WO2018046817A1

WO2018046817A1 - Construction element

Info

Publication number: WO2018046817A1
Application number: PCT/FR2017/052249
Authority: WO
Inventors: Guido Plum; Christian Mueller; Hans-Werner Kuster; Rolf Koette
Original assignee: Saint-Gobain Glass France
Priority date: 2016-09-08
Filing date: 2017-08-21
Publication date: 2018-03-15
Also published as: EP3510212A1; FR3055639B1; EP3510212B1; FR3055639A1

Abstract

The invention relates to a construction element (10), in particular for a floor, staircase or wall, which comprises at least a first sheet (12) and a second sheet (14) stacked and separated from one another, in a stacking direction (Z), and means (20, 30) for fastening the first (12) and second sheets (14) to one another, arranged between said sheets. The fastening means (20, 30) comprise at least one retaining element (20) attached to the first sheet (12) and at least one adhesive product (30) adhering to the second sheet (14), the retaining element (20) forming a receiving groove (28) which can be filled with the adhesive product (30) in a non-hardened state and having at least one anchoring portion (24, 26) suitable for retaining the adhesive product (30) in a hardened state. The retaining element (20) and the adhesive product (30) are each made of a material which allows the adhesive product (30) in the hardened state to be removed from said groove (28) without damaging the retaining element (20).

Description

Building element

TECHNICAL AREA

The present disclosure relates to a building element, in particular a building element that can form all or part of a floor, a staircase or a wall.

More particularly, the present disclosure relates to such a construction element of the type comprising at least a first and a second sheet superimposed at a distance from one another, in a direction of superposition, and means for fixing the first and second sheets between them, arranged between said sheets.

BACKGROUND OF THE INVENTION

The floors, stairs or walls are today made of very diverse materials including noble materials, such as transparent glass or lacquered glass, to give an architectural style to the building, increase the brightness of rooms, or allow a visibility between different rooms or levels of a building.

A glass floor 200 of the current type is illustrated by way of example in FIG. 1. The floor is formed by juxtaposition of building elements 110 each comprising the superposition of a lower glass sheet 112 and a sheet of glass. superior glass 1 4.

Each building element 1 is typically supported at its periphery by one or more holding brackets 190 generally made of metal, to which the lower glass sheet 112 is often adhered by means of an adhesive 194.

A seal 180 is formed between the edge of the upper glass sheet 114 of a building element 110 and the edge of the upper glass sheet 114 of an adjacent building element 110.

The opposite faces of the lower and upper glass sheets of the same building element are kept at a distance from each other by spacers 170, and fixed directly to one another by means of a cord glue 130.

Repeated user passes on such a floor line the top glass sheet, whose overall appearance and transparency can be quickly diminished. This transparent sheet must therefore be changed regularly. However, this change requires time and manpower: the seal between the different building elements must first be removed. Then the bead of glue between the two transparent sheets is cut. For this, it is necessary to first break the top transparent sheet, which can be dangerous.

OBJECT AND SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a construction element of the aforementioned type to solve the aforementioned problems, and in particular allowing a quick and safe change of one of the sheets forming the building element.

This object is achieved with a floor, staircase, or wall construction element, comprising at least first and second sheets superimposed at a distance from each other, in a superposition direction, and fastening means of the first and second sheets between them, arranged between said sheets,

the building element being characterized in that the fixing means comprise at least one retaining element fixed on the first sheet and at least one adhesive product adhering to the second sheet, the retaining element forming a receiving groove being able to be filled with the adhesive product in an uncured state and having at least one anchoring portion adapted to retain the adhesive in a cured state, the retaining element and the adhesive being each made of a material such as the adhesive in the cured state can be extracted from said groove without deterioration of the retaining element.

The two sheets can be easily attached to each other: the retaining element, attached to one of the sheets, retains the adhesive product which has hardened inside its groove and also adheres to the another sheet, against a lateral displacement (ie which would cause a lateral sliding of the transparent sheets) and a transverse displacement (ie which would cause spacing / separation of the two transparent sheets).

It is understood that the adhesive product is a product adapted to pass from an uncured state in which it can be introduced into the groove by conforming to the profile of said groove, to a hardened state in it has sufficient cohesion and rigidity to be mechanically retained by the anchoring portion of the retainer when a pulling force is applied to it away from the retainer.

