FR2816240A1 - Composite noise-resistant panel e.g. for roofing verandahs has core made from combination of heavy viscoelastic and aerated materials - Google Patents

Abstract

The panel consists of two rigid outer layers (2, 3) and an inner noise resistant core (1) made from a combination of a heavy viscoelastic material (5) and an aerated material (4), located one above the other or in alternating strips. The heavy viscoelastic material can be a bitumen, polymer or rubber-based product with mineral charges.

Description

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Composite panel presenting an improvement in impact noise acoustics and thermal stability.

 The present invention relates to a composite panel, more particularly intended for producing surfaces exposed to solidary noises coming from various sources such as for example hail, rain, etc. Composite panels with good qualities of thermal insulation and mechanical strength acceptable for many applications are commonly used in the building sector to make covers for verandas, terraces, roofs, balconies, galleries, walls ( cladding, etc.).

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D'une manière générale, ces panneaux composites sont applicables à la réalisation de surfaces ou parois pouvant avoir des fonctions diverses, les exposant indifféremment à l'ensoleillement, aux intempéries et/ou aux ondes sonores, ces surfaces pouvant être disposées horizontalement, plus ou moins inclinées ou dressées verticalement ; elles peuvent être portées ou autoporteuses. Composite panels of this kind mainly comprise a core of rigid foam of more or less thick plastic material, disposed between two rigid facings, metallic or other, and assembled to the latter by gluing, for example by means of structural adhesives.

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In general, these composite panels are applicable to the production of surfaces or walls which can have various functions, exposing them indifferently to sunshine, weathering and / or sound waves, these surfaces being able to be arranged horizontally, more or less inclined or erect vertically; they can be carried or freestanding.

 In document FR-A-2.780. 334, a composite panel has been described, comprising a honeycomb core disposed between two rigid facings, this core consisting of a relatively thin plate traversed by multiple channels parallel to each other and regularly distributed, said core being disposed at the interface between the facing external, called to receive the solar rays and the internal facing and assembled to said facing by gluing, preferably by means of structural adhesives.

 This honeycomb core provides natural ventilation between the facings, which cools the external facing and thus limits the elevation of

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 temperature when the panel is exposed to sunlight. In addition, it participates in the mechanical strength of the panel for self-supporting panels.

 In order to present better qualities of thermal insulation, the document FR-A-2.780. 334 has provided another embodiment of the composite panel, according to which it also comprises a rigid foam plastic sheet disposed between the self-ventilating honeycomb plate and the internal facing of said panel.

 In this way natural ventilation is obtained inside the insulating panel and, consequently, protection of the plastic foam core against excessive heat, a reinforcement of the mechanical characteristics of said panel preserving its flatness and a increased level of acoustic damping and, of course, thermal insulation.

 However, it seemed desirable to further improve the level of acoustic damping, in particular to impact noise and thermal stability.

 Indeed, the level or index of weakening of the structure-borne noise obtained by such composite panels remains relatively poor.

situées à proximité desdits panneaux, surtout lorsque le parement extérieur de ceux-ci est constitué par une tôle métallique. This results from the fact that these panels, when they are subjected to one or more shock points at their external facing, do not acoustically and effectively absorb impact noises which can reach high levels, and cause a strong hearing impairment for people

located near said panels, especially when the outer facing of these is constituted by a metal sheet.

 To improve the acoustics of panels with impact noise in the building sector, the solutions proposed to date meet a criterion based on a mass-spring system.

 In order to limit the phenomena of transmission of structure-borne noise, acoustics recommends the use of heavy materials with high inertia.

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 These materials, by their own weight, require a much higher acoustic pressure to create a resonance of the material, by the vibratory absorption of these materials transformed into heat.

 An object of the present invention is therefore, in particular, to remedy the aforementioned drawbacks.

 According to the invention, this object is achieved by means of a composite panel of the sandwich panel type, which is remarkable in that it comprises a thermophonic core disposed between two facings, this thermophonic core being constituted by the combination of a heavy viscoelastic material and an aerated or aerated material.

 According to a first embodiment of the invention, the thermophonic core consists of the superposition of a heavy viscoelastic material placed in contact with the external facing and of an aerated or aerated material placed in contact with said heavy viscoelastic material.

 According to a second example of implementation of the invention, the thermophonic core is constituted by one or more portions or strips of heavy viscoelastic material attached, laterally, to one or more portions or strips of aerated material or aérifère.

