GB2496739A

GB2496739A - Insulating material comprising corrugated cellular material and metallised film

Info

Publication number: GB2496739A
Application number: GB1220056.4A
Authority: GB
Inventors: Laurent Thierry
Original assignee: Orion Financement SA
Current assignee: Orion Financement SA
Priority date: 2011-11-07
Filing date: 2012-11-07
Publication date: 2013-05-22
Anticipated expiration: 2032-11-07
Also published as: PL231409B1; NL2009760B1; GB201220056D0; ITTO20120970A1; FR2982193B1; FR2982193A1; HK1185313A1; DE202012104182U1; BE1020843A5; FR2982522A1; PL401497A1; FR2982522B1; GB2496739B; NL2009760A

Abstract

The insulation comprises a film 12 having a metal face 12b bonded to the peaks 14a or troughs 14b of a cellular, corrugated, central element 14; defining channels 16 between the film 12 and the central element 14. The central element 14 has a zigzag cross-section. The cellular material is preferably polyethylene, polypropylene or polyurethane foam. The preferred insulation includes a second (aluminium) metallised 12b (polyethylene) film 12a on the other side of the central element 14. Multilayer insulation material formed from this insulation is used for thermal insulation of buildings.

Description

Strip of multilayer insulating product and strip of insulating complex made from such strips of multilayer insulating product The invenlion relates to the field of multilayer insulating products, designed particularly but not exclusively for thermal insulation of buildings. Such insulation is employed for example on the inner surface of walls giving onto the outside, in insulation under roofing or even on interior walls; but it can also relate to insulation on the outer surface of walls (walls, roofs...) giving onto the outside (called "sarking" type installation).

With a view to proposing a product exhibiting the lowest possible emissivity, particularly if reflection of infrared radiation is considered, as well as low thermal conductivity, numerous solutions have been proposed, each having advantages but also a certain number of disadvantages.

Thus the fact of resorting to a multilayer complex comprising C?) one or more bubble films at the center of the complex and, in the outer portions, a metal or metalized film, is known from document 0 In this type of product, however, the presence of the bubble N-20 films generates a thickness which will become considerable when a large number of layers is stacked together and consequently a significant and permanent bulk.

The present invention has as its object to supply a product allowing the disadvantages of the prior art to be overcome, and in particular a product satisfying multiple conditions, to wit exhibiting good thermal insulation properties (low thermal conductivity in particular), sufficient mechanical strength allowing handling without risk of deterioration of its insulating properties, reduced bulk, as well as very light weight.

To this end, according to the present invention, a strip of multilayer insulating product is proposed that has a principal longitudinal direction and a transverse direction and includes a corrugated central element made of cellular type material bonded to at least a first film having a metal surface facing said central element, wherein the central element exhibits corrugations defining lower peaks and upper peaks, wherein the metal surface of the first film is bonded to the lower peaks or to the upper peaks of the central element, and wherein the corrugations of the central element, in combination with the first film, define channels.

Preferably, said channels are open at one or the other of their two ends.

In this fashion, it is understood that if the channels defined between the corrugations of the central element and said first film are open at one location at least, it is possible to drive out the air contained in said channels by compression of the insulating product.

Characteristically, the profile of the corrugations of said central element correspond to a zigzag-shaped cross-section and said lower peaks and said upper peaks define a flat outer surface that is continuous and straight: the profile is therefore that of a blunted sawtooth.

Thus, due to the geometry and the materials selected for the components of the insulating product, the latter is resilient, meaning that it is able to substantially recover its initial shape and dimensions after having been put under compression. This property corresponds to elasticity in compression.

(Y) Thus, thanks to this property, it is possible to reduce the bulk volume of the strip, or strip segment, of the multilayer insulating product.

7" Thus its storage after manufacture and before use and its 0 transportation require space that is reduced compared to the space occupied by the product in its deployed state as used for its installation or its integration as a component in a multi-component insulating complex.

This constitutes a very significant advantage.

This solution also exhibits the additional advantage of also making it possible, thanks to the presence of at least a first film with a metal surface facing the channels, to obtain a wall with a very strong reflectivity, or low emissivity, facing a thin layer of air, which is an advantage in terms of the insulating properties of the product.

To this end, preferably the film(s) having a metal surface exhibit an emissivity c less than or equal to 0.2.