Preferably, the adhesive product is in pasty form in the uncured state and becomes an elastomer in the cured state.

Curing of the adhesive product may result from a chemical reaction or cooling. The chemical reaction is in particular a polymerization and / or crosslinking reaction initiated by at least the contact with the humidity of the air, heating, radiation, or a mixture between two previously separated components.

Those skilled in the art will be able to choose appropriate materials for the retaining element and the adhesive product, depending in particular on the shape of the retaining element, so that the two parts can be detached from each other by deformation of the retaining element and / or the adhesive product in the cured state. Advantageously, at least one of the retaining element and the adhesive product in the cured state is preferably flexible or soft at least one of the retaining element and the adhesive product in the cured state, and in particular each of them is made of a material having a Shore A hardness of at most 70, in particular between 30 and 60 or even between 50 and 60.

It will be understood that it is also preferable that the retaining element and the adhesive product in the cured state do not adhere to each other in a manner that would prevent their detachment.

According to one example, the retaining element is based on a thermoplastic polymer material, for example polyvinyl chloride (PVC) or polypropylene (PP), or based on an elastomer, in particular a thermoplastic elastomer based on olefinic (TPE-O), for example comprising a mixture of polypropylene and EPDM rubber.

In one example, the adhesive product is based on a curable polymer, in particular a polyurethane or a silane-modified polymer (in particular a modified silane polyether or a silane-modified polyurethane) or a polysiloxane.

All the combinations of materials listed above for the retaining element and the adhesive product are possible and are not listed in the present description so as not to weigh it unnecessarily. A A particularly preferred combination of materials is an olefinic thermoplastic elastomer for the retaining member and a polyurethane for the adhesive product.

In one example, the first sheet and / or the second sheet is made of a transparent material.

A transparent material must be understood here as a material having the property of letting light through. It can be really transparent (in the sense that we can clearly distinguish the objects through) or translucent.

According to a variant, the first or the second sheet may also be made of an opaque material (for example opaque glass).

Advantageously, the first sheet and / or the second sheet is made of glass.

But each sheet may also be made of a plastic material, a combination of glass and plastic or any other suitable material.

The construction element according to the invention is also not limited to the superposition of two sheets, and may comprise more than two superposed sheets.

According to one example, the first and second sheets have dimensions, measured perpendicular to the direction of superposition, which are substantially identical, that is to say that differ by at most 10% (the width of a sheet is at most 1 .1 times the width of the other sheet and in the same way the length of one sheet is not more than 1 .1 times the length of the other sheet), preferably not more than 5%.

In one example, the first and second sheets face, in the superposition direction, at least 80%, preferably at least 90%, of the extent of one of the first and second sheets.

In a particular example, the first and second sheets face each other, in the superposition direction, over the entire extent of one of the first and second sheets.

According to a specific example, the two sheets have identical dimensions, and are arranged so that their edges (chants) are facing in a direction orthogonal to their main faces.

The fastening means, typically disposed at the edges of the first and second sheets, generally define a solid and continuous space between the first and second sheets.

It is understood that the intermediate space is delimited by the first and second sheets in the superposition direction, and laterally by the inner side of the one or more retaining elements and the adhesive product.

The interspace typically has a generally rectangular extent, in section in a plane orthogonal to the superposition direction.

According to an advantageous example, the retaining element forms a continuous frame and closed on itself, and the adhesive product forms a continuous adhesive bead along the entire length of the frame, delimiting an interspace between the first and the second sheet.

Advantageously, sealing means are provided between the first and the second sheet, sealing this interspace.

These provisions make it possible to avoid contamination of the space between the two sheets, and in particular the penetration of dust and moisture, which could deteriorate the transparency and / or the appearance of the construction element.

In one example, the building element further comprises moisture absorbing means adapted to absorb moisture within the interspace.

According to one example, the building element comprises, inside the interspace, a profile forming a continuous frame and closed on itself, filled with a material with moisture absorption properties.

In one example, the construction element further comprises, at a distance from the retaining element, at least one spacer disposed between the first sheet and the second sheet. Preferably, the construction element comprises a plurality of spacers distributed in the spacer space away from the retaining element. The invention also relates to a building system, in particular a floor, a staircase or a wall, comprising at least one building element as defined above and peripheral means for holding said building element in position.

