FR3077028A1 - GLASS TREATMENT AND ASSEMBLY PROCESS COMPRISING A LOW EMISSIVITY LAYER - Google Patents

Abstract

A method for processing and assembling laminated glazing (V1a) and / or laminated multiple glazing (VM) from float glass sheets, comprising the steps of taking care of at least a first sheet of glass and of a second sheet of glass, cutting and shaping of the first and second glass sheet to obtain glass panels (P1, P2), deposition of a layer (C) low emissivity by vacuum spraying on one of the faces of one of the glass panels (P1, P2), and of the assembly of the glass panels (P1, P2) in laminated glazing (V1a), said layer (C) being positioned between the two glass panels (P1, P2) by means of at least one polymeric interlayer film (3, 4) or outside the laminated glazing unit (V1) in face II, said layer (C) being intended to come position facing either an outer polymeric film, or a counterface or a laminated laminated counter (V2, V1a) by via seals (5) and sealing barriers.

Description

WINDOW PROCESSING AND ASSEMBLY COMPRISING A LOW EMISSIVITY LAYER

The present invention relates to the field of mineral or organic glazing for architecture or for motor or maritime vehicles. The invention relates more particularly to methods of processing and assembling glazing for thermal insulation and solar protection.

To reduce warming in summer and heat loss in winter, buildings, in particular of tertiary activity and motor or maritime vehicles, are fitted with glazing coated with a low emissivity layer.

A low emissivity layer preferentially reflects the infrared but is transparent to visible light.

The layers with low emissivity, also called low emissivity, low emissivity or “low-e”, are metallic or metallic oxide layers, deposited on clear glasses of the “float” type, extra clear glasses of the “low-iron” type. Or tinted glasses in the mass, by pyrolytic type methods or obtained by spraying. A pyrolytic type deposit is considered to be a hard or semi-hard layer while a vacuum spray deposit is considered to be a soft or soft layer. A soft layer has a higher performance in terms of thermal insulation than a hard layer, but is more delicate.

Thus a soft layer is generally used on the internal face of multiple glazing.

More specifically, these soft layers are obtained by sputtering (PVD), possibly assisted by magnetic field, commonly performed by a device called "magnetron".

These soft layers are fragile to handling and sensitive to oxidation and to the cleaning processes inherent in the production of laminated glass and in the assembly of double or triple insulating glazing.

The low-emissivity layers can be based on silver, aluminum, copper, gold, palladium, platinum or their mixture or alloy, more commonly silver. This soft layer is commonly deposited under a layer of dielectric material called protective, sacrificial or blocking, or between two dielectric layers, which have the role of fixing oxygen in particular during a heat treatment to limit or even avoid the oxidation of the soft layer. It is moreover commonly used a superposition of several assemblies of dielectric layer and of low emissivity layer. The dielectric layers also have the function of limiting the reflection of the visible wavelengths, and of maintaining a neutrality of color in reflection. Examples of soft layers are described in documents EP 0 233 003, EP 0 611 213 and EP 1375 445.

These dielectric coatings are well known in the field of coated glass panels, deposited by sputtering, which are generally oxides, oxy-nitrides or metallic nitrides, such as oxides of aluminum, chromium, tin, gallium, magnesium, niobium, silicon, titanium, yttrium, zinc and zirconium. More commonly, zinc oxide doped, for example with oxides of aluminum, gallium or tin, is combined with low-emissivity layers based on silver.

In common, the production of a clear glass of the "float" type consists in floating the molten glass on a bath of liquid tin. The molten glass, at a temperature of around 1000 ° C, is poured continuously from an oven to spread over a shallow bath made of molten tin. The glass floats on the tin, spreads out and forms a perfectly flat surface.

An extra clear glass of the “low-iron” type is a glass of the “float” type which comprises a low content of iron oxide, while a glass tinted in the mass is a glass of the “float” type comprising high contents. of metal oxides.

These glass sheets are then directly treated by the glassmakers, by depositing layers which is carried out on the hot glass online (pyrolytic layers) or by electromagnetic process (layers under vacuum).

A low emissivity layer is generally deposited on the tin face of a glass sheet.

These coated glass panels are then delivered to the processors who assemble them in laminated and / or double or triple glazing.

Note that these are not the same players who produce the coated glass sheets and who assemble them in laminated glass and multiple glazing, since the installations necessary for a low-emissivity coating deposition represent a bulk and a substantial investment. , for which the transformers are not equipped.

