Glazing with resonators

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

Field of invention

[0001] The present invention relates to glazing, particularly for buildings, having acoustic insulation properties. Technical background

[0002] Double glazing, consisting of two panes separated by a cavity filled with gas, typically air, is traditionally used in windows and building facades for its thermal and acoustic insulation performance.

[0003] However, the loss of sound transmission caused by such double glazing decreases for frequencies surrounding the so-called " mass / spring / mass » corresponding to the resonance frequency of the double glazing and located in the low frequencies. This phenomenon, called mass / spring / mass effect, is due to significant variations in pressure in the air cavity at the mass / spring / mass frequency.

[0004] In order to improve the sound insulation performance of glazing, different solutions have been developed.

[0005] 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.

[0006] Document US 2005 / 0136198 relates to a double glazing unit comprising two panes of glass and, between the two panes, an open-cell polycarbonate honeycomb insert.

[0007] However, none of these solutions improve sound insulation at low frequencies. To improve sound insulation at low frequencies, an existing passive solution is to increase the thickness of the glass plates or the thickness of the cavity. However, this leads to bulky and very heavy structures.

[0008] Document WO 00 / 75473 describes a double glazing unit comprising a waveguide arranged in the periphery of the cavity, along at least one side of the glazing unit, this waveguide being made up of at least one rectilinear profile provided with a transverse partition positioned according to the acoustic mode that it is desired to disrupt.

[0009] 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 resonant frequency.

[0010] There is therefore a need to provide a system which can 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 needing to be modified or adapted according to the composition of the glazing.

[0011] Document FR 2907490 discloses a glazing unit which comprises at least one resonator positioned in a cavity formed between two glazed walls, which comprises a juxtaposition of tubular microstructures which may have similar or different lengths. Summary of the invention

[0012] The invention relates firstly to glazing as defined by the claims.

[0013] In embodiments, the at least one resonator stack comprises at least three resonators of different length stacked along a stacking axis perpendicular to their longitudinal axis.

[0014] In embodiments, the at least one stack is positioned in a peripheral area of ​​the cavity.

[0015] In embodiments, the glazing comprises a spacer device, preferably positioned in a peripheral area of ​​the cavity, the at least one stack of resonators being located on the spacer device and / or within the spacer device.

[0016] In embodiments, at least one of the resonators of the at least one stack is a closed-open tube or an open-open tube, preferably all of the resonators of the stack are closed-open or open-open tubes.

[0017] 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 of the resonators of the stack are configured to resonate at a frequency less than or equal to 400 Hz.

[0018] In embodiments, the resonators are transparent or opaque.

[0019] In embodiments, at least one resonator, preferably all resonators, comprise a polymeric material, preferably selected from polymethyl methacrylate, polyvinyl chloride, polyethylene terephthalate and / or polyurethane, a metallic material, ferrous or non-ferrous, such as aluminum, or a combination thereof.

[0020] In embodiments, at least one of the resonators of the at least one stack comprises a porous absorbing material within said resonator.

[0021] In 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.

[0022] In embodiments, the glazing is building glazing, such as building facade or window glazing, or interior glazing.

[0023] The present invention makes it possible to meet the need expressed above. More particularly, it provides glazing with improved acoustic insulation, particularly in low frequencies but also in medium and high frequencies, while being able to be relatively light and compact. Furthermore, 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.

[0024] This is achieved by the presence, in the glazing cavity, 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 make it possible 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, the resonators absorb sound energy significantly for frequencies close to their resonant frequency. Thus, the presence of several resonators with different resonant 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, make it possible to also improve the acoustic insulation at frequencies higher than 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 regardless of its composition, and in particular regardless of its mass / spring / mass frequency.

[0025] In addition, the stacking of resonators which are stacked along a stacking axis perpendicular to their longitudinal axis makes it possible to limit the surface area of ​​the glazing occupied by the resonators and to leave a large surface area for visibility (daylight). Brief description of the figures

[0026] [ 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 (on the ordinate, in dB) of an example of glazing according to the invention as described in the example below (grey curve) and of a comparative glazing as described in the example below (black curve), as a function of the sound frequency (on the abscissa, in Hz). Detailed description

[0027] The invention is now described in more detail and in a non-limiting manner in the following description.

[0028] The invention relates to a glazing comprising at least two glazed walls. Advantageously, the glazed walls are parallel or essentially parallel to each other.

[0029] In embodiments, the glazing according to the invention may 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.

[0030] For the purposes of the present invention, a “ glass wall » means any structure comprising (or consisting of) at least one sheet of glass or a glazed assembly. By “ glass unit » means a multi-layer glazed element of which at least one layer is a glass sheet. Thus, the glazed walls may, for example, independently comprise a single glass sheet or a glazed assembly, for example consisting of laminated glazing (as described in more detail below).

