WO2024200481A1

WO2024200481A1 - Glazing with improved acoustic insulation performance

Info

Publication number: WO2024200481A1
Application number: PCT/EP2024/058175
Authority: WO
Inventors: Ahmed ABBAD; Walter Schreiber
Original assignee: Saint-Gobain Glass France
Priority date: 2023-03-31
Filing date: 2024-03-27
Publication date: 2024-10-03

Abstract

The present invention relates to a glazing (100) comprising at least two glass walls (101, 102) forming a cavity (103) therebetween, wherein the cavity (103) comprises at least one sound-absorbent device (1) comprising a profile (2) or box formed of a plurality of walls (4, 5, 6), said walls (4, 5, 6) surrounding a chamber (3), said walls (4, 5, 6) comprising an inner wall face (11) facing said chamber (3) and an outer wall face (10) opposite to the inner wall face (11), said walls (4, 5, 6) comprising at least one perforated wall (4) provided with a plurality of periodically arranged wall perforations (7), with each of said wall perforations (7) extending from said inner wall face (11) to said outer wall face (10), said outer wall face (10) of at least one of said walls (4, 5, 6) being provided with a sound-absorbent layer (8) comprising or consisting of a sound-absorbent material, wherein i) the outer wall face (10) of said perforated wall (4) being provided with said sound-absorbent layer (8), said sound-absorbent layer (8) comprising an inner layer face (13) facing said chamber (3) and an outer layer face (12) opposite to the inner layer face (13), said sound absorbent layer (8) being provided with a plurality of layer perforations (9), with each of said layer perforations extending from said inner layer face (13) to said outer layer face (12), said layer perforations (8) being flush with said wall perforations (7), or ii) said walls (4, 5, 6) comprise an inner wall (4) facing the cavity (103) of the glazing (100) and an outer wall (5) opposite thereto, said inner wall (4) and said outer wall (5) being connected by side walls (6), with the outer wall face (10) of exclusively one or each of said side walls (6) being provided with said sound-absorbent layer (8), or iii) said walls (4, 5, 6) comprise an inner wall (4) facing the cavity (103) of the glazing (100) and an outer wall (5) opposite thereto, said perforated wall (4) being said inner wall, the outer wall face (10) of said outer wall (5) being provided with said sound-absorbent layer (8), with said outer wall (5) being provided with a plurality of periodic or non-periodic openings.

Description

Glazing with improved acoustic insulation performance

The present invention belongs to the technical field of glazing manufacture and relates to a glazing comprising a sound-absorbent device configured to improve the acoustic insulation performance of the glazing. The invention finds a particularly advantageous application, although by no means limiting, in the case of a building glazing.

A double glazing consisting of two panes of glass separated by a cavity filled with gas, typically air, is traditionally used in windows and building facades for its thermal and acoustic insulation performance. However, the loss of sound transmission caused by such double glazing decreases for frequencies around the so-called "mass/spring/mass" frequency, which is the resonant frequency of the double glazing and typically is located in the low frequencies. This phenomenon, also known as 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. For example, WO 2022/234237 relates to a glazing comprising at least two glass walls forming a cavity between them, in which the cavity comprises at least one sound-absorbent device comprising at least one sheet, said sheet comprising a plurality of perforations arranged in a periodic manner and delimiting a chamber arranged in the cavity. The sound-absorbent device is configured to improve the acoustically damping properties of the glazing at low frequencies.

US 4850175 A, US 5683764 and CH 630993 relate to an insulating glazing comprising a spacer provided with a sound absorbing material.

In light of the prior art, there is a need to provide an alternative solution for improving the acoustic insulation properties of a glazing over a broad range of frequencies.

The object of the present invention is to remedy the disadvantages of the prior art as set out above by proposing a solution which makes it possible to obtain a glazing that is very effective in terms of acoustic insulation with regards to a broad range of frequencies. Further, the glazing is to be manufactured in an easy, time- and cost-efficient manner.

According to the invention, a glazing comprises at least two glass walls forming a cavity therebetween, wherein the cavity comprises at least one sound-absorbent device comprising a profile or box formed of a plurality of walls. The walls enclose a chamber, with the walls comprising an inner wall face facing the chamber and an outer wall face opposite to the inner wall face. At least one wall of said walls is provided with a plurality of periodically arranged wall perforations. According to the invention, the outer wall face of at least one of the walls is provided with a soundabsorbent layer comprising or consisting of a sound-absorbent material.

In particular embodiments, the glazing according to the invention may additionally include one or more of the following features, taken alone or in any technically possible combination.

In one embodiment, the walls of the sound-absorbent device (i.e., walls of the profile or box) are polymeric walls made of one or more polymeric materials.

In one embodiment, the outer wall face of said perforated wall comprising a plurality of periodically arranged wall perforations is provided with said sound-absorbent layer, wherein the sound-absorbent layer is provided with a plurality of layer perforations, with the layer perforations being flush with the wall perforations. This embodiment is preferrable as acoustic waves can pass through the layer perforations of the sound-absorbent layer and, thus, have access to the wall perforations of the perforated wall.

In one embodiment, the walls comprise an inner wall facing the cavity of the glazing and an outer wall opposite thereto, with the perforated wall being the inner wall.

In one embodiment, the outer wall face of exclusively the perforated wall is provided with the sound-absorbent layer. In other words, only the perforated wall is provided with the sound-absorbent layer, but not the other walls of the plurality of walls.

