FR3151347A1 - Glazing including a spacer device - Google Patents

Description

Glazing including a spacer device

The present invention belongs to the general field of the manufacture of glazing. It relates more particularly to a spacing device. It also relates to glazing comprising at least one such device. The invention finds a particularly advantageous application, although in no way limiting, in the case of building glazing.

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.

The panes are separated by a spacer (also known as a spacer), which can be a warm edge spacer (meaning that the spacer is made of a material with low thermal conductivity). A spacer is a piece that separates the two panes of the insulating glass unit and seals the gas cavity between them. Conventional spacers are mostly made from a material such as steel or aluminum for their strength, and they are still commonly used because of their lower cost.

However, the production, use and disposal of such a steel or aluminum spacer results in high emissions of _CO2 and other greenhouse gases. Thus, traditional technologies have a high carbon footprint.

There is therefore a real need to provide more sustainable and environmentally friendly glazing, with a reduced carbon footprint.

The present invention aims to overcome all or part of the drawbacks of conventional spacers, in particular that set out above, by proposing a solution which makes it possible to obtain decarbonized glazing (i.e., resulting in a reduction in the consumption of primary energy sources which emit greenhouse gases, such as fossil fuels (coal, oil and natural gas) from a material of renewable origin.

Thus, and according to a first aspect, the invention relates to glazing comprising at least two glazed walls forming a cavity between them, in which the cavity comprises a spacing device comprising at least one layer of material made from bamboo.

In particular embodiments, the glazing may further comprise one or more of the following characteristics, taken individually or in all technically possible combinations.

In embodiments, the thermal conductivity of the material made from bamboo may be 0.05 to 0.20 W/(m K), preferably 0.07 to 0.15 W/(m K).

In embodiments, the density of the material made from bamboo may be 0.3 to 0.6 g/cm3, preferably 0.4 to 0.55 g/cm3.

In embodiments, the bamboo may be selected from Moso bamboo (Phyllostachys edulis), Guadua bamboo (Guadua angustifolia), black bamboo (Phyllostachys nigra), and a mixture thereof.

In embodiments, the spacer device may further include a hydrophobic component, which may be embedded in the bamboo-made material or may be in the form of a coating applied to the layer of bamboo-made material.

In embodiments, the hydrophobic component may comprise a hydrophobic polymer, a functional silane, a wax, carbon nanotubes, nanowaxes, metal oxide nanoparticles, or a mixture thereof; the hydrophobic polymer preferably being selected from a fluoropolymer, polypropylene, polystyrene, polyvinyl chloride, polyethylene, or a mixture thereof.

In embodiments, the spacer device may further comprise an additional layer comprising a metal, glass fibers, polyurethane, butyl rubber, silicone rubber, polyacrylate, polysulfide, silicone, or a mixture thereof; the metal preferably being selected from aluminum, iron, silver, copper, gold, chromium, silicon oxide, silicon nitride, and mixtures and alloys thereof.

In embodiments, the additional layer may have a thickness less than that of the layer of material made from bamboo, and preferably has a thickness of 10 to 1500 nm, more preferably 20 to 200 nm, more preferably 50 to 100 nm.

In embodiments, the material made from bamboo may include bamboo powder or bamboo fibers.

In embodiments, the material made from bamboo may comprise a binder, preferably selected from polylactic acid; plant-based resins, including lignin-based resins, natural latex-based resins, rosin-based resins, cellulose-based resins, starch-based resins, algae-based resins, agricultural waste-based resins, casein-based resins, natural gum-based resins; synthetic resins, including polyolefins; and mixtures thereof.

In embodiments, the spacer device may include a chamber that contains a desiccant.

In embodiments, the spacer device may be a profile, preferably perforated.

In embodiments, the glazing may be building glazing, such as building facade, window or door glazing or interior glazing.

The invention also relates to a method of manufacturing a spacer device as described above, comprising the steps of: preparing a bamboo-based composition; and shaping this bamboo-based composition to form the layer of material made from bamboo.

In embodiments, the shaping step may include one or more steps selected from extruding, rolling, pressing, stamping, cutting, rolling, bending, extrusion blow molding, and gluing.

