EP4291746A1

EP4291746A1 - Glazing with resonators

Info

Publication number: EP4291746A1
Application number: EP22707813.6A
Authority: EP
Inventors: Fabien DALZIN; Jean-Philippe Boure
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2021-02-12
Filing date: 2022-02-11
Publication date: 2023-12-20
Also published as: US20240133227A1; WO2022171963A1; CA3205697A1; FR3119857B1; FR3119857A1

Abstract

The invention relates to glazing comprising at least two glazed walls, which form a cavity between them, and at least one stack of resonators (3) positioned in the cavity, wherein the at least one stack of resonators (3) comprises at least two resonators (3) of different length, said resonators of the at least one stack having a longitudinal axis and being stacked along a stacking axis perpendicular to their longitudinal axis.

Description

Title: Glazing with resonators Field of the invention

The present invention relates to a glazing, in particular for a building, having sound insulation properties.

Technical background Double glazing consisting of two panes separated by a cavity filled with gas, typically air, are conventionally used in windows and facades of buildings for their thermal and acoustic insulation performance.

However, the sound transmission loss caused by such double glazing decreases for frequencies surrounding the so-called “mass/spring/mass” frequency corresponding to the resonance frequency of the double glazing and located in the low frequencies. This phenomenon, called the mass/spring/mass effect, is due to significant pressure variations in the air cavity at the mass/spring/mass frequency. In order to improve the acoustic insulation performance of glazing, various solutions have been developed.

Document US 2010/0300800 describes acoustic glazing, in particular aircraft cockpit glazing, comprising a first glass plate separated from a second intermediate glass plate by a layer of acoustic PVB (poly(vinyl butyral)) , the second glass plate being separated from a third glass plate by a layer of standard PVB or polyurethane.

Document US 2005/0136198 relates to double glazing comprising two panes of glass and, between the two panes, an open cell honeycomb insert made of polycarbonate.

However, none of these solutions makes it possible to improve the acoustic insulation at low frequencies. To improve acoustic insulation at low frequencies, an existing passive solution is to increase the thickness glass plates or the thickness of the cavity. However, this leads to bulky and very heavy structures.

Document WO 00/75473 describes double glazing comprising a waveguide arranged in the periphery of the cavity, along at least one side of the glazing, this waveguide consisting of at least one rectilinear profile provided a transverse partition positioned according to the acoustic mode that one wishes to disorganise.

However, in such glazing, the profile, and in particular its dimensions, must be adapted to the particular glazing in which it is inserted in order to resonate at the resonant frequency of the glazing. However, the double glazings manufactured can have a wide variety of composition and therefore thus have a wide variety of resonance frequencies.

There is therefore a need to provide a system which makes it possible to improve the sound insulation properties of glazing over a wider frequency range and which can be integrated into a very wide variety of double glazing units having different compositions without the need for be modified or adapted according to the composition of the glazing.

Summary of the invention

The invention relates firstly to a glazing comprising at least two glazed walls forming between them a cavity and at least one stack of resonators (3) positioned in the cavity, in which the at least one stack of resonators comprises at least two resonators of length different, said resonators of the at least one stack having a longitudinal axis and being stacked along a stacking axis perpendicular to their longitudinal axis.

In some embodiments, the at least one stack of resonators comprises at least three resonators of different length stacked along a stacking axis perpendicular to their longitudinal axis.

In embodiments, the at least one stack is positioned in a peripheral zone of the cavity.

In some embodiments, the glazing comprises a spacer device, preferably positioned in a peripheral zone of the cavity, the at least one stack of resonators being located on the spacer device and/or inside the device spacing.

In embodiments, at least one of the resonators of the at least one stack is a closed-open tube or an open-open tube, of preferably all the resonators of the stack are closed-open or or green-open tubes.

In embodiments, the stack of resonators is formed by means of a stack of tubes stacked along a stacking axis perpendicular to their longitudinal axis, each tube comprising a transverse partition inside said tube defining two closed resonators - open on either side of the transverse partition.

