GB2398758A

GB2398758A - Supple thermal-insulation material comprising at least one perforated batt

Info

Publication number: GB2398758A
Application number: GB0327607A
Authority: GB
Inventors: Laurent Thierry
Original assignee: Laurent Thierry S A
Current assignee: Laurent Thierry S A
Priority date: 2002-11-27
Filing date: 2003-11-27
Publication date: 2004-09-01
Anticipated expiration: 2023-11-27
Also published as: AU2003288350A1; PL377093A1; EP1565625A1; FR2847650B1; FR2847650A1; DE60323124D1; ATE405711T1; EP1565625B1; GB0327607D0; WO2004051020A1; GB2398758B

Abstract

A thermal insulation material 1 comprises multiple interleaved batts 2, 4, 6, 8 and reflective foils 3, 5, 7, 9. The batts may comprise a foamed material or a non woven fibrous material (eg. polyester, polyamide, polyolefin, viscose, wool, cotton, flax or mixtures thereof). The reflective foils may comprise a metallised thermoplastic film or a laminate of a thin metal foil and a thermoplastic foil. The laminate may also be provided with reflective outer foils 13, 15 and protective outer layers 12,14. The batts (but not the foils) are perforated 17, said perforations having a generally smooth cross section eg. circular or elliptical. The perforations may be arranged in one or more resistive zones that provide a greater thermal resistance than the remainder of the laminate. The laminate layers may be secured by spot bonds 25 eg. thermal or ultrasonic welds and said spot bonds may be formed in areas outside of the apertured resistive zones.

Description

SUPPLE THERMAL-INSULATION MATERIAL

COMPRISING AT LEAST ONE PERFORATED BATT

The invention concerns a supple thermal-insulation material comprising at least one insulating supple batt that is covered, on one side at least, by a reflective supple film.

In particular, the invention concerns a thermal-insulation material of slight thickness (less than 10 cm), a so-called multilayer thin insulator, in the form of strips or other supple panels (square supple pieces, for example) for the thermal insulation of buildings, comprising an alternating sequence of reflective supple films and interposed supple layers consisting of insulating material.

The insulator according to the invention is intended, in particular, for the insulation of roofs and lofts that are suitable for conversion (laying under rafters, on rafters, on laths, etc.), of ceilings and uninhabitable lofts (laying under dormer-window trusses, under or on floor, etc.), of floorings (laying on or under floor), of walls and vertical partition walls, and, if need be, of hydraulic heating floors, of electrical radiant floors, of garage doors, of rolling-shutter cabinets, etc. Exchanges of heat result from three simultaneous modes of transmission: conduction, convection and radiation. It is difficult to minimise these three phenomena jointly: interposing a solid partition wall between two environments at different temperatures permits any exchange between the two environments by convection to be avoided, but induces significant exchanges by conduction and by transmission and emission of thermal radiation; creating a gas space between two solid partition walls at different temperatures limits the conduction phenomena but generates exchanges between

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the two partition walls by radiation. The conception of a thermalinsulation material therefore results from a compromise, which also has to take account of economic constraints (necessitating devising inexpensive materials) and of industrial constraints which necessitate devising materials that are, at the same time, supple - with a view to facilitating the packaging, transportation and laying thereof - light - in order to limit the corresponding loads supported by the structure of the building and not very thick - with a view to limiting the loss of volume or of habitable surface attributable to the thickness of the insulating material or, for a given habitable volume or surface, the size and the cost of the structure of the building.

Today there are two major families of thermal-insulation materials: - the insulating materials known as thick insulators, of thickness greater than 15 cm and very often greater than 20 cm, which generally comprise a single thick batt of a fibrous material of mineral origin, such as rock wool or glass wool, or of a fibrous material of vegetable origin, such as hemp wool or flax wool, or alternatively of a fibrous material of animal origin, such as sheep's wool.

Said batt is covered on each side by a protective film consisting of Kraft paper or of polypropylene. These insulators exhibit satisfactory thermal resistance, on account of their thickness (the thermal resistance of the batt being approximately proportional to its thickness), on account of the fibrous nature of the bats, and on account of the choice of a material having poor thermal conductivity for the production of said fibres. The exchanges by radiative transmission are, moreover, minimised by the choice of opaque protective films. On the other hand, these protective films exhibit non-negligible emissivity, favouring transfers of energy by radiation, which preponderate when the difference in temperature between the exterior and the interior is significant.