In embodiments, the bamboo-based composition may comprise bamboo powder or bamboo fibers.

In embodiments, the shaping step may comprise forming a sheet by pressing and drying from the bamboo-based composition; the bamboo-based composition preferably being an aqueous paste optionally comprising at least one surfactant.

In embodiments, the shaping step may comprise a step of extruding the bamboo-based composition; the bamboo-based composition preferably comprising a binder.

In embodiments, the method may further comprise a step of applying a coating comprising a hydrophobic component to the layer of material made from bamboo.

In embodiments, the method may further comprise a step of depositing an additional layer comprising a metal, glass fibers, a polyurethane, a butyl rubber, a silicone rubber, a polyacrylate, a polysulfide, a silicone or a mixture thereof on the layer of material made from bamboo, preferably by lamination or by calendering; the metal preferably being selected from aluminum, iron, silver, copper, gold, chromium, silicon oxide, silicon nitride and mixtures and alloys thereof.

The present invention makes it possible to meet the need expressed above. More particularly, it provides a spacing device making it possible to obtain decarbonized glazing, resulting in reduced emissions of _CO2 and other greenhouse gases.

This is accomplished by having the spacer device include at least one layer of material made from bamboo. In general, bamboo has a relatively low carbon footprint compared to many other materials, such as aluminum or steel. This is because bamboo grows very quickly and requires very little water and no pesticides or fertilizers. This makes bamboo an environmentally friendly material. Bamboo is also a renewable resource, as it regrows after being harvested, and can be grown sustainably without harming the surrounding ecosystem. Additionally, bamboo is able to absorb more _CO2 from the atmosphere than most other plants, meaning it has a net negative carbon footprint.

Other features and advantages of the present invention will emerge from the description given below, with reference to the attached drawings which illustrate an exemplary embodiment thereof without any limiting character. In the figures:

There represents a schematic and perspective view of an example of a spacing device according to the invention.

Description of embodiments

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

The invention relates firstly to a spacing device for glazing. By “spacing device” is meant any device making it possible to fix the distance of the spacing between the glazed walls of the glazing in which it is intended to be placed.

The glazing may be any type of glazing comprising at least two glazed walls defining a cavity between them. For the purposes of the present invention, the cavity of a glazing is defined as being the volume between two glazed walls of said glazing.

The spacer device comprises two main faces opposite each other, referred to in this text as the "inner face" (corresponding to the face intended to face the centre of the cavity formed between the glazed walls of the glazing) and the "outer face" (corresponding to the face intended to be closest to the edge of the glazed walls of the glazing). The term "edge" of a glazed wall means one side of that glazed wall. For example, for a rectangular or square glazed wall, the edges correspond to the four sides of the rectangle or square.

The spacer device has a width, corresponding to the distance 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 device is intended to be used. The spacer device has a height, corresponding to the distance between the external face and the internal face of the spacer device. The spacer device has a length, corresponding to the distance in a direction perpendicular to the thickness and width of the device.

The width of the spacer device may be from 6 to 30 mm, preferably from 10 to 20 mm, for example 16 mm or 20 mm. In one embodiment, the width is from 6 mm to 20.6 mm, with a manufacturing tolerance of ± 3% from the nominal values. When the width varies in the spacer device, the width refers to the width that determines the spacing distance between the glass walls (the longest width in the spacer device).

The height of the spacer is preferably 2 to 250 mm, more preferably 5 to 50 mm. In embodiments, the height of the spacer is 2 to 5 mm, or 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 120 mm, or 120 to 140 mm, or 140 to 160 mm, or 160 to 180 mm, or 180 to 200 mm. In one embodiment, the height is 4.7 mm, with a manufacturing tolerance of ±6% of the nominal value.

The spacer device may have a cross-section of essentially a rectangular parallelepiped shape, or a more complex shape as discussed in more detail below.

The spacer device comprises at least one layer of material made from bamboo.

The material made from bamboo may include bamboo powder or bamboo fibers.

