone (50), a closure lid (21) is cut out of a sheet of semi-rigid material, this lid is stamped (21) to give it the shape of a bowl with a raised edge, said lid (21) is introduced into said end of said box body (10) above the lid (15), said seal being sealed raised rim of the cover (21) on the inside of said box body (10 ), along a second peripheral sealing zone (60), said second peripheral sealing zone (60) being separated from said first peripheral sealing zone (50) so as to provide a free sector of the can body (10) ) between said first peripheral sealing zone (50) and said second peripheral sealing zone (60), this free sector being able to delimit a free space (43).

Description

The present invention relates to a method of manufacturing a packaging box comprising at least one tubular box body made of a material having sealing properties. and heat-sealing, a bottom, a sealing cap and a closure cap, at least said bottom and said cap being assembled to said can body so as to make the packaging box airtight and moisture-proof, in which process said box body is first formed, said lid and said lid are fixed before filling of the box body and said bottom is fixed after filling of the box, or conversely.

The invention also relates to a packaging box obtained according to this method, this packaging box comprising at least one tubular box body made of a material having sealing and heat-sealing properties, a bottom, a sealing cap and a closure cap, at least said bottom and said cap being assembled to said can body so as to make the packaging box airtight and moisture-proof. PRIOR ART European Patent EP 668 151 B1 describes a method of manufacturing a tubular package which comprises in particular a step of manufacturing a tubular body made of a complexed material, a bottom and a closure lid, as well as a sealing cap disposed between the product contained in the packaging box and the lid. The bottom and the cover are assembled to said body so as to make the box waterproof. The bottom may be made of the same complexed material as the tubular body.

According to this method, the lid and the lid are shaped simultaneously by stamping, in the form of a bowl and the lateral edges of these two elements are welded simultaneously to the inner face of the box body to ensure a tight seal and protection effective of the packaged product. In practice, the lid is cut in an aluminum foil coated with a heat-sealable layer, the complexed material of the body and the bottom is cardboard lined with a heat-sealable film with or without aluminum foil, and the lid is simple cardboard. The cardboard lid and the foil lid are stamped simultaneously. Now these two materials, which are different in nature, but especially of different thickness, form folds at the time of their forming and recesses arranged between the folds, so that the peripheral surface of the lateral rim of the assembly formed by the cover and the cover which are secured after the stamping operation, is not a smooth surface and its welding on the inside of the can body can not guarantee perfect sealing of the packaging box at the level of its membrane. In addition, it is stated in the patent of the prior art that the rim of the lid has a height less than the rim of the lid, and that the two flanges are welded simultaneously using the same tool arranged to provide the thermal energy necessary to melt the heat sealable material which is usually polyethylene and to apply sufficient contact pressure to promote sealing. Therefore, in the lower part of the rim of the cuvettes respectively of the lid and the cover, the heat supply and the pressurization must be carried out through the thickness of the cardboard lid and the seal of complexed material. , while in the upper part of the rim of the cuvettes, the heat supply and the pressurization must be carried out only through the thickness of the carton of the lid, the lid being absent in this zone.

The heat input and the pressurization in these two zones are necessarily different and one can doubt the homogeneity of the sealing performed and therefore the tightness obtained. Finally, the patent provides for a precut of the can body between the two sealing areas mentioned above. Such a precut, at this location and under these conditions, is almost impossible to achieve because it requires precision both in height and depth that exceeds the usual tolerances of manufacture of the box body.

As a result, the packaging box resulting from the process described in the patent of the prior art does not meet the current requirements for tight packaging and long-term storage of packaged products, including products sensitive to moisture and in particular food products or the like. The sealing of the bottom and the seal must be able to guarantee a perfect seal at least as regards the primary seal, that is to say that required before opening the package. The lid must be able to guarantee an acceptable secondary seal according to the nature of the products concerned, ie the one required after opening the packaging.