In one embodiment, the walls of the sound-absorbent device (i.e., walls of the profile or box) comprise an inner wall facing the cavity of the glazing and an outer wall opposite thereto, wherein the inner wall and the outer wall are connected by side walls, wherein the outer face of one or each of the side walls is provided with the sound-absorbent layer. Typically, the inner wall and the outer wall are connected by two side walls. In this embodiment, the sound-absorbent layer does not need not have perforations. Specifically, the outer wall face of exclusively one or each of the side walls is provided with the sound-absorbent layer. In other words, only one or each of the side walls is provided with the sound-absorbent layer, but not the other walls of the plurality of walls. In one embodiment, the walls of the sound-absorbent device (i.e., walls of the profile or box) comprise an inner wall facing the cavity of the glazing and an outer wall opposite thereto, wherein the perforated wall comprising a plurality of periodically arranged wall perforations is the inner wall and the outer face of the outer wall is provided with the sound-absorbent layer.

In this embodiment, the outer wall (which is different from the perforated wall) is provided with a plurality of openings or perforations so that acoustic waves can pass through the openings and, thus, have access to the sound-absorbent layer. In this embodiment, the sound-absorbent layer does not need not have perforations.

In one embodiment, the outer wall face of exclusively the outer wall is provided with the soundabsorbent layer. In other words, only the outer wall is provided with the sound-absorbent layer, but not the other walls of the plurality of walls.

In one embodiment, the sound-absorbent layer is fixed to the outer wall face of said wall of the sound-absorbent device. Preferably, the sound-absorbent layer is glued by means of a glue to the wall. Preferably, the sound-absorbent layer is in direct contact with the wall. "Direct contact" means that a layer of binding material, such as a layer of glue, may be present between the sound-absorbent layer and the wall.

In one embodiment, the sound-absorbent layer comprises or consists of a porous sound-absorbent material. Porous materials are considered preferable in view of its sound-absorbing properties in the range of mid and high frequencies.

In one embodiment, the sound-absorbent layer comprises or consists of a porous sound-absorbent material selected from the group consisting of mineral wools, textile fibers, polymeric foams and combinations thereof. These materials have been shown to have superior sound-absorbing properties.

In one embodiment, the porous polymeric foam comprises an average proportion of open cells of 30 to 99%, preferably of 65 to 98%.

In one embodiment, the porous polymeric foam is selected from the group consisting of silicone foams, polyurethane foams, polyethylene foams, melamine foams, and combinations thereof. In one embodiment, a thickness of the sound-absorbent layer is from 6 to 100 mm, preferably from 6 to 60 mm, or even more preferably from 6 to 30 mm.

In one embodiment, a width of the sound-absorbent layer is 1 to 1/3, preferably 1 to 1/2, of a width of the polymeric sheet or polymeric wall, respectively.

In one embodiment, the glazing comprises a desiccant in or associated with the sound insulation device.

In one embodiment, the desiccant is disposed in at least one envelope, which is preferably held inside or outside the chamber.

In one embodiment, the sound-absorbent device is a glazing spacer.

In one embodiment, the sound insulation device is a one-piece device with the sound-absorbent layer being fixedly attached to the profile or box, e.g., by means of a glue.

In one embodiment, the at least one perforated wall comprises at least three perforations, preferably at least four perforations.

In one embodiment, the glazing further comprises one or more additional sound-absorbent devices, each additional sound-absorbent device comprising at least one perforated wall comprising a plurality of periodically arranged perforations and delimiting a chamber arranged in the cavity, wherein preferably the periodicity of the perforations of the perforated wall of each additional sound-absorbent device are different from each other.

In one embodiment, the sound-absorbent device is positioned in a peripheral area of the glazing cavity.

In one embodiment, the glazing is a building glazing, such as a building facade, window or door glazing or an interior glazing.

The present invention meets the above needs. In particular, it provides a glazing which is easy and simple to manufacture, relatively light and compact, while providing a glazing with improved sound insulation performance. Specifically, the glazing is configured to dampen acoustic waves not only in the range of low frequencies but also in the range of mid and high frequencies.

This is achieved by the presence of a sound-absorbent device comprising a perforated wall having a plurality of periodically arranged perforations, with the perforated wall allowing the formation of a chamber, which is combined with a sound-absorbent layer comprising or consisting of a sound-absorbent material. Such a device allows for a dual acoustic effect, which is accomplished by the absorption of sound energy by the chamber and the plurality of perforations at low frequencies, as well as by the absorption of sound energy by the sound-absorbent layer at mid and high frequencies.

The combination of the chamber with the presence of perforations in the wall, these perforations being periodic, allows the creation of resonators to absorb at least part of the sound energy in the cavity of the glazing formed by the two glass walls, thus reducing the transmission of sound through the glazing. In addition, the sound-absorbent layer further enhances the acoustic insulation by absorbing, by itself, at least part of the sound energy due to the porous structure of the sound-absorbent layer. Specifically, the sound-absorbent material of the sound-absorbent layer need not be introduced into the chamber, but can instead be placed on the outer wall face of the wall, preferably glued onto the outer surface thereof, which considerably facilitates production of the sound-absorbent device. The sound-absorbent device comprising one or more sound-absorbent layers can be pre-fabricated as well and, thus, can be configured to be ready to for use in the production of the glazing. Thus, the device of the present invention, which incorporates the sound absorption capabilities, is easy to manufacture while providing improved sound insulation performance.

Further features and advantages of the present invention will be apparent from the description below, with reference to the attached figures which illustrate non-limiting examples of its implementation. In the figures:

Fig. 1 on the left-hand side, Fig. 1 shows an example of a glazing according to the invention and, on the right-hand side, an enlarged schematic perspective view of an example of a sound-absorbent device according to the invention in the form of a profile used as glazing spacer; Fig. 2 shows an enlarged schematic perspective view of a particular embodiment of a soundabsorbent device according to the invention which can be used in the glazing of Fig. 1 ;

Fig. 3 shows an enlarged schematic perspective view of a further particular embodiment of a sound-absorbent device according to the invention which can be used in the glazing of Fig. 1 ;

Fig. 4 shows an enlarged schematic perspective view of a further particular embodiment of a sound-absorbent device according to the invention which can be used in the glazing of Fig. 1 .