Bamboo powders are commercially available, for example, from suppliers such as Bamboo Village; Hefei TNJ Chemical Industry Co., Ltd; Bioworld Merchandising, Inc; and Maruti Mineral Industries. The bamboo content (by weight) in the layer of material made from bamboo may be 70 to 100%, or 75 to 100%, or 80 to 100%, or 85 to 100%, or 90 to 100%, or 95 to 100%, or 98 to 100% based on the total weight of the layer. The bamboo content in the layer is preferably 90 to 100% in order to minimize the carbon footprint of the device.

The thermal conductivity of the material made from bamboo may be 0.05 to 0.20 W/(m K), for example, 0.10 to 0.15 W/(m K), 0.15 to 0.18 W/(m K), or 0.18 to 0.20 W/(m K). The thermal conductivity is preferably 0.07 to 0.15 W/(m K). The thermal conductivity may be measured by any method known to those skilled in the art, for example, according to standard NF EN 12667 (Thermal performance of building materials and products - Determination of thermal resistance by the guarded hot plate method and the fluxmetric method - Products of high and medium thermal resistance).

The thermal conductivity of the material can be affected by several factors, such as the density of the bamboo, the presence of knots and the direction of the fibers, when present.

The density of the material made from bamboo may vary depending on the species of bamboo and its age. The density may be 0.3 to 0.8 g/cm³, for example, 0.3 to 0.6 g/cm³, 0.6 to 0.7 g/cm³, or 0.7 to 0.8 g/cm³. The density is preferably 0.4 to 0.55 g/cm³. A material made from bamboo with a low density (0.4 to 0.6 g/cm³) has a less dense structure and a relatively lower thermal conductivity. A material made from bamboo with a medium density (0.6 to 0.7 g/cm³) has a slightly higher thermal conductivity. A material made from bamboo with a high density (0.7 to 0.8 g/cm³) has a denser structure and a slightly higher thermal conductivity.

Preferably, the layer of material made from bamboo comprises dry bamboo or is made of dry bamboo. Generally, with the increase of the humidity of bamboo, its thermal conductivity increases. When bamboo is dry, with low humidity, it contains air in its pores, which can reduce the thermal conductivity. However, when the humidity is high, water gradually replaces the air in the pores, which increases the thermal conductivity over time. The relationship between thermal conductivity and humidity also depends on the density of bamboo, the duration of exposure to humidity, temperature, etc.

The bamboo species can be selected based on several factors, such as application, environmental constraints, required properties and performance requirements. Preferably, a bamboo species with low thermal conductivity is chosen.

For example, bamboo can be chosen from: Moso bamboo (Phyllostachys edulis), Guadua bamboo (Guadua angustifolia), Black bamboo (Phyllostachys nigra), and a mixture of these.

Moso bamboo (Phyllostachys edulis) has advantages such as rapid growth, mechanical strength, and low thermal conductivity, which makes it suitable for use in thermal insulation of buildings. Guadua bamboo (Guadua angustifolia), native to South America, has high mechanical strength and insulating properties. Black bamboo (Phyllostachys nigra) has interesting insulating properties.

The thickness of the layer of material made from bamboo is advantageously from 0.1 to 15 mm, more preferably from 0.2 to 1 mm. In particular, the layer of material made from bamboo may have a thickness of 0.1 to 0.2 mm, or from 0.2 to 0.4 mm, or from 0.4 to 0.6 mm, or from 0.6 to 0.8 mm, or from 0.8 to 1 mm, or from 1 to 1.2 mm, or from 1.2 to 1.5 mm, or from 1.5 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 10 mm, or from 10 to 15 mm.

The material made from bamboo may comprise a binder. The binder is preferably selected from: polylactic acid, plant-based resins, lignin-based resins, natural latex-based resins, rosin-based resins, cellulose-based resins, starch-based resins, algae-based resins, agricultural waste-based resins, casein-based resins, natural gum-based resins; synthetic resins, including polyolefins; and mixtures thereof.