Moreover, resorting to a corrugated central element provides, in the deployed state of the insulating product, a sufficiently rigid structure to retain its three-dimensional shape, whether the insulating product is laid flat or stood up on edge.

Overall, thanks to the solution according to the present invention, it is also possible, in an insulating complex installed on a wall, and including the insulating product according to the invention, to channel the circulation of air by choosing the orientation of the channels formed in the central element (or the central elements, when several strips of multilayer insulating product are stacked). This makes it possible in particular to counteract the parasitic phenomena of natural convection, or to favor air circulation upward from below to implement for example air circulation which recovers energy passing through the wall and can participate in the storage wall effect.

According to one preferred arrangement, the strip of multilayer insulating product also includes a second film so that the corrugated central element made of cellular material is positioned between said first film and said second film, said second film being bonded to the other peaks, upper or lower, of the central element and the corrugations of the central element also define channels, in combination with the second film, which are preferably open at one location at least, and particularly at one or the other of the two ends.

CV) In this case, the number of channels of the multilayer insulating product strip, and of the insulating element resulting from cutting it, is doubled.

0 In this case, one or the other, or both, of the two following arrangements is preferably adopted: -said second film exhibits a metal surface oriented facing and bonded to said central element, -said second film exhibits a metal surface oriented in the direction opposite to said central element: this case is implemented in particular when said second film constitutes or is designed to constitute the outer surface of an insulating complex consisting of a stack having one or more insulating elements resulting from cutting them from a strip of multilayer insulating material according to the invention.

The present invention also relates to an insulating element resulting from cutting it from a strip of multilayer insulating product as described previously.

Other advantages and features of the invention will appear upon reading the following description given by way of example and with reference to the appended drawings wherein: -Figure 1 is a partial perspective view of a first embodiment of a strip of multilayer insulating product according to the invention, -Figure 2 is a magnified view of detail II of Figure 1, -Figures 3 and 4 are lateral projections of a strip according to the invention and illustrate the resilience property of the multilayer insulating product constituting the strip, -Figures 5 and 6 are perspective views illustrating examples of insulating complexes according to the invention, made by associating several insulting elements according to the invention, obtained by cutting them from a strip according to the invention, -Figures JA and 7B show embodiment variants of the insulating complexes of Figures 5 and 6 which exhibit easier assembly, -Figures 8A and 8B are partial perspective views showing two variants of a second embodiment of a strip of rnultilayer insulating product according to the invention, -Figure 9 is a magnified view of detail IX of Figure 8A or of Figure 8B, and CV) -Figures 10 and 11 are diagrams comparing the insulation performance of the invention with other products in the prior art.

The strip 10 of multilayer insulating product visible in Figure 1 0 exhibits a width I and its greatest dimension extends along the principal N-20 longitudinal direction L. This strip 10 results from the association of three components: the lower and upper walls consist of a metalized plastic film 12 between which the central element 14 forms a core.

More precisely, as can be seen in Figure 2, the metalized plastic films 12 consist of a layer of plastic 12a coated with a metal layer 12b.

According to an essential feature of the invention, it is the metal layer 12b constituting the metalized surface of the metalized plastic films 12 which is oriented toward the central element 14.

The illustrated metalized plastic films 12 comprise only a single surface provided with a metal surface 12b, called the metalized surface, but it is possible, without departing from the scope of the present invention, to use one or two of the metalized plastic films 12 both surfaces whereof are metalized because they are provided with a metal layer 12b and thus constitute metal surfaces. It is also possible, without departing from the scope of the present invention, to use a single plastic film 12 having one metal surface (metalized film) instead of two metalized plastic films 12.

According to another possibility, the single metalized plastic film 12 or the two metalized plastic films 12 is/are replaced by a solid aluminum film.

The central element 14 consists of a sheet of cellular type material, preferably synthetic, which is shaped so as to form corrugations having a pitch P and alternately defining upper peaks 14a and lower peaks 14b.

In the embodiments illustrated, the corrugations formed by the central element 14 exhibit a corrugated longitudinal section having a particular shape because the profile is a zigzag with the points blunted.

The flat surface of the peaks of the crests makes it possible to retain the zigzag shape after implementing the deformation of the strip forming the central element and even before any bond between the central element CV) 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 0 in a T direction (see Figure 1 and 8A) perpendicular to the principal N-20 longitudinal direction L, that to say according to a direction that forms an angle other than 90° with the principal longitudinal direction L, and in particular an angle comprised between 75 and 85° or between 95 et 115° (an hypothetical case, not shown).