In addition, work habits are well established in the glass industry and production and assembly represent two different trades.

Laminated glazing is an assembly of two or more sheets of mineral or organic glass assembled together by one or more plastic interlayer films, preferably of thermoplastic, while double or triple glazing is an assembly of two or three sheets of glass or laminated glazing assembled together, united around their periphery by one or more metallic interlayer (s) or one or more thermoplastic interlayer (s) commonly called ("hot interlayer glazing") and separated by a air or gas space.

However, prior to these assemblies, a sheet of coated glass must undergo a substantial number of preparation steps consisting of cutting, shaping and heat treatment processes, interspersed with cleaning and quality control steps. of the soft layer. Each of these steps represents a non-negligible risk of damaging the soft layer, generating a non-negligible number of panels discarded by the control steps.

The shaping of the edges of a glass panel essentially consists of removing and polishing the cutting edges and grinding and polishing the edges of the cutting edge, while the cleaning operations consist of the use of water. demineralized and so-called soft brushes. These last steps also present a risk of deterioration of the soft layer.

In order to obtain toughened glasses having a strong mechanical resistance, the glass sheets undergo a heat treatment of reinforcement, at temperatures generally between 450 and 650 ° C, followed by a toughening, the manipulation of a panel Coated glass during these treatments is also a critical operation for maintaining the quality of the low-emissivity layer.

One of the last steps in the preparation of a coated glass sheet is a thermal test, commonly known as the “Heat Soak Test” (HST), also known as High Security Processing. This thermal test makes it possible to remove the panes presenting the risks of spontaneous breaking under the influence of the presence of inclusions of nickel sulfide.

During the float glass production process, nickel sulfide particles can sporadically penetrate the mass of a glass sheet. During the production of a glass sheet in an oven, the nickel sulphide particles reduce in volume and cannot return to their original size during rapid cooling of the tempering.

A glass panel mounted on a facade of a building is thermally stressed by the sun's rays. During the rise in temperature of a glazing comprising an inclusion of nickel sulfide, the latter tends to increase in volume and regain its original volume, which generates an increase in the internal tensions of the glass.

If such a particle is in the area of the glazing expansion tensions, there is a probability that the level of admissible tensions is exceeded and that a spontaneous bursting of the glazing takes place.

This HST thermal test meets national standards and consists in heating the glass sheet to a temperature between 280 and 300 ° C. for a time determined according to the standards, between 2 and 4 hours. This rise in temperature causes the sheet to be exposed, revealing the inclusion of nickel sulfide by the bursting of the glazing.

In order to comply with the standard, this thermal test must be carried out once the glass sheet is cut and shaped.

It is understood that a sheet of coated glass is more expensive than clear glass without a layer, the performance of this compulsory thermal test 5 for glass panels intended to be placed at a height greater than 4 meters, is all the more damaging on a coated glass than on a clear glass, which in particular has already undergone preparation stages, already bringing added value.

The production of laminated glazing, one of the glass panels 10 of which has a low-emissivity layer, is manipulated to form the stack of laminated glazing and the assembly is again manipulated for its passage through a press, carrying out the assembly. by rolling. These manipulations present risks of deterioration of the soft layer.

At this stage, the soft layer is in the air and the risk of oxidation and scratching is not negligible. This is all the more damaging that at this degree of advancement, laminated glazing already has significant added value.

Although a soft layer is generally placed inside a multiple glazing, it is also possible to position it on the outside face of a glazing, but of course requires a protective layer which is presented under an external film. . Such glazing structures are for example described in the documents WO 2013/089185, EP 2 685 294, FR 2 414114 and FR 3 030 496.

In the context of double or triple insulation glazing, the assembly of a sheet of coated glass or of laminated glazing with layer, to a counter face, by means of a sealed sealing barrier, making a spacer between two sheets or two laminated glazings requires, to obtain good adhesion by the use of glue and / or sealant, to grind it. periphery of the coated glass panel. This step of preparing the coated glass panel therefore requires an additional step of cleaning the face comprising the soft layer, again increasing the risk of deterioration of the latter.

These double or triple insulation glazing are finished products, ready to be delivered, the risk of later scratches remains significant.

A defect in the low-emissivity layer causes an iridescence phenomenon in the glazing, which is revealed by an impression of color change depending on the angle of view or illumination.