•Plant-based resins can be resins made from plant raw materials, such as vegetable oils (e.g., soybean oil, linseed oil, and castor oil), starches, and sugars. Lignin-based resins can be by-products of the pulp and paper industry. Natural latex-based resins can be made from tree sap, for example, rubber trees. Rosin-based resins can be obtained from the distillation of the sap of certain types of pine trees. Cellulose-based resins can be extracted from various plant sources, for example, wood, straw, or cotton. Starch-based resins can be extracted from corn, wheat, potatoes, etc. Agricultural waste-based resins can be obtained from agricultural wastes such as walnut shells, wheat straw, and sugarcane stalks. Casein-based resins can be obtained from milk. Natural gum-based resins can be obtained from gum arabic, guar gum or xanthan gum.

Bamboo may be dispersed as particles and/or fibers in a binder matrix. The binder content in the material may be 15 to 95%, preferably 25 to 45%, by weight.

The spacer device of the invention may further comprise a hydrophobic component. The hydrophobic component may be integrated into the material made from bamboo or may be in the form of a coating applied to the layer of material made from bamboo. Such a hydrophobic component may help prevent the spacer device, particularly the layer of material made from bamboo, from retaining water from the atmosphere, thereby helping to maintain low humidity in the material.

When the hydrophobic component is incorporated into the material, its content may be 0.01% to 10%, preferably 0.1% to 5%, by weight.

The hydrophobic component coating may have a thickness of 10 μm to 100 μm. In a preferred embodiment, the thickness of the coating is between 5 μm and 80 μm. In another preferred embodiment, the thickness of the coating is between 10 μm and 80 μm.

The hydrophobic component may comprise a hydrophobic polymer, a functional silane, a wax, carbon nanotubes, nanowaxes, metal oxide nanoparticles or mixtures thereof.

The hydrophobic polymer may preferably be selected from: a fluoropolymer, such as polytetrafluoroethylene (PTFE) or Teflon, polypropylene, polystyrene, polyvinyl chloride, polyethylene or a mixture thereof.

The metal oxide nanoparticles may be selected from: titanium dioxide nanoparticles, silicon oxide nanoparticles or mixtures thereof.

Small particles (nanoparticles) of nanostructures, such as carbon nanotubes, nanowaxes and metal oxide nanoparticles, can be embedded in the material made from bamboo or applied to the surface to create hydrophobic properties.

The spacer device may further comprise an additional layer comprising a metal, glass fibers, a polyurethane, a butyl rubber, a silicone rubber, a polyacrylate, a polysulfide, silicone or a mixture thereof.

The metal is preferably selected from: aluminum, iron, silver, copper, gold, chromium, silicon oxide, silicon nitride and mixtures and alloys thereof.

Such an additional layer provides an additional function to the spacer device, such as minimizing heat transfer and improving energy efficiency (particularly in the case of the additional layer comprising a metal or glass fibers, also called a "thermal additional layer") or sealing (particularly in the case of the layer comprising a polyurethane, a butyl rubber, a silicone rubber, a polyacrylate, a polysulfide, or silicone, also called a "sealing additional layer").

The thermal additional layer may be treated to make it hydrophobic, for example, by applying a hydrophobic component as a coating to the thermal additional layer, as described above.

The spacer device may include at least one additional thermal layer, an additional sealing layer, or a combination thereof.

The additional layer preferably has a thickness less than that of the layer of material made from bamboo, and may in particular have a thickness of 10 nm to 1500 nm, preferably 10 nm to 400 nm, more preferably 10 nm to 300 nm, more preferably 10 nm to 200 nm, more preferably 50 to 100 nm. When the spacer device comprises two or more additional layers, the thickness refers to the total thickness of the additional layers.

The spacer device may include a plurality of additional layers. For example, the spacer device may include 1 to 4 additional thermal layers and/or 1 to 4 additional sealing layers. In one embodiment, the spacer device includes two additional sealing layers, a first additional water, or gas and water vapor sealing layer, and a second additional sealing layer complementing the first, i.e., if the first additional layer is watertight (e.g., comprising polyurethane), the second additional layer (e.g., comprising butyl rubber) is gas and water vapor tight, and vice versa. In another embodiment, the spacer device may include an additional gas and water vapor tight sealing layer such as the additional layer, and an additional watertight sealing layer, such as the additional layer.