According to a second configuration of the invention, it is provided that the corrugations of the central element 14 extend in a direction (see Figure 8B) parallel to the principal longitudinal direction L. Thus, the continuous flat surface of the lower peaks and of the upper peaks is parallel to the principal direction (L).

Due to the presence of the corrugations, it will be understood that the central element 14 defines a much greater volume than when it is flattened. Indeed, the corrugations define, with the two metalized 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 from it by cutting comprises only a single metalized plastic film 12 or only a single solid aluminum film.

The material of the central element 14 is a so-called cellular insulating material, having open cells or closed cells.

Preferably, the material of the central element 14 is synthetic, but it can also include natural material.

Advantageously, the material of the central element 14 is a foam, preferably polyolefin and preferably polyethylene or polypropylene: this is a cellular material having open cells and which is therefore permeable to water and to air, and which also exhibits great flexibility and a certain elasticity.

Alternatively, the material of the central element 14 is a polyurethane foam: this is then a cellular material having closed cells and which is therefore impermeable to water and to air, and which exhibits great flexibility and a certain elasticity.

Alternatively, the material of the central element 14 is made of polyester or polyolel9n batting: in this case, it is assumed to also be a CV) cellular material having open cells and which is therefore permeable to water and to air, and which also exhibits great flexibility and a certain elasticity.

0 Preferably, the cells contain air or another gas having a thermal N-20 conductivity lower than that of air.

Advantageously, said first film 12 (and the optional second film 12) is a plastic film (particularly polyethylene) having one metal face (12b) obtained by metallization. It is the plastic layer 12a which corresponds preferably to a polyethylene film having a thickness comprised bel:ween 10 pm and 200 pm, and preferably between 10 pm and 100 pm and which is generally comprised between 10 and 40 pm and preferably between 15 and 30 pm, the metal layer 12b being preferably aluminum and resulting preferably from a deposition technique (such as physical or chemical deposition under vacuum) which makes it possible to obtain very small thicknesses, particularly a thickness less than 1 pm.

According to one variant, not shown, all or part of said plastic films 12 comprises a reinforcing network made of plastic, constituting a reinforcement, particularly made of thermoplastic, which is for example embedded in the plastic layer 12a. This arrangement is particularly used so that the reinforcing network is positioned in a location designed to constitute an outer surface of the insulating complex constituting the final panel, ready for installation.

Furthermore, according to another optional possibility, all or part of said plastic films 12 comprise, on one or both of its surfaces, a layer of lacquer and/or a design which can be on the surface (for example by printing), or in relief (for example by mechanical deformation). This arrangement is used in particular on a surface designed to constitute an outer surface of the insulating complex constituting the final panel, ready for installation.

Alternatively, it is possible for the first film 12 (and the optional second film 12), and instead of the metalized plastic film, a solid metal film such as an aluminum foil, when then generally has a thickness on the order of 30 pm.

A central element 14 is used the thickness e whereof is comprised between 1 and 5 mm, and is preferably equal to 2 mm, 3 mm CV) or 5 mm, particularly when it is a material consisting of a foam. For the other materials, the thickness e can range from 1 mm to 1 cm.

Further, a value which is comprised between 10 mm and 0 50 mm, preferably between 10 mm and 25 mm, is preferably selected for N-20 the height H of the corrugations of the central element 14, measured between the upper peaks 14a and the lower peaks 14b.

Thus, the insulating strip 10 conforming to the present invention and comprising only a single central corrugated element 14 (Figure 2), as well as any other insulating element generated from said strip, advantageously has a small thickness E, which is at most 300 mm, and preferably comprised between 30 mm and 160 mm.

Also, the pitch P of the corrugations of the central element 14, measured between two upper peaks 14a or between two lower peaks 14b, is preferably comprised between 15 mm and 100 mm, and is preferably comprised between 25 mm and 50 mm, and is preferably substantially comprised between 32 mm and 46 mm.

Moreover, to obtain the desired properties, particularly as regards resilience, the applicant company has determined that it is preferable that the pitch P of the corrugations of the central element 14 be comprised between 1 and 6 times, and preferably between 1.5 and 2.5 times, and advantageously between 1.7 and 2.2 times the height H of the corrugations measured between the upper peaks 14a and the lower peaks 14b.