 It is easily understood that when a facing and more particularly the external facing of the panel is subjected to mechanical shocks (falling hailstones or raindrops), the impacts on this facing give rise to vibratory waves transmitted to the thermo core. - underlying acoustics. These waves are transformed by the viscoelastic heavy material into heat energy, which is dissipated by the air circulating in the channels of the aerated or aerated material remaining open to the open air. In addition, when the temperature of the facing exposed to solar radiation rises, the air circulation in the airy material creates a natural ventilation which ensures the lowering of the temperature of the outer facing and that of the heavy viscoelastic material which thus always keeps its functional potential. Indeed, these viscoelastic materials generally do not have good heat resistance and can become soft, sticky, and thus partly lose their characteristics.

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 (shock absorber quality). However, it should be noted that the temperature of the exterior metal facing of the sandwich panel exposed to solar radiation can easily reach 90 ° C., in the case in particular where this coating is dark in color.

type polypropylène renforce, en plus de l'isolation thermique de l'ensemble de la construction, la tenue mécanique du panneau composite selon l'invention. In addition, the presence of a layer or strips of cellular material of

polypropylene type reinforces, in addition to the thermal insulation of the entire construction, the mechanical strength of the composite panel according to the invention.

The aims, characteristics and advantages above and others will emerge more clearly from the description which follows and from the appended drawings in which:
Figure 1 is an exploded perspective view, partially broken away, of a first embodiment of the composite panel according to the invention.

 Figure 2 is an exploded view in cross section of an alternative embodiment of this panel.

 Figure 3 is a partial view in cross section of a second embodiment of the first embodiment of the composite panel according to the invention.

 Figure 4 is a partial view in cross section of a third embodiment of this first embodiment.

 Figure 5 is a perspective view, partially broken away, of a second embodiment of the composite panel according to the invention.

 Figure 6 is an exploded view in cross section of an alternative embodiment of this panel.

 Figure 7 is a partial view in cross section of a second embodiment of the second embodiment of the composite panel according to the invention.

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 Figure 8 is a partial view in cross section of a third embodiment of this second embodiment.

 Reference is made to said drawings to describe interesting embodiments, although in no way limitative of the thermoacoustic composite panel according to the invention.

 This panel is remarkable in that it comprises a thermophonic core disposed between two facings, this thermophonic core being constituted by the combination of a heavy viscoelastic material and an aerated or aerated material.

 In the following description, the components of the two embodiments described fulfilling the same functions are designated by identical references or references.

 On the other hand, FIGS. 1 and 5 show composite panels of rectangular shape, but it is specified that the panel according to the invention could have other shapes such as triangular, trapezoidal, etc.

 According to the various embodiments illustrated, this composite panel comprises a core designated as a whole by the reference 1 and disposed between two skins or rigid, semi-rigid or flexible facings 2 and 3, for example formed by steel or aluminum or other, lacquered or covered with any other suitable coating. The facings 2, 3 could be made of any other suitable rigid material such as reinforced polyester, epoxy fabric or the like. One of these facings (facing 2) called to be oriented towards the outside will be conventionally called "external facing" in the remainder of this description, while the other facing (facing 3) will be called "internal facing" .

 As shown in Figures 2 and 6, the facings 2 and 3 have longitudinal edges, respectively 2a and 3a, folded in the direction of the median plane of the panel, so as to cover the longitudinal edges of the latter.

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 The aerated or aerated material 4 used for the production of the core 1 consists of an organic product, which can advantageously correspond to that used to constitute the aerated core of the composite panel described in document FR-A-2,780. 334. It is a plate made of a plastic material that is a poor conductor of heat and whose melting temperature is higher than the temperature of the facing exposed to solar radiation and in which a plurality of voids is arranged.

 This plate consists of two parallel flat flanges connected by thin longitudinal partitions, so that the voids formed in said plate occupy an area greater than 80% relative to the surface of said opposite flanges. This ventilated material is advantageously made of plastic material such as polypropylene. Such a plate is shaped by an extrusion process making it possible to obtain a plurality of straight cells or channels 4a, of quadrangular section for example, parallel to each other and regularly arranged with respect to each other. Strips of the desired width are easily cut from said plates along a line parallel to the channels 4a, when preparing composite panels of rectangular shape, said channels remaining open at their ends and in the open air.

 If we consider that the composite panels intended for the abovementioned applications are generally of rectangular shape, the cellular strips 4 are arranged in such a way that their natural ventilation channels 4a are parallel to the lateral edges of said panels.