It is also possible for the spacer device to comprise no additional layers and in particular for the spacer device to be single-layer. Thus, the spacer device may be 100% plant-based (provided that the optional binder or optional hydrophobic component is plant-based, such as cellulose or wax).

The spacer device may include a chamber that contains a desiccant.

The term "desiccant" is conventionally used to refer to an agent that has the property of drying out the atmosphere in which it is placed, or in other words, of absorbing all or part of the moisture contained in this atmosphere (for example, the moisture trapped in the cavity during manufacturing). The use of such a desiccant is based on a desire to absorb said moisture before it turns into liquid water, thereby reducing the dew point of the gas in this atmosphere and preventing condensation when the temperature of the exterior glass drops.

The desiccant may comprise granules, preferably in a non-agglomerated manner (i.e. in an individualized manner). Said granules are for example made of molecular sieve, silica gel, calcium chloride (CaCl ₂ ), sodium sulfate (Na ₂ SO ₄ ), activated carbon, zeolites, silicates, bentonites, or a mixture thereof.

The desiccant may fill the entire chamber. Alternatively, the desiccant may be present in only a portion of the chamber, for example the volume of the desiccant may be from 2 to 20%, or from 20 to 40%, or from 40 to 60%, or from 60 to 80%, or from 80 to 98%, of the total volume of the chamber. The desiccant may be held fixed within the chamber by any method known to those skilled in the art, for example by using suitable adhesive means.

Alternatively or additionally, the desiccant may be incorporated into the material made from bamboo, for example, by co-extrusion of the desiccant with the material made from bamboo during the manufacture of the layer of material made from bamboo. In this case, the content of desiccant in this material (per unit length of the device) is preferably 1 to 20 g/m, more preferably 2 to 4 g/m.

The chamber may comprise a gas. The gas may in particular be air and/or argon, and/or carbon dioxide, and/or krypton and/or xenon.

The spacer device may be a profile. The profile may include a plurality of walls. The internal space of the profile defined by the walls constitutes a chamber as described above.

Each wall may consist of a layer of material made from bamboo as described above. Alternatively, each wall may consist of a set of layers of material made from bamboo bonded together. Alternatively, each wall may consist of one or more layers of material made from bamboo as described above, and one or more additional layers and/or coverings as described above.

The profile may comprise at least one upper wall, one lower wall and two side walls. In this text, the terms “upper” and “lower” are used in reference to the orientation of the spacer device in the glazing. The upper wall corresponds to the wall intended to face the center of the cavity formed between the glazed walls of the glazing (the upper wall therefore comprises the internal face of the spacer device) and the lower wall corresponds to the wall intended to be closest to the edge of the glazed walls of the glazing (the lower wall therefore comprises the external face of the spacer device).

Advantageously, the plane of the upper wall and the plane of the lower wall are parallel to each other and, even more advantageously, they are perpendicular to the planes of the two side walls.

The profile may further comprise at least one connecting wall which connects the side wall and the bottom wall (as illustrated in ).

The connecting wall (preferably both connecting walls) may form an angle of 30° to 60° with respect to the side walls.

The connecting wall improves the stability of the spacer device and allows for better bonding and insulation of the spacer device.

Preferably, the upper, lower, side and/or connecting walls each have a plate shape.

Everything described in this text in relation to the layer of material made from bamboo applies to the walls of the profile.

Preferably, the profile may be perforated. By "perforated profile" is meant that at least one wall of the profile (especially the top wall) comprises a plurality of perforations. The perforations may be arranged in any suitable manner, allowing the desiccant in the chamber to absorb moisture between the glass walls of the glazing.

The maximum stress in the final product (glazing) produced with the inventive spacer device (the stress due to the heating of the air in the cavity and to the difference in altitude) may be less than or equal to 20 MPa for annealed glass, 35 MPa for so-called “hardened” glass and 50 MPa for tempered glass.

Referring to the , according to one embodiment, the spacing device 1 according to the invention comprises at least one layer of material made from bamboo 3, 4, 5, 6. More precisely, the spacing device 1 is a profile, comprising an upper wall 3, a lower wall 4, two side walls 5, and two connecting walls 6 which each connect a respective side wall 5 to the lower wall 4.