In embodiments, at least one of the resonators of the at least one stack is configured to resonate at a frequency less than or equal to 400 Hz, preferably all the resonators of the stack are configured to resonate at a frequency less than or equal to 400Hz.

In embodiments, the resonators are transparent or opaque.

In embodiments, at least one resonator, preferably all the resonators, comprise a polymeric material, preferably chosen from polymethyl methacrylate, poly(vinyl chloride), poly(ethylene terephthalate) and/or polyurethane, a metallic material, ferrous or non-ferrous, such as aluminum, or a combination thereof.

In embodiments, at least one of the resonators of the at least one stack comprises a porous absorbent material inside said resonator.

In some embodiments, the glazing comprises at least two stacks of resonators stacked along a stacking axis perpendicular to their longitudinal axis, each of the stacks comprising at least two resonators of different length.

In embodiments, the glazing is building glazing, such as facade or building window glazing, or interior glazing.

The present invention makes it possible to meet the need expressed above. It more particularly provides glazing with improved sound insulation, in particular at low frequencies but also at medium and high frequencies, while being able to be relatively light and compact. In addition, the solution used in the invention can be implemented in a wide variety of glazing without needing to be specifically adapted to the glazing in which it is integrated.

This is accomplished thanks to the presence, in the cavity of the glazing, of a stack of resonators comprising at least two resonators of different lengths. These resonators, having a different length, will have a different resonant frequency. The resonators allow to absorb at least part of the sound energy in the cavity formed by the two glazed walls, which makes it possible to reduce the transmission of sound through the glazing. In particular, resonators absorb sound energy significantly for frequencies close to their resonant frequency. Thus, the presence of several resonators having different resonance frequencies allows absorption of sound energy over a wider frequency range, improving the acoustic performance of the glazing. In addition, the absorption of energy also for the harmonic frequencies of the resonators as well as physical phenomena related to the modification of the properties of the gas cavity, due to the presence of the resonators, allow to also improve the acoustic insulation. at frequencies above the resonant frequencies of the resonators. Consequently, the presence of a stack of resonators of different lengths makes it possible to improve the acoustic insulation of the glazing whatever its composition, and in particular whatever its mass/spring/mass frequency.

In addition, the stacking of the resonators which are stacked along a stacking axis perpendicular to their longitudinal axis makes it possible to limit the surface of the glazing occupied by the resonators and to leave a large surface for visibility (daylight).

Brief description of figures

[Fig.1] represents a schematic view of an example of stacks of resonators according to the invention as described in the example below.

[Fig.2] represents the sound reduction index R (in ordinate, in dB) of an example of glazing according to the invention as described in the example below (gray curve) and of a glazing comparison as described in the example below (black curve), as a function of the frequency of the sound (in abscissa, in Hz).

detailed description

The invention is now described in more detail and in a non-limiting manner in the description which follows.

The invention relates to a glazing comprising at least two glazed walls. Advantageously, the glazed walls are parallel or essentially parallel to each other.

In some embodiments, the glazing according to the invention can comprise exactly two glazed walls (it is then called "double glazing”), or exactly three glass walls (it is then called “triple glazing”), or at least three glass walls.

Within the meaning of the present invention, a “glazed wall” designates any structure comprising (or consisting of) at least one sheet of glass or a glazed assembly. By “glazed assembly” is meant a multilayer glazed element of which at least one layer is a sheet of glass. Thus, the glazed walls can for example independently comprise a single sheet of glass or else a glazed assembly, for example consisting of laminated glazing (as described in more detail below).

The glass sheet can be organic or mineral glass. It can be tempered glass.

