EP0728877A1 - Element for acoustical insulation and noise insulation wall made of the same - Google Patents

Abstract

The insulation element, designed to be used in conjunction with others to make a partition, consists of a box (2) with side walls (6), a base (5) and a top which is at least partially open, containing a structure in at least three layers (18-21). The layers are made from recycled materials, such as ground rubber, with a binding agent, on the outside, and a middle layer (19) of lower density, made from ground plastic particles in a free state, creating a layer which is at least 50 percent empty. In a variant the intermediate layer can be of air alone. The outer layer (20) lying adjacent to the top face of the element contains prefabricated recycled rubber inserts (22) of greater density than the remainder of the layer. In addition, the element can incorporate a further layer, next to the base, which is of greater density than the adjacent inner layer.

Description

The present invention relates to an acoustic insulation element as well as to an “anti-noise” wall produced by the assembly of a plurality of such acoustic insulation elements.

The object of the invention is to acoustically isolate a first medium from a second noise-generating medium, by absorption of high-frequency noise in particular, and this by simple, effective and inexpensive means.

To this end, the invention relates to an acoustic insulation element, characterized in that it comprises a parallelepipedal tank having side walls, a bottom and an at least partially open front face, in which is housed a structure with at least three separate layers parallel to the bottom and at least two layers of which are made from recycled material particles, with a middle layer having a density less than that of the two adjacent layers.

• la couche médiane comprend des particules de matière plastique broyées, notamment libres, de manière à constituer une couche comportant au moins 50 % de vide ;
• la couche médiane est constituée d'air ;
• lesdites couches adjacentes comprennent chacune des particules de caoutchouc broyées et agglomérées par un liant, de préférence sans tassement ;
• les couches adjacentes ont sensiblement la même densité ;
• l'une (20) des deux couches (18, 20) la plus proche de la face avant (4) comprend en outre des inserts en caoutchouc recyclé préfabriqués, de densité plus grande que le reste de la couche, de manière à obtenir une couche à densité variable ;
• il comprend une quatrième couche adjacente au fond, de densité supérieure à celle de la couche qui lui est adjacente ;
• les trois couches sont plaquées les unes contre les autres par des moyens de maintien ;
• la face avant ouverte du bac est fermée par une plaque perforée, notamment sur sensiblement 30 % de sa surface, qui forme les moyens de maintien des couches les unes contre les autres ;
• les parois latérales comprennent des profilés creux à section transversale rectangulaire, de préférence emplis de caoutchouc recyclé ; et
• le cadre possède dans son volume intérieur une armature destinée à augmenter sa rigidité.

The acoustic insulation element according to the invention may include one or more of the following characteristics:

• the middle layer comprises particles of ground plastic material, in particular free, so as to constitute a layer comprising at least 50% void;
• the middle layer consists of air;
• said adjacent layers each comprise particles of rubber crushed and agglomerated by a binder, preferably without compaction;
• the adjacent layers have substantially the same density;
• one (20) of the two layers (18, 20) the closer to the front face (4) further comprises prefabricated recycled rubber inserts, of greater density than the rest of the layer, so as to obtain a variable density layer;
• it comprises a fourth layer adjacent to the bottom, of density greater than that of the layer which is adjacent to it;
• the three layers are pressed against each other by holding means;
• the open front face of the tank is closed by a perforated plate, in particular over substantially 30% of its surface, which forms the means for holding the layers against one another;
• the side walls include hollow profiles with rectangular cross section, preferably filled with recycled rubber; and
• the frame has in its internal volume a frame intended to increase its rigidity.

The invention also relates to an "anti-noise" wall produced by the assembly of a plurality of acoustic insulation elements as defined above.

• la figure 1 est une vue en perspective du bac d'un élément d'isolation acoustique selon l'invention ;
• la figure 2 est une coupe transversale de cet élément d'isolation acoustique suivant la ligne II-II de la figure 1, muni de sa structure selon un premier mode de réalisation de l'invention ;
• la figure 3 est une vue de dessus de l'élément d'isolation acoustique de la figure 2, avec arrachement partiel ;
• la figure 4 est une vue analogue à la figure 2 d'une première variante ; et
• la figure 5 est une vue analogue à la figure 2 d'une deuxième variante.

