FR3034408B1 - PACKAGING ELEMENT FOR PACKAGING A STACK OF SUBSTRATE SHEETS AND ASSOCIATED PACKAGING ASSEMBLY - Google Patents

Abstract

The invention relates to a packaging element (1A, 1B) for packaging a stack of substrate sheets placed on a pallet, the packaging element (1A, 1B) comprising: - a central panel intended to be pressed against a vertical face of the stack, and - two side panels connected to the central panel and clean, when the central panel is pressed against the vertical face of the stack, to be positioned respectively on either side of the stack of sheets, each side panel coming into contact with a vertical face of the pallet. The invention also relates to a method including the establishment of a cap (41) and a closure system (42A, 42B) for the application of a seal of inviolability.

Description

FIELD OF THE INVENTION The invention relates to a packaging element for packaging a stack of sheets placed on a pallet. The invention applies in particular, but not exclusively, to the packaging of stacks of printed sheets used for the manufacture of banknotes.

STATE OF THE ART

The manufacture of banknotes comprises a series of steps, during which substrate sheets pass successively in different machines in order to be printed and cut. The substrate may be paper or any other support that can be printed. At the end of each step, the substrate sheets are packaged in stacks that may comprise several thousand sheets, each stack of sheets being stored in racks while waiting to proceed to the next manufacturing step. The storage of the batteries makes it possible, in particular, to dry the sheets between two manufacturing steps.

It should be noted that, in the case where the substrate is paper-based, the paper being a material whose properties change depending on the temperature and humidity conditions, the height of a stack may decrease between the moment when the battery leaves a printing machine (at a temperature and humidity higher than the ambient temperature and humidity) and the moment when the battery is at rest, in the storage place.

In order to allow the handling and storage of batteries, the batteries are generally deposited, at the output of the machine, on a pallet suitable for being supported by a forklift or a transport device.

Stacks of leaves are very unstable due to a sliding of the sheets relative to each other. These batteries must be maintained during their handling and storage. For this purpose, one possible solution is to position rigid holding brackets at the four corners of each stack of sheet and surround the assembly with an adhesive tape to tighten the brackets against the stack.

In addition, to protect the sheets of the stack and prevent sheets can be taken from the pile, a tray is placed above the brackets and a flexible protective cap is threaded on the set, then the stack with the cap is circled crosswise with a polymer strap.

However, despite these precautions, it has been found that the stacks of leaves always tend to deform during handling. The main cause of the sliding of the sheets relative to each other is the jolts generated by the starting and the braking of the forklift or the transport apparatus.

In the case of freshly printed sheets, the sliding of the sheets relative to each other is detrimental because it causes a degradation of these sheets and / or burrs.

In addition, the installation of brackets and tape requires the simultaneous intervention of several operators.

In addition, the establishment of brackets, tape, tray, cap and strip requires a large number of operations, and requires the use of consumable material (tape, strip) and tools specific (wire feeder, electric strap, electric strapping machine). This has the disadvantage of requiring the operator to manage a large number of references of consumables and equipment, which he must ensure the availability at all times.

Finally, in the case where the stack of sheets is not properly centered on the pallet, there is a risk that a square comes off the stack.

SUMMARY OF THE INVENTION

An object of the invention is to provide a packaging solution of a stack of sheets that effectively limits the sliding of the sheets relative to each other during handling and storage of the stack.

This object is achieved in the context of the present invention, thanks to a conditioning element for packaging a stack of substrate sheets placed on a pallet, the packaging element comprising: a central panel intended to be pressed against a vertical face of the stack, and - two side panels connected to the central panel and clean, when the central panel is pressed against the vertical face of the stack, to be positioned respectively on either side of the stack of sheets, each side panel coming into contact with a vertical face of the pallet.

It has indeed been found that the deformation of the stack of sheets occurs mainly in a direction of movement of the transport apparatus. The proposed packaging element may be arranged with the central panel in contact with the front or the rear face of the battery, which extends transversely to the direction of travel of the transport apparatus.