These insulators are, moreover, particularly cumbersome and heavy, by definition, and are consequently poorly adapted to applications for rehabilitation or renovation of existing buildings, for which the loss of volume or of surface attributable to the insulator, and the overload that said insulator imposes on the structure of the building, have not initially been taken into account. In certain cases the use of these insulators is even incompatible with the existing structure; - the thermal-insulation materials known as thin insulators, of thickness less than 10 cm and very often less than 5 cm, which comprise a plurality of metallised supple films and of interposed supple layers consisting of insulating material. The reflectivity of the films is utilised, in order to limit the thermal transfers by radiation. In fact, when incident radiation emanating from a warm environment reaches a reflective face of a film, the great majority of its energy is reflected towards the warm environment without penetrating the film, so that the fraction of its energy that is absorbed, and therefore re emitted by the film, is small (the fraction of energy directly transmitted to the colder environment situated on the other side of the film being, furthermore, zero or negligible in the case of an opaque film). And the superposition of several spaced metallised films permits the exchanges between two environments by radiation to be reduced progressively and in more effective manner. The exchanges between two successive films by radiation and by convection are, furthermore, limited by interposition of an insulating interposed layer between said films. The interposed layer plays the role of an optical spacer permitting the two reflective films to be separated, in order to avoid any thermal bridge by contact (conduction) between the two films. Several known types of interposed layer for multilayer thin insulator exist, among which are: À layers consisting of fibrous material, in particular batts consisting of synthetic fibrous material such as waddings made of polyester (or possibly batts consisting of a fibrous material of mineral, vegetable or animal origin - glass wool, rock wool, hemp wool, sheep's wool - possibly impregnated with synthetic resins), À layers consisting of closed-cell or open-cell cellular foam, made of a synthetic material such as a polyethylene; À bubble films, which exhibit, in a direction orthogonal to the layer, one or more rows of closed pockets (so- called bubbles) consisting of synthetic material, measuring 5 mm to 20 mm in diameter and containing air; À woven or extruded grilles or meshes, such as the grilles of synthetic foam mentioned by FR 2 765 305 in its introductory part, or alternatively the nets described by US 4,230,057, which are knitted, woven, formed from threads, yarns, filaments or fibres, or manufactured by extrusion or by perforation or by perforation and expansion of plastic or non-woven webs.

The thin insulators are particularly adapted to applications for rehabilitation and renovation of existing buildings, as well as to certain specific applications (such as the insulation of a floor or of a screed receiving a floating parquet floor). But, whatever the type of interposed layer employed, its thermal efficiency is still judged to be insufficient, considering that it is often lower than that of the most high-performance thick insulators.

US 4,230,057 advocates the use of a net by way of interposed layer, which provides interesting results. The mesh-size of the net is chosen to be sufficiently small, so that the films do not touch one another, and as large as possible, in order to benefit from the effects of film-to- film reflexivity. But progress remains to be made as regards the efficiency of the interposed layers in terms of thermal insulation.

In addition, the inventor has ascertained that the prior grilles and nets also have mechanical disadvantages, in particular a resistance to traction that is too low, and great deformability in the directions of the diagonals of the mesh of the grille (or of the net). These disadvantages prove to be inconvenient both for the manufacture of the grilles or nets and of the material, and for the packaging of the material and the laying thereof; they necessitate handling of the grilles (or nets) and of the material with many precautions, in order to avoid any tearing or deformation of said grilles.

The invention aims to reduce these disadvantages by proposing a supple thermal-insulation material having improved thermal-insulation properties, as well as an interposed layer having reinforced mechanical strength.

In particular, one objective of the invention is to provide a thin insulating material, of total thickness less than cm, in particular less than 5 cm, having a thermal- insulation performance that is enhanced and, in particular, superior to that of the prior thick insulators.

The invention also aims to provide an interposed layer having improved insulation properties and having, moreover, greater resistance to tearing and reduced deformability, at least in certain directions.

Another objective of the invention is to propose a thermal- insulation material and a corresponding laying process permitting, without notable excessive thickness, improved thermal insulation to be obtained at the junctions between strips or other adjacent panels of material. In particular, the invention aims to propose a material that is impervious to water (rainwater, run-off water, sleet, powder snow), and to propose a process for laying such a material, which is simple and quick and which permits perfect watertightness of the junctions between strips or other panels of material to be obtained.

