FR2982522A1 - MULTILAYER INSULATING PRODUCT BAND, INSULATING COMPLEX BAND FORMED FROM SUCH BANDS OF MULTILAYER INSULATING PRODUCT - Google Patents

Abstract

The invention relates to a strip (10) of multilayer insulating product having a main longitudinal direction (L) and comprising a corrugated central element (14) of cellular-type material connected to at least one first film (12) having a metal face ( 12b) facing said central element (14), the central element (14) having corrugations defining lower peaks (14b) and upper peaks (14a) with a continuous and rectilinear flat outer face, the metal face (12b). of the first film (12) being connected to the lower peaks (14b) or the upper peaks (14a) of the central element (14), and in which the corrugations of the central element (14) delimit, with the first film ( 12) channels (16). Application to the manufacture of multilayer insulating complexes, in particular for the thermal insulation of buildings.

Description

The invention relates to the field of multilayer insulating products, intended in particular but not exclusively for the thermal insulation of buildings. Such insulation is for example implemented on the inner face of the walls facing the outside, insulation under roof or on the inner walls; but it can still be an insulation on the outer face of the walls (walls, roofs ...) facing the outside (so-called "sarking" type of laying). In the perspective of proposing a product having the lowest possible emissivity, considering in particular the infrared radiation reflection and a low thermal conductivity, many solutions have been proposed, each having advantages. but also a number of disadvantages. Thus, it is known from WO 2007/118321, the fact of using a multilayer complex comprising one or more bubble films in the center of the complex and, in the outer parts, a metal or metallized film. However, in this type of product, the presence of the bubble film or films results in a thickness which will become significant during the stacking of a large number of layers and consequently a significant and permanent bulk. The object of the present invention is to provide a product which makes it possible to overcome the drawbacks of the prior art and in particular a product meeting multiple conditions, namely having good thermal insulation properties (in particular a low thermal conductivity). , a sufficient mechanical strength for handling without risk of degrading its insulating properties, a small footprint and a great lightness. For this purpose, according to the present invention, there is provided a strip 30 of multilayer insulating product having a longitudinal main direction and a transverse direction and comprising a corrugated central element made of cellular-type material connected to at least a first film having a metal face in view of said central element, in which the central element has undulations 35 defining lower peaks and upper peaks, in which the metal face of the first film is connected to the lower peaks or to the upper peaks of the central element, and in which the undulations of the central element delimit, with the first film, channels. Preferably, said channels are open at one or the other or both ends.

In this way, it is understood that if the channels delimited between the corrugations of the central element and said first film are open in at least one location, it is possible to drive the air contained in these channels, by compressing the insulating product. Characteristically, the profile of the corrugations of said central element corresponds to a zigzag-shaped section and said lower ridges and said upper ridges delimit a continuous and straight flat outer face: it is therefore a clipped sawtooth profile. . Thus, because of the geometry and the materials chosen for the components of the insulating product, the latter is resilient, in the sense of being able to substantially recover its shape and its initial dimensions after having been put in compressive stress. This property corresponds to elasticity in compression. Thus, by virtue of this property, it is possible to reduce the volume of space of the multilayer insulating product in strips or in strip sections. Thus, its storage after manufacture and before use and its transportation require a reduced space compared to the space occupied by the product in its deployed state as used for its installation or integration as a component in a multicomponent insulating complex. This is a very significant advantage. This solution also has the additional advantage of allowing, in addition, by virtue of the presence of at least a first film with a metal face facing the channels, to obtain a wall with a high reflective capacity, or low emissivity, in a view of an air gap, which is an advantage in terms of the insulating properties of the product. For this purpose, preferably, the film (s) with a metal face has an emissivity E less than or equal to 0.2. Moreover, the use of a corrugated central element provides, in the deployed state of the insulating product, a rigid enough structure 35 to keep its three-dimensional shape, the insulating product is laid flat or standing on its edge.