[0031] The glass sheet can be made of organic or mineral glass. It can be made of tempered glass.

[0032] The glazed walls (or one of the glazed walls) may comprise (or consist of) a glazed assembly comprising at least one glass sheet which may be as described above. The glazed assembly is preferably a laminated glazing unit. By " laminated glazing", means at least two sheets of glass between which is inserted at least one interlayer film, generally made of viscoelastic plastic material. The interlayer film made of viscoelastic plastic material 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 may be made of standard PVB or acoustic PVB (such as single-layer or three-layer acoustic PVB). Acoustic PVB is generally made of three layers: two outer layers of standard PVB and an inner layer of PVB with added plasticizer so as 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.

[0033] Each glazed wall comprises two main faces opposite each other corresponding to the faces of the glazed wall having the largest surface 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 2 to 12 mm, more preferably 4 to 10 mm, for example 4 or 6 mm. The glazed walls of the glazing according to the invention may all have the same thickness or have different thicknesses. The greater the thickness and / or the higher the density of the glazed walls, the greater the acoustic insulation will be. In addition, the thicker the glazed walls, the lower the mass / spring / mass frequency of the glazing will be.

[0034] Preferably, all the glazed walls of the glazing have an identical height and width. The glazing according to the invention may have any possible shape, and preferably has a quadrilateral shape, in particular a rectangular or essentially rectangular shape. Alternatively, the glazing may have a circular, or essentially circular, shape, or an elliptical, or essentially elliptical shape, or a trapezoidal or essentially trapezoidal shape.

[0035] The glass walls define a cavity between them. For the purposes of the present invention, the cavity is defined as the volume between two glass 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, i.e. corresponding to the main face of the glass wall opposite the face facing the cavity.

[0036] 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 (i.e. the thickness of the cavity between the glazed 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 can for example be an interlayer in the form of a frame, in particular a frame composed of a single interlayer folded at the corners or composed of several (for example four) interlayer sections 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 spacing device is parallel to an edge of the glazing.

[0037] Preferably, the spacer device is made of metallic material, such as aluminum and / or stainless steel, and / or 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.

[0038] Preferably, the glass walls are attached to the spacer device. More preferably, the glass walls are attached to the spacer device by gluing, for example by a polyisobutylene (PIB) based glue.

[0039] A seal may also be present, preferably arranged on the external face of the spacer device (i.e. the face of the spacer device closest to the edge of the glass walls), more preferably the seal extends from this face to the edge of the glass walls. This seal may be made with a mastic (called " sealing putty ”) based on polyurethane, polysulfide and / or silicone.

[0040] In the glazing according to the invention, at least one stack of resonators is positioned in the cavity. The resonators of the 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.

[0041] 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.

[0042] The resonators can be attached to each other by means of adhesive tape, preferably double-sided, glue (suitable for the resonator materials) and / or by welding. In embodiments, the resonator stack can be directly produced as a single piece, for example by an extrusion process.

[0043] The at least one stack of resonators may 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 may 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. In an advantageous embodiment, the stack comprises three resonators of different length.

[0044] The at least one resonator stack may include resonators having an identical length, provided that at least two resonators have a different length.

[0045] The resonators may be of any type. Preferably, at least one of the resonators of the at least one stack is selected from closed-open tube resonators, with a circular or rectangular or square cross-section, open-open tube resonators, with a circular or rectangular or square cross-section, and Helmholtz resonators, and more preferably is a closed-open or open-open tube resonator (with a circular or rectangular or square cross-section). More preferably, the resonators may independently or all be closed-open tube resonators, with a circular or rectangular or square cross-section, open-open tube resonators, with a circular or rectangular or square cross-section, Helmholtz resonators, or a combination thereof. Preferably, the resonators are tube resonators (with a circular or rectangular or square cross-section).Even more preferably, the resonators are closed-open tubes (with circular section or rectangular or square section, more preferably with rectangular or square section).

[0046] 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. 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 forms two stacks of resonators.

[0047] The transverse partition may 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 may be at a position other than in the middle of the tube. The transverse partitions of the stacked tubes may or may not be aligned with each other. Each tube may have its own transverse partition or the same partition may pass through all the tubes and form a transverse partition for each of the tubes.

[0048] The middles of stacked tubes can be aligned or not.

[0049] In the case of a closed-open resonator, the relationship between its resonant frequency fr and its length L is given by the formula: fr = C 4 L where C is the air speed in m / s and Lis the length of the resonator in m. When the resonator is formed by a tube comprising a transverse partition in its middle, L is half the total length of the tube. The sizing of the resonators can be chosen according to the frequency at which they are desired to resonate.

