Improved device for thermal insulation and manufacturing process

Abstract

Improved reflective insulation system. Thermal insulation system for a building, comprising an insulating veil, said insulating veil comprising two external films (10, 20) bonded together to form pockets, said insulating veil further comprising a separating film (60), comprising a primary separating film (70) and a secondary separating film (80) partially bonded together, so as to present an alternation of bonded portions and unbonded portions between the two elementary films so as to define a plurality of airtight cavities (62), said separating film (60) bonded in contact with an external film (10, 20) of the layer, said separating film having a plurality of airtight cavities, in which each insulating veil comprises at least one internal film (30), extending between the external films so as to subdivide each pocket into sub-pockets, each sub-pocket comprising a layer of insulating material (50),said insulating material mat (50) being composed of non-woven material fibers and having recesses (52). Figure for the abbreviation: Fig. 1.,

Description

Title of the invention: Improved device for thermal insulation and manufacturing method technical field

[0001] The present invention relates to reflective thermal insulators. Previous technique

[0002] Reflective thermal insulation is an insulating system used in confined spaces. Unlike conventional insulation, which is bulky, this type of insulation has a reduced footprint, which is advantageous, for example, in terms of layout, typically for spaces located under roofs.

[0003] However, the problems associated with such insulators imply that an improvement in insulation requires an improvement in the product, rather than a simple increase in the thickness of the insulation as can be achieved with conventional insulators such as rock wool.

[0004] The proposed invention thus aims to improve the thermal insulation properties of such reflective insulators. Description of the invention

[0005] To this end, the present invention proposes a thermal insulation system for a building, comprising an insulating veil, said insulating veil comprising two external films joined together to form pockets, said insulating veil further comprising a separating film, comprising a primary separating film and a secondary separating film partially joined together, so as to present an alternation of joined and unjoined portions between the two elementary films so as to define a plurality of airtight cavities said separator film bonded to an external film of the sheet, said separator film having a plurality of sealed cavities, in which each insulating layer comprises at least one inner film, extending between the outer films so as to subdivide each pocket into sub-pockets, each sub-pocket comprising a layer of insulating material, said layer of insulating material being composed of non-woven material fibers and having recesses.

[0006] According to one example, the primary separator film is bonded to an external film of the mat, the secondary separator film is partially bonded to the primary separator film, and the primary separator film has two external faces metallized, the secondary separator film has a hook face by which it is partially attached to the primary separator film, and a metallized outer face.

[0007] According to one example, the primary separator film is a multilayer comprising two layers of polyethylene separated by a layer of polyamide, said polyethylene layers each being covered with a metallized layer.

[0008] According to one example, the secondary separating film is a multilayer film comprising: - a layer of polyethylene, covered with a metallized layer, - a layer of polyamide, - an adhesion layer comprising a mixture of polyethylene and ethylene acrylic acid copolymer, partially bonded to the primary separating film.

[0009] According to one example, said insulating veil comprises at least two internal films, so as to divide each pocket into several sub-pockets.

[0010] According to one example, the separator film has a density of airtight cavities between 900 and 40,000 bubbles / m2.

[0011] According to one example, the insulating material layer is composed of textile fibers, having an openness rate of between 10% and 80%, or between 40% and 60%.

[0012] According to one example, the textile fibers are joined together by heat fixing.

[0013] The present invention also relates to an assembly comprising a plurality of systems as defined above, said insulating veils being superimposed.

[0014] According to one example, said insulating veils are perforated. Brief description of the drawings

[0015] The invention and its advantages will be better understood upon reading the detailed description below of various embodiments of the invention given by way of non-limiting examples.

[0016] [Fig-1] [Fig. 1] schematically presents an example of a product for forming a thermal insulation system according to one aspect of the invention

[0017] [Fig.2] Fig.2 presents a view of an example of a layer of insulating material of a product according to the invention.

[0018] [Fig.3] Fig.3 presents another view of an example of a layer of insulating material of a product according to the invention.

[0019] [Fig.4] Fig.4 presents an exploded schematic view of an example primary separator film.