Another objective of the invention is to propose a material providing the aforementioned advantages, the "supplied laid" cost of which (said cost comprising the totality of the costs associated with the manufacture and laying of the material) remains similar to the average "supplied laid" cost of the known prior thermal-insulation materials.

In all of the following, a face of a body (of a film, for example) of the material according to the invention is said to be hardly emissive as long as it exhibits a directional monochromatic emissivity BA,& less than 0.2 for wavelengths between 400 nm and 800 nm - and preferably for wavelengths between 300 nm and 1000 nm, or even for all wavelengths (grey body) - for directions approximately orthogonal to said face - and preferably for all directions (isotropic emissivity) - and for temperatures of the body corresponding to normal conditions of use of the material.

In addition, a face of a body (of a film, for example) of the material according to the invention is said to be reflective as long as it exhibits a directional monochromatic reflectivity P',i (hemispherical or specular) greater than 0.8 for wavelengths between 400 nm and 800 nm - and preferably for wavelengths between 300 nm and 1000 nm, or even for all wavelengths - for directions i of incident radiation approximately orthogonal to said face - and preferably for all directions of incidence and for normal conditions of use of the material (temperature of the body, luminance of the incident flux, etc.).

Furthermore, the term "bats" is understood to mean an interposed layer that takes the form of a supple strip or other supple panel (of any shape) in one piece that has been produced from an insulating supple material having appropriate cohesion. Such a batt is, moreover, thicker than each film covering it. This definition of a batt does not include the solid interposed layers, the non-continuous interposed layers formed from localized and independent separating blocks (such as the "wedging pieces' [morceaux calants] described by FR 2 765 305), or the paddings of bulk materials which are devoid of appropriate cohesion when the bulk material is not adhesion-bonded to a film or maintained between two films. The invention applies essentially to a material comprising at least one such bats.

The invention concerns a supple thermal-insulation material comprising at least one supple batt and at least one supple film, which are superposed, characterized in that said material comprises at least one supple bats, a so-called perforated bats, that is À covered on one side at least by a supple film, a so called reflective film, exhibiting a face that is, at the same time, reflective and hardly emissive, and/or two hardly emissive faces, and/or two reflective faces, À and provided with at least one through-hole, a so called insulation hole, containing a volume of gas which normally comes into contact with each portion of film opposite the insulation hole, each insulation hole having a frontal cross-section devoid of sharp corners.

Advantageously, and according to the invention, the perforated batt comprises at least one zone, a so-called resistive zone, of greater thermal resistance, in which there are arranged insulation holes defining a total area of opening greater than half of the area of the resistive zone, the totality of said resistive zones extending over more than half of the area of the perforated bats.

The expression "the volume of gas (contained in each of the insulation holes) which normally comes into contact with each portion of film opposite the insulation hole" means that the volume of gas is at least in contact, on one side of the perforated bats, with the reflective film over the entire portion of said film delimited by the insulation hole. On the other side of the perforated bats, said volume is in contact with a portion - delimited by the insulation hole - either of another film, if the batt is covered on either side by a film, or of a partition wall to be insulated, if the batt forms a front face of the material and is (in use) applied against such a partition wall or stretched out opposite and at a distance from such a partition wall. In other words, under normal conditions of utilisation and use of the material according to the invention the volume of gas contained in the insulation hole interposes itself between the two films that the perforated batt separates (or else between the film covering the batt and a partition wall opposite which said batt is applied), so that the two films (or the film and the partition wall) do not come into contact with one another. Any thermal bridge between the two films (or between the film and the partition wall opposite) across the insulation hole is thus avoided.

It should be noted that, under normal conditions of utilization and use, the material is unfolded, stretched out approximately flat against a partition wall, or fixed to a support (such as a trellis of cleats) approximately parallel to a partition wall or another surface that is plane overall (a surface defined by the covering of a roof, for example). Conversely, when the material is folded up or rolled up on itself, with a view to its transportation for example, it is not impossible that, on account of its suppleness and on account of the compressibility of the bats, two films opposite one another touch one another across an insulation hole.

The invention therefore consists in using, by way of interposed layer, a batt in which one or more insulation holes devoid of sharp corners have been arranged.