The glazed walls (or one of the glazed walls) may comprise (or consist of) a glazed assembly comprising at least one sheet of glass which may be as described above. The glazed assembly is preferably laminated glazing. By “laminated glazing”, is meant at least two sheets of glass between which is inserted at least one interlayer film generally made of viscoelastic plastic material. The viscoelastic plastic interlayer film may comprise one or more layers of a viscoelastic polymer such as poly(vinyl butyral) (PVB) or an ethylene-vinyl acetate copolymer (EVA), more preferably PVB. The interlayer film can be standard PVB or acoustic PVB (such as single-layer or three-layer acoustic PVB). Acoustic PVB generally consists of three layers: two outer layers of standard PVB and an inner layer of PVB with added plasticizer to make it less rigid than the outer layers. The use of glazed walls comprising laminated glazing makes it possible to improve the acoustic insulation of the glazing, the acoustic insulation being further increased when the interlayer film is made of acoustic PVB.

Each glazed wall has two main faces opposite each other corresponding to the faces of the glazed wall having the largest areas. Advantageously, the glazed walls independently have a thickness (between their two main faces) greater than or equal to 1.6 mm, for example a thickness of 1.6 to 24 mm, preferably from 2 to 12 mm, more preferably from 4 to 10 mm, for example 4 or 6 mm. The glazed walls of the glazing according to the invention can all have the same thickness or have different thicknesses. The thicker and/or denser the glazed walls, the greater the sound insulation. In addition, the thicker the glass walls, the lower the mass/spring/mass frequency of the glazing will be.

Preferably, all the glazed walls of the glazing have an identical height and width. The glazing according to the invention can have any possible shape, and preferably has a quadrilateral shape, in particular a rectangular or essentially rectangular shape. Alternatively, the glazing can have a circular shape, or essentially circular, or an elliptical shape, or essentially elliptical, or a trapezoidal or essentially trapezoidal shape.

The glazed walls define between them a cavity. Within the meaning of the present invention, the cavity is defined as being the volume comprised between two glazed walls. Each of the glass walls defining the cavity comprises an inner face corresponding to the main face of the glass wall facing the cavity in question and an outer face corresponding to the second main face of the glass wall, that is to say corresponding to the main face of the glazed wall opposite the face facing the cavity.

Preferably, the glazing comprises a spacing device, making it possible to fix the length of the spacing between the glazed walls. The length of this spacing (that is to say the thickness of the cavity between the glass walls) can be from 6 to 30 mm, preferably from 10 to 20 mm, for example 16 mm or 20 mm. Advantageously, the spacing device is positioned in the cavity, more particularly in a peripheral zone. It may for example be an interlayer in the form of a frame, in particular a frame composed of a single interlayer bent at the corners or composed of several (for example four) sections of interlayer assembled together to form the frame. Preferably, the spacing device has a number of sides identical to the number of edges of the glazing, and more preferably a shape identical to that of the glazing. Preferably, each side of the spacer is parallel to an edge of the glazing.

Preferably, the spacing device is made of metallic material, such as aluminum and/or stainless steel, and/or of polymeric material, such as polyethylene, polycarbonate, polypropylene, polystyrene, polybutadiene, polyisobutylene, polyester, polyurethane , polymethyl methacrylate, polyacrylate, polyamide, polyethylene terephthalate, polybutylene terephthalate, acrylonitrile, butadiene styrene, acrylonitrile styrene acrylate, styrene-acrylonitrile copolymer, or a combination thereof, optionally reinforced with glass fibers. Preferably, the glass walls are attached to the spacer. More preferably, the glazed walls are attached to the spacing device by gluing, for example by an adhesive based on polyisobutylene (PIB).

A seal may also be present, preferably placed on the external face of the spacing device (that is to say the face of the spacing device closest to the edge of the glazed walls), more preferably the seal extends from this face to the edge of the glazed walls. This seal can be made with a mastic (called “sealing mastic”) based on polyurethane, polysulphide and/or silicone.

In the glazing according to the invention, at least one stack of resonators is positioned in the cavity. The resonators of at least one stack have a longitudinal axis and are stacked along a stacking axis perpendicular to their longitudinal axis. The at least one stack according to the invention comprises at least two resonators of different lengths.