The invention is now described in more detail and in a non-limiting manner in the following description. The invention relates primarily to a glazing comprising a sound-absorbent device. The following description aims firstly to set out, according to various embodiments, features of the sound-absorbent device enabling the glazing equipped with it to provide excellent performance in terms of acoustic insulation at low, mid and high frequencies.

The glazing may be any type of glazing comprising at least two glass walls defining a cavity between them. For the purposes of the present invention, the cavity of a glazing is defined as the volume between two glass walls of the glazing. The sound-absorbent device may be or may comprise a glazing spacer. By "spacer" is meant any device for fixing the length of the spacing between the glass walls of the glazing in which it is intended to be placed. Alternatively, the soundabsorbent device may not be used as a spacer but may be associated with a spacer.

According to the invention, the sound-absorbent device comprises a profile or box, preferably configured as a spacer of a glazing, formed of a plurality of walls comprising at least one wall provided with a plurality of periodically arranged wall perforations (perforated wall). The soundabsorbent device further comprises a sound-absorbent layer comprising or consisting of a soundabsorbent material arranged on the outer wall face of at least one wall.

The perforated wall and any other wall has two main faces opposite each other and bearing the perforations, referred to as the "inner wall face" corresponding to the face facing the chamber of the profile or box and the "outer wall face", which is opposite to the inner face. The perforated wall can be defined as having a length, corresponding to the largest dimension of the wall in the plane of its main faces, a width (main plane), corresponding to the dimension in a direction perpendicular to the direction of the length in the main plane, and a thickness, corresponding to the dimension in a direction perpendicular to the main plane (and thus corresponding to the dimension between the two main faces). The perforated wall is preferably rectangular parallelepipeds (i.e., it has a constant length, width and thickness).

In one embodiment, the sound insulation device comprises one or more unperforated walls. In one embodiment, the sound insulation device comprises one or more walls comprising non-periodic perforations.

The walls of the sound-absorbent device may be made of polymeric material and/or of metallic material. The polymeric material preferably is polyethylene, polycarbonate, polypropylene, polystyrene, polybutadiene, polyisobutylene, polyester, polyurethane, polymethyl methacrylate, polyacrylate, polyamide, polyethylene terephthalate, polybutylene terephthalate, acrylonitrile, styrene butadiene, acrylonitrile styrene acrylate, styrene-acrylonitrile copolymer, or a combination thereof, with the polymer material optionally being reinforced with glass fibers. The polymeric material may optionally be a polymeric foam. The metallic material preferably is aluminum and/or stainless steel.

The sound-absorbent material of the sound-absorbent layer may be a porous sound-absorbent material, preferably selected from the group consisting of mineral wools, textile fibers, polymeric foams and combinations thereof. Preferably, the porous polymeric foam comprises an average proportion of open cells of 30 to 99%, preferably of 65 to 98%. Preferably, the porous polymeric foam is selected from the group consisting of silicone foams, polyurethane foams, polyethylene foams, melamine foams, and combinations thereof.

By "polymer foam" is meant a material with a porous structure, which is composed of a large number of small air bubbles, called "cells", in a solid polymer matrix. The terms "open cells" and "closed cells" refer, respectively, to cells that are interconnected with each other (i.e., there are open passages between the cells), and cells that are isolated from each other (i.e. there are no open passages between the cells). In general, open cell foams have a better sound absorption capacity due to the transmission of the sound wave between the cells, while closed cell foams have a higher stiffness. Of course, the stiffness and sound absorption capacity of polymer foam depends on various factors, such as the density of the foam, the cell size, and the chemical composition of the foam. Advantageously, the polymer foam may comprise an average proportion of open cells of 30 to 100%, preferably 30 to 99%, more preferably 65 to 98%. The average proportion of open cells can be measured using a microscope. For example, a cross section of a polymer foam can be examined under a microscope to determine whether each cell is open or closed. The average proportion of open cells is then calculated by dividing the total number of open cells by the total number of cells. The microscope may be, for example, a light microscope or a scanning electron microscope. The polymeric foam may comprise an average proportion of closed cells of 0 to 70%, preferably 1 to 70%, more preferably 2 to 35% %. The average proportion of closed cells can be measured in the same way as the average proportion of open cells.

In one embodiment, the polymeric foam may be characterized by an average porosity greater than or equal to 0.7 and/or an average air flow resistivity of 5,000 to 150,000 N s nr⁴. The porosity of the material can be measured with a porosimeter using the fluid saturation method by mercury intrusion. The air flow resistivity can be measured according to NF EN ISO 9053-1 . Such a porous structure of the polymer foam can increase the acoustic performance of the device and thus improve the acoustic insulation of the glazing in which it is placed. The polymeric foam may have an average porosity of greater than or equal to 0.75, or greater than or equal to 0.8, or greater than or equal to 0.85, or greater than or equal to 0.9, or greater than or equal to 0.95, e.g., a porosity of 0.7 to 0.75, or of 0.75 to 0.8, or of 0.8 to 0.85, or of 0.85 to 0.90, or of 0.90 to 0.95, or of 0.95 to 0.99. In one embodiment, the polymeric foam has an average porosity of 0.7 to 0.99, and more preferably 0.9 or greater. In one embodiment, the average air flow resistivity of the polymeric foam is from 5,000 to 10,000 N s nr⁴, or from 10,000 to 20,000 N s nr⁴, or from 20,000 to 40,000 N s nr⁴, or 40,000 to 60,000 N s nr⁴, or 60,000 to 80,000 N s nr⁴, or 80,000 to 100,000 N s nr⁴, or 100,000 to 120,000 N s nr⁴, or 120,000 to 140,000 N s nr⁴, or 140,000 to 150,000 N s nr⁴.