Each connecting wall 6 has an angle of 45° relative to the side walls 5.

The spacer device 1 comprises a chamber 2 which can contain a desiccant agent.

Although the does not show perforation, the profile can be perforated.

The height of the spacer 1 (distance between the top and bottom walls) can be 4.7 mm, and the width of the spacer 1 (distance between the side walls) can be 6 mm to 20.6 mm.

The spacer device 1 may further comprise a hydrophobic component as described above.

In the , the spacer device 1 does not comprise an additional layer. However, the spacer device 1 may of course comprise, in a variant, at least one additional layer on at least one of the upper, lower, side and connecting walls, preferably on all walls.

The invention also relates to a method of manufacturing a spacer device described above. The method comprises the steps of: preparing a bamboo-based composition; and shaping this composition to form the layer of material made from bamboo.

The bamboo-based composition may include bamboo powder or bamboo fibers.

Such a composition may be prepared, for example, by cutting the harvested bamboo into small pieces; removing the outer layer of the bamboo by splitting or scraping; processing the bamboo pieces into powder or fibers (e.g., pulp) by a method such as shredding, grinding, and/or chemical treatment, for example, by contacting with an alkaline agent such as sodium hydroxide, or with a carbon disulfide, or a silane, or by acetylation. The bamboo material thus processed may then be sieved to obtain a uniform particle size, which improves the efficiency of the shaping step, in particular, the extrusion step.

The preparation of such a composition may include pre-drying. Bamboo can be dried by methods such as air drying or using specific dryers. Pre-drying helps reduce the natural moisture content of the bamboo.

The shaping step may include one or more steps selected from extrusion, rolling, pressing, stamping, cutting, rolling, bending, extrusion blow molding, and gluing.

For example, the shaping step may comprise forming a sheet by pressing and drying from the bamboo-based composition. In this case, prior to pressing and drying, the bamboo-based composition may be mixed with water and optionally with at least one surfactant, to obtain an aqueous paste.

The resulting sheet (corresponding to the layer of material made from bamboo) may have a thickness of 0.1 to 15 mm, for example, 1 mm. The layer of material made from bamboo may comprise several sheets. For example, from 2 to 20 sheets, preferably from 2 to 10 sheets may be superimposed using an adhesive or glue, or by pressing, to form a layer of material made from bamboo. The layer may then be formed into a profile (when the spacer device is a profile) by one or more steps selected from cutting, stamping, rolling, folding and gluing. For example, the sheet may be rolled (or folded), and the two ends of the sheet may be glued to each other, forming a profile, which may then be cut into devices of the appropriate length.

Alternatively, the shaping step may comprise a step of extruding the bamboo-based composition. In this case, the bamboo-based composition preferably comprises a binder. The binder is as defined above.

Specifically, bamboo fibers (optionally in the form of pulp) or bamboo powder can be mixed with a binder to create a bamboo-based composition, which can be fed into an extruder.

For example, the bamboo composition can be extruded into a profile, which allows for great flexibility in the shape of the profile. Alternatively, the bamboo composition can be extruded into a plate or sheet which can then be shaped, such as into a profile.

Extrusion parameters (temperature, pressure, screw speed) can be determined based on the bamboo species, desired properties of the final product, and/or the equipment used. The design of the extrusion die varies depending on the desired shape and size of the final product.

• Température d'extrusion : entre 160°C et 220°C.
• Pression d'extrusion : entre 20 à 60 MPa.
• Vitesse de la vis : 10 à 40 tr/min.

In one embodiment, the extrusion parameters are as follows:

• Extrusion temperature: between 160°C and 220°C.
• Extrusion pressure: between 20 to 60 MPa.
• Screw speed: 10 to 40 rpm.

Extruded material can be a more durable and stable material than other forms of bamboo because extrusion removes the natural moisture in the bamboo, optimizing the use of extruded bamboo as a glazing spacer.