The length of the resonator corresponds to its dimension along its longitudinal axis. When the resonators are of the tube type, the length of the resonator corresponds to the length of the tube or to the length of the portion of the tube which forms the resonator.

The resonators can be fixed to each other by means of adhesive tape, preferably double-sided, glue (suitable for the materials of the resonators) and/or by welding. In embodiments, the resonator stack can be directly produced as a single piece, for example by an extrusion process.

The at least one stack of resonators can comprise exactly two resonators of different length or, preferably, more than two resonators of different length. For example, the at least one stack of resonators can comprise two or at least two resonators of different length, or three or at least three resonators of different length, or four or at least four resonators of different length, or five or at least five resonators of different length, or six or at least six resonators of different length, or eight or at least eight resonators of different length, or ten or at least ten resonators of different length. The greater the number of resonators of different length, the better the sound insulation will be. In an advantageous embodiment, the stack comprises three resonators of different length. The at least one stack of resonators may include resonators having an identical length, provided that at least two resonators have a different length.

The resonators can be of any type. Preferably, at least one of the resonators of at least one stack is chosen from resonators of the closed-open tube type, with a circular section or with a rectangular or square section, resonators of the open-open tube type, with a circular section or with rectangular or square section and Helmholtz resonators, and more preferably is a resonator of the closed-open or open-open tube type (with circular section or with rectangular or square section). More preferably, the resonators may independently or all be resonators of the closed-open tube type, with a circular cross-section or with a rectangular or square cross-section, resonators of the open-open tube type, with a circular cross-section or with a rectangular or square cross-section, resonators of Helmholtz, or a combination thereof. Preferably, the resonators are tube-type resonators (with circular section or with rectangular or square section). Even more preferably, the resonators are closed-open tubes (with circular section or with rectangular or square section, more preferably with rectangular or square section).

Advantageously, the at least one stack of resonators is formed by means of a stack of tubes (preferably of circular section or of rectangular or square section, more preferably of rectangular or square section) each comprising a longitudinal axis, the tubes being stacked along a stacking axis perpendicular to their longitudinal axis, each of the tubes comprising a transverse partition (i.e. orthogonal to the longitudinal axis of the tube) inside said tube (i.e. - say at a position in the tube different from the ends of the tube, which are not closed). The partition defines two open-closed resonators on either side of the partition (the partition constituting the closed end of each of the two resonators). When all the tubes comprise a transverse partition forming two resonators on either side of the partition, the at least one stack of tubes then form two stacks of resonators.

The transverse partition can be located in the tube at a position corresponding to half the length of the tube. The two resonators formed on either side of the partition then have an identical length. Alternatively, the transverse partition in the tube can be at a position other than in the middle of the tube. The transverse bulkheads of the stacked tubes may or may not be aligned with each other. Each tube may include its own transverse partition or the same partition may pass through all the tubes and form a transverse partition for each of the tubes.

The midpoints of the stacked tubes may or may not be aligned.

In the case of a closed-open resonator, the relationship between its resonant frequency and its length L is given by the formula:

[Math. 1]

C en —

¹ 4L where C is the air speed in m/s and L is the length of the resonator in m. When the resonator is formed by a tube comprising a transverse partition in its middle, L is equal to half the total length of the tube. The dimensioning of the resonators can be chosen according to the frequency at which it is desired that they resonate.

In a particularly advantageous manner, at least one of the resonators of the at least one stack is configured to resonate at a frequency less than or equal to 400 Hz. More advantageously, all the resonators of the at least one stack are configured to resonate at a frequency less than or equal to at 400 Hz. In embodiments of the invention, at least one of the resonators of the at least one stack can be configured to resonate at a frequency less than or equal to 350 Hz, or less than or equal to 325 Hz, or less than or equal to 300 Hz, or less than or equal to 275 Hz, or less than or equal to 250 Hz, or less than or equal to 225 Hz, or less than or equal to 200 Hz, or less than or equal to 175 Hz, or less than or equal to 150 Hz. Even more preferably, each resonator of the at least one stack can independently have a resonant frequency within the ranges mentioned above. In embodiments, all the resonators of the at least one stack have their resonant frequency in a range mentioned above.