SUMMARY OF THE INVENTION The present invention aims at overcoming all of the drawbacks identified by proposing a method of manufacturing a packaging box which absolutely guarantees the primary seal while facilitating the completion of the phases of the process. simplifying the equipment necessary for the implementation of these process phases. For this purpose, the invention relates to a method as mentioned in the preamble, and characterized in that the said seal is cut and shaped in a material having sealing and heat-sealing properties, the said insert is introduced. cup-shaped lid in said box body at one end thereof, said raised flange of the lid is sealed to the wall of said body along a first peripheral sealing zone, said lid in a sheet of a semi-rigid material, this lid is stamped to give it the shape of a bowl with a raised edge, said cup-shaped lid is introduced into said box body by said provided end. of said seal, said raised rim of the cover is sealed to the wall of said can body along a second peripheral sealing area, said second peripheral sealing area being separated from said first sealing area peripheral so as to provide a free sector of the can body between said first peripheral sealing zone and said second peripheral sealing zone. According to an advantageous embodiment, at least partial pre-cutting of the box body is carried out in said free space of the box body, located between said first peripheral sealing zone and said second peripheral sealing zone. According to a first method of manufacture, said at least partial precut of the box body is carried out prior to sealing said raised rim of the cover to the wall of said body. According to a first variant, said at least partial precut of the box body is carried out before sealing said raised rim of the cover to the wall of said body.

According to a second variant, said at least partial pre-cut of the can body after sealing of said raised rim of the lid and sealing of said raised edge of the lid to the wall of said body is carried out.

Particularly advantageously, the cover is positioned at a distance from the cover to define between them a free space. Depending on the application, this free space can be used to position at least one accessory object selected from the following objects: promotional items, toys, contest items, collectibles, consumables, utility items. Preferably, the box body is circumferentially creased in an end zone having at least a portion of the rim of said cover located beyond said second peripheral sealing zone and said end zone is wound up. the wall of the grooved box body to form a bead. For certain applications, it is possible to flatten said bead and seal the resulting bend. For this purpose also, the invention relates to a packaging box as defined in the preamble, characterized in that said lid is sealed to the wall of said body, along a first peripheral sealing zone, in that said lid is sealed to the wall of said box body, along a second peripheral sealing zone, said second peripheral sealing zone being separated from said first peripheral sealing zone so as to provide a free sector of the can body between said first zone peripheral sealing and said second peripheral sealing zone. According to an advantageous embodiment, the packaging box comprises at least one pre-cutout disposed between said first peripheral sealing zone and said second peripheral sealing zone. According to another advantageous embodiment, the packaging box comprises a rim hemmed at the end of said box body beyond said second peripheral sealing zone. According to the variant embodiments, the lid can be positioned at a distance from the operculum to delimit between them a free space. BRIEF DESCRIPTION OF THE DRAWINGS The present invention and its advantages will become more apparent in the following description of embodiments given by way of non-limiting example, with reference to the accompanying drawings, in which: Figure lA illustrates a first phase of the process according to the invention. invention, during which the body of the packaging box is produced, Figure 1B illustrates a complementary phase of the method according to the invention, during which the body of the packaging box is pre-cut, - Figure 2 illustrates a second phase of the process according to the invention, during which the lid is cut, stamped and positioned in the body of the packaging box, - Figure 3 illustrates a third phase of the method according to the invention, during the which the seal is sealed to the body of the packaging box, - Figure 4 illustrates a fourth phase of the method according to the invention, during the which the lid is cut, formed by stamping and positioned in the body of the packaging box; - Figure 5 illustrates a fifth phase of the method according to the invention, during which the lid is sealed to the body of the packaging box FIG. 6 illustrates a sixth phase of the method according to the invention, during which the end of the body of the packaging box corresponding to the lid and the lid is subjected to creasing; FIG. seventh phase of the method according to the invention, during which the end of the body of the packaging box corresponding to the lid and the lid is subjected to a curling, - Figure 8 illustrates an eighth phase of the method according to the invention, during which the flange formed at the end of the body of the conditioning box corresponding to the lid and lid during the seventh phase, is flattened, - the figur e 9 illustrates a ninth phase of the process according to the invention, during which the body of the packaging box is turned over to allow its filling with the product or products to be packaged, - Figure 10 illustrates a tenth phase of the process according to the invention. invention during which the bottom is cut, formed by stamping and positioned in the body of the filled packaging box, - Figure 11 illustrates an eleventh phase of the method according to the invention, in which the bottom is sealed at 12 illustrates the filled packaging box, in a first embodiment of the invention, FIG. 13 illustrates the filled packaging box, in a second embodiment of the invention which corresponds in a variant of the first embodiment, FIG. 14 schematically represents the box body after the first phase of the process illustrated by FIG. FIG. 1A, FIG. 15 schematically represents the box body after the complementary phase of the method illustrated in FIG. 1B, after the precut, FIG. 16 schematically represents the box body after the second phase of the process illustrated in FIG. 2, FIG. 17 schematically represents the box body after the third phase of the method illustrated in FIG. 3, FIG. 18 schematically represents the box body after the fourth phase of the process illustrated in FIG. 4, FIG. 19 schematically represents the body of the box. after the fifth stage of the process illustrated in FIG. 5, FIG. 20 schematically represents the can body after the sixth phase of the process illustrated in FIG. 6, FIG. 21 schematically represents the can body after the seventh phase of the illustrated process. in FIG. 7, FIG. 22 is a diagrammatic representation of the body of after the ninth phase of the process illustrated in FIG. 9, FIG. 23 schematically represents the can body after the tenth phase of the process illustrated in FIG. 10, and FIG. 24 schematically represents the can body after the eleventh phase of the process. illustrated in Figure 11.