[0050] Particularly advantageously, 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 of the resonators of the at least one stack are configured to resonate at a frequency less than or equal to 400 Hz. In embodiments of the invention, at least one of the resonators of the at least one stack may 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 may independently have a resonant frequency in the ranges mentioned above.In embodiments, all resonators of the at least one stack have their resonant frequency in a range mentioned above.

[0051] 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 of the glazing but also at frequencies higher than the mass / spring / mass frequency.

[0052] The mass / spring / mass frequency f msm of the glazing can be determined by the following formula: f msm = 1 2 π ρ 0 c 0 2 d m s1 + m s2 m s1 m s2 in which ρ 0 is the air density in kg / m 3< , c 0 is the speed of sound in the air cavity in m / s, d is the thickness of the air cavity between the two glass walls in m and m s1 and m s2 are respectively the masses per unit area of ​​the first and second glass walls in kg / m 2< .

[0053] However, preferably, in the present invention, the resonators are not specifically sized 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 in the low frequencies, it allows absorption of sound energy over a wide frequency range which may include the mass / spring / mass frequency of a wide variety of glazings of various compositions.

[0054] Resonators can have a maximum diameter or maximum thickness (depending on the direction of the cavity thickness) equal to the cavity thickness, or less than the cavity thickness.

[0055] Resonators can be (independently or all) transparent or opaque.

[0056] The resonators may comprise one or be made of a polymer material, such as polymethyl methacrylate, polyvinyl chloride (PVC), polyethylene terephthalate (PET) and / or polyurethane, of a metallic material, ferrous or non-ferrous, for example aluminum, or of a combination thereof. Advantageously, the material(s) of the resonators and their sizing are chosen so as to limit their mass and therefore the increase in the total mass of the glazing.

[0057] A porous absorbent material, preferably a porous textile, mineral wool and / or polymer foam, may be disposed within one or more resonators (or all of the resonators). This may improve the acoustic performance of the resonator. Preferably, the term " porous absorbent material», a material characterized by a porosity greater than or equal to 0.7 and / or a resistivity to the passage of air of 5,000 to 150,000 Nsm -4< . The porosity of the material can be measured using a porosimeter according to the fluid saturation method, by mercury intrusion. 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, coconut, polyester, cellulose fibers, or a combination thereof. Mineral wool can be chosen from the group consisting of glass wool, rock wool and combinations thereof. Polymer foam can be chosen from the group consisting of melamine foams, polyurethane foams, polyethylene foams, and combinations thereof.

[0058] Advantageously, the length of the resonators is less than the dimension of the glazing or 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) may 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 each resonator independently, or all resonators in the stack) may be 1 to 5%, or 5 to 10%, or 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 in the same direction as the length of the resonator.

[0059] Unless otherwise stated, all of the resonator characteristics described above may apply to at least one resonator in the stack or cavity (i.e., one or more of the resonators in the stack or cavity), or to each resonator in the stack or cavity independently, or to all of the resonators in the stack or cavity.

[0060] The at least one stack of resonators is preferably located in a peripheral area of ​​the cavity. By " peripheral zone of the cavity", means an area of ​​the cavity adjacent to the edges of the glazed walls and preferably of width (i.e. in a direction orthogonal to the edge of the glazed walls, in the plane of the glazed walls) 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. Particularly advantageously, the at least one stack of resonators is positioned on the spacer device, on the internal face of the spacer device, i.e. on its face which faces the cavity of the glazing. In other words, the resonators are stacked on the spacer device. The stack can be fixed on the spacer device by means of adhesive tape, preferably double-sided, glue (suitable and compatible with the materials of the resonator and the spacer device), clips and / or staples.Alternatively, or additionally, the stack of resonators may be present inside the spacer device. In the latter embodiment, the open ends of the resonators are in fluid communication with the interior of the cavity (i.e., gas from the cavity can flow into the interior of the resonator), for example by means of orifices present in the inner face of the spacer device.

[0061] 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 length, for example two or at least two stacks of resonators, or three or at 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 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.

[0062] When the glazing comprises in its cavity several stacks of resonators, they may all be identical or different. They may independently be as described above. In particular, they may all be positioned in a peripheral zone of the cavity. They may all be arranged on the spacer device and / or inside the spacer device. 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 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 preferably 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 spacing device and / or inside each side of the spacing device. For example, for a glazing of rectangular or square shape, the spacing device is preferably a frame of rectangular or square shape respectively, and one or two stacks of resonators as described above are arranged on the internal face of each of the four sides (or portions) of the frame and / or inside each of the four sides (or portions) of the frame.

[0063] 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 seal). The gas may be air and / or argon, and / or krypton and / or xenon. The use of argon, krypton or xenon, in addition to or instead of air, makes it possible to improve the thermal insulation of the glazing.