Advantageously, the material of the central 14 exhibits a density less than or equal to 50 kg/rn3, and preferably less than 25 kg/m3.

Preferably, said outer surface of the lower peaks 14b and of the upper peaks 14a exhibits a width w greater than the thickness e of the strip material constituting the central element 14; preferably, said width w is comprised between 1 and 5 mm, preferably less than 4 mm and preferably between 2 and 4 mm.

Thus, the lower peaks 14b and the upper peaks 14a exhibit a flattened peak because the corrugations are crushed or blunted, which defines a continuous flat having width w. In this fashion, each corrugation exhibits a cross-section in the shape of a chevron or a V, alternately point up and point down, which gives the central element 14 the structure of an accordion bellows.

CV) Thanks to the structure just described, the strip of insulating product 10 conforming to the present invention, as well as any insulating element generated from said strip, advantageously exhibits a low density.

0 Indeed, thanks to the structure defined according to the present invention, a density is obtained that is less than or equal to kg/rn3, preferably less than or equal to 10 kg/rn3 and preferably on the order of 8 kg/rn3 (8 kg/rn3, plus or minus up to 15%).

Different possibilities exist for bonding together the metalized surfaces of the two plastic films 12 and the central element 14. Preferably, the bond between the metal surface of the first film 12 (and the metal or non-metallic surface of the optional second film 12) and the central element 14 is achieved by means of glue: in Figure 2, glue dots 18 can be seen which are present at the locations of all the upper peaks 14a and of all the lower peaks 14b of the central element 14.

More precisely, the upper peaks 14a and the lower peaks 14b of the central element 14 are all bonded at one point at least to one of the two films 12 and in Figure 2, this bond is embodied by the glue 18.

Alternatively, the glue dots 18 are present on only a portion of the upper peaks 14a and a portion of the lower peaks 14b of the central element 14.

These glue dots 18 can be deposited continuously, in the form of glue lines, continuous or discontinuous (dotted lines) or as points, aligned with one another or not (zig-zagged for example). Other types of bonding such as hot gluing or ultrasonic bonding are possible.

Referring to Figure 3 which illustrates the rolling of a strip of multilayer insulating product 10 according to the invention, after running through a compressing station 20, it is revealed that the thickness of the strip 10 changes from an initial thickness EU in the area 21 located upstream of the compression station 20 to the final thickness El (less than the value EU) which is maintained for rolling at station 23, thanks to the use of guides 24 allowing the strip 10 to be held in the flattened and compressed position.

A variation of between 3O0!o and 8O%, and generally at least 50%, is observed between the initial thickness EU and the final thickness El of the strip 10 which thus forms a roll 26 having reduced bulk.

CV) As can be seen in Figures 3 and 4, after entering the compression station 20, the corrugations of the central element 14 are flattened and stacked together. The channels 16 then exhibit a straight 0 section having much reduced surface area compared to the deployed state of the strip 10 (thickness E0 or EU').

It should be noted that rolling (station 23) a strip 10 under sufficient tension allows compression of the strip 10; nevertheless, resorting to a compression station 20 and to guides 24 makes it possible to ensure better reproducibility and thus regularity of the compression obtained.

Figure 4 illustrates the use of the roll 26 at a station 28 which allows the strip 10 to be unrolled: said strip 10 then returns naturally (arrows 29) to a thickness EU' greater than thickness El and which is relatively close to the initial thickness EO. In practice, a deviation of 5% to 3O% is noted, and preferably between 10% and 20%, between the thickness EQ' of the strip 10 upon its deployment after compression, compared to the initial thickness EQ of the strip 10 when manufactured.

However, it is observed that E0' tends to naturally approach EU over time.

Further, it is possible to assist this return to the initial thickness EQ or to a value nearly equal to the initial thickness E0, using a dedicated system in order to shorten this time to return to the initial shape and volume.

This resilience property, to with the capacity to recover, after compression, a volume and a thickness very close to the initial values, or virtually equal to the initial values, is a significant asset for overcoming the problem of the insulating product.

It is understood from the foregoing that the flattening of the strip 10 (Figure 3) does not cause in the latter, when it resumes its original form, any alteration of its mechanical strength and/or thermal insulation properties: in particular, the central element 14 is not damaged by the compression accomplished at the compression station 20.