Overall, thanks to the solution according to the present invention, it is possible, in addition, in an insulating complex placed on a wall, and comprising said insulating product according to the invention, to channel the air circulation by the choice of the orientation of the channels formed in the central element (or the central elements when several strips of multilayer insulating product are superimposed). This makes it possible, in particular, to combat the parasitic phenomena of natural convection, or to favor an upward flow of air to implement, for example, an air circulation which recovers the energy passing through the wall and can participate in the effect. pariétodynamique. According to a preferred arrangement, the strip of multilayer insulating product further comprises a second film, so that said corrugated central element made of cellular-type material is situated between said first film and said second film, said second film being connected to the others among the upper ridges and lower ridges of the central element and that the corrugations of the central element also delimit with the second film channels, preferably open in at least one location, and in particular to one or the other or both ends. In this case, the number of channels of the strip of multilayer insulating product and of the insulating element resulting from its cutting is doubled. In this case, the following one or both of the following arrangements are preferably adopted: said second film has a metal face turned opposite and connected to said central element; said second film has a metal face turned in the opposite direction; to the central element: this case is in particular implemented when this second film constitutes or is intended to constitute the outer face of an insulating complex forming a stack comprising one or more insulating elements resulting from the cutting of the strip of multilayer insulating product according to the invention. The present invention also relates to an insulating element resulting from the cutting of a strip of multilayer insulating product as described above.

Other advantages and characteristics of the invention will emerge on reading the following description given by way of example and with reference to the appended drawings, in which: FIG. 1 is a partial perspective view of a first embodiment a strip of multilayer insulating product according to the invention, - Figure 2 is an enlarged view of detail II of Figure 1, - Figures 3 and 4 are side projection views of a strip according to the invention and illustrate the resilience property of the multilayer insulating product forming this strip, - Figures 5 and 6 are perspective views illustrating examples of insulating complexes according to the invention, made by combining together several insulating elements according to the invention, obtained by cutting of the strip according to the invention, - Figures 7A and 7B show alternative embodiments of the insulating complexes of Figures 5 and 6, which have an easier assembly, - Figures 8A and 8B are partial perspective views showing two variants of a second embodiment of a strip of multilayer insulating product according to the invention; FIG. 9 is an enlarged view of detail IX of FIG. 8A or FIG. 8B; and FIGS. 10 and 11 are diagrams comparing the insulation performance of the invention to other prior art products. The strip 10 of multilayer insulating product visible in FIG. 1 has a width I and its largest dimension extends along the main longitudinal direction L. This strip 10 results from the combination of three components: the lower and upper walls are composed of a metallized plastic film 12 between which the central element 14 forms a core. More specifically, as can be seen in Figure 2, the metallized plastic films 12 are composed of a plastic layer 12a coated with a metal layer 12b.

According to an essential characteristic of the invention, it is the metallic layer 12b forming the metallized face of the metallized plastic films 12, which is turned towards the central element 14. The illustrated metallized plastic films 12 comprise only one face provided with a metal layer 12b, said metallized face, but it is possible, without departing from the scope of the present invention, to use one or two metallized plastic films 12 whose two faces are metallized because they are provided with a metal layer 12b and thus form metal faces. It is also possible, without departing from the scope of the present invention, to use a single plastic film 12 having a metal face (metallized film) in place of the two metallized plastic films 12. According to another possibility, the only metallized plastic film 12 or the two metallized plastic films 12 is / are replaced by a solid aluminum film. The central element 14 consists of a foil of cellular-type material, preferably synthetic, which is shaped to form corrugations, having a pitch P, and alternately defining upper ridges 14a and lower ridges 14b.