At least one of the resonators may be configured to resonate at the mass/spring/mass frequency of the glazing. The presence in the glazing according to the invention of resonators configured to resonate at a frequency close to the mass/spring/mass frequency of the glazing makes it possible to increase the sound transmission loss at frequencies close to the mass/spring/mass frequency. mass of the glazing but also at frequencies higher than the mass/spring/mass frequency. The mass/spring/mass frequency f _mS m of the glazing can be determined by the following formula:

[Math. 2] where po is the density of the air in kg/m ³ , co is the speed of sound in the air cavity in m/s, d is the thickness of the air cavity between the two glazed walls in m and m _si and m _S 2 are respectively the masses per unit area of the first and of the second glazed wall in kg/m ² .

However, preferably, in the present invention, the resonators are not specifically dimensioned according to the glazing in which they are placed, to resonate at the mass/spring/mass frequency of the glazing. Indeed, in the invention, the at least one stack comprising resonators resonating at different frequencies, preferably at low frequencies, allows sound energy to be absorbed over a wide frequency range which may include the ground frequency/ spring/mass of a wide variety of glazings of various compositions.

The resonators can have a maximum diameter or a maximum thickness (depending on the direction of the thickness of the cavity) equal to the thickness of the cavity, or less than the thickness of the cavity.

The resonators can be (independently or all) transparent or opaque.

The resonators can comprise one or be made of polymeric material, such as polymethyl methacrylate, poly(vinyl chloride) (PVC), poly(ethylene terephthalate) (PET) and/or polyurethane, of metallic material, ferrous or non-ferrous, for example aluminum, or a combination thereof. Advantageously, the material(s) of the resonators and their dimensioning are chosen so as to limit their mass and therefore the increase in the total mass of the glazing.

A porous absorbent material, preferably a porous textile, mineral wool and/or polymeric foam, may be disposed within one or more resonators (or all of the resonators). This can make it possible to improve the acoustic performance of the resonator. Preferably, the term "porous absorbent material" means a material characterized by a porosity greater than or equal to 0.7 and/or a resistivity to the passage of air ranging from 5,000 to 150,000 Nsnrr ⁴ . The porosity of the material can be measured using a porosimeter according to the saturation method of fluid, by intrusion of mercury. The resistivity to the passage of air can be measured according to standard NF EN ISO 9053-1. The porous textile can be a textile made of cotton, linen, hemp, coir, polyester, cellulose fibers, or a combination thereof. The mineral wool can be selected from the group consisting of glass wool, rock wool and combinations thereof. The polymeric foam can be selected from the group consisting of melanin foams, polyurethane foams, polyethylene foams, and combinations thereof.

Advantageously, the length of the resonators is less than the dimension of the glazing or of the cavity in the same direction as the length of the resonator. At least one resonator (or each resonator independently, or all the resonators in the stack) can have a length ranging from 1 to 99% of the dimension of the cavity in the same direction as the length of the resonator. In embodiments, the length of at least one resonator (or of each resonator independently, or of all the resonators of the stack) may be from 1 to 5%, or from 5 to 10%, or from 10 to 15%, or 15 to 20%, or 20 to 25%, or 25 to 30%, or 30 to 35%, or 35 to 40%, or 40 to 45%, or 45 to 50 %, or 50 to 55%, or 55 to 60%, or 60 to 65%, or 65 to 70%, or 70 to 75%, or 75 to 80%, or 80 to 85% , or 85 to 90%, or 90 to 95%, or 95 to 99%, of the length of the dimension of the cavity along the same direction as the length of the resonator.