In order to improve the performance of glazing with multiple insulations, the interlayer film of a laminated glass can have thermochromic, electrochromic or photovoltaic properties. These glazings are commonly called functional or dynamic glazings.

A thermochromic interlayer film is composed of materials whose optical properties change as a function of temperature, in a reversible manner, for example a polymer film doped with transition metal complexes such as vanadium oxide. The metals of these complexes change coordination, modifying the transmission and the color of the polymer film under the effect of temperature.

An electrochromic interlayer film has the particularity of changing optical properties under the effect of the application of an electric field. These changes in optical properties can be remanent but reversible or non-remanent, corresponding to stained glass called “darkening” and “shutter” respectively, as indicated in the document “layered glasses, Serge Etienne, Laboratory of Materials Physics, UMR CNRS 7756, Nancy Pôle Verrier / Cerfav, February 09 ”.

A film of a glazing unit having non-retentive optical properties consists of a polymer matrix containing droplets of liquid crystals, while a film having retentive optical properties comprises, for example, tungsten oxide.

These interlayer films are placed in contact with conductive faces by a deposit of ITO (based on tin and indium oxide), of glass panels of laminated glazing.

Glazing, having a change in non-retentive optical properties, is translucent when no electrical voltage is applied, while it is transparent when an alternating electrical voltage is applied.

Glazing having a change in remanent but reversible optical properties, has a change in optical absorption, from a light state to a dark state and vice versa, by the application of a direct current having an opposite direction.

These functional laminated glazings are more expensive to produce, than conventional laminated glazings, the deterioration of the low-emissivity layer is all the more serious, since all of the functional laminated glass, in the event of scratches, is to be discarded. discarded.

Note also that under the effect of climatic constraints, a glazing must be able to deform freely. The effect of climatic loads brings about changes in the geometry of the glazing. It deforms like a boat sail inflates.

Thus, in the context of the so-called VEA (attached exterior glass) technique, the glazing of a facade of a building wholly or partially made up of glass panels, are linked together by generally articulated fasteners, such as by ball joints, so that the glazing is free to deform under the effect of climatic loads. These fixings pass on both sides of the glazing. As a result, coated glass panels must be drilled, which poses an additional risk of damaging the soft, low-emissivity layer.

The present invention provides a method of processing and assembling glazing comprising a soft layer with low emissivity, making it possible to overcome the aforementioned drawbacks.

Thus, the method of processing and assembling laminated glazing and / or multiple laminated glazing, according to the invention, from sheets of float type glass, comprises the steps of taking charge of at least one first sheet. glass and a second glass sheet, cutting and shaping the first and second glass sheet to obtain glass panels, depositing a low emissivity layer by spraying under vacuum on one of the sides of one of the glass panels, and assembly of the glass panels in laminated glazing, while the layer being positioned between the two glass panels by means of at least one polymeric interlayer film or by exterior of the laminated glazing opposite 11, said layer being intended to be positioned facing either an exterior polymeric film, or a counter face or a laminated counter glazing by means of seals and barriers Sealing.

According to one characteristic, after the cutting and shaping steps, and before the deposition of the low-emissivity layer, the glass panels undergo a heat treatment step of mechanical reinforcement followed by tempering.

According to an additional characteristic, the method comprises steps of drilling the glass panels prior to the step of depositing the low-emissivity layer.

According to one embodiment, the method comprises a single step 15 of washing the low-emissivity layer prior to the assembly of one of the glass panels, of an external polymer film, of a backing or of laminated counter glazing.

According to an additional characteristic, the method comprises a step of producing a saving on the outer periphery of the face intended to receive the deposit of the low-emissivity layer.

According to a preferred embodiment, the step of assembling laminated glazing of the glass panels by means of at least one polymeric interlayer film, is carried out prior to the step of depositing the layer with low emissivity.

According to one embodiment, at least one of the polymeric interlayer films is a functional film of thermochromic, electrochromic or photovoltaic type, preferably thermochromic.

According to one characteristic, the low-emissivity layer is directly deposited on the surface of a glass panel, namely that the layer does not include dielectric materials.

Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

Figures 1 to 3 are sectional views illustrating the processing steps and assembly of sheets, panels or glazing, according to the invention.

Figure 1 is a view illustrating the cutting and shaping of clear glass sheet of the float type.

Figure 2 is a view illustrating the assembly of clear glass panels in laminated glazing.

Figure 3 is a view illustrating the deposition of a low emissivity layer on a laminated glazing.