The presence of these insulation holes between two successive films has two contrary effects: it brings about a diminution of the exchanges of energy between the two films by conduction, but favours the exchanges of energy between said films by radiation and convection. The use of a reflective film on one side at least of the batt permits the increase in the exchanges by radiation to be partially compensated, and it turns out, a posterior), that these contrary effects ultimately result in an improvement of the thermal-insulation performance of the material (under normal conditions - in particular of temperature - of utilization and use of the material). It should be noted that the transfers by radiation across a reflective film as previously defined are limited, whatever the side of the film where the warm environment is situated, so that the material is just as efficient in summer as in winter.

The shape of the insulation holes according to the invention presents several advantages: - in unexplained manner, said shape appears to be responsible, to an unexpected extent, for an improvement in the insulation performance of the bats. The inventor has in fact ascertained that the comparison of insulation performance between a perforated batt according to the invention and a batt of the same nature and the same thickness, but devoid of insulation holes, results in a ratio that is clearly superior to the ratio resulting from the comparison between a prior foam grille and a layer of foam of the same nature and the same thickness as the grille (but devoid of mesh). The insulation performance of such a perforated batt therefore exceeds all possible expectations; - the shape of the insulation holes imparts greater mechanical resistance to the bats, in particular greater resistance to traction in all the directions contained in a frontal plane of the bats. The inventor has in fact ascertained that the possible tears which appear in the known prior grilles arise principally in the corners of the mesh of the grille, where the splitting stresses are most significant. The rounded shape (devoid of sharp corners) of the insulation holes according to the invention permits the stresses to which the insulation hole is subject to be distributed over the totality of its perimeter, permits a concentration of splitting stresses at one point on this perimeter to be avoided, and therefore permits the formation of tears to be limited; - said shape also reduces the deformability of the perforated batt by distributing the stresses to which the holes are possibly subjected over the totality of its perimeter, and in all directions. Ultimately, the improvement in the mechanical strength of the batt (greater resistance to tearing and reduced deformability) facilitates the manufacture and subsequent handling of the material; - for the two preceding reasons, the rounded shape of the insulation holes according to the invention permits holes to be produced in a fibrous bats, in particular by cutting, without risking seeing the batt being torn in the course of withdrawal of the off-cuts which have been cut out in order to form said holes. It is therefore possible to envisage industrial and cost-effective manufacture of such fibrous perforated batts.

Advantageously, and according to the invention, the perforated batt is made of a non-woven, thermobonded and/or needled and/or adhesion-bonded fibrous material. Such a perforated batt therefore differs from the known prior grilles or nets, not only by virtue of the shape of its insulation holes but also by virtue of its nature and structure. Such a batt exhibits two levels of perforation: on the one hand, the space between the intermingled fibres, which forms a multitude of winding tunnels of the order of microns (possibly extending as far as millimetres), and on the other hand by virtue of the insulation holes, across which the reflective films (or the film and the partition wall) directly face one another. The thermal results of such a fibrous perforated batt are particularly satisfactory.

In a variant, the perforated batt is made of synthetic foam.

The perforated batt preferably exhibits a multitude of insulation holes. Each of these insulation holes is arranged in such a way as to avoid the formation of a thermal bridge across the insulation hole. In particular, the dimensions of each insulation hole, the thickness of the perforated batt and the suppleness of each film that covers it are adapted in order to avoid any untimely contact (under normal conditions of utilization and use of the material) across said insulation hole, between the reflective film and a film or a partition wall opposite the other side of the perforated bats. It should be noted that the perforated batt is preferably covered on each side by a reflective supple film.

The insulation holes are produced by stamping of the batt or by cutting of the batt by means of mechanical cutting tools (for example, a rotating cylinder with cutting blades, and associated counter-cylinder), thermal cutting tools, optical cutting tools (laser), hydraulic cutting tools (high-pressure water jet), high-frequency vibratory cutting tools (ultrasound), etc. Advantageously, and according to the invention, each insulation hole exhibits a maximal dimension less than ten times the thickness of the perforated bats. The expression "dimension of a hole" is understood to mean a dimension of the hole in a frontal plane of the bats. The maximal dimension of the hole is its largest dimension in such a frontal plane.

In particular, the perforated batt advantageously exhibits a thickness (at rest) between 1 mm and 12 mm - preferably of the order of 8 mm - and each insulation hole exhibits a maximal dimension between 10 mm and 30 mm preferably of the order of 20 mm.

Advantageously, and according to the invention, the perforated batt exhibits insulation holes of circular cross-section. This shape of the insulation holes gives the best results in terms of mechanical resistance and deformability of the perforated bats, as well as in terms of thermal insulation.