According to an example, the construction system comprises the juxtaposition of at least a first and a second building element as defined above.

In one example, a seal is formed between a sheet of the first building element and a sheet of the second building element.

The invention also relates to a method of manufacturing a construction element as defined above, comprising at least:

- fixing at least one retaining element on a first sheet, the retaining element forming a receiving groove having at least one anchoring part,

filling the receiving groove with an adhesive curable product in an uncured state,

before curing the adhesive product, positioning a second sheet opposite the first sheet, so that the first and second sheets are superposed and the uncured adhesive product is in contact with the second sheet,

- Curing the adhesive product, so that the adhesive product in the cured state is retained by the anchoring portion, forming the construction element.

The invention finally relates to a method of maintenance of a building element, in particular for a floor, staircase, or wall, as defined above, in which a traction force is exerted on at least one of the first and the second sheet in the superimposition direction, away from the other sheet, whereby the cured adhesive product is extracted out of the receiving groove, without deterioration of the retainer, and the first and second sheets are separated. one of the other.

According to a particular example,

the reception groove is then filled with an adhesive curable product in an uncured state, and then - Before curing the adhesive product, positioning a new second sheet facing the first sheet, so that the first and second new sheet are superimposed and the uncured adhesive product is in contact with the second sheet.

The traction force is for example exerted by means of at least one suction cup, preferably placed at a corner of the building element.

Several modes or examples of embodiments are described in this presentation. However, unless otherwise specified, the features described in connection with any one embodiment or embodiment may be applied to another embodiment or embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of several embodiments shown by way of non-limiting examples. The description refers to the accompanying drawings in which:

Figure 1 illustrates a floor according to the prior art, in cross section;

Figure 2 illustrates a floor according to an embodiment of the present invention, in cross section;

Figure 3 illustrates the floor of Figure 2 in plan view; FIGS. 4A to 4C illustrate a variant of the embodiment of FIG. 2, in which a material providing the sealing function is added;

FIGS. 5A to 5C schematically illustrate steps of the method of manufacturing a construction element according to the invention;

Figure 6 schematically illustrates the separation of the first and second sheet of a building element according to the invention, as part of its maintenance;

Figures 7A to 7C illustrate alternative embodiments of the retainer.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Figures 2 and 3 illustrate a floor 100 according to a first embodiment of the invention, and more particularly a glass floor joining between two superimposed parts of a building.

The floor 100 comprises a plurality of building elements 10, and means for holding these building elements, here in the form of a support grid 90 consisting of interlocking metal slats 92 fixed at their ends to the wall of a wall. building (not shown) or any other suitable structure.

In the example, each construction element 10 covers a mesh of the lattice 90, bearing with its edges on the four metal laths (orthogonal two by two) delimiting said mesh. To ensure good stability of the assembly, each building element is advantageously fixed on the support mesh with glue 94.

Each building element 10 comprises a first sheet 12 and a second sheet 14, here made of glass, and of generally rectangular section.

The first and second sheets 12, 14 are parallel to each other and superimposed in a Z superposition direction.

The first sheet 12 has two parallel main faces, an inner face 12a and an outer face 12b, of length L and width I respectively measured in a longitudinal direction X and in a transverse direction Y orthogonal to the superposition direction Z, connected by a song 12c.

The second sheet 14 has two parallel main faces, an inner face 14a, an outer face 14b, length L measured in the longitudinal direction X and width I measured in the transverse direction Y, connected by a edge 12c.

In the particular example illustrated, the dimensions - in length and width - of the two sheets of a building element are identical. The thicknesses of the two leaves are different. This configuration is however not limiting, and the sheets may have either the same dimensions or different dimensions in the different directions X, Y, Z. However, the two sheets preferably have substantially identical dimensions in the X, Y directions. Advantageously, the first and the second sheet facing each other, in the superposition direction, at least 80% of the extent of one of the first and second sheets. In the particular example shown, the sheets coincide and face each other over their entire extent. Their edges (songs) are aligned in the direction of superposition Z.

Figures 2 and 3 which illustrate the floor 100, it is understood that the outer faces 12b of the first sheets 12 form the lower face of the floor 100 oriented towards and bonded to the wire mesh 90.

The outer faces 14b of the second sheets 14 constitute the upper face of the floor 100. This directly suffers the wear associated with the normal use of the building (passage of users, shocks related to falling objects, etc.).