In addition, the two side panels allow to maintain the central panel relative to the pallet, whatever the position of the stack on the pallet (the stack is not necessarily centered on the pallet). The packaging element may furthermore have the following characteristics: the substrate sheets being stacked in a stacking direction, each side panel has a dimension measured in the stacking direction greater than one dimension of the central panel measured according to the direction of stacking, so that each side panel forms a clean extension to come into contact with a vertical face of the pallet, - each side panel is pivotally mounted on the central panel, - each side panel is connected to the central panel by a fold line, - the panels are formed by cutting from a single plate of material, - the plate comprises two layers of skin and a honeycomb core formed between the two skin layers, - the plate is formed of plastic material, such as polypropylene for example, - each side panel has clean feet to bear on the floor of m maintaining the central panel above the pallet, - the conditioning element comprises fastening means arranged on each side panel, for fixing each side panel to the vertical faces of the pallet, - each side panel has an inner face. intended to be positioned facing the cell and an outer face, opposite to the inner face, the conditioning element comprising first fixing means arranged on the inner face and second fixing means arranged on the outer face, the second means fixing means being adapted to cooperate with first means for fixing another identical packaging element for fixing the lateral panels of the conditioning element to the side panels of the other conditioning element, the first fixing means comprise a fixing strip extending on the inner face in a first direction, and the second the fixing means comprise a fastening strip extending on the outer face in a second direction, the second direction being non-parallel to the first direction; the first fastening means comprise a hook structure extending on the inner face; and the second fastening means comprise a loop structure on the outer face, the hooks being adapted to engage the loops to secure each side panel to another side panel, - each panel has through openings allowing air to flow through the panel to promote drying of the sheets of the stack, - the substrate sheets being stacked in a stacking direction, each opening has an elongate shape in a direction parallel to the stacking direction. The invention also relates to a packaging assembly for packaging a stack of substrate sheets disposed on a pallet, comprising: two conditioning elements as defined above, each conditioning element being able to be arranged with its panel center respectively against a front face and a rear face of the stack, and - a clean cap to be disposed above the two elements to close the packaging. The packaging assembly may have the following characteristics: the assembly further comprises a first clean hook to engage with the pallet of a first side of the stack, a second clean hook to engage with the pallet of a second side of the stack, and at least one strap adapted to connect each hook to the cap to hold the two conditioning elements and the cap on the pallet, the set comprises a first strap connected to the first hook and a second strap connected to the second hook, - each strap comprises an orifice, and the cap comprises a pin adapted to be inserted into the hole for fixing the strap to the cap, - the pin has an end with a transverse through hole for insertion of a seal, - the cap has a recess, the pawn extending from the bottom of the recess, - the cap has a groove for the passage of each strap, - c each strap comprises a first fastening strip and the cap has a second fastening strip, one of the two strips comprising a loop structure and the other of the strips comprising a hook structure, the hooks being adapted to engage with the loops for releasably securing the strap on the cap; the cap comprises a main panel adapted to be resting on top edges of the packaging elements and flaps extending perpendicular to the main panel to prevent access to the lid; inside the packaging. The invention also relates to a method for packaging a stack of substrate sheets disposed on a pallet by means of a packaging assembly as defined above, comprising steps of: - disposing a first conditioning element by plating the central panel against a first face of the stack, - pressing the side panels of the first element against the side faces of the pallet, - arranging a second conditioning element by pressing the central panel against a second face of the stack, opposite to the first side, - connect the side panels of the second element to the side panels of the first element, and - arrange the cap above the conditioning elements to close the packaging.

Finally, the invention relates to a stack of conditioned substrate sheets obtained by a packaging method as defined above.

PRESENTATION OF THE DRAWINGS Other characteristics and advantages will become apparent from the description which follows, which is purely illustrative, and not limiting, and should be read with reference to the appended figures, among which: FIGS. 1A and 1B show schematically, in front view and in rear view, a packaging element according to an embodiment of the invention; - Figure 2 schematically shows, in cross-section, a possible structure of a plate of material forming the 3A to 3C schematically represent different configurations of the conditioning element; FIG. 4 schematically shows a packaging assembly including the conditioning element of FIGS. 1A and 1B; FIGS. 5 to 14 schematically illustrate steps of a method of packaging according to a mode of mi FIG. 15 schematically shows a stack of conditioned substrate sheets.

DETAILED DESCRIPTION OF AN EMBODIMENT

In Figures 1A and 1B, the conditioning element 1 shown has a generally planar shape. The conditioning element 1 may be formed by cutting from a single plate of material.