In the illustrated embodiments, the corrugations formed by the central element 14 have a wavy longitudinal section in a particular shape since the profile is zigzag with the flattened tips. The flat face of the peak peaks makes it possible to preserve the zigzag shape after implementation of the deformation of the band forming the central element, and even before any connection between the central element 14 and the film (s) 12 Furthermore, according to a first configuration of the invention, it is provided that the corrugations of the central element 14 extend either in a direction T (see FIGS. 1 and 8A) perpendicular to the longitudinal principal direction L, or according to a direction which forms an angle different from 90 ° with the main longitudinal direction L, and in particular an angle of between 75 and 85 ° or between 95 and 115 ° (case not shown). According to a second configuration of the invention, it is provided that the corrugations of the central element 14 extend in one direction (see FIG. 8B) parallel to the longitudinal main direction L. Thus, the flat face continues lower ridges and upper ridges parallel to the main direction (L). Because of the presence of the corrugations, it will be understood that the central element 14 delimits a much larger volume than when it is flat. Indeed, the corrugations delimit, with the two metallized plastic films 12, channels 16 open at their ends. Said advantageous property remains true in the case where the strip 10 or the insulating element 30 resulting therefrom comprises only one metallized plastic film 12 or only one solid aluminum film. The material of the central element 14 is an open-cell or closed cell alveolar insulating material. Preferably, the material of the central element 14 is synthetic, but it may also comprise natural material. Advantageously, the material of the central element 14 is a foam, preferably polyolefin and preferably polyethylene or polypropylene: it is a cellular material having open cells and is therefore permeable to water and in the air, and which also has great flexibility and elasticity. Alternatively, the material of the central element 14 is a polyurethane foam: it is then an alveolar material having closed cells and is therefore impermeable to water and air, and which has a great flexibility and elasticity. Alternatively, the material of the central element 14 is made of a wadding, in particular a polyester or polyolefin wadding: in this case, it is considered that it is also a cellular material having open cells and which is therefore permeable to water and air, and which also has great flexibility and elasticity. Preferably, the cells contain air or other gas having a thermal conductivity lower than that of air. Advantageously, said first film 12 (and the optional second film 12) is a plastic film (in particular polyethylene) having a metal face (12b) obtained not metallization. It is the plastic layer 12a which preferably corresponds to a polyethylene film having a thickness of between 10 μm and 200 μm, and preferably between 10 μm and 100 μm, and which is generally between 10 and 40 μm and preferably between 15 and 30 μm, the metal layer 12b being preferably aluminum and preferably results from a deposition technique (such as a physical or chemical deposition under vacuum) which makes it possible to obtain very small thicknesses, in particular a thickness less than 1 μm. According to a variant not shown, all or part of said plastic films 12 comprises a plastic reinforcing grid, forming a reinforcement, in particular thermoplastic, which is for example embedded in the plastic layer 12a. This arrangement is particularly useful for the plastic reinforcing grid is placed at a place intended to form an outer face of the insulating complex forming the final panel ready to mount. Moreover, according to another optional option, all or part of said plastic films 12 comprises, on one or both sides, a layer of lacquer and / or a pattern which may be surface (for example by printing) or in relief (for example by mechanical deformation). This arrangement is in particular advantage a face intended to form an outer face of the insulating complex forming the final panel ready to mount.

Alternatively, one can use for the first film 12 (and the optional second film 12), and instead of the metallized plastic film 12, a solid film of metal, such as an aluminum film, which then generally has a thickness of the order of 30 pm. A central element 14 whose thickness e is between 1 and 5 mm, and preferably equal to 2 mm, 3 mm or 5 mm, is used, especially when it is a material consisting of a foam. For other materials, the thickness e can range from 1 mm to 1 cm. In addition, the corrugations of the central element 14, measured between the upper peaks 14a and the lower peaks 14b, are preferably chosen for the height H from a value of between 10 mm and 50 mm, preferably between 10 mm and 50 mm. mm and 25 mm. Thus, the strip of insulating product 10 according to the present invention and comprising only one corrugated central element 14 (FIG. 2), as well as any insulating element coming from said strip, advantageously has a small thickness E, which is at least maximum of 300 mm, and preferably between 30 mm and 160 mm.

Also, the pitch P of the corrugations of the central element 14, measured between two upper ridges 14a or between two lower ridges 14b, is preferably between 15 mm and 100 mm, and is preferably between 25 mm and 50 mm, and is preferably substantially between 32 and 46 mm. Moreover, in order to obtain the desired properties, particularly with regard to resilience, the applicant company has determined that it is preferable that the pitch P of the corrugations of the central element 14 be between 1 and 6 times, and preferably between 1.5 and 2.5 times and advantageously between 1.7 and 2.2 the height H of the corrugations measured between the upper ridges 14a and the lower ridges 14b. Advantageously, the material of the central element 14 has a density of less than or equal to 50 kg / m 3, and preferably less than 25 kg / m 3.

Preferably, said outer face of the lower ridges 14b and upper ridges 14a has a width w greater than the thickness e of the band material constituting the central element 14; preferably, said width w is between 1 and 5 mm, preferably 4 mm and preferably between 2 and 4 mm.