When the sound-absorbent device according to the invention is a spacer, the width of the perforated wall preferably determines the length of the spacing between the glass walls (i.e. the thickness of the cavity between the glass walls) of the glazing in which the spacer is intended to be used. The width of the perforated wall may be from 6 to 30 mm, preferably from 10 to 20 mm, for example 16 mm or 20 mm, particularly in embodiments in which the device is a spacer. The thickness of the perforated wall is advantageously from 0.1 to 15 mm, more preferably from 0.2 to 1 mm. In particular, the perforated wall may have a thickness of 0.1 to 0.2 mm, or 0.2 to 0.4 mm, or 0.4 to 0.6 mm, or 0.6 to 0.8 mm, or 0.8 to 1 mm, or 1 to 1 to 1 .2 mm, or 1 .2 to 1 .5 mm, or 1 .5 to 2 mm, or 2 to 3 mm, or 3 to 4 mm, or 4 to 5 mm, or 5 to 10 mm, or 10 to 15 mm. Preferably, a thickness of the sound-absorbent layer is from 6 to 100 mm, more preferably from 6 to 60 mm, or even more preferably from 6 to 30 mm. Preferably, a width of said sound-absorbent layer is 1 to 1/3, more preferably 1 to 1/2, of a width of said at least one perforated wall.

The walls may be manufactured by any method known to the skilled person, for example injection molding. A physical and/or chemical blowing agent may be used to achieve expansion of the polymer, for example in the mold. Alternatively, the walls may be manufactured by a foaming extrusion technique.

The perforated wall comprises a plurality of wall perforations arranged in a periodic manner. By "plurality of perforations" is meant at least two perforations. More particularly, the perforated wall may comprise two, or three, or at least three, or four, or at least four, or five, or at least five, or six, or at least six, or seven, or at least seven, or eight, or at least eight, or nine, or at least nine, or ten, or at least ten, periodically arranged perforations. The more periodically arranged perforations the perforated wall comprises, the better the sound insulation of the glazing in which the device is present. Particularly preferably, the perforated wall comprises at least three, more preferably at least four, periodically arranged perforations.

"Periodically arranged perforations" means that the perforations are identical and are present at regular intervals in the perforated wall (i.e., the distance between the centers of two adjacent perforations is essentially constant). The perforations are made throughout the thickness of the perforated wall (i.e., they extend from the inner face of the perforated wall to its outer face) and put in fluid communication the spaces located on both sides of the perforated wall (i.e., they allow the circulation of a fluid, and more particularly of a gas, from one space to the other). Advantageously, the periodic perforations are all aligned, more preferably along a longitudinal axis of the perforated wall (i.e., along the direction of its length). Even more advantageously, the perforations are arranged along a longitudinal axis of the perforated wall located in the middle of the width of the perforated wall.

In one embodiment, in which the outer wall face of the perforated wall is provided with the soundabsorbent layer, with the sound-absorbent layer being provided with a plurality of layer perforations, with the layer perforations being flush with the wall perforations, the number of layer perforations corresponds to the number of wall perforations. Alternatively, the number of layer perforations may be larger or smaller than the number of wall perforations. The perforations can be made by any method known to the skilled person. Depending on the method, the perforations can be made during the extrusion of the device (in-line) or using drilling technology (off-line) by an additional process step.

The perforations may be of any suitable shape. In embodiments, they have a cross-section (i.e., in the main plane of the perforated wall) which is circular or substantially circular. Advantageously, the perforations are micro-perforations. By "micro-perforations" is meant holes with a diameter or maximum dimension (in the main plane of the perforated wall) of 8 mm or less. Preferably, the perforations have a diameter, or maximum dimension (in the main plane of the perforated wall) of 0.2 to 8 mm, more preferably 0.5 to 8 mm. In embodiments, the diameter or maximum dimension of the perforations may be from 0.2 to 0.5 mm, or from 0.5 to 1 mm, or from 1 to 2 mm, or from 2 to 3 mm, or from 3 to 4 mm, or from 4 to 5 mm, or from 5 to 6 mm, or from 6 to 7 mm, or from 7 to 8 mm. Particularly preferably, the periodic perforations are distributed along the entire length of the perforated wall. Alternatively, the perforations may be periodically arranged along only part of the length of the perforated wall, for example along a portion of the perforated wall having a length of less than or equal to 90%, or less than or equal to 80%, or less than or equal to 70%, or less than or equal to 60%, or less than or equal to 50%, or less than or equal to 40%, or less than or equal to 30%, or less than or equal to 20%, or less than or equal to 10%, of the length of the perforated wall.

For each perforation, a geometric center of said perforation can be defined (hereinafter referred to simply as "center"). The distance between the centers of two adjacent perforations is preferably from 5 to 200 mm, more preferably from 10 to 110 mm. The distance between the centers of two adjacent periodic perforations may be 5 to 10 mm, or 10 to 20 mm, or 20 to 30 mm, or 30 to 40 mm, or 40 to 50 mm, or 50 to 60 mm, or 60 to 70 mm, or 70 to 80 mm, or 80 to 90 mm, or 90 to 100 mm, or 100 to 1 10 mm, or 110 to 120 mm, or 120 to 140 mm, or 140 to 160 mm, or 160 to 180 mm, or 180 to 200 mm.