Figure 4 is a view of a laminated multiple glazing.

Figure 5 is a view of laminated glazing with an internal layer.

Figure 6 is a view of a simple laminated glazing with an outer layer.

Thus, the methods according to the invention relate to the treatment and assembly of laminated glazing, of double or triple laminated glazing, preferably of double or triple functional laminated glazing, in which at least one glass panel (PI, P2) is subjected a step of depositing a layer (C) with low emissivity deposited by vacuum spraying.

More specifically, the methods according to the invention relate to at least one step of depositing a layer (C) with low emissivity on at least one glass panel (PI, P2) previously cut, shaped, advantageously having undergone a heat treatment of mechanical reinforcement and an HST thermal test, in view of an assembly in laminated glazing and / or in double or triple laminated glazing, preferably in a functional double or triple laminated glazing.

Note that only the processes relating to simple laminated glazing and laminated double glazing, preferably functional, will be described in the following description, since the production of triple glazing from double glazing is a well-known process. of the field concerned, consisting of repeating the steps of bonding seals, positioning a second counter glazing and producing sealing barriers.

In the following description, the mention of “float” type glass sheet corresponds both to the mention of clear glass, that of extra clear glass of “low-iron” type or of mass-tinted glass.

Note that the details of the process steps relating to the steps of bonding seals and making sealing barriers are well known in the field concerned and are not the subject of the invention, these steps will only be briefly mentioned in the continuation of the description.

It is understood that a double or triple glazing is a multiple glazing, while a functional multiple glazing, as specified above, is a thermochromic, electrochromic or photovoltaic glazing, preferably thermochromic.

It is also understood that a layer (C) with low emissivity is considered to be a soft layer, as specified above.

Note that a “float” type glass sheet or a glass panel is considered to be clear, when its surfaces are devoid of a layer, in particular of a layer with low emissivity.

In the following description, reference is made to "a glass sheet" for a raw substrate of the float type, while reference is made to "a glass panel" or "panel" for a cut glass sheet. , shaped and having advantageously undergone a reinforcing heat treatment.

Note that a glass panel (PI, P2) is mineral or organic, preferably mineral.

Note that reference is made to the terms "external" and "internal" for the positioning of a face or a layer outside or inside an assembly or a space between two sheets respectively. .

Usually, the numbering of the faces of the glass panels in the following description refers to the nomenclature conventionally used for glazing, namely that the face intended to be arranged outside bears the reference I, while the side intended to be placed inside a building or the passenger compartment of a vehicle has the highest reference, for example II for laminated glazing with two sheets of glass, IV for double glazing and VI for triple glazing.

References VI, Via and Vlb correspond to a laminated glazing without a layer, a laminated glazing with an external layer and a laminated glazing with an internal layer respectively.

Recall that a laminated glazing (VI, Via, Vlb) according to the invention is produced by assembling glass panels (PI, P2) which are obtained by the prior preparation of sheets of glass (Fl, F2) clear of "float" type.

These preparation steps include taking charge of glass sheets (F1, F2) which are cut to the size of the desired glazing, shaped by removing and polishing the cutting edges and grinding and polishing the edges of the wafer. cutting, advantageously followed by a mechanical reinforcement heat treatment at a temperature between 450 and 650 ° C, followed by quenching. These preparation steps are interspersed with cleaning steps commonly used in the field concerned, by the use of demineralized water and so-called soft brushes.

The preparatory steps of the method according to the invention make it possible in particular not to subject a panel (PI, P2) to a layer to a heat treatment of mechanical reinforcement.

According to an additional characteristic, the clear glass panels (PI, P2) undergo preparatory drilling steps in view of the formation of orifices intended to receive fastening elements.

According to the previous characteristic, carrying out the steps for drilling clear glass panels (PI, P2), prior to the step of depositing the low-emissivity layer, makes it possible not to damage the latter.

Once the clear glass panels (PI, P2) are finalized, the latter advantageously undergo an HST thermal test.

Let us also add that the glass panels comprising nickel sulfide inclusions are removed by the HST thermal test, prior to the step of depositing the low-emissivity layer (C), as explained below.

Add that once the clear glass panels (PI, P2) are either ready to be assembled in laminated glazing (VI, Via, Vlb), or pre-assembled in laminated glazing (VI) without a layer, at least one of the faces 10 of a clear glass panel undergoes a step of depositing a low-emissivity layer by vacuum spraying, advantageously assisted by magnetic field.