[0020] [Fig.5] Fig.5 presents an exploded schematic view of an example secondary separator film.

[0021] [Fig.6] Fig.6 presents a schematic view of an insulating system assembly implementing a product according to one aspect of the invention.

[0022] Throughout all the figures, the common elements are identified by identical numerical references. Description of the implementation methods

[0023] Fig. 1 schematically presents an example of a product for the formation of a thermal insulation system according to one aspect of the invention.

[0024] The product as proposed includes an insulating veil comprising two external films 10 and 20 joined together so as to form pockets.

[0025] Figure 1 shows a partial view, in which only two pockets are illustrated. It is understood that this figure is not limiting, and that the insulating veil may have any number of pockets.

[0026] The outer films 10 and 20 are joined together to form pockets; the joining between the two films 10 and 20 is therefore carried out in such a way as to define portions at the level of which the two films 10 and 20 are not joined together, these portions defining the pockets.

[0027] The joining of the two outer films 10 and 20 can be achieved by sewing, gluing, welding, or calendering. It can be carried out discreetly or continuously, and according to straight line patterns, curves, or any other suitable trajectory or pattern, for example, a diamond pattern.

[0028] The joining can be carried out in a longitudinal and / or transverse direction, thus defining pockets that can be delimited on all or part of their periphery.

[0029] The insulating veil as proposed further comprises at least one inner film 30, interposed between the two outer films 10 and 20. In the illustrated example, the insulating veil comprises two inner films, 30A and 30B. These inner films 30A and 30B subdivide each pocket into sub-pockets. In the illustrated example, the outer films 10 and 20, combined with the inner films 30A and 30B, thus define 3 sub-pockets: - a sub-pocket between the outer film 10 and the inner film 30A, - a sub-pocket between the internal films 30A and 30B, and - a sub-pocket between the inner 30B film and the outer 20 film.

[0030] It is understood that the illustrated example is purely illustrative and not limiting. The veil may have any number of internal films 30, so as to subdivide the pockets into a desired number of sub-pockets. In particular, the veil may have one internal film 30, two internal films, or three internal films so as to form 2, 3, or 4 sub-pockets, respectively.

[0031] The different sub-pockets each comprise a layer of insulating material 50. In the example illustrated in [Fig.1], 50A, 5B and 50C are designated as the layers of insulating material arranged in the 3 sub-pockets.

[0032] The insulating material layer 50 is typically a foam layer, typically made of polyethylene. This foam layer is typically solid (or not perforated) when formed, and is then typically perforated by a suitable process. Alternatively, the openings can be formed during the production of the layer.

[0033] Figures 2 and 3 show two views of an example of an insulating material mat 40 that can be used. [Fig. 2] is a top view, while [Fig. 3] is a schematic cross-sectional view. The insulating material mat 50 as illustrated is a perforated mat; it has a plurality of openings 52 passing through said mat. In the illustrated example, the openings 52 are rhombic or square in shape and are arranged in a staggered pattern. The openings 52 can have any suitable shape, and this illustrated embodiment is not limiting.

[0034] Such an openwork structure is typically obtained from a solid sheet of insulating material, in which cuts are made along a first direction, then stretched along a second direction perpendicular to the first direction and stabilized, for example by heat fixing.

[0035] Alternatively, the insulating material layer 50 is formed by a layer of entangled nonwoven fibers, for example, by means of a carding machine or any other suitable device. The openings 52 can then be made either during the formation of the layer, or after the layer has been formed by material removal or cutting.

[0036] The use of a layer of insulating material 50 is advantageous in terms of insulation. Indeed, once the layer of insulating material 50 is wrapped on both sides, the perforated areas form air gaps or air bubbles which have better thermal insulation properties than foam or fibers.

[0037] According to one example, the insulating material layer 50 has an openness rate of between 10% and 80%, or between 40% and 60%.

[0038] The opening ratio is defined as the area of ​​the recesses in relation to the total area of ​​the insulating material layer 50, viewed along a plane defined by the longitudinal direction XX and the transverse direction YY of the primary layer 10.