Thus, the lower ridges 14b and the upper ridges 14a have a flattened top because the corrugations are crushed or clipped, which defines a continuous flat of width w. In this way, each corrugation has the cross-sectional shape of a chevron or a V, alternately pointing upwards and downwards, which gives the central element 14 the structure of an accordion bellows. Thanks to the structure that has just been described, the strip of insulating product 10 according to the present invention, as well as any insulating element derived from said strip, advantageously has a low density. Indeed, the structure defined according to the present invention gives a density of less than or equal to 15 kg / m 3, preferably less than or equal to 10 kg / m 3 and preferably of the order of 8 kg / m 3 (8 kg / m3 with up to 15% more or less). Different possibilities exist for fixing between them the metallized face of the two plastic films 12 and the central element 14. Preferably, the connection between the metal face of the first film 12 (and the metallic or non-metallic face of the possible second film 12 ) and the central element 14 is made by means of adhesive: in Figure 2, is visible the section of adhesive points 18 which are present at the location of all the upper ridges 14a and all the lower ridges 14b of the central element 14.

More precisely, the upper ridges 14a and the lower ridges 14b of the central element 14 are all connected in at least one point to one of the two films 12 and in FIG. 2 this connection is embodied by the glue 18. Alternatively , the glue points 18 are present on only a part of the upper ridges 14a and a portion of the lower ridges 14b of the central element 14. These glue points 18 may be continuously deposited, in the form of adhesive lines, continuous or discontinuous (dotted lines) or punctually, being aligned with each other or not (staggered for example). Other types of bonds such as a bond by heat-sealing by means of ultrasound are possible. Referring to FIG. 3 which illustrates the roll-up of a strip of multilayer insulating product 10 according to the invention, after passing through a compression station 20, it appears that the thickness of the strip 10 passes of an initial thickness E0 in the zone 21 situated upstream of the compression station 20, at the final thickness El (less than the value E0) which is retained for the roll-up at the station 23, thanks to the use of guides 24 for maintaining in the flattened and compressed position of the strip 10.

There is a variation of between 30% and 80%, and usually at least 50%, between the initial thickness E0 and the final thickness E1 of the strip 10, which thus forms a roll 26 of reduced size. As it appears in FIGS. 3 and 4, after passing through the compression station 20, the corrugations of the central element 14 are flattened and superimposed on each other. The channels 16 then have a cross section that is very small compared to the expanded state of the strip 10 (thickness E0 or E0 '). It should be noted that the roll (station 23) of a band 10 under sufficient tension allows compression of the band 10; nevertheless, the use of a compression station 20 and guides 24 makes it possible to ensure better reproducibility and thus a regularity of the compression obtained. FIG. 4 illustrates the use of the roller 26 at a station 28 which makes it possible to unroll the strip 10: this strip 10 then naturally finds (arrows 29) a thickness E0 'greater than the thickness E1 and which is relatively close to the initial thickness E0. In practice, there is a difference of 5% to 30%, and preferably between 10 and 20%, between the thickness E0 'of the strip 10 during its deployment after compression, compared to the initial thickness E0 of the band 10 during its manufacture. However, we observe that E0 'tends to naturally approach E0 with time. Moreover, it is possible to assist this return to the initial thickness E0 or to a value almost equal to the initial thickness E0 by a dedicated system in order to shorten this return time to the initial shape and volume.

This property of resilience, namely the ability to recover, after compression, a volume and thickness very close to the initial values, or almost equal to the initial values, is a significant asset to overcome the problem of the bulk of the insulating product. It is understood from the foregoing that the flattening of the strip 10 (FIG. 3) does not cause the latter, when it resumes its initial shape, to modify its mechanical strength and / or thermal insulation properties. in particular, the central element 14 is not damaged by the compression set made on the compression station 20.