Recall that it is understood that a clear panel does not include a layer, while a layered panel comprises a soft layer, as explained above.

It should be noted that a laminated glazing (Via, Vlb) with a layer comprises a first glass panel (PI), intended to be directed towards the exterior of a building or of a passenger compartment of a motor or maritime vehicle, assembled to a second glass panel (P2) by means of at least one polymeric interlayer film, at least one of the faces of the glass panels (PI, P2) comprising a deposit of a soft layer.

According to one embodiment, the method comprises a step of depositing a low-emissivity layer (C) on the face II of the panel (PI) intended to be directed towards the outside.

According to the previous embodiment, the step of assembling a laminated glazing (Vlb) with an internal layer comprises positioning under press, the side II of the panel (PI) in contact with at least one polymeric interlayer film ( 3, 4), which is itself positioned in contact with the face III of the second clear panel (P2) intended to be directed inward.

According to another embodiment, the method comprises a step of depositing a low emissivity layer (C) on the face IV of the second panel (P2).

According to the previous embodiment, the step of assembling a laminated glazing (Via) with an external layer comprises the positioning, under press, of the first clear glass panel (PI) in contact with a polymeric interlayer film (3, 4) which is itself in contact with the face III of the second panel (F2), the face IV of which is intended to be directed towards the interior of a building or passenger compartment of a motor or maritime vehicle.

According to one characteristic, prior to the step of depositing the low-emissivity layer on the side IV of the second panel (P2), there is produced a step of making a saving on the periphery of the side IV of the second panel (P2). ), for example by installing a savings tape.

The laminated glazing (Via) with external layer presented in the previous embodiment, is a semi-finished product, intended to be assembled to a counter face or to a laminated counter glazing (V2, Via, Vlb) in view of the assembly of multiple glazing (VM).

According to another alternative, the method comprises a step of assembling an external polymeric film (6) assembled on the side IV covered with a soft layer of laminated glazing (Via) with an external layer described in the previous embodiment, in alternative to the installation of a laminated counter face or glazing (V2, Via, Vlb).

According to the previous alternative, the laminated glazing (Via) is intended to be a simple laminated glazing with a layer.

According to a preferred embodiment, a first clear panel (PI) is assembled to a second clear panel (P2) in laminated glazing (VI) without a layer, by means of at least one interlayer film (3, 4), while a layer (C) with low emissivity is deposited on the side II of the laminated glazing (VI) previously obtained.

The process for obtaining a laminated glazing (VI) without a layer, from a clear panel (PI, P2), further limits the handling and exposure to air of the soft layer (C).

According to an additional characteristic, prior to the deposition of the soft layer (C) on the face II of the laminated glazing (VI), a saving is made (7) on the periphery of the latter, for example by applying a scotch tape savings.

This last characteristic makes it possible to produce a clear zone devoid of a soft layer (C), intended for the installation of sealing of multiple glazing (VM).

This step of making a savings (7) makes it possible to produce a clear, high-quality peripheral zone at the edge of the second panel (P2) with a layer or of the laminated glazing (Via) with an external layer, for assembling a glazing multiple (VM) of quality, in opposition to a glazing on which the sealing zone is carried out with the grinding wheel, more precisely carried out using a torch and a grinding operation.

It is understood that the savings tape is removed before the seals are bonded (5).

According to an additional characteristic, according to the preceding embodiments, in which a soft layer (C) is deposited either on the face IV of the second panel (P2) prior to the assembly of a first laminated glazing (Via) with an external layer , either on the side II of a first laminated glazing (VI) without layer, a single washing step of the soft layer (C) is carried out prior to the assembly of a back face or of a second laminated glazing (V2, Via, Vlb).

Thus, the method according to the invention allows the production of laminated glazing (Via, Vlb) with a layer, constituting a quality semi-finished product, reducing the scrap rate inherent in recurrent handling of coated panels or laminated glazing with a layer. .

Unlike the sheets of coated glass of the prior art, the process of the present invention not only allows a time of exposure to oxidation of the soft layer with low emissivity reduced and controlled, to limit the handling and the steps washing layer glass panels reducing the risk of damaging the soft layer, but also not being limited to so-called “toughenable” soft layers, namely composed of a stack of dielectric materials and of materials with low emissivity.

According to one embodiment, the soft layer does not include dielectric materials, namely consists of materials with low emissivity.