Here are two non-limiting embodiments of a strip 10 conforming to the invention and the associated properties that were observed, the central element 14 being made of polyethylene foam and two films 12 being used with a 21 pm polyethylene film coated with aluminum:

CO Example

-Thickness e of the foam of the central element 14: 2mm; 1" -Height H of the corrugations: 13 mm; 0 -Pitch P of the corrugations: 38 mm; N-20-Equivalent thermal conductivity: 0.031 W/(m.K);

Example 2

-Thickness e of the foam of the central element 14: 2mm; -Height H of the corrugations: 20 mm; 25-Pitch P of the corrugations: 38 mm; -Equivalent thermal conductivity: 0.038 W/(m.K); From these two examples it can be observed that a reduction in the height H of the corrugations improves thermal performance.

In the examples illustrated, the channels 16 are filled only with ambient air but having the channels filled completely or in part by a flexible air-permeable material, also allowing compression and return to the initial state of the strip 10, could be contemplated.

Thus, the structure of the strip 10 is intended to constitute a compromise between the parameters, particularly geometrical ones, to be taken into account for evaluating thermal insulation performance and mechanical performance, including resilience, which are maintained at high-performing levels.

Furthermore, thanks to the invention, a strip 10 is obtained the thermal conductivity whereof is comprised between 0.025 and 0.065 W/m.°C, and preferably between 0.030 and 0.036 W/m.°C.

Furthermore, the performance of such a strip are advantageous in more than one way as can be learned from Figures 10 and 11 on which the invention is compared to traditional insulation products as follows: -A: low-density mineral wool (thermal conductivity = 40 m W/K.m) -B: medium density mineral wool (thermal conductivity = 32 m W/K.m) -C: polystyrene (thermal conductivity = 32-35 m W/K.m) -D: polyurethane (thermal conductivity = 21-23 m W/K.m) -invention: this is a segment of a strip 10 conforming to the CV) invention, the central element 14 being made of 2 mm thick polyethylene foam, H=100 mm, P=38 mm, and the two films 12 being 21 pm polyethylene coated with aluminum (thermal conductivity = 34- 0 3SmW/K.m) N-20 In Figure 10, the thermal resistance performance of products having a thickness of 100 mm, namely a solid strip for materials A, B, C and D and an openwork strip 10 due to the corrugation of the central element 14 for the invention.

Thus we see that the product according to the invention exhibits thermal resistance on the order of 3 m2,K/W, comparable to that of other traditional solid insulating materials like mineral wool (A and B) or polystyrene (C), but the invention proposes a density that is 2.5 to 4 times lower, on 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 quantity of material.

In Figure 11, the value of the thermal resistance of the same materials is shown with the interposition of two vertical air gaps in front of and behind the product: it is observed that the thermal resistance obtained with the invention is at least three times better than for materials A,B,CandD.

Furthermore, it has been observed that the structure of the invention constitutes a very good acoustic insulation.

Other advantages result from the structure of the invention: -the multilayer technology makes it possible either to S confer increased resistance (vapor-tightness) to the passage of water vapor (closed cell foam for the central element 14 and film 12 preferably made of low density metallized polyethylene) or low resistance to the passage of water vapor (open cell foam for the central element 14 and film 12 preferably made of micro-perforated low density polyethylene).

-the cellular structure of the strip allows packaging in the form of rolls or rigid panels.

Refer now to Figures 5 and 6, illustrating respectively a first example and a second example of an insulating complex made by associating, through stacking, several insulating elements 30 obtained by cutting them from the strip 10 just described.

C?) The insulating complexes 40 according to the invention comprise a stack of at least two insulating elements 30, wherein the 7....... stacked insulating elements 30 are bonded at the back surface, oriented in 0 the direction opposite the central element 14 (to wit turned toward the outside of one of their plastic films 12, or more generally of their first film 12) to form a one-piece insulating complex.

By way of a preferred method of bonding, glue is used that is applied by dots and/or by streaks and/or by lines, continuous or discontinuous, on at least one of the two surfaces facing one another prior to assembly of the insulating elements 30.

Other bonding methods are possible, and particularly heat sealing of the plastic layers 12a positioned opposite one another during stacking of the insulating elements 30.

In Figure 5, all the insulating elements 30 of the insulating complex 40 are placed so that the I directions of the corrugations remain parallel to one another.

This configuration forms an insulating complex 40 which it is possible to compress for storage, by compressing in a C direction orthogonal to the surface of the insulating elements 30 or of the insulating complex 40, and which is able to recover at least approximately its initial thickness once the compression force is released. To maintain the compressed state during storage, clamping elements can be used such as straps wrapped around the complex 40.