Illustrations of the invention and a better way of carrying it out: With reference to FIG. 1A, the manufacturing method which is described comprises a first phase which consists of shaping a tubular box body 10 from a semi-rigid complexed material. strip-shaped 11, having sealing and heat-sealing properties. This complexed material may consist of one or more layers of cardboard, covered with a layer of a waterproof and heat-sealable material, such as for example polyethylene. Depending on the requirements, the tightness of this complexed material can be improved by adding between the cardboard and the heat-sealing material, a barrier layer, such as for example an aluminum strip or any other synthetic film having sealing properties. The strip 11 can be obtained either by coextrusion, rolling, or any other method. Shaping of the box body 10 can be performed by folding or winding on a mandrel 12 which can be rotatable or fixed, depending on the forming mode chosen. This shaping technique is known per se and this phase of the process does not correspond to one of the features of the invention. The tubular box body 10 is shaped by folding or winding of said strip 11 on the mandrel 12 to form a tubular element of circular, square, polygonal or other section, cut by means of knives 13. These knives 13 cut out the element tubular to the desired length corresponding to the final length of the can body 10 increased in over-lengths required to form the end flanges and beads. FIG. 1B illustrates a complementary phase that can take place immediately or even during the cutting of the can body 10 in the tubular element formed on the mandrel 12 or subsequently during the manufacturing process of the can. This complementary phase concerns the precut of the body of the packaging box using knives 14 along a pre-cut line 70 whose positioning is predetermined. For economic reasons and for the simplicity of the manufacturing process, this complementary phase is advantageously carried out at this time, while the box body 10 is still firmly fixed on the mandrel 12. This is why it is presented as a complementary phase of the first phase of manufacture of the box body 10.

FIG. 2 illustrates the second phase of the process during which the cover 15 is cut in a strip of a barrier material which may consist of an aluminum strip coated with a heat-sealable base of paper, aluminum strip and heat-sealable material, or one or more synthetic films combining the sealing and heat sealing functions. The cut blank has a surface corresponding to the increased box body section. the surface of the raised rim which will be fixed against the inner face of this body. It is cut by means of a knife or a punch 16 which co-operates with a counter-part 17. The folding in a bowl and the placing in a sector close to the upper end of the box body 10s are carried out by means of a pusher 18, which has a section substantially of the same size as the box body 10 and whose function is to push this bowl inside the upper opening. This pusher 18 is removed at the end of the second phase and the bowl remains in position in order to form the sealing cap 15 for sealing the upper opening of the box body 10 sealingly. Note that this and the following steps take place while the box body 10 is disposed in a support 28 ensuring good guidance and good maintenance of the box body 10. The third phase illustrated in Figure 3 consists of sealing, for example, to weld the flange of the bowl to the inner face of the can body 10 and to form said seal 15 ensuring the primary sealing of the packaging box. This operation takes place after the withdrawal of the pusher 18 and after the introduction inside the upper part of the can body 10 of a heating element 19 arranged to exert pressure on an outer counterpart 20 which retains the body and avoids a deformation likely to occur under the lateral thrust of the heating element 19. This operation ensures the sealing of the rim of the lid of the lid 15 over all or part of its height to the inner face of said can body 10 along a first peripheral sealing zone 50, arranged to lie below the precut line 70.

