EP0032074A1 - Thermal and acoustical insulating structure for a cladding or other non supporting walling - Google Patents

Abstract

This insulating structure comprises a thermally insulating panel (4), mounted between an internal metal covering (1) formed by a succession of U-shaped plates, nested one after the other, and an external covering (2) provided with ribs (10) projecting towards the panel (4) and perpendicular to the wings of the covering plates (1). A thin core (12), formed by a glass veil or the like, covers the outer tank (2) and is applied against the latter by a sheet (14) provided with ribs (16) which pinch the veil (12) in the ribs (10) of the tank (2).

Description

There are currently many types of building elements or structures intended for thermal and acoustic insulation. Unfortunately, the standards of comfort and the increasing volume of noise are such that these elements do not meet needs satisfactorily.

Improving their effectiveness is particularly difficult when they are intended for cladding or other non-load-bearing walls, which must be very light and thin. Indeed, the two main factors of the acoustic weakening are the volumetric mass of the structure and, consequently, the density and the thickness of the various components, and the distance between the successive components.

Furthermore, the conditions for the absorption of interior noise are generally not very compatible with an effective weakening of the transmission of exterior or air noise.

For example, a known insulating structure, comprising a thermal insulator held between two metallic coatings, absorbs insufficiently the internal noises if the internal coating is not perforated, but this perforation reduces the weakening of the external noises.

A significant improvement in insulation is obtained by giving the internal coating the form of a closed box containing a high density insulation, but this improvement is limited by the requirements of lightness and small size, when it comes to '' siding or the like.

The present invention therefore aims to solve this problem by improving the insulation qualities of known structures without significantly increasing their weight or their thickness.

The object of this invention is in fact an insulating structure of the type in which a thermally insulating panel is held between metallic coatings, respectively internal and external, provided with ribs projecting from the panel, the ribs of each coating being perpendicular to those of the 'other, which has a thin core of insulating material applied by a solid and thin metal sheet against a solid plate of one of the coatings.

Preferably, the thin core has a laminated structure, elastic, and having a high resistance to the passage of air.

The metal sheet is thin and it is fixed to the core only by its fixing on the covering, that is to say at the level of the ribs, the core being only pinched at these points so that it does not not likely to work in shear.

It can then be seen that despite the low mass of the core and of the sheet, the acoustic attenuation is clearly improved, especially at low frequencies. The resonant frequency of the structure is in fact considerably lowered.

Of course, the core and the sheet can be arranged on the external coating, the sheet then having ribs similar to those of this coating which interlock therein, or be mounted on the internal coating between it and s 'thermal insulator.

• - la fig. 1 est une vue schématique en perspective, avec arrachement partiel, d'une portion de structure isolante selon l'invention;
• - les fig. 2 et 3 sont des vues analogues à la figure 1, de variantes de réalisation de la structure isolante.

The description below of embodiments given by way of nonlimiting examples and represented in the appended drawings, will highlight the advantages and characteristics of the invention. In these drawings:

• - fig. 1 is a schematic perspective view, with partial cutaway, of a portion of insulating structure according to the invention;
• - figs. 2 and 3 are views similar to FIG. 1, of alternative embodiments of the insulating structure.

As shown in FIG. 1, the insulating structure comprises an internal covering 1 and an external covering or tank 2 between which is held a panel made of thermally insulating material 4.

In the embodiment shown, the internal coating 1 is constituted by a series of U-shaped plates, nested one after the other. The lateral wings 6 of each of the plates 1a, 1b, are folded at their free end, all in the same direction so as to be able to hang on the wings of the adjacent plate. In addition the bottom of each plate is provided with ribs 8, parallel to the wings 6 and projecting in the same direction.

These ribs 8, like the wings 6, maintain the insulating panel 4 which is preferably in one piece and fits on the succession of plates 1a, 1b, etc.

On the opposite face of the panel 4 the outer tank 2 is constituted by a relatively thin sheet metal, provided with ribs 10 projecting in the direction of the panel 4 and in contact therewith, but perpendicular to the ribs 8 and wings 6 of the covering 1. The internal coverings 1 and external cover 2 are fixed to each other locally, at the crossing points of the ribs 10 and wings 6, so as to ensure the assembly of the structure.

According to the invention, the insulating structure further comprises a thin core 12 which covers the outer surface of the covering 2 by conforming to its shape, that is to say by penetrating into the ribs 10.

The core 12 is preferably made of a veil of glass fibers having a laminated structure, that is to say say having several layers, so as to have a high resistance to air. This veil 12 is itself covered by a thin sheet 14 of steel, or other similar metal, provided with ribs 16 similar to the ribs 10 of the tank 2 and fitting into them. The core 12 is thus pinched between the ribs 10 and 16 and kept in contact with the tank 2 and the sheet metal 14 without it being necessary to use any fixing means for this.

The members fixing the sheet 14 and the sheet of the tank 2 and passing through these sheets in line with the wings 6 of the covering 1 are sufficient to effectively maintain the core 12.

Furthermore, the absence of bonding or other means of securing the core 12 with the sheets 14 or 2 avoids any risk of work in shearing of this core which may cause deformations or act on the frequency of resonance of the whole.