 The heavy and viscoelastic "complex" material 5 can advantageously consist of a product or a mixture of organic products of bitumen type, of EPDM, of polyurethane, of PVC loaded with barium oxide, or any other mass. based on rubber, or elastomer with, as needed, high density mineral fillers, and / or a plasticizer. This "complex" material has a high density, preferably around 2,000 Kg / m3 to 3,000 Kg / m3. According to different embodiments of a first embodiment of the invention illustrated in Figures 1 to 4, the core 1 of the panels comprises at least one intermediate thermophonic complex formed by the superposition of a layer or plate of heavy viscoelastic material 5 placed

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 in contact with the internal surface of the external facing 2 and a plate of aerated or aerating material 4 disposed in contact with said plate of viscoelastic heavy material.

 According to the example illustrated in FIG. 1, the thermophonic core 1 is only constituted by the superposition of a plate of viscoelastic heavy material and a plate of aerated or aerated material, arranged between the facings 2 and 3.

varier en fonction de la destination des panneaux composites, cette épaisseur pouvant être, par exemple, de l'ordre de +/-50 mm. According to the variant shown in FIG. 2, the plate of aerated or aerating material is placed between two layers 5A and 5B of heavy viscoelastic material. This embodiment can be advantageously retained when the two faces of the panels are liable to be exposed to solar radiation. This is for example the case of signs used in the field of communication (display boards, traffic signs, etc.)
According to another embodiment of the first embodiment, the core 1 of said panel also comprises a thickness or layer of rigid foam 6 (FIG. 3) bonded between the thermo-acoustic layer 4-5 previously described and the internal facing 3 This rigid foam layer 6 can be formed by a plate of polyurethane foam, polyvinyl chloride foam, extruded polystyrene, or the like, the thickness of which can

vary depending on the destination of the composite panels, this thickness can be, for example, of the order of +/- 50 mm.

This rigid foam plate 6 fulfills the function of thermal insulator and is protected from excessive heat by the presence of the thermo-acoustic layer 4-5. It is assembled by gluing, preferably by means of structural adhesives, to the thermophonic layer 4-5 and to the internal facing 3.

 According to a third embodiment of the composite panel according to the first embodiment (FIG. 4), the internal facing 3 has several areas of perforations 3b and layers of a sound absorption material 7 are embedded, preferably without glue , in the cavities or recesses 8 formed in the internal surface of the core of rigid extruded foam 6. These

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 layers of sound absorption material can for example be formed by a flexible plastic foam.

 This flexible material acts as a sound trap emanating from the room of the building covered and / or surrounded by this type of panel. It can be constituted by a flexible melamine, polyethylene or other foam.

 According to the three exemplary embodiments above, the layer or strip of heavy viscoelastic material 5 can have a thickness equal to twice the thickness of the external facing 2.

 According to different exemplary embodiments of a second embodiment of the invention illustrated in FIGS. 5 to 8, the core is constituted by one or more portions of cellular material 4 joined (s), laterally, to one or more several portions of heavy and viscoelastic material 5.

 Preferably, considering that the composite panels used in the building most often have a rectangular shape, the portion or portions of cellular material 4 and the portion or portions of heavy, viscoelastic material 5 are, in this case, advantageously formed by strips arranged alternately and joined by their longitudinal edges, these strips preferably extending in the direction of the length of the panels.

 These strips have an identical thickness (or height) and length. For example, they can have a height of between 1 mm and 10 mm, while their length corresponds to the length of the panels, that is to say of the order of 3 m to 7.5 m.

 On the other hand, within the insulating core 1, the number and the width of the alternating strips of the two materials are variable; each type of strip can advantageously be present in proportions of between 25% and 75%. Thus, in Figure 5, we see a composite panel whose thermoacoustic core is made of a strip of heavy and viscoelastic material 5, disposed between two strips of cellular material 4, while according to Figure 6, the core of the panel is made up of two strips of heavy and viscoelastic material 5 joined alternately to three strips of cellular material 4.

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occuper avantageusement un pourcentage identique (50 %) de la superficie totale de l'âme thermo-acoustique 1. The foam material 4 and the heavy, viscoelastic material 5 can

advantageously occupy an identical percentage (50%) of the total area of the thermo-acoustic core 1.

However, the percentage of the surface occupied by the heavy and viscoelastic material 5 could be less than 50%, depending on the destination of the panels.

 In view of the fact that the viscoelastic heavy material 5 is present in the thermo-acoustic complex 1 in the form of portions or strip (s), covering only part of the surface of the thermo-acoustic core 1 ′, such arrangement makes it possible not to considerably increase the final weight of the composite panel and thus to avoid the problems associated with its industrialization.