[0039] The product as proposed also includes at least one separator film 60, each separator film 60 being attached to one of the outer films 10 or 20. In the illustrated example, the product includes a separator film 60 attached to the outer film 10.

[0040] The separator film 60 comprises a primary separator film 70 and a secondary separator film 80. The primary separator film 70 is bonded to an outer film of the sheet, here at the outer film 10. The secondary separator film 80 is partially bonded to the primary separator film 70.

[0041] We thus distinguish between bonded portions which are bonded to the primary separator film 70 for example by gluing, thermoforming, welding or any other suitable means, and unbonded portions which are not bonded to the primary separator film 70. These bonded and unbonded portions are alternated, so that the unbonded portions are framed by bonded portions which are gas-tight.

[0042] The unbonded portions typically have a surface area greater than their projection onto the primary separating film 70, so as to define an internal volume filled with a gas and thus to form bubbles 62 or sealed cavities.

[0043] The bubbles 62 are typically filled with air or an inert gas such as, for example, Argon, Xenon, or Carbon Dioxide, or a mixture thereof with Nitrogen. These different gases are particularly advantageous compared to air due to their reduced thermal conductivity, while remaining inert.

[0044] Figure 4 presents an exploded schematic view of an example of a primary separator film 70 which is a multilayer film comprising two layers of polyethylene 74 and 78 (typically high density) separated by a layer of polyamide 72, said polyethylene layers 74 and 78 each being covered with a metallized layer 75 and 79. Adhesion layers 73 and 77, typically made of modified polyethylene, are typically interposed between the polyethylene layers 74 and 78 and the polyamide layer 72 to promote adhesion between these layers.

[0045] Figure 5 presents an exploded schematic view of an example secondary separator film 80, which is a multilayer film comprising: - a layer of Polyethylene 84, typically high-density polyethylene, covered with a metallized layer 85, - a layer of polyamide 82, - a layer 88 comprising a mixture of polyethylene and ethylene acrylic acid copolymer, partially bonded to the primary separator film 40.

[0046] Adhesion layers 82 and 87, typically made of modified polyethylene, are typically interposed between the polyethylene layer 84 and the polyamide layer 82, and between the polyamide layer 82 and the layer 88 to promote adhesion between these layers.

[0047] It is understood that these examples are purely illustrative and not limiting. The primary separation film 70 and secondary separation film 80 can also be ethylene vinyl alcohol (EVOH) based films. They then typically have a structure similar to the primary separation film 70 and secondary separation film 80 structures described above, in which the polyamide layers (72 and 80, respectively) 82, which are layers forming a barrier to gases) are replaced by a layer of Ethylene-vinyl alcohol.

[0048] The various metallized layers are, for example, made of aluminum. The various metallized layers typically have a thickness on the order of one hundred Angstroms.

[0049] The bubbles are typically formed by suction after partial bonding of the secondary separator film 80 to the primary separator film 70, for example, by means of a roller with cavities adapted to create a suction effect. Such a process causes local deformation of the secondary separator film 80, which typically degrades the metallization on the unbonded portions. The presence of continuous metallization on at least one face of the primary separator film 70 ensures the maintenance of high insulation properties.

[0050] The separator film 60 typically has a bubble density of between 900 and 40,000 bubbles / m2, or between 1,000 and 20,000 bubbles / m2.

[0051] The separating film 60 ensures spacing when several products are stacked, typically several products as shown, or the product as shown with any other product. Such spacing ensures the formation of an air gap between the products, which improves the thermal insulation properties of an assembly composed of several stacked products compared to such an assembly without such a separating film.

[0052] The product as proposed is suitable for use in the construction of roof insulation systems. It is thus interposed between roof rafters and battens, typically in combination with other identical or complementary products.

[0053] In such an application, a recurring problem concerns the points where products are attached to the rafters. Indeed, at the rafters, conventional insulating products are compressed, which degrades their thermal insulation performance.

[0054] Figure 6 schematically represents such an assembly.