As illustrated in Figure 2, the plate 2 of material used comprises two skin layers 3 and 4 and a cellular core 5 formed between the two skin layers 3 and 4. The plate 2 is formed of plastic, such as polypropylene for example. The conditioning element 1 comprises a first face 6 (or internal face), visible in FIG. 1A, and a second face 7 (or external face), opposite to the first face 6 and visible in FIG. 1B. conditioning element 1 comprises a central panel 8, a first side panel 9 and a second side panel 10, the central panel 8 extending between the two side panels 9 and 10.

The central panel 8 has an upper edge 11, a lower edge 12, a first side 13 and a second side 14.

The first side panel 9 has an upper edge 15, a lower edge 16, a lateral edge 17 and a side 18.

The second side panel 10 has an upper edge 19, a lower edge 20, a lateral edge 21 and a side 22.

The first side panel 9 and the second side panel 10 extend respectively from the first lateral side 13 and the second lateral side 14 of the central panel 8.

The first side panel 9 and the second side panel 10 are connected to the central panel 8 respectively by a first fold line and a second fold line extending respectively along the first side 13 and the second side 14. The fold lines may be formed by creasing the material plate forming the conditioning element.

In this way, the side panels 9 and 10 are articulated on the central panel 8.

Alternatively, the first side panel 9 and the second side panel 10 could be connected to the central panel 8 by mechanical hinges.

Each side panel 9, 10 has a height H2, measured in a first direction X (or vertical direction), parallel to the sides 13 and 14 of the central panel 8, greater than the height H1 of the central panel 8, measured along the same direction X .

The material plate 2 forming the conditioning element 1 has a notch 23 delimited by the lower edge 12 of the central panel 8, the notch 23 being intended to allow the insertion of a handling pallet under the central panel 8.

Each side panel 9 and 10 has two protrusions respectively 24, 25 and 26, 27, extending from its lower edge 16 and 20. Each protrusion 24, 25, 26 and 27 forms a clean foot to bear on the so as to maintain the central panel 8 above the pallet during assembly of the packaging assembly.

Furthermore, the conditioning element 1 comprises first fixing means 28, 29 (visible in FIG. 1A), arranged on the internal face 6 of the element. The first fastening means 28, 29 comprise first fastening strips extending on each of the side panels 9 and 10. The first strips extend along the edges 17 and 21 of the side panels 9 and 10, in a parallel direction. in the first direction X. The conditioning element 1 also comprises second fastening means 30 to 35 (visible in Figure 1 B), arranged on the outer face 7 of the element. The second fastening means 30 to 35 comprise second fastening strips extending on each of the side panels 9 and 10. The second strips extend in a second direction Y, perpendicular to the first direction X.

The first and second strips form a hook and loop fastening system, Velcro® type. For this purpose, the first bands comprise a hook structure while the second bands comprise a loop structure.

In this way, the second attachment means 30 to 35 arranged on the outer face 7 are adapted to cooperate with first fastening means 28 and 29 of another identical packaging element for fixing the side panels 9 and 10 of the conditioning element to the side panels of the other conditioning element. Specifically, the hooks of the first strips engage the loops of the second strips to secure each side panel 9, 10 to another side panel, detachably. The conditioning element also comprises third fixing means 36, 37 (visible in FIG. 1A) arranged on the internal face 6 of the element. The third fastening means 36, 37 comprise third fastening strips extending on each of the side panels 9 and 10. The third strips extend along the lower edges 16 and 20 of the side panels 9 and 10, according to the second direction Y.

The third attachment means 36, 37 are adapted to cooperate with means for fixing the pallet handling. More specifically, the third strips comprise a clean hook structure to engage a loop structure of the pallet attachment means.

Each panel 8 to 10 has through apertures 38 allowing air to flow through the panel. Each opening 38 has an elongate shape in the first direction X.

In Figure 3A, the conditioning element 1 is shown in folded configuration.

In this configuration, the two side panels 9 and 10 are folded against the central panel 8. The inner face 6 of the first side panel 9 is in contact with the outer face 7 of the second side panel 10. Thus, the first fastening means 28 , 29 arranged on the first side panel 9 are engaged with the second fastening means 30 to 35 arranged on the second side panel 10, thereby maintaining the conditioning element 1 in the folded position.