Here are two non-limiting examples of embodiment of a strip 10 according to the invention and the associated properties which have been observed, the central element 14 being made of polyethylene foam, and two films 12 being used with a polyethylene film of 21 μm coated with aluminum: Example Thickness e of the foam of the central element 14: 2mm; Height H of the corrugations: 13 mm; P ripples: 38 mm; 35- equivalent thermal conductivity: 0.031 W / (m.K); Example 2 Thickness e of the foam of the central element 14: 2 mm; H height of the corrugations: 20 mm; P ripples: 38 mm; 5- equivalent thermal conductivity: 0.038 W / (m.K); From these two examples it can be seen that a reduction of the height H of the corrugations improves the thermal performance. In the illustrated examples, the channels 16 are only filled with ambient air, but it could be envisaged that these channels 16 could be filled in whole or in part with an air-permeable and flexible material which would also allow the compression and return to the initial state of the strip 10. Thus, the structure of the strip 10 intends to form a compromise between parameters, in particular geometrical parameters, which are taken into account for the evaluation of the thermal insulation performances and the mechanical performances, including including resilience, which are maintained at high levels. Furthermore, by virtue of the invention, a strip 10 is obtained, the thermal conductivity of which is between 0.025 and 0.065 W / m 2 ° C., and preferably between 0.030 and 0.036 W / m 2 ° C. Moreover, the performance of such a strip is interesting in more than one way as can be seen from FIGS. 10 and 11, on which the invention has been compared with traditional insulation products 25 as follows: - A: mineral wool low density (thermal conductivity = 40 m W / Km) - B: medium density mineral wool (thermal conductivity = 32 m W / Km) 30 - C: polystyrene (thermal conductivity = 32-35 m W / Km) - D: polyurethane (thermal conductivity = 21-23 m W / Km) - invention: it is a section of a strip 10 according to the invention, the central element 14 being made of polyethylene foam of thickness 2 mm, H = 100 mm, P = 38 mm, and the two films 12 being aluminum-coated 21 dam polyethylene (thermal conductivity = 34-35 m W / Km). In FIG. 10, the thermal resistance performances are compared. products having a thickness of 100 mm, ie a solid band for the materials A, B, C and D and a perforated strip 10 of the it of the corrugation of the central element 14 for the invention.

Thus, it can be seen that the product according to the invention has a thermal resistance of the order of 3 m2.K / W, comparable to that of other traditional insulating solid materials such as mineral wool (A and B) or polystyrene ( C), but that the invention proposes a density 2.5 to 4 times lower, ie of the order of 6 to 8 Kg / m3, which makes it possible to obtain a product with good insulation performance for a low price due to the small amount of material. FIG. 11 shows the value of the thermal resistance of the same materials, with the interposition of two vertical air knives at the front and at the rear of the product: it can be seen that the thermal resistance obtained with the invention is at least three times better than for materials A, B, C and D. Furthermore, it has been found that the structure of the invention constitutes a very good acoustic insulation. Other advantages derive from the structure of the invention: the multilayer technology makes it possible either to confer a high resistance (watertightness) to the passage to water vapor (closed-cell foam for the central element 14 and film 12 preferably metallized low density polyethylene) is a low resistance to the passage of water vapor (open cell foam for the central element 14 and film 12, preferably micro-perforated low density polyethylene). the honeycomb structure of the strip allows packaging in the form of rolls or rigid panels. Reference will now be made to FIGS. 5 and 6 respectively illustrating a first example and a second example of an insulating complex made by stacking together several insulating elements 30 obtained by cutting the band 10 which has just been described. The insulating complexes 40 according to the invention comprise a stack of at least two insulating elements 30, in which the insulating elements 30 superimposed between them are connected by the rear face, turned in the opposite direction to said central element 14 (ie turned towards the outside of one of their plastic films 12, or more generally their first film 12) to form an insulating complex in one piece. As a preferred mode of bonding, use is made of glue reported by points and / or by lines and / or by lines, continuous or discontinuous, on at least one of the two facing surfaces before the assembly of the insulating elements. between them. Other modes of connection are possible, and in particular the heat-sealing between the layers of plastics 12a which are found facing each other during the stacking of the insulating elements 30.