[0055] We can thus identify in this figure a roofing element 1 such as tiles 1 forming the roof, support battens 2 forming the support for the tiles, as well as rafters 3 and a finishing facing 4. Battens 5 are interposed between the support battens 2 and the rafters 3.

[0056] An insulation system is interposed between the rafters 3 and the battens 5, this insulation system 10 being formed of a product as described above. Alternatively, the insulation system may comprise several superimposed products, typically several products as described above.

[0057] The support portions between the rafters 3 and the battens 5 define assembly portions of the system which are identified by the references Cl and C2. Fastening means such as nails or any other suitable element are inserted so as to connect the rafters 3 to the battens 5, and therefore pass through the product.

[0058] As described previously, these assembly portions usually have degraded thermal performance and thus typically form thermal bridges. The invention addresses this problem; the presence of the separating film 60 ensures minimum spacing and the formation of an air gap due to the presence of the bubbles 62.

[0059] The product as proposed thus exhibits superior insulating properties compared to conventional products, resulting from the combination of the separator film 60, the subdivision of the pocket into sub-pockets by the internal film(s) 30, and the use of a perforated material in the sub-pockets.

[0060] Conventionally, thin reflective insulation systems combine a waterproof product with a permeable product, in order to allow condensation to escape.

[0061] The implementation of a system combining several products as proposed involves, on the contrary, superimposing two similar products. In order to ensure the evacuation of water vapor, the product as proposed typically has through perforations.

[0062] Such perforations are typically created using hot needles or a laser. The perforations typically have a diameter between 0.1 and 3 mm, a density of approximately 0.01% to 10% per m² of product, and are typically distributed in a regular, grid, or staggered pattern. Creating such perforations ensures water vapor permeability. However, the applicant has found that, surprisingly, such perforations have only a very small impact on thermal insulation performance.

[0063] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0064] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. A thermal insulation system for a building, comprising an insulating layer, said insulating layer comprising two external films (10, 20) bonded together to form pockets, said insulating layer further comprising a separating film (60), comprising a primary separating film (70) and a secondary separating film (80) partially bonded together, so as to present an alternation of bonded portions and unbonded portions between the two elementary films so as to define a plurality of airtight cavities (62), said separating film (60) bonded in contact with an external film (10, 20) of the layer, said separating film having a plurality of airtight cavities, in which the insulating layer comprises at least one internal film (30), extending between the external films so as to subdivide each pocket into sub-pockets, each sub-pocket comprising a layer of insulating material (50),said insulating material mat (50) being composed of non-woven material fibers and having recesses (52).

2. System according to claim 1, wherein: the primary separator film (70) is bonded to an external film (10, 20) of the mat, the secondary separator film (80) is partially bonded to the primary separator film (70), the primary separator film (70) has two metallized external faces (75, 79), the secondary separator film (80) has a hook face (88) by which it is partially bonded to the primary separator film (70), and a metallized external face (85).

3. System according to claim 2, wherein the primary separator film (70) is a multilayer comprising two layers of polyethylene (74, 78) separated by a layer of polyamide (72), said polyethylene layers (74, 78) each being covered with a metallized layer (75, 79).

4. A system according to claim 2 or 3, wherein the secondary separator film (80) is a multilayer film comprising: - a polyethylene layer (84), covered with a metallized layer (85), - a polyamide layer (82), - an adhesion layer (88) comprising a mixture of polyethylene and ethylene acrylic acid copolymer, partially bonded to the primary separating film (70).

5. System according to any one of claims 1 to 4, wherein said insulating veil comprises at least two inner films (30a, 30b), so as to divide each pocket into several sub-pockets.

6. System according to any one of claims 1 to 5, wherein the separator film has a density of airtight cavities (62) between 900 and 40,000 bubbles / m2.

7. System according to any one of the preceding claims, wherein the insulating material layer is composed of textile fibers, having an openness ratio of between 10% and 80%, or between 40% and 60%.

8. System according to claim 7, wherein the textile fibers are joined together by heat fixing.

9. Assembly comprising a plurality of systems according to any one of the preceding claims, said insulating veils being superimposed.

10. Assembly according to claim 9, wherein said insulating veils are perforated.

Images