Advantageously, seals 80 are formed between the edges of the second sheets of the floor, as illustrated in FIGS. 2 and 3.

As illustrated in Figure 2, the first and the second sheet are fixed together by fastening means disposed between their respective inner faces 12a, 14a. The first and second sheets form, so to speak, double glazing, and more particularly insulating double glazing.

The fixing means here comprise a retaining element 20 fixed on the first sheet 12, and an adhesive product 30 adhering to the second sheet 14.

The retaining element 20 is here in the form of a continuous frame and closed on itself, along the edge 12c of the first sheet 12, at a distance d thereof.

It is for example based on a thermoplastic polymer material, for example polyvinyl chloride (PVC) or polypropylene (PP), or based on an elastomer, in particular an olefinic thermoplastic elastomer (TPE-O). .

By way of example having given particularly good results, the retaining element 20 is based on an olefinic thermoplastic elastomer (TPE-O), more precisely of the PP / EPDM type, that is to say comprising a blend of polypropylene and EPDM rubber, having a Shore A hardness of about 55, and the adhesive product 30 is moisture-curing, one-component polyurethane sealant having a Shore A hardness of about 50 in the cured state.

In cross section, the retaining element 20 typically comprises a base 22, fixed to the internal face 12a of the first sheet 12, and two branches 24, 26 forming together and with the base 22 a U delimiting a receiving groove 28 for to receive the adhesive product 30, as will be described in more detail below.

As illustrated in FIG. 5A, the branches 24, 26 of the U are slightly inclined towards the inside of the groove 28, defining two anchoring parts adapted to retain the adhesive product 30 housed in the groove 28, in the superposition direction Z.

According to alternative embodiments, illustrated in FIGS. 7A to 7C, the branches could also be less inclined but include one or more teeth or projections oriented towards the inside of the groove 28 in order to adjust the traction force necessary for the extraction of the adhesive product out of the throat 28.

Fixing the retaining element 20 to the first glass sheet 12 is typically by gluing, by means of a glue 40 adapted.

According to a preferred arrangement, a double-sided adhesive strip is fixed to the retaining element 20 by one of its two faces. At the time of manufacture of the construction element 10, the second adhesive face of the strip, advantageously protected by a removable film, is discovered and then fixed to the first sheet 12.

In another example, bonding of the retainer member 20 to the first sheet of glass 12 may be performed at the time of extrusion of the retainer (i.e. at the time of manufacture). To do this, a robot is moved along the edge 12c of the first glass sheet 12 and simultaneously performs the extrusion of the retaining element 20 and its bonding to the first glass sheet 12.

The glue 40 used advantageously has, in addition to its fixing properties, sealing properties making it possible to prevent the passage of air between the retaining element 20 and the first sheet 12.

According to a variant illustrated in FIGS. 4A and 4B, a sealing means 42 may be added when the fixing adhesive 40 does not make it possible to ensure a sufficient seal. In the example illustrated in FIG. 4A, the sealing means 42 is disposed between the retaining element 20 and the internal face of the first sheet 12. In this case, the fixing adhesive 40 forms a continuous and closed bead on itself between a first portion of the base 22 of the retaining member 20 and the first sheet 12, and the sealing means 42 forms a continuous seal and closed on itself between a second portion of the base 22 of the retaining element 20 and the first sheet 12.

In the example illustrated in FIG. 4B, the sealing means 42 is disposed against a branch of the retaining element 20 and forms a continuous and closed seal on itself covering the edge of the fixing adhesive 40. sealing means may also be arranged against the outer branch 26 of the retaining element 20, that is to say the branch closest to the edge of the first glass sheet 12 (as shown in FIG. 4B ), only against the inner branch 24.

The adhesive product 30 fills the groove 28 of the retaining element 20 and partially projects out of this groove 28, to be fixed on the internal face 14a of the second sheet 14.

In the example, the adhesive product 30 forms a continuous adhesive bead along the entire length of the retainer (this is visible in FIG. 3).

The adhesive product 30 is curable, that is to say adapted to pass from an uncured state in which it can be introduced inside the groove 28 in conformity with the profile of said groove 28, to a state cured in which it has sufficient cohesion and rigidity to be mechanically retained by the legs 24, 26 of the retaining element 20 forming anchoring portions, when a traction force is applied to it away from the element of retained 20.