The veil has a very small thickness, of the order of 2 to 4 mm, and preferably 2 mm. Similarly, the sheet 14 is preferably a sheet of 10 / 10ths. As a result the outer tank 2, combined with the core 12 and the sheet 14, constitutes a double wall of very small thickness on the outer face of the insulating structure.

However, it is noted that this double wall significantly increases the performance of the structure and in particular the acoustic reduction obtained by means of this wall. This attenuation is particularly sensitive to low frequencies since the resonant frequency of the structure is lowered below 100 Hz, that is to say practically below the usual resonant frequencies on the metallic double walls (from 100 to 315 Hz).

Such a structure therefore provides effective protection against airborne noise, and this with an increase in weight and small thickness compared to those of known structures.

The increase in thickness can moreover be further reduced, and even practically eliminated, by producing the insulating structure in the manner shown in FIG. 2.

In fact, in this embodiment, a thin core 22 is mounted against the coating 1, between the latter and a thin sheet 24. The thin core 22 is then applied against the ribs 8 of each of the plates 1a, 1b, and curved at its ends against the wings 6 of this tray.

In the same way, the sheet 24, bent at its two ends, is fitted into each tray 1a, 16, and fixed on the wings 6 of this tray. The panel 4 of mineral wool felt, or any other thermal insulator, is in contact with the successive sheets 24, on either side of the wings 6 of connection between the various plates. This panel may have the same thickness as that used in the embodiment of FIG. 1 or have a slightly smaller thickness, so as to give the whole of the structure a thickness which is less than that of the structure without a web. of glass and sheet metal 14, the external coating 2 being produced in the same way by means of a thin sheet metal provided with ribs 10.

In this case, as in the previous one, the web 22 is simply pinched between the sheet 24 and the ribs 8 of the covering against which it is placed. No particular means of adhesion or fixing is necessary.

Such a structure also meets the lightness requirements of cladding or other facings of buildings and in particular of industrial buildings.

When the damping of interior noise is an important parameter in the creation of the bar dage, it may be considered useful to perforate the internal coating and preferably, in this case, this coating is produced in the form of boxes, as shown in FIG. 3.

Each internal cladding box then has: a U-shaped perforated plate 31 between the wings 36 of which a solid sheet 32 is fitted which holds a thin panel of high density mineral wool 34, filling the space between the sheet solid 32 and the perforated plate 31. The thin core 22 is then mounted against the sheet 32 for closing the box and the sheet 24 maintains this core 22 between the wings 36 of the plate. As in the previous cases, a panel of mineral wool felt 4, or the like, covers the ribs formed by the wings 36 of the successive plates and is protected by an external tank 2 comprising ribs 10 perpendicular to these wings 36.

The structure thus produced provides real damping of interior noise thanks to the perforation of the internal plate 31, but has a significant sound reduction index thanks to the combination of the walls 32 and 24 with the thin core 22, which is added to the action of the outer tank 2 and of the insulation 4. This structure, which may have a thickness very close to that of the embodiment of FIG. 2, has a very low resonance frequency which no longer interferes with the acoustic attenuation and makes it possible to obtain a curve of weakening which rises in an almost regular way as a function of the frequency, and that starting from frequencies lower than 100 hz.

This structure, all the elements of which are light and relatively thin, is particularly suitable for the production of facing or cladding of buildings, or other non-load-bearing walls, intended to be placed on metal or concrete elements. The plate 1 (fig. 1 and 2) or the box 31 (fig. 3) are mechanically attached to the supporting frame by any suitable means. A flexible joint (Neoprene or flexible cellular PVC type) can be interposed between the supporting structure and the plate or box in order to reduce the transmission of vibrations from the frame to the wall. The air tightness and therefore the acoustic insulation of the wall are also reinforced by the installation, on the wing 6 of the plate 1 or 36 of the plate 31, of a flexible adhesive seal. This joint is pinched during installation between the various plates which fit together successively. The performances obtained are close to those of a concrete veil of several hundreds of _k g _{/ m} ² _.

Claims (7)

1. Thermo-acoustic insulating structure for cladding, or other non-load-bearing wall, comprising a thermally insulating panel (4) held between metallic coatings (31,12) respectively internal and external, provided with ribs projecting from the panel, the ribs (6,10) of the two coatings being perpendicular to each other, characterized in that it further comprises a thin core (12,22) of insulating material, applied by a solid and thin metal sheet (14,24) against the one of the coatings. 2. Structure according to claim 1, characterized in that the thin core (12,22) has a laminated and elastic structure having good resistance to the passage of air. 3. Structure according to one of claims 1 and 2, characterized in that the thin core (12,22) is a veil of glass fibers. 4. Structure according to one of claims 1 to 3, characterized in that the thin core (12) covers the outer covering. 5. Structure according to one of claims 1 to 3, characterized in that the thin core (22) and the sheet (24) which holds it are placed between the inner covering (1,31) and the thermally insulating panel ( 4). 6. Structure according to claim 5, characterized in that the internal coating (1) has a U-shaped section, the thin web (22) and the metal sheet (24) being folded at their ends and fixed on the wings (36, 6) from U. 7. Structure according to one of claims 1 to 3, characterized in that the internal coating (31) consists of a closed box comprising a perforated U-shaped plate (31) closed by a full sheet (32) and filled of a high density insulating panel (34), and in that the thin core (22) and the metal sheet (24) are mounted on this box, between the wings (36) of the plate and the thermally insulating panel ( 4).

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