Examples of embodiments of the invention will now be described with reference to the appended drawings, in which:

• Figure 1 is a perspective view of the tray of an acoustic insulation element according to the invention;
• Figure 2 is a cross section of this acoustic insulation element along the line II-II of Figure 1, provided with its structure according to a first embodiment of the invention;
• Figure 3 is a top view of the sound insulation member of Figure 2, partially broken away;
• Figure 4 is a view similar to Figure 2 of a first variant; and
• Figure 5 is a view similar to Figure 2 of a second variant.

Figures 1 to 3 show a first embodiment of an acoustic insulation element designated by the general reference 1, consisting of a frame 2 containing a structure 3 with three layers, visible only in Figure 2. The element 1 will be described below in its illustrated position, which is that of its manufacture.

Frame 2 is a rectangular-shaped tank (Figure 1), for example with a rectangular base, of relatively low height compared to its other dimensions. A first face 4 of this frame or upper face is open, and the opposite face 5 or bottom is full; this bottom is for example made of a thin sheet of stainless steel.

The side walls 6 of the frame 2 are produced using four flat sections 7, 8, 9 and 10. These sections are hollow, of rectangular cross section, thus defining empty spaces 11 in each of the walls 6. They are also made of stainless steel. The profiles are, for example, welded together and on the bottom 5 of the frame 2, so as to define an internal volume 12 of the frame whose shape is rectangular with rectangular base.

In each of the four interior angles of the frame 2 are welded supports 13, substantially one third of the height of this frame from the bottom 5, so as to be able to attach to these supports, by clipping or pinning for example, two dishes 14 and 15. These are thus arranged in the cross of Saint Andrew, parallel to the bottom 5.

Figures 2 and 3 show that a plate 16 or cover is attached to the upper face 4 of the frame 2. This plate, also made of stainless steel, has the same dimensions as the bottom 5 of the frame 2 so as to cover the entire face 4, including the upper surface of the profiles 7, 8, 9 and 10. The plate 16 is perforated by a series of holes 17 whose cumulative areas represent a fraction of the surface of this plate typically equal to approximately 30% of the surface of the plate 16. The latter is also fixed to the frame 2 by any known fixing means (not shown).

The structure 3, shown in FIG. 2, consists of three superimposed layers: a lower layer 18 or layer close to the bottom 5 of the frame 2, a middle layer 19 and an upper layer 20 or layer close to the upper face 4 of the frame 2.

The three layers 18, 19 and 20 are made from recycled materials. Thus, the lower layers 18 and upper 20 are made up of particles of ground rubber, in particular from recycled used tires or from industry. These particles are mixed with a binder, which is for example a polyurethane prepolymer, to form a complex which can be shaped in box 2.

The middle layer 19 consists of plastic flakes obtained by grinding, for example from recycled PVC bottles, 8 to 10 mm long approximately.

To obtain this three-layer structure 3, the frame 2 (empty) is filled with the recycled rubber-binder complex up to approximately one third of the height of the frame, corresponding to the level defined by the supports 13, and thus defining the layer lower 18. The complex is not packed so as to leave a certain volume of vacuum between the rubber particles.

The plates 14 and 15 are then placed and fixed to the supports 13. They make it possible to regulate the frame in order to resist deformations.

The PVC flakes are then poured to form the middle layer 19, over a height substantially equivalent to that of the lower layer 18. The shape of the flakes leads to the existence of a very large void volume in the layer 19, from the 'order of 50% of the total volume of this layer.

Then, the upper layer 20 is obtained in the same way as the lower layer 18, up to the upper level of the tank. The rubber-binder complex is also poured inside the walls 6, to occupy their volume 11. This makes it possible to increase the inertia of the frame 2 without significantly affecting the acoustic performance.

The plate 16 is then fixed to the frame 2 so as to hold the three layers 18, 19 and 20 together. After polymerization of the binder, the sound insulation element is ready to be used.

The elements 1 thus produced are easy to handle; for example, they are 2.40 m long and 1.20 m wide. They are easily modular: their thickness can be increased to absorb more sounds. Their thickness is typically between 15 and 30 cm, but can reach 50 cm.

The relative thicknesses of the three layers 18, 19, 20 may moreover be different depending on the range of noise to be absorbed and in particular, the lower layer 18 may be of thickness less than that of the upper layer 20.

The perforated plate 16 can also have an aesthetic function.

In service, element 1 is straightened, the plate 16 being disposed towards the front, that is to say towards the noise to be absorbed.

The structure of the frame 2 allows the element 1 to withstand the climatic effects, such as the wind which exerts a thrust, as well as the piston effect due to the passage of a road vehicle or a train set to the neighborhood of element 1.