 It is understood that the complex constituted by the combination of portions of cellular material 4 and portions of heavy and viscoelastic material 5 also makes it possible to carry out, at the same time, the absorption of sound vibrations from the external facing 2 and the transformation of this vibrational energy in heat energy thanks to the action of the parts of the heavy and viscoelastic material, and the cooling of the external facing 2 thanks to the ventilation action provided by the portions of cellular material which also contribute to the mechanical strength of the panel.

 According to a second example of implementation of the second embodiment of the composite panel of the invention (FIG. 7), the core of said panel also includes, in a manner comparable to the example illustrated in FIG. 3, a thickness or rigid foam layer 6 bonded between the thermoacoustic layer 4-5 previously described and the internal facing 3. This rigid foam layer 6 can be formed, as indicated above, by a plate of polyurethane foam, polyvinyl chloride foam, polystyrene extruded, or other, the thickness of which may vary depending on the destination of the composite panels, this thickness possibly being, for example, of the order of +/- 50 mm.

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 This rigid foam plate 6 fulfills the function of thermal insulator and is protected from excessive heat by the presence of the thermo-acoustic layer 4-5.

 According to a third example of implementation of the second embodiment of the composite panel, illustrated in FIG. 8, the internal facing 3 comprises, in a manner similar to the example illustrated in FIG. 4, several zones of perforations 3b and layers of a sound absorption material 7 are embedded, preferably without glue, in cavities or recesses 8 formed in the internal surface of the core of extruded rigid foam 6. These layers of sound absorption material can for example be constituted by a flexible plastic foam.

 The various layers or plates of materials 4,5 and 6 constituting the insulating core 1 or the (with the exception of the layers or plates of flexible plastic foam 7) are bonded together, as well as to the facings 2 and 3, preferably by means of structural adhesives in order to ensure intimate contact between the various constituent parts of the composite panel.

Claims (10)

 CLAIMS 1.-Composite panel comprising a core (1 or 1 ') disposed between two rigid facings (2,3), characterized in that said core is constituted by the combination of a heavy viscoelastic material (5) and a aerated or aerated material (4).  2.-composite panel according to claim 1, characterized in that it comprises a thermophonic core (1) constituted by the superposition of a layer or plate of viscoelastic heavy material (5) placed in contact with the external facing (2 ) of said panel, and of a plate of aerated or aerated material (4) disposed in contact with said layer or plate of viscoelastic heavy material.  3.-composite panel according to claim 1, characterized in that it comprises a thermophonic core (1 ') constituted by one or more portions of aerated or aerated material (4) joined (s), laterally, to one or several portions of heavy and viscoelastic material (5).  4.-composite panel according to claim 3, characterized in that the portions of aerated or aerated material (4) and heavy and viscoelastic material (5) constituting the thermophonic core (1 '), are formed by strips arranged alternately and joined by their longitudinal edges, these strips preferably extending in the direction of the length of the panel. <Desc / Clms Page number 12> 5.-composite panel according to any one of claims 1 to 4, characterized in that the heavy and viscoelastic material (5) is composed of a viscoelastic organic product or a mixture of viscoelastic organic products such as, for example bitumen or bituminous-type materials, or EPDM, or polyurethane, or PVC loaded with barium oxide, or any other mass based on rubber, or elastomer, with, as required, mineral fillers high density, and / or a plasticizer. 6.-composite panel according to any one of claims 1 to 5, characterized in that the layer or plate or each portion or strip of aerated or aerated material (4) consists of two soles connected by longitudinal partitions, so to present a plurality of cells or rectilinear channels (4a) parallel to each other.  7.-composite panel according to claim 6, characterized in that the layer or plate of aerated or aerated material (4) or the strips of aerated or aerated material (4), are made of rigid extruded plastic, for example polypropylene .  8.-composite panel according to any one of claims 1 to 7, characterized in that it comprises a thickness or layer (6) of rigid foam extruded from plastic material, disposed between the thermophonic layer (4,5) and the internal facing (3), this layer of rigid foam (6) being, for example, constituted by a plate of rigid polyurethane foam, or polyvinyl chloride, or polystyrene.  9. Composite panel according to claim 8, characterized in that the internal facing (3) comprises several perforation zones (3b), and <Desc / Clms Page number 13> 4,6) constituting the insulating core (1, 1 ') are bonded, by means of a structural adhesive, to each other and to the facings (2,3), in order to ensure intimate contact between the constituent parts said panel.  layers of a sound absorption material (7) are embedded, preferably without glue, in cavities or recesses (8) formed in the internal surface of the core of extruded rigid foam (6). 10.-composite panel according to any one of claims 1 to 9, characterized in that the different layers or plates of material (5,