As illustrated in FIG. 3B, the conditioning element 1 can be deployed. For this purpose, the side panels 9 and 10 are successively rotated relative to the central panel 8. Each side panel 9 and 10 is pivoted around the fold line which connects it to the central panel 8.

In FIG. 3C, the conditioning element 1 is shown in deployed configuration.

In this configuration, each side panel 9 and 10 is positioned in a plane substantially perpendicular to the plane in which extends the central panel 8 to which it is articulated. The conditioning element 1 is able to hold itself on the ground, resting on the feet 24 to 27.

In FIG. 4, the conditioning unit 40 comprises a first conditioning element 1A, a second conditioning element 1B, a cap 41, a first attachment member 42A and a second attachment member 42B.

Each conditioning element 1A, 1B is identical to the conditioning element 1 described with reference to FIGS. 1A and 1B.

The cap 41 comprises a main panel 43, of generally rectangular shape and flaps 44 extending rigidly, perpendicular to the main panel 43 from each side of the main panel 43. The main panel 43 and the flaps 44 are formed by cutting from a single plate of material. The plate may have a structure identical to that of FIG. 2. Once cut, the plate is shaped so as to orient the flaps 44 with respect to the main panel 43.

The cap 41 also comprises an additional layer 45 forming an extra thickness on the upper face of the main panel 43. The additional layer 45 may be formed by cutting from a second plate of material. The additional layer 45 does not completely cover the main panel 43. The additional layer 45 thus delimits a recess in the form of a groove 47 extending across the main panel 43. The groove 47 extends from a first side of the main panel 43 to a second side of the main panel 43, opposite the first side.

The cap 41 also comprises a pin 49 disposed in the center of the main panel 43, in the groove 47. The pin 49 extends from the bottom of the groove 47, projecting from the main panel 43. The pin 49 can be positioned from such that it exceeds little or no additional layer 45 to run less risk of damage during handling of the cap 41. The pin 49 has one end with a transverse through hole 50.

The fasteners 42A and 42B are identical to each other. Each fastener 42A, 42B comprises a flexible strap 51 and a hook 52.

The strap 51 has a first end connected to the hook 52, and a second end having an orifice 53. The strap 51 also comprises an eyelet made of rigid material, surrounding the orifice 53.

The hook 52 comprises a rod 54 connected to the strap 51 and two claws 55.

In Fig. 4, the stack 60 of substrate sheets to be packaged comprises a plurality of stacked substrate sheets in a stacking direction X (or vertical direction). The stack of sheets 60 may comprise several thousand substrate sheets, for example 6000 sheets of substrate. Each substrate sheet is blank, or printed on at least one face with a pattern representing a plurality of bills. The substrate forming the sheets may be paper or any other support capable of being printed.

The substrate sheets are substantially aligned with each other in the stack 60. The stack 60 of substrate sheets thus has four substantially vertical faces 61, 62, 63 and 64, each face being formed of superimposed edges of the substrate sheets. .

The stack 60 of sheets rests on a handling pallet 70. The handling pallet 70 comprises a planar upper face 75 on which is disposed the stack 60 of sheets, and four lateral faces 71, 72, 73 and 74 extending perpendicularly to the upper face 75. At least one of the side faces 71 to 74 has openings 76 for the insertion of a fork of a handling device. Moreover, the lateral faces 73 and 74 comprise fastening means 77, in the form of strips having a loop structure.

Figures 5 to 14 illustrate the different steps of a method of mounting the packaging assembly 40 around a stack of substrate sheets 60.

Each conditioning element 1A, 1B is initially in an expanded configuration, as illustrated for example in FIG. 3C.

In a first step (FIG. 5), the first conditioning element 1A is positioned against a first vertical face 61 of the stack 60 of sheets.

More specifically, the first conditioning element 1A is positioned so that the inner face 6 of the central panel 8 is pressed against the first vertical face 61 of the stack 60. The central panel 8 is disposed above the pallet 70, the lower edge 12 of the central panel 8 passing above the upper face 75 of the pallet 70.

In this position, the two side panels 9 and 10 extend on either side of the stack 60 of sheets and the pallet 70. The feet 24 to 27 of the side panels 9 and 10 rest on the ground and maintain the central panel 8 above the pallet 70.