In FIG. 5, all the insulating elements 30 of the insulating complex 40 are placed so that the directions T of the corrugations remain parallel to one another. This configuration forms an insulating complex 40 that can be compressed for storage, by compression in a direction C orthogonal to the surface of the insulating elements 30 or the insulating complex 40, and which is able to find at least approximately its initial thickness once the compressive force is released. To maintain the compressed state during storage, it is possible to use clamping elements such as strips encircling the complex 40. More generally, in an insulating complex comprising n superposed elements, it is possible to use pairs of elements insulators 30 respecting this parallelism of the direction T of the corrugations. In this case, the directions T of the corrugations of two insulating elements 30 superimposed between them are parallel to form an insulating complex 40 in which the corrugations are parallel between two superimposed insulation elements 30. In FIG. 6, all the insulating elements 30 of the insulating complex 42 are placed in such a way that the directions T of the corrugations intersect at 90 ° between two insulating elements 30 superimposed on each other. This arrangement of the insulating complex 42 provides maximum rigidity, especially in the direction C orthogonal to the surface of the insulating elements 30 or the insulating complex 42. More generally, in an insulating complex having n superposed elements, it is possible to use pairs of insulating elements 30 respecting this crossing or position at right angles to the direction T of the corrugations. In this case, the directions T of the corrugations of two insulating elements 30 superimposed between them are crossed to form an insulating complex 42 in which the corrugations are crossed between two insulating elements 30 superimposed. Alternatively (not shown), the crossing between two insulating elements 30 superimposed between them is not at right angles but at a non-zero angle other than 90 °. Furthermore, whether in this configuration of FIG. 5 (with parallel corrugations between them, ie channels 16 parallel to each other for all the insulating elements constituting the insulating complex 40) or in the configuration of Figure 6 with the insulating complex 42, this allows to place, during the laying of the insulating complex 40 or 42, one or more of the channel layers 16 parallel to each other from bottom to top to favor a circulation of the air down from above in said channel layers, and this to implement a voluntary air flow in the air gap. In this case, this moving air can recover the energy that passes through a wall according to the pariétodynamique effect. According to the third embodiment shown in FIGS. 7A and 7B, if we consider the two pairs formed by the three superimposed insulating elements 30, for each pair, the two superimposed insulating elements 30 have an offset on two edges between them. 31 and 32, while the other two edges 33 and 34 remain aligned and strictly superimposed between all the insulating elements of the complex 44. Thus, there is a lateral offset d of the two opposite edges 31 and 32, on the one hand between the first insulating member 30 (forming the upper insulating member 30 in Figs. 7A and 7B) and the second insulating member 30 (forming the middle insulating member 30 in Figs. 7A and 7B), and secondly between the second insulating member 30 (forming the medial insulating member 30 in Figs. 7A and 7B) and the third insulating member 30 (forming the lower insulating member in Figs. 7A and 7B). Thus, in the case of the variant of FIG. 7A where the offset between two superimposed insulating elements 30 is not always in the same direction, but has an alternation of directions, a groove 45 is formed between the first insulating element 30 (forming the upper insulating member 30 in Fig. 7A) and the third insulating member 30 (forming the lower insulating member 30 in Fig. 7A) at the location of the edge 31 (right in Fig. 7A), while at the location of the edge 32 (on the left in FIG. 7A), the second insulating element 30 (forming the median insulating element 30 in FIG. 7A) delimits a rib 46. This configuration according to FIG. 7A allows an assembly of type tenon and mortise, said by bouvetage. With such a lateral shift, it is understood that the assembly between two complexes 44a is facilitated by the possible interlocking between the rib 46 of an insulating complex 44a and the groove 45 of another insulating complex 44a placed next.

In the variant of FIG. 7B, called "offset edge" or "step", the three insulating elements 30 which are superimposed have a lateral offset which is always in the same direction between two superposed insulating elements 30 at the edges opposed 31 and 32, so that steps are obtained of a first type 47 on the side of the edges 31, and steps of a second type 48 on the side of the edges 32. The steps of the first type 47 of a first insulating complex 44b (left in FIG. 7B) fit perfectly in form complementarity with the steps of the second type 48 of a second insulating complex 44b (on the right in FIG. 7B). Alternatively, the lateral offset is not only on two opposite edges 31 and 32 but on the four edges 31, 32, 33 and 34, with two adjacent edges having the same type of offset, i.e. a first pair of adjacent edges defining a rib 46 (or marc hes of a second type 48) and a second pair of adjacent edges defining a groove 45 (or steps of a first type 47). In practice, the lateral offset d is at least 1 cm, preferably between 2 and 10 cm and advantageously of the order of 5 cm (5 cm with up to 15% more or less).