Advantageously, the open area ratio (i.e., the ratio of the area of all the periodically arranged perforations to the total area of the perforated wall (including the area of the perforations) is from 0.01 to 8 %, preferably from 0.05 to 0.8 %. The open area ratio may be 0.01 to 0.05%, or 0.05 to 0.1%, or 0.1 to 0.2%, or 0.2 to 0.3%, or 0.3 to 0.4%, or 0.4 to 0.5%, or 0.5 to 0.6%, or 0.6 to 0.7%, or 0.5 to 0.7%, or 0.6 to 0.7,6 to 0.7%, or 0.7 to 0.8%, or 0.8 to 0.9%, or 0.9 to 1%, or 1 to 2%, or 2 to 3%, or 3 to 4%, or 4 to 5%, or 5 to 6%, or 6 to 7%, or 7 to 8%. The perforated wall delimits a chamber which is located within the cavity of the glazing. The thickness of the chamber is preferably from 2 to 200 mm, more preferably from 5 to 50 mm. The thickness of the chamber corresponds to the dimension of the chamber in a direction perpendicular to the main plane of the perforated wall. In embodiments, the chamber has a thickness of 2- 5 mm, or 5-10 mm, or 10-20 mm, or 20-30 mm, or 30-40 mm, or 40-50 mm, or 50-60 mm, or 60- 70 mm, or 70-80 mm, or 80-90 mm, or 90-100 mm, or 100-120 mm, or 120-140 mm, or 140-160 mm, or 160-180 mm, or 180-200 mm. The size and configuration of the perforated wall, its perforations and the chamber can be chosen according to the frequency at which it is desired that the perforated wall and chamber assembly resonate. This is known to the skilled person (see, e.g., WO 2022/234237) and, thus, need not be further elaborated herein.

Above statements with regards to the wall perforations apply similarly to the layer perforations.

The sound absorbent layer has two main faces opposite each other, referred to as the "inner layer face" corresponding to the face facing the chamber of the profile or box and the "outer layer face", which is opposite to the inner layer face. The sound absorbent layer comprises a plurality of layer perforations arranged in a periodic or non-periodic manner, preferably in a periodic manner. By "plurality of perforations" is meant at least two perforations. More particularly, the sound absorbent layer may comprise two, or three, or at least three, or four, or at least four, or five, or at least five, or six, or at least six, or seven, or at least seven, or eight, or at least eight, or nine, or at least nine, or ten, or at least ten, perforations. Particularly preferably, the perforated wall comprises at least three, more preferably at least four perforations.

"Periodically arranged perforations" means that the perforations are identical and are present at regular intervals in the sound absorbent layer (i.e., the distance between the centers of two adjacent perforations is essentially constant). The perforations are made throughout the thickness of the sound absorbent layer (i.e., they extend from the inner layer face of the sound absorbent layer to its outer layer face) and put in fluid communication the spaces located on both sides of the sound absorbent layer (i.e., they allow the circulation of a fluid, and more particularly of a gas, from one space to the other). Advantageously, the periodic perforations are all aligned, more preferably along a longitudinal axis of the sound absorbent layer (i.e., along the direction of its length). Even more advantageously, the perforations are arranged along a longitudinal axis of the sound absorbent layer located in the middle of the width of the perforated wall. In one embodiment, the system consisting of the perforated wall and the chamber is configured to resonate in the low frequency range. Low frequencies are defined as sound waves with a frequency below 300 Hz. For example, the perforated wall and chamber system may be configured to resonate at a frequency of 250 Hz or less, or 225 Hz or less, or 200 Hz or less, or 175 Hz or less, or 150 Hz or less. In other embodiments, the perforated wall and chamber system may be configured to resonate at a frequency of 400 Hz or less, or 350 Hz or less. Mid and high frequencies are defined as sound waves with a frequency at and above 300 Hz.

The perforated wall preferably comprises a single series of periodically arranged perforations. Alternatively, it may comprise several series of periodically arranged perforations, such as at least two series or at least three series, each series being different from the others (for example, the size of the perforations and/or the distance between the centers of two adjacent perforations may be different in each series). Where the perforated wall comprises a plurality of series of periodic perforations, each series is located in a different portion of the perforated wall (depending on its length). The presence of several different sets of periodic perforations allows the perforated wall and chamber system to resonate at several frequencies, with each portion of the perforated wall and chamber assembly that includes a different set of periodic perforations having a different resonant frequency.

In one embodiment, a desiccant is in or associated with the sound insulation device. By "desiccant" is meant an agent which has the property of drying the atmosphere in which it is placed by absorbing all or part of the moisture contained in the atmosphere. The use of such a desiccant is based on the desire to absorb moisture before it turns into liquid water.

In one embodiment, the desiccant comprises granules, preferably in a non-agglomerated (i.e., individualized) manner. The granules are, for example, made of molecular sieve, silica gel, calcium chloride (CaCI₂), sodium sulphate (Na₂SO4), activated carbon, or zeolites. In general, any material known to the skilled artisan for making desiccants can be used as granules.

In one embodiment, the desiccant is disposed in at least one envelope, which is preferably held inside or outside the chamber. Each envelope may comprise the desiccant in granular form as described above. Each envelope may be made of a flexible or rigid material, such as paper, plastic, polymeric or vegetable or woven fibers. The envelope may be provided with perforations to allow the granules to absorb moisture. These perforations are typically smaller in diameter than the granules so that the granules cannot escape from the envelope containing them. The use of envelopes advantageously prevents any release of the granules through the wall perforations in the perforated wall.

The glazing according to the invention comprises at least two glass walls. Advantageously, the glass walls are parallel or essentially parallel to each other. In one embodiment, the glazing comprises exactly two glass panes (in which case it is referred to as "double glazing"), or exactly three glass panes (in which case it is referred to as "triple glazing"), or at least three glass panes, for example four glass panes (in which case it is referred to as "quadruple glazing"). For the purposes of this invention, a "glass wall" means any structure comprising (or consisting of) at least one sheet of glass or a glazed assembly. By "glazed assembly" is meant a multi-layered glazed element of which at least one layer is a glass sheet. Thus, for example, the glass walls may independently comprise a single sheet of glass or a glazed assembly, for example consisting of laminated glass. The glass sheet can be made of organic or mineral glass. It can be made of tempered glass.