In addition, each side panel 9 and 10 of the first conditioning element 1A is pressed against a respective lateral face 73 and 74 of the pallet 70.

The third attachment means 36, 37 arranged on the inner face 6 of the side panels 9, 10 engage with fixing means 77 arranged on the side faces 73 and 74 of the handling pallet. The hook structure of the third fastening means 36, 37 engage with the loop structure of the fastening means 77 of the pallet 70. The conditioning element 1A is thus found in a semi-rigid configuration where the inner face 6 of the central panel 8 of the conditioning element 1A is in contact with the face 61 of the stack of sheets 60, and is simultaneously held on the side walls 73 and 74 of the handling pallet 70.

According to a second step (FIG. 6), the second conditioning element 1B is positioned against a second vertical face 62 of the stack 60 of sheets, opposite to the first vertical face 61.

More specifically, the second conditioning element 1B is positioned so that the inner face 6 of the central panel 8 is pressed against the second vertical face 62 of the stack 60. The central panel 8 is disposed above the pallet 70, the lower edge 12 of the central panel 8 passing above the upper face 75 of the pallet 70.

During the introduction of this second packaging element 1B, it is possible to apply a mechanical action to reduce any slight stacking defects of the substrate sheets and thus obtain a better quality stack.

In addition, each side panel 9, 10 of the second conditioning element 1B is pressed against a respective side panel 10, 9 of the first conditioning element 1 A.

The first fixing means 28, 29 arranged on the internal face 6 of the lateral panels 9, 10 of the second conditioning element 1B engage with second fastening means 30 to 35 arranged on the outer face 7 of the side panels 9 and 10. of the first conditioning element 1A. The hook structure of the first attachment means 28, 29 of the second conditioning element 1B engages with the loop structure of the second fastening means 30 to 35 of the first conditioning element 1A.

Since the first fastening strips and the second fastening strips extend in non-parallel directions, the loop hook structures come into engagement even though the side panels 9 and 10 of the two packaging elements 1A and 1B are not perfectly aligned with each other. In addition, this arrangement makes it possible to limit the fastening force between the conditioning elements.

With this arrangement of the fastening strips, the packaging elements 1A and 1B are suitable for gripping stacks of substrate sheets 60 of different sizes.

In a third step (Figures 7 and 8), the cap 41 is disposed above the two packaging elements 1A and 1B to close the package.

The cap 41 is arranged so that the main panel 43 is placed in abutment on the upper edges 11, 15 and 19 of the packaging elements 1A and 1B and that the flaps 44 partially cover the panels 8, 9 and 10 of the packaging elements. to prevent access to the stack of sheets.

The cap 41 is held by the conditioning elements 1A and 1B above the stack of sheets 60, so that the cap 41 does not rest on the stack of sheets 60. The cap 41 thus exerts no stress according to the X direction on the stack of leaves.

In addition, the dimensions of the cap 41 are preferably chosen to be sufficiently large relative to the area delimited by the packaging elements 1A and 1B, so as to make it possible to package stacks of substrate sheets 60 of different sizes.

According to a fourth step (FIGS. 9 and 10), once the packaging has been closed, the attachment members 42A and 42B are installed.

The hook 52 of the first attachment member 42A is positioned on a first side of the stack 60 and engaged with the pallet 70. Specifically, the hook 52 is engaged with one of the side faces 73 of the pallet 70. The side face 73 of the pallet 70 with which the hook 52 is engaged is the side face 73 against which the second side panel 10 of the first conditioning element 1A is plated.

Similarly, the hook 52 of the second attachment member 42B is positioned on a second side of the stack 60, opposite to the first side, and engaged with the pallet 70. Specifically, the hook 52 is engaged with one of the side faces 74 of the pallet 70 against which is plated the first side panel 9 of the first conditioning element 1 A.

According to a fifth step (FIGS. 11 and 12), the pin 49 is inserted into the orifice 53 of the strap 51 of the first attachment member 42A to fasten the strap 51 to the cap 41.

Similarly, the pin 49 is inserted into the hole 53 of the strap 51 of the second attachment member 42B to attach the strap 51 to the cap 41.

The straps 51 of the first attachment member 42A and the second attachment member 42B extend into the groove 47 of the cap 41.