This sealing operation can be modulated according to the materials to be heat sealed, and their thickness. Applying the two heat-sealable layers together and heating them so as to melt the polyethylene makes it possible to weld the two layers by guaranteeing absolutely tightness of the inside of the box thanks to the continuity of the barrier layer in the sealing zone. The fourth phase illustrated in Figure 4 is substantially identical to the second phase illustrated in Figure 2. It consists in cutting the cover 21 in a strip of a semi-rigid material, for example cardboard or the like. The cut blank has a surface corresponding to the section of the box body 10 increased from the surface of the raised flange which will be fixed against the inner wall of this body. It is cut by means of a knife or a punch 22 which cooperates with a counter-part 23. The folding dish and placing in a sector near the upper end of the box body 10 s are carried out by means of a pusher 24, which has a section substantially of the same size as the box body 10 and whose function is to push this bowl inside the upper opening. This pusher 24 is removed at the end of the second phase and the bowl remains in position in order to fix the lid 21 by sealing at the upper end of the can body 10. The fifth phase illustrated in FIG. 5 is substantially identical to the third phase described above. It consists of sealing, for example soldering, the rim of the cover 21 to the inner face of the box body 10 to ensure the closure of this packaging box and the protection of the products it contains. This operation takes place after the withdrawal of the pusher 24 and the placement inside the upper part of the can body 10 of a heating element 25 arranged to exert pressure on an outer counterpart 26 which holds the body and avoids a deformation likely to occur under the lateral thrust of the heating member 25. This operation ensures the sealing of the rim of the bowl of the lid 21 over all or part of its height to the inner face of said body, along a second peripheral sealing zone 60, arranged to be located above the precut line 70.

It should be noted that the first peripheral sealing zone 50 and the second peripheral sealing zone 60 are completely independent. They are created separately, with separate tools and as the two elements, the lid 15 on the one hand and the lid 21 on the other hand are put in place separately, their relative positioning can be determined freely. Thus it is possible to provide an interval between the cover 15 and the cover 21 to define a space 43 which can remain empty or which can receive at least one accessory object selected for example from advertising objects, toys, contest items, collector's items, consumables, such as a seasoning accompanying the product packaged in the box, promotional items such as coupons, gifts, raffle tickets, utility items, such as a measuring spoon ( see Fig. 13) or any other object that may be useful as an accessory to the packaged product. FIG. 6 illustrates the sixth phase which consists of performing a creasing, cold or hot, of the end zone of the wall of the can body 10 protruding from the cover 21. This operation is intended to prepare this edge by grooving by means of a tool, which is in the example illustrated, a rotary wheel 27 engaged inside the area to be treated cooperating with a support piece 29 disposed outside the box body 10. If the box body 10 has a polygonal section, this tool may consist of radial jaws movable in translation. This operation is intended to facilitate the winding, also called padding, of this end zone 30 which will be provided with circumferential grooves 31. FIG. 7 illustrates the seventh phase which consists precisely in winding the end zone 30 inwardly of the box body 10 in order to form a bead 32. This operation is done by means of a curling tool 33 which is brought to the top of the can body 10. The eighth phase of the process is illustrated in FIG. 8 and consists in flattening the bead 32 by means of a cold or heated part 34 introduced inside the space delimited by the bead 32 and a counterpart 35 of complementary shape brought around this area. The flattening of the bead 32, which is an optional operation, consists, if necessary, in bringing against one another two portions of the inner face of the box body 10, that is to say two coated parts. of heat-sealable material. The heat input of the heating element 34 makes it possible to seal between them the two portions of the end zone 30 of the body. At this stage, the box body 10 is ready to receive the products to be packaged, after turning, as shown in FIG. 9. The filling, corresponding to the ninth phase of the process, is carried out by the bottom of the box body 10. Of course, according to the applications, it is possible to proceed in the opposite direction and to form and seal the bottom 36 of the conditioning box, to be able to fill it from above, before forming and sealing successively the seal 15 then the lid 21.