The glass walls (or one of the glass walls) may comprise (or consist of) a glazed assembly comprising at least one sheet of glass which may be as described above. The glazing assembly is preferably a laminated glazing. "Laminated glazing" means at least two sheets of glass with at least one interlayer film, generally of viscoelastic plastics, inserted between them. The viscoelastic plastic interlayer film may comprise one or more layers of a viscoelastic polymer such as polyvinyl butyral (PVB) or an ethylene-vinyl acetate copolymer (EVA), or ethylene copolymer (corresponding to the definition of an ionomer), more preferably PVB. The interlayer film may be standard PVB or acoustic PVB (such as single or triple layer acoustic PVB). Acoustic PVB usually 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 glass walls with laminated glass improves the sound insulation of the glazing, with the sound insulation being further increased when the interlayer film is made of acoustic PVB.

Each glass wall has two main faces opposite each other corresponding to the faces of the glass wall with the largest surface areas. Advantageously, the glass 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 glass 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 glass panes, the greater the acoustic insulation. In addition, the thicker the glass panes are, the lower the mass/spring/mass frequency of the glazing.

Preferably, all the glass walls of the glazing are of equal 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 substantially circular shape, or an elliptical or substantially elliptical shape, or a trapezoidal or substantially trapezoidal shape.

The glass walls define a cavity between them. Each of the glass walls defining the cavity comprises an inner face corresponding to the main face of the glass wall facing the cavity 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.

Advantageously, the sound-absorbent device is positioned in the glazing cavity, more particularly in a peripheral zone of the glazing cavity. By "peripheral zone of the cavity" is meant a zone of the cavity adjacent to the edges of the glass walls and preferably of width (i.e., in a direction orthogonal to the edge of the glass walls, in the plane of the glass walls) less than or equal to 20 cm, preferably still less than or equal to 10 cm, and even more preferably less than or equal to 5 cm. Preferably, the perforated wall of the sound-absorbent device is parallel to an edge of the glass walls, with the side walls thereof being parallel to the main faces of the glass walls.

Particularly preferably, the sound-absorbent device is placed in the glazing cavity so that the chamber bounded by the perforated wall in fluid communication with the glazing cavity formed between the glass walls via the perforations in the perforated wall. Where the sound-absorbent device is a spacer, the glass walls are attached to the spacer.

Preferably, the glazing cavity (between the glass walls) comprises a gas. The gas may be air and/or carbon dioxide, and/or argon, and/or krypton and/or xenon. The use of argon, krypton or xenon, in addition to or instead of air, improves the thermal insulation of the glazing.

The glazing according to the invention may be totally opaque, totally transparent, or partly opaque and partly transparent. Preferably, the glazing is at least partly transparent. One (or more) of the glass walls may be tinted through its thickness over all or part of its surface. One (or more) of the glass walls may be wholly or partly covered with an opaque coating, for example, a paint and/or enamel. The opaque coating may be present on the inner side of the glass wall, or on its outer side, or on both sides, preferably coating is present on the inner side of the glass wall. In one embodiment, only one of the glass walls of the glazing is covered with an opaque coating. This glass wall is advantageously the glass wall intended to be the outermost glass wall of the glazing when the latter is used in an external building fagade or window.

In one embodiment, the glass walls of the glazing, or at least one of the glass walls, may have been treated to improve the thermal insulation of the glazing. In particular, one or more of the glass walls may comprise one (or more) insulating layers 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 glass 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 may be arranged on different sides of the glass wall (for example, the insulating layer may be on the inside and the opaque coating on the outside). Alternatively, where 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 PVB layer and a glass sheet.

The mass/spring/mass frequency of the glazing can be determined by a formula well-known to the skilled artisan (see, e.g., WO 2022/234237) and, thus, need not be further elaborated herein.

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

With reference to Figs. 1 and 2, the glazing 100 comprises a first glass wall 101 and a second glass wall 102 forming a cavity 103 therebetween. A sound-absorbent device 1 is placed in the cavity 103. The sound-absorbent device 1 comprises at least one perforated profile 2 made of polymeric material comprising an upper wall 4 and a lower wall 5 which are connected by two side walls 6, thereby enclosing a chamber 3. The upper wall 4 comprises a plurality of wall perforations 7 in periodic arrangement. The upper wall 4 faces the interior of the glazing cavity 3, with the lower wall 5 facing the exterior and the edges of the glazing 100. Thus, the chamber 3 of the perforated profile 2 is in fluid communication with the glazing cavity 103 via the wall perforations 6 present in the upper wall 3 of the profile 2 (i.e. a fluid, and preferably a gas, can flow from the glazing cavity 103 to the interior of the chamber 3 of the profile 2, and vice versa).

A seal may also be present, preferably arranged on the outer wall face of the sound-absorbent device 1 (i.e., the wall face of the sound-absorbent device 1 closest to the edge of the glass walls 101 , 102), which is preferably the outer wall face of the lower wall 5 of the profile 2. More preferably, the seal extends from this outer wall face to the edge of the glass walls 101 , 102. This seal may be formed by a mastic (known as "sealing mastic") based on polyurethane, polysulphide and/or silicone.

When the sound-absorbent device 1 is a spacer, or when the sound-absorbent device is not a spacer but is associated with a spacer, the spacer allows the length of the spacing between the glass walls 101 , 102 to be fixed. The length of the spacing (i.e., the thickness of the cavity 103 between the glass walls 101 , 102) may be between 6 and 30 mm, preferably between 10 and 20 mm, for example 16 mm.