More generally, in an insulating complex comprised of n stacked elements, it is possible to use pairs of insulating elements 30 satisfying the condition of parallelism in the T direction of the corrugations. In this case, the T directions of the corrugations of two stacked insulating elements 30 are parallel to form an insulating complex 40 wherein the corrugations of two insulating elements 30 stacked together are parallel with one another.

In Figure 6, all the insulating elements 30 of the insulating complex 42 are placed so that the T directions of the corrugations cross each other at 900 from one to the other of two insulating elements 30 stacked together.

This arrangement of the insulating complex 42 provides maximum rigidity, particularly in the C direction orthogonal to the surface of the insulating elements 30 or of the insulating complex 42.

CV) More generally, in an insulating complex comprising n stacked elements, it is possible to use pairs of insulating elements 30 satisfying this crossing or right-angle positioning of the T direction of the 0 corrugations. In this case, the T directions of the corrugations of two N-20 insulating elements 30 stacked together are crossed to form an insulating complex 42 wherein the corrugations of two stacked insulating elements are crossed.

Alternatively (not shown), the crossing of two insulating elements 30 stacked together is not at a right angle but at a nonzero angle different from 900.

Further, whether in this configuration of Figure 5 (with parallel corrugations, that is with parallel channels 16 for all insulating elements constituting the insulating complex 40) or in the configuration of Figure 6 with the insulating complex 42, this makes it possible to place, during installation of the insulating complex 40 or 42, one or more of the layers of channels 16 parallel with one another from bottom to top in order to favor air circulation upward from below in said layers of channels, this to implement deliberate air circulation in the air gap. In this case, this moving air in can make it possible to recover the energy passing through a wall using the storage wall effect.

According to the third embodiment that can be seen in Figures JA and JB, if two pairs made up of three stacked insulating elements 30 are considered, for each pair the two stacked insulating elements 30 exhibit an offset on two opposite edges 31 and 32, while the two other edges 33 and 34 remain aligned and strictly superimposed for all the insulating elements of the complex 44. Thus, there is a lateral offset d of the two opposite edges 31 and 32, firstly between the insulating element 30 (constituting the upper insulating element 30 in Figures JA and 7B) and the second insulating element 30 (constituting the middle insulating element in Figures 7A and 7B), and secondly between the second insulating element 30 (constituting the middle insulating element 30 in Figures 7A and 7B) and the third insulating element 30 (constituting the lower insulating element3O in Figures 7A and 73).

Thus, in the case of the variant of Figure 7A where the offset between two stacked insulating elements 30 is not always in the same CV) direction, but shows an alternation of directions, a groove 45 is formed between the first insulating element 30 (constituting the upper insulating element 30 in Figure 7A) and the third insulating element 30 (constituting 0 the lower insulating element 30 in Figure 7A) at the location of the edge 31 (to the right in Figure JA), while at the location of the edge 32 (to the left in Figure 7A) the second insulating element 30 (constituting the middle insulating element 30 in Figure 7A) defines a tongue 46. This configuration according to Figure 7A makes possible a joint of the mortise and tenon type, called tongue-and-groove. With such a lateral offset, it will be understood that the assembly of two complexes 44a is facilitated due to the possibility of interlocking the tongue 46 of one insulating complex 44a and the groove 45 of another insulating complex 44a set beside it.

In the variant of Figure 73, called "offset edge" or "stairstep," the three insulating elements 30 that are stacked exhibit a lateral offset which is always in the same direction between two stacked insulating elements 30, at the opposite edges 31 and 32, so that steps of a first type 47 are obtained 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 (to the left in Figure 78) interlock perfectly by complementary shapes with the steps of the second type 48 of a second insulating complex 44b (to the right in Figure 75).

Alternatively, the lateral offset is present not only on two opposite edges 31 and 32 but on all four edges 32, 32, 33 and 34, with two adjacent edges exhibiting the same type of offset, that is a first pair of edges defining a tongue 46 (or steps of a second type 48) and a second pair of edges defining a groove 45 (or steps of a first type 47).

In practice, the lateral offset d is at least 1 cm, preferably comprised between 2 and 10 cm and advantageously on the order of 5 cm (5 cm, plus or minus up to iS%).