As previously indicated, curing of the adhesive product may result from a chemical reaction or cooling. The chemical reaction is in particular a polymerization and / or crosslinking reaction initiated by at least the contact with the humidity of the air, heating, radiation, or a mixture between two previously separated components.

The adhesive product 30 is for example based on a curable polymer, in particular a polyurethane or a silane-modified polymer. (In particular a silane-modified polyether or a silane modified polyurethane) or a polysiloxane. It may advantageously be a moisture-curing, one-component polyurethane sealant having a Shore A hardness of about 50 in the cured state.

The adhesive product 30 advantageously has sealing properties, especially with respect to humidity.

According to a variant illustrated in Figure 4C, a sealing means 42 may be added when the adhesive product 30 does not provide sufficient sealing. The sealing means 42 is disposed against a branch (for example the branch 26) of the retaining element 20 so as to form a continuous joint and closed on itself whose height in the direction Z is equal to the distance between the first sheet 12 and the second sheet 14.

The intermediate space 50 defined by the retaining element and the adhesive product between the first sheet and the second sheet, is thus a sealed space.

Advantageously, the building element 10 comprises in the intermediate space 50, at a distance from the retaining element 20, a plurality of spacers 70 arranged between the first sheet 12 and the second sheet 14.

The building element may further include moisture absorbing means adapted to absorb moisture within the interspace. In the example, a profile 60 continuous and closed on itself, filled with a material 62 with moisture absorption properties, for example silica gel, is provided inside the intermediate space 50 .

The profile 60 is for example a metal or plastic section, of a type commonly used to form the spacer frame of insulating glass units. The profile may for example have a general shape of tube, as shown in Figure 2, the inner space of the tube being filled with moisture absorbing material.

According to variants, the profile may for example have a cross section C or U, allowing the maintenance of the absorbent material.

According to another variant or in addition, the retaining element 20 comprises at least one component with absorption properties moisture, especially when the hardening of the adhesive product 30 is achieved by reaction with moisture. The retaining element 20 is then capable of absorbing part of the humidity of the air and of returning it to the adhesive product 30, thus accelerating the hardening of the latter.

Figs. 5A to 5C illustrate various steps in the fabrication of a building element 10 according to the present invention.

As illustrated by FIG. 5A, the retaining element 20 is first fixed, by gluing, to the internal face 12a of the first sheet 12.

As shown in FIG. 5B, the adhesive product 30 in the uncured state is introduced into the groove 28. The amount of adhesive used is such that the groove 28 of the retaining element 20 is completely filled and that the retaining element 20 is further surmounted by an additional mass of product 30.

Before curing the adhesive product 30, the second sheet 14 is positioned facing the first sheet 12, so that the first and second sheets 12, 14 are superimposed and the mass of uncured adhesive material comes crashing against the inner face 14a of the second sheet 14.

As previously explained, the hardening of the adhesive product 30 may result from a simple chemical reaction with the moisture of the air, or may also be achieved by heating, radiation, or any other suitable technique.

Once cured, the adhesive product 30 is mechanically retained by the anchoring portions 24, 26 of the retaining element 20.

The second sheet 14 is thus maintained relative to the first sheet 12, so that in normal use of the floor, the second sheet 14 does not move relative to the first sheet 12.

As previously explained, repeated user passes on the outer face of the second sheet result in scratches and marks which deteriorate the appearance and decrease the transparency of the floor.

Figure 6 illustrates how the second sheet 14 can easily be removed and exchanged, without deterioration or disassembly of the other elements of the floor 100. A traction force F is exerted on the second sheet 14 in the superposition direction Z, away from the first sheet 12 (upwards, in the example), for example by means of a suction cup.

The cured adhesive product and / or the retaining member 20 is deformed under stress, allowing the adhesive product 30 to be removed from the groove 28, without deterioration of the retaining element 20.

Advantageously, the retaining element 20 has not deformed, or has elastically deformed and then has substantially returned to its original shape.

In this case, the retaining element 20 can be reused.

Its groove 28 is then again filled with an uncured adhesive product 30 in the uncured state, and then, before curing, a new second sheet 14 is positioned facing the first sheet 12, so that the first sheet 12 and the new second sheet 14 is superimposed and the uncured adhesive product is in contact with the second sheet 14.