To facilitate the mounting of the fasteners 42A and 42B, it is possible to provide that each strap 51 comprises a first fastening strip and the cap 41 has a second own fastening strip to cooperate with the fastening strip of the strap. One of the two strips may comprise a loop structure and the other of the strips may comprise a hook structure, the hooks being adapted to engage the loops to secure the strap 51 to the cap 41 in a detachable manner.

According to a sixth step (FIGS. 13 and 14), a seal 80 is inserted through the transverse through hole 50 of the pin 49. Once the seal 80 is inserted into the hole 50, it is no longer possible to remove the straps 51 without damage the seal 80.

Each strap 51 extends between the hook 52 to which the strap is connected and the pin 49. Each strap 51 extends in front of one of the side panels 9, 10 of the second packaging element 1B, thereby preventing the release of the strap. second conditioning element 1B of the first conditioning element 1A. Furthermore, the flanges 44 of the cap 41 also prevent any disassembly of the packaging elements 1A and 1B. All the above steps can be easily performed by a single operator and does not require the use of specific tool.

The disassembly of the packaging unit 40 requires first to break the seal 80.

Once the assembly 40 disassembled, the various elements of the packaging assembly 40 can be reused to condition a new stack of sheets.

In addition, the packaging elements 1A and 1B can be easily stored in folded configuration, when not in use.

Figure 15 schematically shows a stack of conditioned substrate sheets.

The stack of conditioned substrate sheets may be transported by a transport apparatus and stored.

During transport, the stack of sheets is held between the central panel 8 of the first conditioning element 1A in contact with the first face 61 of the stack and the central panel 8 of the second conditioning element 1B in contact with the second face 62 of the battery.

The pallet 70 is grasped by the transport apparatus and moved so that the first face 61 and the second face 62 of the stack 60 extend transversely to the direction of travel of the transport apparatus.

In this way, the central panels 8 of the packaging elements 1A and 1B prevent deformation of the stack of sheets due to jerks occurring in the moving direction of the transport apparatus.

During storage, the vent openings 38 allow air to flow through the package members 1A and 1B to promote drying of the sheets of the stack within the package.

The elongate shape of the apertures 38 in a direction parallel to the stacking direction X prevents a sheet of the stack from being picked up through one of the apertures 38.

Claims (24)