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

In these examples if insulating complexes 40, 42 and 44a (44b) C?) illustrated in Figures 5 through 7B, the insulating elements 30 constitute segments of the strip 10 having a length Li that is equal to the width I of 7....... the strip 10, in other words square shaped insulating elements. Other 0 dimensions can of course be contemplated, particularly for making insulating complexes the length whereof is double the width.

These insulating complexes 40, 42 and 44a (44b) can be used as they are as insulation products, or can be associated with other components placed on one or both surfaces of the complex 40, 42 or 44a (44b).

Refer now to Figures 8A, 8B and 9 showing an embodiment variant of the strip 10 of Figures 1 through 4: in this case, four identical central elements 141, 142, 143 and 144 are stacked during manufacture of the strip 10', together with five metalized plastic films 12, or nine components constituting the stack.

Of these metalized plastic films 12, four metalized plastic films 121 of a first type are distinguished, having only a single metal layer 12b positioned facing one of the four central element 141, 142, 143 and 144 (toward the top of Figure 9), and one single plastic film 122 of a second type, placed as the outer films in the stack (toward the top of Figure 9), exhibiting a metal layer 12b oriented toward the top central element 141, and a plastic layer 12a' thicker than the plastic layers of the metalized plastic films 121 of the first type (for example 60 pm versus 20 pm), and which constitute the outward facing surface of the stack.

In Figures 8A, 8B and 9, the corrugations of each pair of two adjacent central elements in the stack 141 through 145 are offset in phase: the position of the upper peaks 14a (lower peaks 14b) of the central element 141 for example being not aligned but offset with respect to the position of the upper peaks 14a (lower peaks 14b) of the adjoining central element 142. In Figures 8A, 8B and 9 this offset is one-half of the pitch P, so that the corrugations of the two adjoining central elements 141 and 142 are in opposite phase.

A strip 10' is thus formed comprising four identical single strips (a metalized plastic film 121 of the first type and a corrugated central element 141 or 142 or 143 or 144 or 145) stacked with a one-half-pitch offset of the sawtooth-shaped corrugations between two adjoining central elements, and one plastic film 122 of the second type.

CV) This strip 10' exhibits a configuration where the peaks 14a, 14b are vertically aligned (when the strip 10' is horizontal) in groups of four, with an alternation of one upper peak 14a and one lower peak 14b. This 0 arrangement is cellular and close to a honeycomb structure, which confers N-20 upon it good mechanical strength in the T direction of the corrugations.

By cutting from such a strip 10', one thickness of metallized plastic film is saved compared to the complex 40 of Figure 5, which reduces the thickness and the costs without degrading the mechanical and thermal insulation performance of the strip 10' compared to those of the strip 10.

Furthermore, a strip 10' or an insulating element 30 consisting of a stack comprising several corrugated central elements 14, for example the stack of Figure 8A or SB (strip 10'), retains the same resilience property as that observed and described previously in relation to Figures 3 and 4 for the strip 10, to wit the ability to be compressed to reduce its bulk, while still being able to recover its initial dimensions after release of the compression.

In Figure 8A, the corrugations of the central elements 141 through 145 are parallel to one another and parallel to the transverse T direction of the of the strip 10'.

In Figure SB, the corrugations of the central elements 141 through 145 are parallel to one another and parallel to the longitudinal direction L of the strip 10'.

The deformation of the strip made of cellular type material which is initially flat, and which constitutes after corrugation the corrugated central element 14, can be obtained in multiple ways, using hot or cold processing.

The bonding, particularly by gluing, of one or two metal films 12b onto the upper peaks 14a and/or the lower peaks 14b makes it possible to retain the corrugated shape of the central element 14. r