[0064] The glazing according to the invention may be completely opaque, completely transparent, or partly opaque and partly transparent. Preferably, the glazing is at least partly transparent.

[0065] One (or more) of the glazed walls may be tinted in the thickness over a portion of its surface, for example over the portion of its surface defining a portion of the cavity comprising the stacks of resonators. One (or more) of the glazed walls may be partly covered with an opaque coating, for example, a paint and / or an enamel. The opaque coating may be present on the inner face of the glazed wall, or on its upper face, or on both faces; preferably, it covers the inner face of the glazed wall. More preferably, 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.

[0066] In particular, at least a portion, preferably all, of the portion of the cavity comprising the stacks of resonators is hidden by the application of an opaque coating (for example an enamel and / or a paint) on at least one of the glazed 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 on which the resonators extend in the cavity.

[0067] In 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 a metal and / or metal oxide-based insulating layer, on one or more of their main faces, preferably on the inner face. When the glazed wall is also covered with an opaque coating (such as an enamel and / or a paint), an insulating layer compatible with the opaque coating is preferably used. Alternatively, the insulating layer and the opaque coating may be arranged on different faces of the glazed wall (for example, the insulating layer may be on the inner face and the opaque coating on the outer face).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.

[0068] In embodiments, for example as an alternative to using an opaque coating camouflaging the part of the cavity comprising the resonators, resonators having different colors and / or a different geometry may be used, for example to form patterns, to improve the aesthetics of the glazing.

[0069] In advantageous embodiments, the glazing according to the invention may have higher acoustic insulation (determined for example by measuring the sound reduction index, in particular according to the ISO 10140 standard) than identical glazing but not including a resonator in the cavity, over a frequency range from 100 Hz to 5000 Hz, preferably from 50 Hz to 20,000 Hz.

[0070] 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 can be intended to provide the interface between the exterior and the interior of the building, and can, for example, be facade glazing or window glazing. Alternatively, the glazing can be intended to be placed inside the building.

[0071] The invention also relates to a method of manufacturing glazing as described above comprising: providing at least two glass walls; arranging the two glass walls so as to form a cavity between them; introducing into the cavity 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 arranged on or in a spacing device; optionally, fixing the two glass walls to the spacing device.

[0072] The manufacturing method may also comprise a step of depositing an opaque coating, such as an enamel and / or a paint, on at least one of the glass walls, preferably on the inner face of one of the glass walls. This step is advantageously carried out before the step of arranging the two glass walls so as to form a cavity between them. Example

[0073] The following example illustrates the invention without limiting it.

[0074] A glazing unit according to the invention has been manufactured. This glazing unit comprises two rectangular glazed walls of non-tempered, non-laminated monolithic glass, each having the following dimensions: 1480 mm in length, 1230 mm in width and 4 mm in thickness. The two glazed walls are fixed to a spacer, so as to form a 20 mm thick cavity between them. The spacer is a rectangular aluminum frame positioned along the edges of the glazed walls. On the internal face (i.e. 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 1has 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 made 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 longest to shortest and the longest tube is fixed on the spacer. Each of the tubes 1 of the stacks comprises a transverse partition 2 made of aluminum 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 resonant frequency of about 200 Hz, the 66 cm tube 1 has a resonant frequency of about 250 Hz, and the 54 cm tube 1 has a resonant frequency of about 315 Hz. The remainder of the cavity comprises air.

[0075] A comparative double glazing of 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.

[0076] 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.

[0077] The results are shown in Figure 2.

[0078] It is observed that, compared to the comparative glazing, the presence of the resonator stacks 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 frequencies higher than the mass / spring / mass frequency of the glazing. Thus, an increase in the acoustic index RA,tr, determined according to the ISO 717-1 standard, of up to 3 decibels is observed for the glazing including the resonator stacks compared to the comparative glazing.

Claims

1. A glazing comprising at least two glazed panels, 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 characterized in that 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).

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

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

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

5. The 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 stack are closed-open or open-open tubes.

6. The glazing according to one of claims 1 to 5, 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.

7. The glazing according to one of claims 1 to 6, wherein the resonators (3) are transparent or opaque.

8. The glazing according to one of claims 1 to 7, wherein at least one resonator (3), preferably all the resonators (3), comprise a polymer material, preferably chosen from polymethyl methacrylate, polyvinyl chloride, poly(ethylene terephthalate) and / or polyurethane, a ferrous or non-ferrous metal material, such as aluminum, or a combination thereof.

9. The glazing according to one of claims 1 to 8, wherein at least one of the resonators (3) of the at least one stack comprises a porous absorbent material inside said resonator.

10. The glazing according to one of claims 1 to 9, 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.

11. The glazing according to one of claims 1 to 10, being a construction glazing, such as a facade glazing or window glazing, or an interior glazing.

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