The moisture content of the bamboo-based composition is preferably less than 10% prior to extrusion. To achieve this moisture content, pre-drying, grinding and/or sieving may be performed prior to extrusion as described above. The extrusion temperature and speed may also be adjusted to minimize moisture. Higher temperatures may facilitate the evaporation of residual moisture, while an appropriate extrusion speed may help maintain optimal processing conditions.

The manufacturing method may further comprise a step of applying a coating comprising a hydrophobic component to the layer of material made from bamboo. The hydrophobic component is as defined above.

The coating may be deposited by any known means such as by means of bonding (for example, using a hot melt adhesive, in particular polyurethane), liquid application, vapor deposition or any other suitable method. The liquid application may comprise applying a solution comprising the hydrophobic component to the layer of material made from bamboo by spraying, immersion or dipping. It may be followed by drying.

Alternatively or additionally, the hydrophobic component may be integrated into the layer of material made from bamboo (in particular, when the component comprises a nanostructure). In this case, the hydrophobic component may be integrated into the bamboo-based composition during manufacture, before shaping the composition.

The manufacturing method may further comprise a step of depositing an additional layer comprising a metal, glass fibers, a polyurethane, a butyl rubber or a mixture thereof on the layer of material made from bamboo. The additional layer is as defined above.

Methods for depositing the additional layer are well known to those skilled in the art. The additional layer may be deposited by bonding using an adhesive, by vapor deposition, by lamination, or by calendering.

Several additional layers can be deposited in this way.

The invention also relates to glazing comprising a spacing device as described above.

The glazing according to the invention comprises at least two glazed walls. Advantageously, the glazed walls are parallel or essentially parallel to each other.

In embodiments, the glazing according to the invention may comprise exactly two glazed walls (it is then called “double glazing”), or exactly three glazed walls (it is then called “triple glazing”), or at least three glazed walls, for example four glazed walls (it is then called “quadruple glazing”).

For the purposes of the present invention, a “glazed wall” means any structure comprising (or consisting of) at least one glass sheet or a glazed spacer. By “glazed spacer” is meant a multilayer glazed element of which at least one layer is a glass sheet. The glass sheet may be made of organic or mineral glass. It may be made of tempered glass.

The glass walls (or one of the glass walls) may comprise (or consist of) a glass spacer device comprising at least one glass sheet which may be as described above. The glass spacer device is preferably laminated glazing. By “laminated glazing” is meant at least two glass sheets 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), or ethylene copolymer (corresponding to the definition of an ionomer), more preferably PVB. The interlayer film may be made of standard PVB or acoustic PVB (such as single-layer or three-layer acoustic PVB). The use of glass walls comprising laminated glazing makes it possible to improve the acoustic insulation of the glazing, the acoustic insulation being further increased when the interlayer film is made of acoustic PVB.

Each glazed wall 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 density of the glazed walls, the greater the sound insulation will be.

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, for example, a circular shape, an elliptical shape, a trapezoidal shape or a quadrilateral shape, in particular a rectangular shape. Preferably, the glazing may have a rectangular shape.

Advantageously, the device according to the invention is positioned in the cavity of the glazing, more particularly in a peripheral zone of the cavity of the glazing. By “peripheral zone of the cavity” is meant a zone 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.

Preferably, the spacer device is parallel to an edge of the glass walls.

Advantageously, the glass walls are attached to the spacer device by gluing, for example by an adhesive, such as a polyisobutylene (PIB) adhesive, by a silicone sealant or by double-sided adhesive tape.

Preferably, the cavity of the glazing 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, makes it possible to improve the thermal insulation of the glazing.

One (or more) of the glass walls may be tinted in the thickness over all or part of its surface. One (or more) of the glass walls may be covered in whole or in part with an opaque coating, for example, a paint and/or an enamel. In embodiments, 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 a facade or exterior window of a building.

In embodiments, one (or more) of the glass walls may have undergone a treatment to improve the thermal insulation of the glazing, such as the application of an insulating layer based on metal and/or metal oxide, 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 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 glass wall. Still alternatively, when at least one of the glass walls is a glass spacer, the insulating layer may be interposed in the glass spacer, for example between a PVB layer and a glass sheet.