In the present description, the terms "upper" and "lower"are used with reference to the orientation of the profile 2 shown on the right-hand side of Fig. 1 . It goes without saying that the profile 2 may have any other possible orientation, such as an orientation in which the longitudinal axis of the profile 2 is vertical or an orientation in which the upper wall 4 is below the lower wall 5 (as shown on the left-hand side of Fig. 1 ). The profile 2 may have open ends in the longitudinal direction. However, the chamber 3 of the profile 2 can be closed by sealing the open ends of the profile 2 (e.g., against the upper wall of another profile)

Referring again to Fig. 1 and additionally referring to Figs. 2 and 3, as can be seen in Fig. 3, one of the walls, i.e. the upper wall 4, is a perforated wall comprising a plurality of wall perforations 7 arranged in a periodic manner, as described above. Stated more particularly, the wall perforations 7 are made throughout the thickness of the upper wall 4 and put the chamber 3 in fluid communication with the environment outside the profile 2.

Advantageously, the main plane of the upper wall 4 and the main plane of the lower wall 5 are parallel to each other. Even more advantageously, the main planes of the upper wall 4 and the lower wall 54 are perpendicular to the main planes of the two side walls 6. Preferably, the profile 2 has a parallelepiped shape, even more preferably a rectangular parallelepiped shape. Each of the walls 4, 5, 6 of the profile 2 may independently have a rectangular parallelepiped shape, preferably each of the walls 4, 5, 6 of the profile 2 has a rectangular parallelepiped shape. The thickness of each wall 4, 5, 6 is advantageously from 0.1 to 15 mm, more preferably from 0.2 to 1 mm. In particular, each wall 4, 5, 6 may have a thickness of 0.1 to 0.2 mm, or 0.2 to 0.4 mm, or 0.4 to 0.6 mm, or 0.6 to 0.8 mm, or 0.8 to 1 mm, or 1 to 1 to 1 .2 mm, or 1 .2 to 1 .5 mm, or 1 .5 to 2 mm, or 2 to 3 mm, or 3 to 4 mm, or 4 to 5 mm, or 5 to 10 mm, or 10 to 15 mm.

Advantageously, the length of the upper wall 4 of the profile 2 is equal to the length of the cavity 103 between the glass walls 101 ,102 of the glazing 100 in which the sound-absorbent device 1 is placed, in the same direction.

Specifically, the outer wall 4 (i.e. perforated wall) comprises an inner wall face 11 facing the chamber 3 and an outer wall face 10 opposite to the inner wall face 11 . Each of the wall perforations 7 extend from the inner wall face 11 to the outer wall face 10.

With particular reference to Fig. 2, the sound-absorbent device 1 comprises a sound-absorbent layer 8 made of sound-absorbing material, with the sound-absorbent layer 8 being arranged on the outer wall face 10 of the upper wall 4, preferably fixed to the upper wall 4 by means of a glue. Specifically, the sound-absorbent layer 8 having an elongated shape comprises an inner layer face 13 facing the chamber 3 and an outer layer face 12 opposite to the inner layer face 13. As can be seen in Fig. 2, the sound-absorbent layer 8 is placed with its inner layer face 13 on the outer wall face 10 of the upper wall 4. The outer wall face 10 of exclusively the upper wall 4 is provided with the sound-absorbent layer 8.

In one embodiment, a width of the sound-absorbent layer 8 is 1 to 1/3, preferably 1 to 1/2, of a width of the upper wall 4. As illustrated, the width of the sound-absorbent layer 8 may, e.g., be equal to the width of the upper wall 4. In one embodiment, a thickness of the sound-absorbent layer 8 is from 6 to 100 mm, preferably from 6 to 60 mm, or even more preferably from 6 to 30 mm.

The sound-absorbent layer 8 comprises a plurality of layer perforations 9 in correspondence with the wall perforations 7 of the upper wall 4 and flush therewith. Each of the layer perforations 9 extends from the inner layer face 13 to the outer layer face 12.

Accordingly, acoustic waves, preferably acoustic waves in a low frequency range, may penetrate through the layer perforations 9 so as to be dampened by the upper wall 4/chamber 3 system of the sound-absorbent device 1 . Further, acoustic waves, preferably acoustic waves in a mid and high frequency range, may be dampened by the sound-absorbent layer 8.

Advantageously, the sound-absorbent device 1 is one-piece, i.e., the sound-absorbent layer 8 is fixedly attached to the profile 2 (in Fig. 2 to the upper wall 4).

With respect to Figs. 3 and 4, further embodiments will be illustrated, wherein, for the sake of simplicity, only differences to the embodiment of Figs. 2 are described. Otherwise, reference is made to the description set out above in connection with Figs. 1 and 2.

With particular reference to Fig. 3, according to a further embodiment, the sound-absorbent device 1 comprises a profile 2 (similar to the profile 2 of the sound-absorbent device 1 of Fig. 2) and two sound-absorbent layers 8 arranged on the outer wall faces of exclusively the side walls 6 of the profile. Stated more particularly, one sound-absorbent layer 8 is arranged on the outer wall face of one side wall 6, with the other sound-absorbent layer 8 being arranged on the outer wall face of the other side wall 6. The sound-absorbent layers 8 do not need to have layer perforations 9 as the wall perforations 7 are freely accessible.

With particular reference to Fig. 4, according to a yet further embodiment, the sound-absorbent device 1 comprises a profile 2 and a sound-absorbent layer 8 arranged on the outer wall face of the lower wall 5. Contrary to the profiles 2 of Figs. 2 and 3, the lower wall 5 comprises a plurality of openings (not shown) which can be arranged in a periodic or non-periodic manner. The soundabsorbent layer 8 does not need to have layer perforations 9 as the wall perforations 7 of the upper wall 4 are freely accessible. In this embodiment. Due to the openings of the lower wall 5, acoustic waves, preferably acoustic waves in a mid and high frequency range, can penetrate through the lower wall 5, and, thus can be dampened by the sound-absorbent layer 8.