Unless otherwise indicated, all the characteristics of the resonators described above can apply to at least one resonator of the stack or of the cavity (i.e. to one or more of the resonators of the stack or of the the cavity), or to each resonator of the stack or of the cavity independently, or to all the resonators of the stack or of the cavity.

The at least one stack of resonators is preferably located in a peripheral zone of the cavity. By “peripheral zone of the cavity”, is meant a zone of the cavity adjacent to the edges of the glazed walls and preferably in width (that is to say in a direction orthogonal to the edge of the glazed walls, in the plane of the walls windows) less than or equal to 20 cm, more preferably less than or equal to 10 cm, more preferably less than or equal to 5 cm. In a particularly advantageous manner, the at least one stack of resonators is positioned on the spacing device, on the internal face of the spacing device, that is to say on its face which faces the cavity of the glazing. In other words, the resonators are stacked on the spacer. The stack can be attached to the spacer by means of adhesive tape, preferably double-sided, glue (suitable and compatible with the materials of the resonator and the spacer), clips and/or staples . Alternatively, or additionally, the stack of resonators may be present inside the spacer device. In this last embodiment, the open ends of the resonators are in fluid communication with the interior of the cavity (that is to say that the gas of the cavity can circulate to the interior of the resonator), by example by means of orifices present in the internal face of the spacing device.

The glazing may comprise several stacks of resonators in which the resonators are stacked along a stacking axis perpendicular to their longitudinal axis and comprising at least two resonators of different lengths, for example two or at least two stacks of resonators, or three or least three stacks of resonators, or four or at least four stacks of resonators, or five or at least five stacks of resonators, or six or at least six stacks of resonators, or seven or at least seven stacks of resonators, or eight or at least least eight stacks of resonators,. In embodiments, the glazing comprises as many stacks of resonators as described above as it has edges or the glazing comprises a number of stacks corresponding to a multiple (for example 2) of the number of edges of the glazing.

When the glazing comprises several stacks of resonators in its cavity, they may all be identical or be different. They may independently be as described above. In particular, they can all be positioned in a peripheral zone of the cavity. They can all be arranged on the spacer and/or inside the spacer. In a particularly advantageous manner, the glazing comprises in its cavity one or at least one stack of resonators as described above in a peripheral zone adjacent to each edge of the cavity, more preferably the glazing comprises in its cavity two or at least two stacks of resonators as described above in a peripheral zone adjacent to each edge of the cavity. Preferably, the resonators of the stacks are parallel to the edge of the cavity to which the peripheral zone in which the said stacks are located is adjacent. More preferably, the glazing comprises in its cavity one or at least one stack as described above positioned on the internal face of each side of the spacing device and/or inside each side of the spacing device, even more preferentially the glazing comprises in its cavity two or at least two stacks as described above positioned on the internal face of each side of the spacer and/or within each side of the spacer. For example, for rectangular or square-shaped glazing, the spacing device is preferably a frame of respectively rectangular or square shape, and one or two stacks of resonators as described above are arranged on the internal face of each on the four sides (or portions) of the frame and/or inside each of the four sides (or portions) of the frame.

Preferably, the cavity further comprises a gas. In embodiments, the cavity may consist of the resonators and the gas (and optionally the spacer and/or the gasket). The gas can be air and/or argon, and/or krypton and/or xenon. The use of argon, krypton or xenon, in addition to or replacing air, improves the thermal insulation of the glazing.

The glazing according to the invention can be totally opaque, totally transparent, or partly opaque and partly transparent. Preferably, the glazing is at least partially transparent.

One (or more) of the glazed walls can be tinted in the thickness on part of its surface, for example on the part of its surface defining part of the cavity comprising the stacks of resonators. One (or more) of the glazed walls can be partly covered with an opaque coating, for example, paint and/or enamel. The opaque coating may be present on the interior face of the glazed wall, or on its upper face, or on both sides, preferably it coats the interior face of the glazed wall. Preferably again, only one of the glazed walls of the glazing is covered with an opaque coating. This glazed wall is advantageously the glazed wall intended to be the outermost glazed wall of the glazing when the latter is used in a facade or exterior window of a building.