The inventive glazing may comprise one or more spacer devices, each spacer device comprising at least one layer of material made from bamboo. Each spacer device may be disposed along a different edge of the glazing. For example, for a glazing having four edges, the device may comprise three spacer devices disposed along three of the edges, or four spacer devices disposed along all four edges.

The spacers may be disjointed (all or some of them) or may be joined to each other (all or some of them), preferably at their ends. Preferably, all the spacers of the spacer may be joined to form a frame, as a single piece (the spacers being for example derived from a single spacer folded at one or more places, for example to form the corners of the frame) or may be joined together by any suitable means, for example by means of staples, glue, clips and/or by interlocking or welding.

A seal may also be present, preferably arranged on the external face of the spacer device. More preferably, the seal extends from this external face to the edge of the glass walls. This seal may be made with a sealant (called a “sealing sealant”) based on polyurethane, polysulfide and/or silicone.

The maximum force per unit length in the seal may be less than or equal to 1.12 daN/cm.

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, window glazing or door glazing. Alternatively, the glazing can be intended to be placed inside the building.

The invention also relates to a method of manufacturing glazing as described above comprising:
- the supply of at least two glass walls;

- the provision of a device as described above;

- the arrangement of the two glass walls so as to form a cavity between them; and

- introduction of the device into the cavity.

Claims (13)

Glazing comprising at least two glazed walls forming a cavity between them, in which the cavity comprises a spacer device comprising at least one layer of material made from bamboo. Glazing according to claim 1, wherein the thermal conductivity of the material made from bamboo is 0.05 to 0.20 W/(m K), preferably 0.07 to 0.15 W/(m K). Glazing according to claims 1 or 2, wherein the density of the material made from bamboo is 0.3 to 0.6 g/cm ³ , preferably 0.4 to 0.55 g/cm ³ . Glazing according to any one of claims 1 to 3, in which the bamboo is selected from Moso bamboo ( Phyllostachys edulis ), Guadua bamboo ( Guadua angustifolia ), black bamboo ( Phyllostachys nigra ), and a mixture thereof. Glazing according to any one of claims 1 to 4, wherein the spacer further comprises a hydrophobic component, which is integrated into the material made from bamboo or which is in the form of a coating applied to the layer of material made from bamboo. Glazing according to claim 5, wherein the hydrophobic component comprises a hydrophobic polymer, a functional silane, a wax, carbon nanotubes, nanowaxes, metal oxide nanoparticles or a mixture thereof; the hydrophobic polymer preferably being selected from a fluoropolymer, polypropylene, polystyrene, polyvinyl chloride, polyethylene or a mixture thereof. Glazing according to any one of claims 1 to 6, wherein the spacer further comprises an additional layer comprising a metal, glass fibres, a polyurethane, a butyl rubber, a silicone rubber, a polyacrylate, a polysulphide, a silicone or a mixture thereof; the metal preferably being selected from aluminium, iron, silver, copper, gold, chromium, silicon oxide, silicon nitride and mixtures and alloys thereof. Glazing according to claim 7, wherein the additional layer has a thickness less than that of the layer of material made from bamboo, and preferably has a thickness of 10 to 1500 nm, more preferably of 20 to 200 nm, more preferably of 50 to 100 nm. Glazing according to any one of claims 1 to 8, wherein the material made from bamboo comprises bamboo powder or bamboo fibres. Glazing according to any one of claims 1 to 9, in which the material made from bamboo comprises a binder, preferably chosen from polylactic acid, resins of plant origin, in particular lignin-based resins, natural latex-based resins, rosin-based resins, cellulose-based resins, starch-based resins, algae-based resins, agricultural waste-based resins, casein-based resins, natural gum-based resins; synthetic resins, in particular polyolefins; and mixtures thereof. Glazing according to any one of claims 1 to 10, in which the spacer device comprises a chamber which contains a desiccant. Glazing according to any one of claims 1 to 11, in which the spacing device is a profile, preferably perforated. Glazing according to one of claims 1 to 12, being building glazing, such as glazing for a facade, window or door of a building or interior glazing.