Structure 3, in which the densities of layers 18 and 20 are identical and homogeneous, is particularly well suited to absorb airborne noise at high frequencies. In addition, the presence of layer 19 gives the assembly a "double wall" configuration, giving element 1 barrier properties against the transmission of airborne noise.

The absorption of noise at low frequencies can be improved by varying the density of the upper layer 20, as in the variant shown in FIG. 4.

The second embodiment (FIG. 4) differs from the first embodiment (FIGS. 1 to 3) by the density of the upper layer 20, and by the presence of a base layer 21 between the bottom 5 of the frame 2 and the lower layer 18.

This base layer 21 is of high density (between 0.8 and 1). It is prefabricated from rubber. It provides better isolation of the bottom 5 from low frequency sounds, in particular to avoid overheating of the bottom of the frame.

The density of the upper layer 20 varies by exposing, at its external face, strips 22 of relatively dense recycled rubber, previously prefabricated under compression. The remainder 23 of the layer 20 has the same composition as in the first embodiment.

The strips 22 are of higher density than those of layer 18 and part 23 of layer 20, but lower than that of base layer 21.

In the third embodiment (FIG. 5), the layer of PVC flakes is replaced by a layer of ambient air.

To this end, the frame 2 is made in two parts 25 and 26 mounted head to tail by interlocking and mutual fixing by fixing means (not shown) and / or by welding. In some cases, a rubber seal can be interposed between the two nested parts.

The structures of the frame parts 25 and 26 are respectively substantially identical to the upper and lower half of the frame 2 of FIG. 4 (apart from the interlocking zones).

After having laid the two parts 25 and 26 flat, these are each filled, to approximately two thirds of their height, with the layers 20 and 18 of the second embodiment (FIG. 4).

The consistency of the material of the layer 20 prevents any overflow of this material through the holes 17 of the perforated plate 16 (the latter playing the role of the bottom during casting).

Then after polymerization, the two parts 25 and 26 are mounted head to tail to form the frame 2, thus creating a layer 19 of ambient air between the layers 18 and 20.

An “anti-noise” wall can be produced by juxtaposition and mutual connection of a plurality of these elements 1, by any suitable technique.

Claims (12)

Sound insulation element (1), characterized in that it comprises a rectangular tank (2) having side walls (6), a bottom (5) and a front face (4) at least partially open, in which is housed a structure (3) with at least three distinct layers (18 to 21) parallel to the bottom (5) and of which at least two layers (18, 20, 21) are produced based on recycled material particles, with between them a middle layer (19) having a density lower than that of the two adjacent layers (18, 20). Acoustic insulation element according to claim 1, characterized in that the middle layer (19) comprises crushed plastic particles, in particular free, so as to constitute a layer comprising at least 50% vacuum. Acoustic insulation element according to claim 1, characterized in that the middle layer (19) consists of air. Sound insulation element according to any one of Claims 1 to 3, characterized in that the said adjacent layers (18, 20) each comprise particles of rubber crushed and agglomerated by a binder, preferably without packing. Acoustic insulation element according to claim 4, characterized in that the adjacent layers (18, 20) have substantially the same density. Acoustic insulation element according to claim 4, characterized in that one (20) of the two layers (18, 20) closest to the front face (4) further comprises inserts (22) made of prefabricated recycled rubber , of greater density than the rest of the layer, so as to obtain a layer with variable density. Acoustic insulation element according to one any one of claims 1 to 6, in that it comprises a fourth layer (21) adjacent to the bottom (5), of density greater than that of the layer which is adjacent to it (18). Acoustic insulation element according to any one of claims 1 to 7, characterized in that the three layers (18, 19, 20) are pressed against each other by holding means (16). Acoustic insulation element according to claim 8, characterized in that the front face (4) of the tank (2) consists of a perforated plate (16), in particular over substantially 30% of its surface, which forms the holding means layers (18, 19, 20) against each other. Acoustic insulation element according to any one of claims 1 to 9, characterized in that the side walls (6) comprise hollow profiles (7, 8, 9, 10) with rectangular cross section, preferably filled with recycled rubber . Acoustic insulation element according to any one of claims 1 to 10, characterized in that the frame (2) has in its internal volume a frame (13, 14, 15) intended to increase its rigidity. Anti-noise wall produced by assembling a plurality of acoustic insulation elements (1) according to any one of the preceding claims.

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