In these examples of FIGS. 5 to 7B, three insulating elements 30 are superimposed to form an insulating complex 40, 42 or 44a (44b), but it is possible to stack several, two or more, and in particular three , four, five or six insulating members 30, or more.

In these examples of insulating complexes 40, 42 and 44a (44b) illustrated in FIGS. 5 to 7B, the insulating elements 30 form sections of the strip 10 of the same length L1 as the width I of the strip 10. or insulating elements of square shape. Other dimensions are of course conceivable, in particular to form insulating complexes whose length is twice the width. These insulating complexes 40, 42 and 44a (44b) can be used as such as an insulation product, or can be associated with other components placed on one or both sides of the complex 40, 42 or 44a (44b). ). Referring now to FIGS. 8A, 8B and 9 showing an alternative embodiment of the strip 10 of FIGS. 1 to 4: in this case, during the manufacture of the strip 10 ', four central elements 141, 142 are superimposed, 143 and 144 identical, and five metallized plastic films 12, nine components forming the stack. Among these metallized plastic films 12, there are four metallized plastic films 121 of a first type, having only one metal layer 12b placed opposite one of the four central elements 141, 142, 143 and 144 (to the top in FIG. 9), and a single plastic film 122 of a second type, placed as outer films in the stack (at the top in FIG. 9), having a metal layer 12b turned towards the element central 141 of the top, and a plastic layer 12a 'thicker than the plastic layers of the metallized plastic films 121 of the first type (for example 60 pm against 20 pm), and which forms the outwardly facing face of the stack. In FIGS. 8A, 8B and 9, the corrugations of each pair of two adjacent central elements among the stack 141 to 145 are phase shifted: for example, the position of the upper ridges 14a (lower ridges 14b) of the central element 141 not being aligned but offset from the position of the upper peaks 14a (lower peaks 14b) of the neighboring central element 142. In FIGS. 8A, 8B and 9, this offset is a half-step P so that the corrugations of the two central elements 141 and 142 adjacent are in opposition of phase. Thus, a strip 10 'is formed which comprises four identical single strips 10 (a metallized plastic film 121 of the first type and a corrugated central element 141 or 142 or 143 or 144 or 145) superimposed 35 with a half-pitch shift of the corrugations. sawtooth-shaped between two adjacent central elements, and a plastic film 122 of the second type. This strip 10 'has a configuration where the ridges 14a, 14b are aligned vertically (when the strip 10' is horizontal) in groups of four, alternately with an upper ridge 14a and a lower ridge 14b. This arrangement is alveolar and close to a honeycomb structure, which gives it good mechanical strength in the direction of the corrugations. By cutting such a strip 10 ', compared to the complex 40 of FIG. 5, a thickness of metallized plastic film is saved, which reduces the thickness and the costs without degrading the mechanical and thermal insulation performances. of the strip 10 'with respect to those of the strip 10. Furthermore, a strip 10' or an insulating element 30 formed of a stack comprising a plurality of corrugated central elements 14, for example the stack of FIG. 8A or 8B ( band 10 '), retains the same resilience property as that observed and described above in connection with FIGS. 3 and 4 for band 10, namely that it can be compressed to reduce its bulk, while still being able to recover its initial dimensions after loosening compression. In FIG. 8A, the corrugations of the central elements 141 to 145 are parallel to each other and parallel to the transverse direction T of the strip 10 '. In FIG. 8B, the corrugations of the central elements 141 to 145 are parallel to each other and parallel to the longitudinal direction L of the strip 10 '. The deformation of the strip of foam-like material which is initially flat, and which constitutes, after waving, the corrugated central element 14 can be obtained in many ways, hot or cold.

Fixing, in particular by bonding one or two metal films 12b to the upper ridges 14a and / or the lower ridges 14b, makes it possible to retain the corrugated shape of the central element 14.