In particular, at least part, preferably all, of the part of the cavity comprising the stacks of resonators is hidden by the affixing of an opaque coating (for example an enamel and/or a paint) on at least one glass walls. Thus, advantageously, at least one of the glazed walls is coated with an opaque coating (for example an enamel and/or a paint) on a surface comprising at least the surface over which the resonators extend in the cavity. . In some embodiments, the glazed walls of the glazing, or at least one of the glazed walls, may have undergone a treatment to improve the thermal insulation of the glazing. In particular, the glazed wall(s) may comprise one (or more) insulating layer(s) such as an insulating layer based on metal and/or metal oxide, on one or more of their main faces, preferably on the inside face. When the glazed wall is also covered with an opaque coating (such as enamel and/or paint), an insulating layer compatible with the opaque coating is preferably used. Alternatively, the insulating layer and the opaque coating can be placed on different faces of the glazed wall (for example, the insulating layer can be on the inside face and the opaque coating on the outside face). Still alternatively, when at least one of the glazed walls is a glazed assembly, the insulating layer may be interposed in the glazed assembly, for example between a layer of PVB and a sheet of glass.

In some embodiments, for example as an alternative to the use of an opaque coating camouflaging the part of the cavity comprising the resonators, it is possible to use resonators having different colors and/or a different geometry, for example to form patterns , to improve the aesthetics of the glazing.

In advantageous embodiments, the glazing according to the invention may have a higher sound insulation (determined for example by a measurement of the sound reduction index, in particular according to the ISO 10140 standard) than identical glazing but comprising no resonator in the cavity, over a frequency range from 100 Hz to 5000 Hz, preferably from 50 Hz to 20,000 Hz.

The glazing according to the invention can be used in any application using glazing. In particular, the glazing according to the invention can be building glazing. The glazing may be intended to form the interface between the exterior and the interior of the building, and may for example be facade glazing or window glazing. Alternatively, the glazing can be intended to be placed inside the building.

The invention also relates to a method of manufacturing a glazing as described above comprising:

- the supply of at least two glazed walls;

- the arrangement of the two glazed walls so as to form a cavity between them; - the introduction into the cavity of at least one stack of resonators stacked along a stacking axis perpendicular to their longitudinal axis, said at least one stack comprising at least two resonators of different lengths, said at least one stack preferably being disposed on or in a spacer;

- optionally, the fixing of the two glazed walls on the spacing device.

The manufacturing process may also include a step of depositing an opaque coating, such as an enamel and/or a paint, on at least one of the glazed walls, preferably on the interior face of one of the glazed walls. This step is advantageously carried out before the step of arranging the two glazed walls so as to form a cavity between them.

Example

The following example illustrates the invention without limiting it.

A glazing according to the invention was manufactured. This glazing comprises two rectangular glazed walls of non-tempered non-laminated monolithic glass, each having the following dimensions: 1480 mm long, 1230 mm wide and 4 mm thick. The two glazed walls are fixed on a spacer, so as to form between them a cavity 20 mm thick. The spacer is a rectangular aluminum frame positioned along the edges of the glass walls. On the inner face (that is to say the face facing the cavity) of each of the four portions (or sides) of the spacer, a set of two stacks each comprising three resonators of three different lengths as shown in Figure 1 has been fixed. The four sets of two stacks of resonators on the four sides of the spacer are all identical and consist of a stack of three tubes 1 of 0.5 mm thick aluminum, of rectangular section (dimensions 19.5 mm x 6 mm) and having a length of 84 cm, 66 cm and 54 cm respectively. The tubes 1 are stacked from the longest to the shortest and the longest tube is fixed on the spacer. Each of the tubes 1 of the stacks comprises a transverse aluminum partition 2 at mid-length of the tube 1 closing the tube and defining two identical closed-open resonators 3 on each side of the partition 2 (the partition 2 corresponding to the closed end of the two resonators 3). Two stacks of identical resonators are therefore formed by each stack of tubes, on either side of the plane defined by the partitions 2. The 84 cm tube 1 has a resonance frequency of approximately 200 Hz, 66 cm tube 1 has a resonance frequency of approximately 250 Hz, and 54 cm tube 1 has a resonance frequency of approximately 315 Hz. The rest of the cavity comprises air. A comparative double glazing type 4(20)4 was also manufactured.