FIG. 10 illustrates the tenth phase of the method relating to the establishment of the bottom 36 of the box body 10. This operation is similar to that of the fourth phase which corresponds to the forming and positioning of the cover 21. it consists in cutting the bottom 36 in a strip of a semi-rigid complexed material, identical or similar to that which was used to shape the box body 10. The cut blank has a surface corresponding to the section of the body of raised box of the raised rim surface which will be fixed against the inner wall of this body. It is cut by means of a knife or a punch 37 which cooperates with a counter-piece 38. The folding in a dish and the placing in a sector close to the lower end of the box body 10s are carried out by means of a pusher 39, which has a section substantially of the same size as the box body 10 and whose function is to push this bowl inside the lower opening. This pusher 39 is removed at the end of the tenth phase and the bowl remains in position to be able to fix the bottom by sealing at the lower end of the can body 10 and completely close the previously filled conditioning box. Note that this step is performed while the box body 10 is disposed in a support 40 for good guidance and good maintenance of the box body 10. Figure 11 illustrates the eleventh phase of the process concerning the sealing of the bottom 36 of the can body 10. It is similar to the fifth phase of sealing the cover 21. It consists in welding the rim of the bottom 36 to the inner face of the can body 10 to ensure the closure of the conditioning box after its filling in a sealed manner. This operation takes place after removal of the pusher 39 and the introduction into the upper part of the can body of a heating element 41 arranged to exert pressure on an outer counterpart 42 which retains the walls and avoids a deformation likely to occur under the lateral thrust of the heating element 41. This operation ensures the sealing of the rim of the bowl of the bottom 36 over all or part of its height to the inner face of said box body 10.

As previously mentioned, the precut 70 made between the first sealing zone 50 and the second sealing zone 60 can be carried out immediately at the time of shaping and cutting of the can body 10 in the tubular element on the mandrel 12. this precut 70 may also be performed later, for example after sealing of the lid 15 and before sealing the lid 21, or after sealing of the lid 15 and lid 21. In addition, although the process mentions the use of heat-sealable materials, the heat-sealing operations could be replaced by gluing operations or any equivalent technique.

The resulting packaging box can be in two different aspects, schematically illustrated in FIGS. 12 and 13. The box 101 of FIG. 12 is distinguished by the fact that the cover 21 and the cover 15, although distinctly shaped and sealed separately are arranged close to each other, that is to say, slightly spaced, even adjacent. Their sealing zone 50, 60 in the form of peripheral belts are separated while remaining close. The box 102 of FIG. 13 is distinguished by the fact that the cover 21 and the cover 15, shaped separately and sealed separately, are arranged at a certain distance from each other, leaving a space 43 sufficient to allow, in the illustrated example, the introduction of an object 44 as specified above. Their respective sealing zones 50, 60 in the form of peripheral belts are separated and more or less distant. Depending on the destination of the packaging box, this space 43 can of course remain empty.30 The precut 70 of the conditioning box is located between said first peripheral sealing zone 50 and said second peripheral sealing zone 60. It allows an opening rapid packaging box without tearing the lid 15. It also allows the repositioning of the lid 21 on the box after opening. The cap 15 meanwhile can be removed by means of a pull tab (not shown) or any equivalent means, and is not repositionable. The flanged hem, and optionally folded and sealed, after creasing of the upper edge of the can body 10 is located at the upper end 30 of the can body 10 in an area beyond said second peripheral sealing zone 60 .

Figure 14 schematically shows the box body 10 after the first phase of the process illustrated in Figure 1A. A section of tubular element has been cut by the knives 13, the length of said section corresponding to the length of the box body 10 increased by the length necessary to achieve at least the bead 32. FIG. 15 schematically represents the box body 10 after the complementary phase of the process illustrated by Figure 1B performing the precut 70. This precut 70 can be performed in this phase, but could also be performed later. FIG. 16 schematically represents the box body 10 after the second phase of the process illustrated in FIG. 2. The cover 15, which is either pre-cut off the production line in a separate station, is cut continuously on the production line. in a suitable sheet, is formed and set up. Fig. 17 schematically shows the box body 10 after the third phase of the process illustrated in Fig. 3. The seal 15 is sealed and defines said first peripheral sealing area 50.30 Fig. 18 schematically shows the box body 10 after the fourth process step illustrated in Figure 4. The cover 21, which is either pre-cut off-line manufacturing in a separate station, or cut continuously on the manufacturing line in a suitable sheet, is formed and put in place above 15. FIG. 19 schematically represents the box body 10 after the fifth phase of the process illustrated in FIG. 5. The cover 21 is sealed and defines said second peripheral sealing zone 60.

Figure 20 schematically shows the box body 10 after the sixth phase of the process illustrated in Figure 6. The end zone 30 is grooved to form circumferential grooves 31.