N-

Claims

<claim-text>CLAIMS1. A strip (10) of multilayer insulating product having a principal longitudinal direction (L) and a transverse direction (T) and having a corrugated central element (14) made of cellular type material bonded against at least a first film (12) having a metal surface (12b) facing said central element (14), wherein the central element (14) exhibits corrugations defining lower peaks (14b) and upper crests (14a), wherein the metal face (12b) of the first film (12) is bonded to the lower peaks (14b) or to the upper peaks (14a) of the central elements (14), and wherein the corrugations of the central element (14) define with the first film (12) channels (16), characterized in that the profile of the corrugations of said central element (14) corresponds to a zigzag-shaped section and in that said lower peaks and said upper peaks define a continuous and straight flat outer surface.</claim-text> <claim-text>2. The 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 comprised between 10 and 100 mm, is preferably comprised between 15 and 40 mm, and is preferably comprised between and 50 mm, and is preferably comprised between 32 and 46 mm.</claim-text> <claim-text>3. The strip (10) of multilayer insulating product according any one of the foregoing 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 comprised between 10 and 50 mm, preferably between 10 and 25 mm.</claim-text> <claim-text>4. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that the pitch (P) of the corrugations of the central element (14) is comprised 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).</claim-text> <claim-text>5. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that said outer surface of the lower peaks (14b) and of the upper peaks (14a) exhibits a width w greater than the thickness (e) of the strip material constituting the central element (14).</claim-text> <claim-text>6. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that it also includes a second film (12), such that said corrugated central element (14) made of cellular material is situated between said first film (12) and said second film (12), said second film (12) being bonded to the others of the upper peaks (14a) and lower peaks (14b) of the central element (14) and that the corrugations of the central element (14) define channels (16) with the second film (12).</claim-text> <claim-text>7. The strip (10) of multilayer insulating product according to the foregoing claim, characterized in that said second film (12) has a metal surface (12b) oriented facing and bonded to said central element (14).</claim-text> <claim-text>8. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that it exhibits a density less than or equal to 15 kg/m3, preferably less than or equal to kg/m3 and preferably on the order of 8 kg/m3.</claim-text> <claim-text>9. The strip (10) of multilayer insulaung product according to any one of the foregoing claims, characterized in that the central element (14) is made of a polyolefin material, preferably polyethylene, polypropylene or polyurethane.</claim-text> <claim-text>10. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that the material of the central element (14) exhibits a density less than or equal to 50 kg/m3.</claim-text> <claim-text>11. The strip (10) of multilayer insulating product according to any one of the foregoing daims, characterized in that the bond between the metal face of said first film and the central element (14) is achieved by means of glue.</claim-text> <claim-text>12. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that the continuous flat surface of the lower peaks and of the upper peaks is parallel to the principal direction (L).</claim-text> <claim-text>13. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that it comprises a single film exhibiting a metal surface.</claim-text> <claim-text>14. The strip (10) of multilayer insulating product according to any one of the foregoing claims, characterized in that it also comprises a second film exhibiting a metal surface bonded to the others of the lower peaks and the upper peaks (14a) of the central element (14).</claim-text> <claim-text>15. The strip (10) of multilayer insulating product according to the foregoing claim, characterized in that the thermal conductivity is comprised between 0.025 and 0.065 W/m.°C, and preferably between 0.030 and 0.036W/m.°C.</claim-text> <claim-text>16. A strip of insulating complex (40; 42) comprising a stack of at least two strips of insulating products (30) according to any one of the foregoing claims, wherein the strips of insulating products (30) stacked together each comprise a single film consisting of the first film (12) and are bonded together by a bond between the back surface, oriented in the direction opposite to said central element (14) of the first film (12) and one of the strips of insulating products (30) and the lower peaks (14b) or the upper peaks (14a) of the other of the strips of insulating products (30) to constitute a one-piece strip of insulating complex and wherein the corrugations of the central element are offset one-half pitch in the transverse direction between two stacked strips of insulating products (30).</claim-text> <claim-text>17. An insulating element (30) resulting from cutting from a strip of multilayer insulating product (10) according to any one of the foregoing claims.</claim-text> <claim-text>18. An insulating complex (40; 42) comprising a stack of at least two insulating elements (30) according to the foregoing claim, wherein the insulating elements (30) stacked together are bonded by the back surface, oriented in the direction opposite that of said central element (14) , of their first film (12) to constitute a one-piece insulating complex.</claim-text> <claim-text>19. The insulating complex (42) according to the foregoing claim, characterized in that the directions (T) of the corrugations of two insulating elements (30) stacked together are crossed to form an insulating complex (42) wherein the corrugations are crossed from one stacked insulating element (30) to the next.</claim-text> <claim-text>20. The insulating complex (40) according to Claim 18, characterized in that the directions CT) of the corrugations of two insulating elements (30) stacked together are parallel to constitute an insulating complex (40) wherein the corrugations are parallel from one insulating element (30) to the next.</claim-text> <claim-text>21. The insulating complex (44) according to Claim 18, 19 or 20, characterized in that the two stacked insulating elements exhibit an offset between them at two opposite edges.</claim-text>