Claims

1. A building element (10) for a floor, stairway, or wall, comprising at least one first (12) and a second sheet (14) superimposed at a distance from one another in a superposition direction (Z), and fastening means (20, 30) of the first (12) and second sheets (14) therebetween, arranged between said sheets, the building element (10) being characterized in that the fastening means (20, 30) comprise at least one retaining element (20) fixed to the first sheet (12) and at least one adhesive product (30) adhering to the second sheet (14), the retaining element (20) forming a receiving groove ( 28) that can be filled by the adhesive product (30) in an uncured state and having at least one anchor portion (24, 26) adapted to retain the adhesive product (30) in a cured state, the retainer (20) and the adhesive product (30) being each made of a material such as the adhesive product (30) the cured state can be extracted from said groove (28) without deterioration of the retaining element (20).

The building element of claim 1, wherein the first and second sheets face each other, in the superposition direction, over at least 80% of the extent of one of the first and second sheets.

3. Construction element according to claim 1 or 2, wherein the first sheet (12) and / or the second sheet (14) is made of a transparent material.

4. Construction element according to any one of claims 1 to 3, wherein the first sheet (12) and / or the second sheet (14) is glass.

5. Construction element according to any one of claims 1 to 4, wherein the first (12) and the second sheet (14) have dimensions, measured perpendicular to the superposition direction (Z), which are substantially identical.

6. Construction element according to any one of claims 1 to

5, wherein at least one of the retaining member (20) and the cured adhesive product (30) is of a material having a Shore A hardness of not more than 70, in particular between 30 and 60, even between 50 and 60.

7. Construction element according to any one of claims 1 to

6, wherein the retaining element (20) is based on a thermoplastic polymer material, for example polyvinyl chloride or polypropylene, or based on an elastomer, in particular an olefinic thermoplastic elastomer.

8. Construction element according to any one of claims 1 to

7, wherein the adhesive product (30) is based on a curable polymer, in particular a polyurethane or a modified silane polymer or a polysiloxane.

9. Construction element according to any one of claims 1 to

8, wherein the retaining element (20) forms a continuous frame and closed on itself, and the adhesive product (30) forms a continuous adhesive bead along the entire length of the frame, delimiting an interspace (50) between the first (12) and second (14) sheets.

10. Construction element according to claim 9, wherein sealing means (42) are provided between the first (12) and the second sheet (14), sealing the interspace (50).

1 1. The structural member of claim 9 or 10, further comprising moisture absorbing means (62) adapted to absorb moisture within the interspace (50).

12. Building element according to claim 1 1, comprising, inside the interspace (50), a profile (60) forming a continuous frame and closed on itself, filled with a material with properties of moisture absorption (62).

13. Building system (100), in particular a floor, a staircase or a wall, comprising at least one building element (10) according to any one of claims 1 to 12 and peripheral means (92) for maintaining said element construction in position.

The building system of claim 13, comprising juxtaposing at least a first and a second building element (10) according to any one of claims 1 to 12.

A method of manufacturing a building element (10) according to any one of claims 1 to 12, comprising at least:

- Fixing at least one retaining element (20) on a first sheet (12), the retaining element (20) forming a receiving groove (28) having at least one anchoring part (24, 26). )

filling the receiving groove (28) with a curable adhesive product (30) in an uncured state,

before curing the adhesive product, positioning a second sheet opposite the first sheet so that the first sheet and the second sheet uncured adhesive product (30) in contact with the second sheet (14),

- curing the adhesive product (30), so that the adhesive product in the cured state is retained by the anchoring portion (24, 26), forming the construction element.

16. A method of maintaining a building element (10), in particular for a floor, staircase, or wall, according to any one of claims 1 to 12, in which a traction force is exerted on at least one of the first (12) and the second sheet (14) in the superposition direction (Z), away from the other sheet, whereby the hardened adhesive product (30) is extracted from the receiving groove (28) , without deterioration of the retaining element (20), and the first (12) and the second sheet (14) are separated from each other.

The method of claim 16, wherein:

the reception groove (28) is then filled with an adhesive product (30) curable in an uncured state, and then - Before curing the adhesive product (30), positioning a new second sheet (14) facing the first sheet (12), so that the first (12) and the new second sheet (14) are superimposed and that the uncured adhesive product (30) is in contact with the second sheet (14).