Fig. 21 schematically shows the box body 10 after the seventh phase of the process illustrated in Fig. 7. The end zone 30 with grooves 31 is hemmed to form the bead 32. Fig. 22 schematically shows the box body 10 after the ninth phase of the process illustrated in Figure 9. The box body 10 was filled with the product to be packaged after turning. 23 schematically represents the box body 10 after the tenth phase of the process illustrated in FIG. 10. The bottom 36, which is either precut off-line in a separate station, or cut continuously on the production line in FIG. a suitable sheet is formed and put in place to permanently seal the packaging box. FIG. 24 schematically represents the box body 10 after the eleventh phase of the process illustrated in FIG. 11. The bottom 36 is sealed to the box body 10.

The present invention is not limited to the embodiments described but extends to any modification and variation obvious to a person skilled in the art while remaining within the scope of protection defined in the appended claims.

Claims (14)

REVENDICATIONS1. A method of manufacturing a packaging box comprising at least one tubular box body (10) made of a material having sealing and heat-sealing properties, a bottom (36), a seal (15) and a cover (21), said bottom (36) and said cap (15) being assembled to said box body (10) so as to make the airtight and moisture-proof packaging box, in which one firstly forms said box body (10), said lid (15) and said lid (21) are fixed before filling of the box body (10), and said bottom (36) is fixed after filling of the box, or conversely, characterized in that one cuts and shapes said lid (15) in a material having sealing and heat-sealing properties, said lid (15) in the form of cup in said box body (10) at one end thereof, said raised flange is sealed e from the cover (15) to the inner face of said body, along a first peripheral sealing zone (50), said cover (21) is cut in a sheet of a semi-rigid material, this lid (21) is stamped to give it the shape of a bowl with a raised edge, said dish (21) in the form of a bowl is introduced into said box body (10) by said end provided with said lid (15). ), said raised flange of the cover (21) is sealed to the inside face of said can body (10), along a second peripheral sealing area (60), said second peripheral sealing area (60) being separated from said first peripheral sealing zone (50) so as to provide a free sector of the can body (10) between said first peripheral sealing area (50) and said second peripheral sealing area (60). 2. Method according to claim 1, characterized in that one carries out a precut (70) at least partial of the box body (10) in said free space of the box body (10) located between said first peripheral sealing zone (50) and said second peripheral sealing zone (60). 3. Method according to claim 2, characterized in that one carries out said precut (70) at least partial of the box body (10) prior to sealing said raised rim of the cover (15) to the inner face of said body . 4. Method according to claim 2, characterized in that one carries out said precut (70) at least partial of the box body (10) prior to sealing said raised edge of the lid (21) to the inner face of said body. 5. Method according to claim 2, characterized in that one carries out said pre-cut (70) at least partial of the box body (10) after sealing said raised flange of the lid (15) and sealing said raised flange from the cover (21) to the inner face of said body. 6. Method according to claim 1, characterized in that said lid (21) is positioned at a distance from said lid (15) to define between them a free space (43). 7. Method according to claim 6, characterized in that said free space (43) is used to position at least one accessory object selected from the following objects: promotional items, toys, contest items, collectibles, products consumables, utility items (44). 8. Method according to claim 1, characterized in that it is carried out a peripheral creasing of the box body (10) in an end zone (30) having at least a portion of the rim of said cover (21) lying at said second peripheral sealing zone (60). 9. The method of claim 8, characterized in that said end zone (30) is wound from the wall of the grooved box body (10) to form a bead (32). 10. The method of claim 9, characterized in that one carries out a flattening of said bead (32) and a sealing of the fold obtained. Packaging box comprising a tubular box body (10) made of a material having sealing and heat-sealing properties, a bottom (36), a sealing cap (15) and a closure lid (21). at least said bottom (36) and said cap (15) being assembled to said box body (10) so as to render the packaging box airtight and moisture-proof, characterized in that said lid (15) ) is sealed to the inner face of said can body (10) along a first peripheral sealing area (50), in that said cover (21) is sealed to the inner face of said can body (10) on along a second peripheral sealing zone (60), said second peripheral sealing zone (60) being separated from said first peripheral sealing zone (50) so as to provide a free sector of the box body (10) between said first peripheral sealing zone e t said second peripheral sealing zone. 12. Packaging box according to claim 11, characterized in that it comprises at least one precut (70) disposed between said first peripheral sealing zone (50) and said second peripheral sealing zone (60). Packaging box according to claim 11, characterized in that it comprises a rim hemmed at the end (30) of said box body (10) beyond said second peripheral sealing zone (60). 14. Packaging box according to claim 11, characterized in that said lid (21) is positioned at a distance from said lid (15) to delimit between them a free space (43).