According to a preferred embodiment, at least one of the polymeric interlayer films of a laminated laminated glazing is a functional film (4), namely of the thermochrome, electrochromic or photovoltaic type, preferably thermochrome.

Note that a thermochromic functional glazing is an autonomous dynamic glazing, requiring no deposition of conductive layers and electrical power.

According to the previous embodiment, the method according to the invention makes it possible to obtain a layer (C) with low quality emissivity, on a functional laminated glazing (Via, Vlb), which is a product, with high added value. , semi-finished or a finished product in the case of a deposit of an external polymer film (6) on the soft layer (C).

These functional laminated glazing (Via, Vlb) with a high added-value layer, makes it possible to obtain high-quality functional multiple glazing (VM), significantly reducing the risk of damaging the soft layer (C).

The method according to the invention also makes it possible to obtain a finished product in which the risk of later finding scratches on the layer (C) with low emissivity is extremely reduced.

Add that according to one embodiment, the method comprises, after the deposition of a layer (C) with low emissivity on the first glass panel (PI), the positioning of at least one polymeric interlayer film (3), followed by positioning of a functional film (4), possibly after and prior to the deposition of conductive layers, and the placement of the second glass panel (P2), the assembly being placed under a press for assembly, in view of the production of a single functional laminated glazing (Vlb) comprising an internal soft layer (C).

It is understood that according to known embodiments, the deposition of conductive layers is carried out either on either side of the functional film (4)

electrochromic type, for example on one side of the functional film (4) and on the inner side of the second glass panel (P2).

According to a preferred embodiment, the method comprises the production of a functional laminated double glazing, comprising the steps of pressing the first panel (PI), a polymeric interlayer film (3) and / or a functional film (4), preferably thermochromic, and the second panel (P2), the assembly being placed under a press to

According to the previous embodiment, the method comprises a step of depositing a layer (C) with low emissivity on the side II of the laminated glazing (VI) without a layer previously assembled, preferably after the production of a savings ( 7).

According to the previous embodiment, the method further comprises the conventional steps of sealing bonding (5) and the production of sealing barriers.

Note that against one side, according to embodiments, are single glazing, laminated glazing (Via) with an external layer, laminated glazing (Vlb) with internal layer or conventional laminated glazing (V2), without departing from the scope of the invention.

Claims (8)

1. Method for processing and assembling laminated glazing (Via, Vlb) and / or multiple laminated glazing (VM) from float-type glass sheets, comprising the following steps: a) Support for at least a first glass sheet (F1) and a second glass sheet (F2), b) Cutting and shaping of the first and second glass sheets (F1, F2) to obtain glass panels (PI, P2), c) depositing a layer (C) with low emissivity by vacuum spraying on one of the faces of one of the glass panels (PI, P2), d) Assembly of the glass panels (PI, P2) in laminated glazing (Via, Vlb), said layer (C) being positioned between the two glass panels (PI, P2) by means of at least one interlayer film polymeric (3,4) or outside of the laminated glazing (VI) on face II. 2. Method according to claim 1, characterized in that after the cutting and shaping steps, and before depositing the layer (C) with low emissivity, the glass panels (PI, P2) undergo a heat treatment step mechanical reinforcement followed by quenching. 3. Method according to claim 1 or 2, characterized in that it comprises steps of drilling the glass panels (PI, PI) prior to the step of depositing the layer (C) with low emissivity. 4. Method according to any one of the preceding claims, characterized in that it comprises a single step of washing the layer (C) with low emissivity prior to the assembly of one of the glass panels (PI, P2 ), an external polymer film (6), a back face or a laminated back glass (V2, Via, Vlb). 5. Method according to any one of the preceding claims, characterized in that it comprises a step of producing a sparing (7) on the outer periphery of the face intended to receive the deposit of the layer (C) with low emissivity . 6. Method according to any one of the preceding claims, characterized in that the assembly step in laminated glazing (Via) 5 glass panels (PI, P2) by means of at least one polymeric interlayer film (3, 4), is produced prior to the step of depositing the layer (C) with low emissivity. 7. Method according to any one of the preceding claims, characterized in that at least one of the polymeric interlayer films is a 10 functional film (4) of thermochromic, electrochromic or photovoltaic type, preferably thermochromic. 8. Method according to any one of the preceding claims, characterized in that the layer (C) with low emissivity is directly deposited on the surface of a glass panel (PI, P2).