This comparative glazing differs from the glazing according to the invention only in that it does not include a resonator, the entire cavity being filled with air.

The spectrum of the sound reduction index (R) (or sound transmission loss) of the two glazings was measured as a function of frequency, according to the measurement protocol defined by the ISO 10140 standard.

The results are shown in figure 2.

It is noted that, compared to the comparative glazing, the presence of the stacks of resonators allows a significant improvement in the acoustic performance of the glazing, in particular for frequencies close to the mass/spring/mass frequency of the glazing, but also for higher frequencies. at the mass/spring/mass frequency of the glazing. Thus, an increase in the acoustic index R _A .t _r , determined according to standard ISO 717-1, of up to 3 decibels is observed for the glazing comprising the stacks of resonators with respect to the comparative glazing.

Claims

1. Glazing comprising at least two glazed walls forming between them a cavity and at least one stack of resonators (3) positioned in the cavity, in which the at least one stack of resonators (3) comprises at least two resonators (3) of different length, said resonators of the at least one stack having a longitudinal axis and being stacked along a stacking axis perpendicular to their longitudinal axis.

2. Glazing according to claim 1, wherein the at least one stack of resonators (3) comprises at least three resonators (3) of different lengths stacked along a stacking axis perpendicular to their longitudinal axis.

3. Glazing according to claim 1 or 2, wherein the at least one stack is positioned in a peripheral zone of the cavity.

4. Glazing according to one of claims 1 to 3, comprising a spacing device, preferably positioned in a peripheral zone of the cavity, the at least one stack of resonators (3) being located on the spacing device and/or within the spacer.

5. Glazing according to one of claims 1 to 4, wherein at least one of the resonators (3) of the at least one stack is a closed-open tube or an open-open tube, preferably all the resonators of the at least one stacking are closed-or green or or green-open tubes.

6. Glazing according to one of claims 1 to 5, wherein the at least one stack of resonators is formed by means of a stack of tubes (1) stacked along a stacking axis perpendicular to their longitudinal axis, each tube (1) comprising a transverse partition (2) inside said tube (1) defining two closed-open resonators (3) on either side of the transverse partition (2).

7. Glazing according to one of claims 1 to 6, wherein at least one of the resonators (3) of the at least one stack is configured to resonate at a frequency less than or equal to 400 Hz, preferably all the resonators (3) of the at least one stack are configured to resonate at a frequency less than or equal to 400 Hz.

8. Glazing according to one of claims 1 to 7, wherein the resonators (3) are transparent or opaque.

9. Glazing according to one of claims 1 to 8, wherein at least one resonator (3), preferably all the resonators (3), comprise a polymer material, preferably chosen from polymethyl methacrylate, poly(chloride vinyl), poly(ethylene terephthalate) and/or polyurethane, a metallic material, ferrous or non-ferrous, such as aluminum, or a combination thereof.

10. Glazing according to one of claims 1 to 9, wherein at least one of the resonators (3) of the at least one stack comprises a porous absorbent material inside said resonator.

11. Glazing according to one of claims 1 to 10, comprising at least two stacks of resonators (3) stacked along a stacking axis perpendicular to their longitudinal axis, each of the stacks comprising at least two resonators (3) of different length .

12. Glazing according to one of claims 1 to 11, being a building glazing, such as facade glazing or building window, or interior glazing.