A packaging element (1) for packaging a stack (60) of substrate sheets placed on a pallet (70), the packaging element (1) comprising: - a central panel (8) intended to be pressed against a vertical face (61,62) of the stack (60), and - two side panels (9, 10) connected to the central panel (8) and clean, when the central panel (8) is pressed against the vertical face (61,62) of the stack, to be positioned respectively on either side of the stack of sheets, each side panel (9, 10) coming into contact with a vertical face (73, 74) of the pallet (70 ), wherein, the substrate sheets being stacked in a stacking direction (X), each side panel (9, 10) has a dimension (H2) measured in the stacking direction (X) greater than one dimension ( H1) of the central panel (8) measured in the stacking direction, so that each side panel (9, 10) forms an ext A cleaner assembly for coming into contact with a vertical face (73, 74) of the pallet (70). 2. Packaging element, according to claim 1, wherein each side panel (9, 10) is pivotally mounted on the central panel (8). 3. Packaging element according to one of the preceding claims, wherein each side panel (9, 10) is connected to the central panel (8) by a fold line. 4. Packaging element according to one of the preceding claims, wherein the panels (8-10) are formed by cutting from a single plate of material. 5. A packaging element according to claim 4, wherein the plate (2) comprises two skin layers (3, 4) and a cellular core (5) formed between the two skin layers (3, 4). 6. Packaging element according to one of claims 4 and 5, wherein the plate (2) is formed of plastic, such as polypropylene for example. 7. Packaging element according to one of the preceding claims, wherein each side panel (9, 10) has feet (24-27) adapted to bear on the floor so as to maintain the central panel (8). above the pallet (70). 8. Packaging element according to one of the preceding claims, comprising fixing means (36, 37) arranged on each side panel (9, 10), for fixing each side panel (9, 10) to the vertical faces (73). 74) of the pallet (70). 9. Packaging element according to one of the preceding claims, wherein each side panel (9, 10) has an inner face (6) intended to be positioned facing the stack (60) and an outer face (7), opposed to the inner face (6), the conditioning element (1) comprising first fixing means (28, 29) arranged on the inner face (6) and second fixing means (30-35) arranged on the external face (7), the second fixing means (30-35) being adapted to cooperate with first fixing means (28, 29) of another identical conditioning element for fixing the lateral panels (9, 10) of the conditioning element (1) to the side panels of the other conditioning element. 10. Packaging element according to claim 9, wherein the first fastening means (28, 29) comprise a fastening strip extending on the inner face (6) in a first direction (X), and the second means of fastening. fixation (30-35) comprise a fastening strip extending on the outer face (7) in a second direction (Y), the second direction (Y) being non-parallel to the first direction (X). 11. Packaging element according to one of claims 9 and 10, wherein the first fastening means (28, 29) comprise a hook structure extending on the inner face (6) and the second fastening means (30). -35) comprise a loop structure on the outer face (7), the hooks being adapted to engage the loops for securing each side panel (9, 10) to another side panel. 12. A packaging element according to one of the preceding claims, wherein each panel (8-10) has through openings (38) allowing air to flow through the panel to promote drying of the leaves of the stack (60). The packaging element of claim 12, wherein, the substrate sheets being stacked in a stacking direction (X), each opening (38) has an elongated shape in a direction parallel to the stacking direction (X). ). A packaging assembly (40) for packaging a stack of substrate sheets (60) disposed on a pallet (70), comprising: - two packaging elements (1A, 1B) according to one of the preceding claims. , each conditioning element (1A, 1B) being adapted to be arranged with its central panel (8) pressed respectively against a front face (61) and a rear face (62) of the battery (60), and - a cap ( 41) adapted to be disposed above the two elements (1A, 1B) to close the packaging. The packaging assembly (40) of claim 14, further comprising a first hook (52) adapted to engage the pallet (70) of a first side of the stack (60), a second hook (52) ) adapted to engage the pallet (70) of a second side of the stack (60), and at least one strap (51) adapted to connect each hook (52) to the cap (41) to hold the two conditioning elements (1A, 1B) and the cap (41) on the pallet (70). 16. Packaging assembly according to claim 15, comprising a first strap (51) connected to the first hook (52) and a second strap (51) connected to the second hook (52). 17. Packaging assembly according to one of claims 15 and 16, wherein each strap (52) comprises an orifice (53), and the cap (41) comprises a pin (49) adapted to be inserted into the orifice ( 53) to attach the strap (52) to the cap (41). The packaging assembly of claim 17, wherein the pin (49) has an end with a transverse through hole (50) for insertion of a seal (80). 19. Packaging assembly according to one of claims 17 and 18, wherein the cap (41) has a recess (47), the pin (49) extending from the bottom of the recess (47). 20. Packaging assembly according to one of claims 15 to 19, wherein the cap (41) has a groove (47) for the passage of each strap (51). 21. Packaging assembly according to one of claims 15 to 20, wherein each strap (51) comprises a first fastening strip and the cap (41) has a second fastening strip, one of the two strips comprising a structure with the loops and the other of the bands comprising a hook structure, the hooks being adapted to engage the loops for securing the strap on the cap (41) detachably. 22. Packaging assembly according to one of claims 14 to 21, wherein the cap (41) comprises a main panel (43) adapted to be placed in abutment on the upper edges (11, 15, 19) of the conditioning elements. (1A, 1B) and flaps (44) extending perpendicularly to the main panel (43) to prevent access to the interior of the package. A method of packaging a stack of substrate sheets (60) disposed on a pallet (70) by means of a packaging assembly (40) according to one of claims 14 to 22, comprising steps of: - arranging a first conditioning element (1A) by pressing the central panel (8) against a first face (61) of the stack (60), - pressing the side panels (9, 10) of the first element (1A) against the side faces (73, 74) of the pallet (70), - arranging a second conditioning element (1B) by pressing the central panel (8) against a second face (62) of the stack (60), opposite the first face (61), - connect the side panels (9, 10) of the second element (1B) to the side panels (9, 10) of the first element (1A), and - arrange the cap (41) above the elements of conditioning (1A, 1B) to close the packaging. 24. Stack of conditioned substrate sheets obtained by a packaging method according to claim 23.