While not shown in the exemplary embodiments, the sound-absorbent device may contain desiccant, preferably within the chamber. Preferably, the desiccant is present in the form of granules and disposed in envelopes such as bags or containers, so that the desiccant cannot escape through the wall perforations due to the action of gravity.

As can be seen from the above description, the present invention discloses a glazing which is very effective in terms of acoustic insulation with regards to a broad range of frequencies. Further, the sound-absorbent device and the glazing can be manufactured in an easy, time- and costefficient manner.

List of reference signs

1 Sound-absorbent device

2 Profile

3 Chamber

4 Upper wall, inner wall

5 Lower wall, outer wall

6 Side wall

7 Wall perforation

8 Sound-absorbent layer

9 Layer perforation

10 Outer wall face

11 Inner wall face

12 Outer layer face

13 Inner layer face

100 Glazing

101 First glass wall

102 Second glass wall

103 Cavity

Claims

1. A glazing (100) comprising at least two glass walls (101 , 102) forming a cavity (103) therebetween, wherein the cavity (103) comprises at least one sound-absorbent device (1 ) comprising a profile (2) or box formed of a plurality of walls (4, 5, 6) , said walls (4, 5, 6) surrounding a chamber (3), said walls (4, 5, 6) comprising an inner wall face (1 1 ) facing said chamber (3) and an outer wall face (10) opposite to the inner wall face (11 ), said walls (4, 5, 6) comprising at least one perforated wall (4) provided with a plurality of periodically arranged wall perforations (7), with each of said wall perforations (7) extending from said inner wall face (11 ) to said outer wall face (10), said outer wall face (10) of at least one of said walls (4, 5, 6) being provided with a soundabsorbent layer (8) comprising or consisting of a sound-absorbent material, wherein i) the outer wall face (10) of said perforated wall (4) being provided with said soundabsorbent layer (8), said sound-absorbent layer (8) comprising an inner layer face (13) facing said chamber (3) and an outer layer face (12) opposite to the inner layer face (13), said sound absorbent layer (8) being provided with a plurality of layer perforations (9), with each of said layer perforations extending from said inner layer face (13) to said outer layer face (12), said layer perforations (8) being flush with said wall perforations (7), or ii) said walls (4, 5, 6) comprise an inner wall (4) facing the cavity (103) of the glazing (100) and an outer wall (5) opposite thereto, said inner wall (4) and said outer wall (5) being connected by side walls (6), with the outer wall face (10) of exclusively one or each of said side walls (6) being provided with said sound-absorbent layer (8), or iii) said walls (4, 5, 6) comprise an inner wall (4) facing the cavity (103) of the glazing (100) and an outer wall (5) opposite thereto, said perforated wall (4) being said inner wall, the outer wall face (10) of said outer wall (5) being provided with said sound-absorbent layer (8), with said outer wall (5) being provided with a plurality of periodic or non-periodic openings.

2. The glazing (100) according to claim 1 , i), wherein said walls (4, 5, 6) comprise an inner wall (4) facing the cavity (103) of the glazing (100) and an outer wall (5) opposite thereto, said perforated wall (4) being said inner wall (4).

3. The glazing (100) according to claim 1 , i), or claim 2, wherein the outer wall face (10) of exclusively said perforated wall (4) is provided with said sound-absorbent layer (8).

4. The glazing (100) according to claim 1 , iii), wherein the outer wall face (10) of exclusively said outer wall (5) is provided with said sound-absorbent layer (8).

5. The glazing (100) according to any one of claims 1 through 4, wherein said soundabsorbent device (1 ) is configured to resonate at a frequency range of 400 Hz or less, or 350 Hz or less or below 300 Hz.

6. The glazing (100) according to any one of claims 1 through 5, wherein said soundabsorbent layer (8) is fixed, in particular by means of an adhesive, to the outer wall face (10) of said at least one wall (4, 5, 6).

7. The glazing (100) according to any one of claims 1 through 6, wherein said soundabsorbent layer (8) comprises or consists of a porous sound-absorbent material selected from the group consisting of mineral wools, textile fibers, polymeric foams and combinations thereof, wherein said polymeric foam preferably comprises an average proportion of open cells of 30 to 99%, more preferably 65 to 98%.

8. The glazing (100) according to claim 7, wherein said polymeric foam is selected from the group consisting of silicone foams, polyurethane foams, polyethylene foams, melamine foams, and combinations thereof.

9. The glazing (100) according to any one of claims 1 through 8, wherein a thickness of said sound-absorbent layer (8) is from 6 to 100 mm, preferably from 6 to 60 mm, or even more preferably from 6 to 30 mm.

10. The glazing (100) according to any one of claims 1 through 9, wherein a width of said sound-absorbent layer (8) is 1 to 1/3, preferably 1 to 1/2, of a width of said at least one perforated wall (4).

11. The glazing (10, 20, 30) according to any one of claims 1 through 10, comprising a desiccant in the chamber (3) of or associated with the sound insulation device (1 ).

12. The glazing (100) according to any one of claims 1 through 1 1 , wherein the desiccant is disposed in at least one envelope, which is preferably held inside or outside the chamber (3).

13. The glazing (100) according to any one of claims 1 through 12, wherein the glazing (100) further comprises one or more additional sound-absorbent devices, each additional soundabsorbent device comprising at least one perforated wall comprising a plurality of periodically arranged perforations and delimiting a chamber arranged in the cavity, wherein preferably the periodicity of the perforations of the perforated wall of each additional sound-absorbent device are different from each other.

14. The glazing (100) according to any one of claims 1 through 13, wherein the soundabsorbent device (1) is a glazing spacer.

15. The glazing (100) according to any one of claims 1 to 14, being a building glazing, such as a building facade, window or door glazing or an interior glazing.