Claims (21)

REVENDICATIONS1. Strip (10) of multilayer insulating product having a longitudinal main direction (L) and a transverse direction (T) and comprising a corrugated central element (14) of cellular-type material connected against at least a first film (12) having a face metal member (12b) facing said central element (14), wherein the central element (14) has undulations defining lower peaks (14b) and upper peaks (14a), in which the metal face (12b) of the first film (12) is connected to the lower ridges (14b) or to the upper peaks (14a) of the central element (14), and in which the corrugations of the central element (14) delimit with the first film (12) channels (16), characterized in that the profile of the corrugations of said central element (14) corresponds to a section in zigzag shape and in that said lower peaks and said upper peaks delimit a planar outer face co straight and straight. 2. Strip (10) of multilayer insulating product according to claim 1, characterized in that the pitch (P) of the corrugations of the central element (14) is between 10 and 100 mm, is preferably between 15 and 40 mm, and is preferably between 25 and 50 mm, and is preferably between 32 and 46 mm. Band (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the height (H) of the corrugations of the central element (14), measured between the upper peaks and the lower peaks, is between 10 and 50 mm, preferably between 10 and 25 mm. 4. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the pitch (P) of the corrugations of the central element (14) is between 1 and 6 times, and preferably between 1.5 and 2.5 times the height (H) of the corrugations measured between the upper peaks (14a) and the lower peaks (14b). 5. strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that said outer face of the lower ridges (14b) and upper ridges (14a) has a width w greater than the thickness (e ) of the band material constituting the central element (14). 6. strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that it further comprises a second film (12), so that said central element (14) corrugated honeycomb-type material is located between said first film (12) and said second film (12), said second film (12) being connected to the other of the upper peaks (14a) and lower peaks (14b) of the central element (14) and that the corrugations of the central element (14) delimit with the second film (12) channels (16). 7. Strip (10) of multilayer insulating product according to the preceding claim, characterized in that said second film (12) has a metal face (12b) facing opposite and connected to said central element (14). 8. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that it has a density less than or equal to 15 kg / m3, preferably less than or equal to 10 kg / m3 and preferably of the order of 8 kg / m3. 9. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the central element (14) is made of a polyolefin material, preferably polyethylene, polypropylene or polyurethane. 10. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the material of the central element (14) has a density less than or equal to 50kg / m3. 11. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the connection between the metal face of said first film and the central element (14) is made by means of glue. 12. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that the continuous faceplane of the lower peaks and upper peaks is parallel to the main direction (L). 13. Strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that it comprises a single film having a metal face. 14. strip (10) of multilayer insulating product according to any one of the preceding claims, characterized in that it further comprises a second film having a metal face connected to the other of the lower ridges and the upper ridges (14a) of the central element (14). 15. Strip (10) of multilayer insulating product according to the preceding claim, characterized in that the thermal conductivity is between 0.025 and 0.065 W / m ° C, and preferably between 0.030 and 0.036 W / m ° C. 16. Insulating complex strip (40; 42) comprising a stack of at least two strips of insulating products (30) according to any one of the preceding claims, wherein the strips of insulating products (30) superimposed between them each comprise a single film formed of the first film (12) and are interconnected by a connection between the rear face, facing away from said central element (14), of the first film (12) of one of the strips of insulating products ( 30) and the lower ridges (14b) or the upper ridges (14a) of the other insulating product strips (30) to form an integral insulating complex strip and in which the corrugations of the central element are shifted by half a step in the transverse direction between two strips of insulating products (30) superimposed. An insulating member (30) resulting from the cutting of a strip (10) of multilayer insulating product according to any one of the preceding claims. 18. Insulating complex (40; 42) comprising a stack of at least two insulating elements (30) according to the preceding claim, wherein the insulating elements (30) superimposed between them are connected by the rear face, turned in the opposite direction to said central element (14) of their first film (12) to form an integral insulating complex. 19. Insulating complex (42) according to the preceding claim, characterized in that the directions (T) of the corrugations of two superimposed insulating elements (30) therebetween are crossed to form an insulating complex (42) in which the corrugations are crossed between two insulating elements (30) superimposed. 20. Insulating complex (40) according to claim 18, characterized in that the directions (T) of the corrugations of two insulating elements (30) superimposed between them are parallel to form an insulating complex (40) in which the corrugations are parallel between two insulating elements (30) superimposed. 21. Insulating complex (44) according to claim 18, 19 or 20, characterized in that the two superposed insulating elements (30) have an offset between them on two opposite edges.