In a variant, or in combination, the perforated batt exhibits insulation holes of oval or elliptical cross section. This shape also provides satisfactory results.

It should be noted that one and the same perforated batt may comprise different shapes of insulation holes.

Advantageously, and according to the invention, the insulation holes of a resistive zone of the perforated batt are aligned in two orthogonal directions, in particular in a longitudinal direction and in a transverse direction of the material. If the material takes the form of a strip, the longitudinal and transverse directions of the material correspond respectively to the directions of the length of the strip and of its width (standard breadth). If it is a question of a square panel, the longitudinal and transverse directions of the material correspond respectively to the directions of two adjacent sides of the panel.

In a variant, the insulation holes of a resistive zone are disposed in staggered manner. They are, for example, aligned in a longitudinal direction of the material and offset in a transverse direction of said material, or, conversely, aligned in the transverse direction and offset in the longitudinal direction.

These two distributions not only impart good mechanical strength to the perforated batt but also optimise, in unexplained manner, the results thereof in terms of thermal insulation. It should be noted that one and the same batt may exhibit resistive zones having different distributions.

Advantageously, and according to the invention, the resistive zone(s) forms/form one or more bands in the perforated bats, in particular one or more longitudinal bands extending mainly longitudinally, preferably over the entire length of the material, or alternatively one or more transverse bands extending mainly transversely, possibly over the entire length of the material, or alternatively rectangular bands that are separated, at the same time, by longitudinal solid bands and by transverse solid bands (a solid band being devoid of insulation holes).

In a preferred version of the invention, the material comprises a plurality of batts, and each of the batts of the material is perforated in accordance with the invention. A material comprising at least one perforated bats, as well as one or more other non-perforated interposed layers, such as known prior layers, is also in accordance with the invention. If the material comprises a plurality of perforated batts according to the invention, said batts may be all identical or, conversely, may exhibit different characteristics (nature and thickness of the bats, shape, size and distribution of the insulation holes, etc.).

The material according to the invention preferably exhibits a total thickness of less than 10 cm, in particular less than 5 cm (it advantageously numbers four to six bates, which are preferably perforated) .

Advantageously, and according to the invention, each perforated batt is a wadding or a felt or a flannelette consisting of a non-woven fibrous material (thermobonded and/or needled and/or adhesion-bonded) produced from a material chosen from among the synthetic materials made of polyester, polyamide, chlorofibres, polyolefin (polyethylene, polypropylene, etc.), the artificial materials such as viscose rayon, the natural materials of vegetable origin, such as cotton, hemp, flax, the natural materials of animal origin, such as sheep's wool, mixtures of several of the materials previously cited. The fibres that are used may be solid or hollow (preferably hollow).

They are advantageously elastic.

The thermal-insulation material according to the invention preferably comprises at least two batts (in particular, two perforated batts) separated by a reflective supple film, a so-called intermediate film. Advantageously, and according to the invention, each intermediate film is made of a synthetic material chosen from among the polyolefins such as polyethylenes and polypropylenes, the polyesters such as polycarbonates, the polyethers, the polyurethanes, the polystyrenes, the vinyl polychlorides, mixtures of several of the materials cited previously. Each intermediate film advantageously exhibits at least one face that is covered by a reflective metallic facing, such as aluminium, by vacuum deposition or by lining or by coating. Such a face is hardly emissive and is reflective, bearing in mind the material constituting the film and the metallic facing thereof.

The thermal-insulation material according to the invention preferably comprises an exterior film, a so-called covering film, exhibiting an external face forming a front face of the material, which is preferably intended to be oriented towards the exterior of the building or of the part to be insulated. Advantageously, and according to the invention, said covering film is impervious to water and permeable to water vapour and exhibits a rupture strength greater than 150 N. It is preferably a question of a nonwoven, produced from a material chosen from among the polypropylenes, the polyesters, viscose rayon, mixtures of several of the aforementioned materials. The external face of said nonwoven is advantageously embossed and/or calendered and/or finished with a view to enhancing the mechanical strength and reinforcing the resistance of the film. Said film is, moreover, preferably covered by a reflective metallic facing, such as aluminium, by vacuum deposition or lining or coating, in such a manner as to exhibit elevated reflectivity (preferably whatever the incident radiation, its wavelength, its angle of incidence, the material constituting the film, etc.).

Such a covering film constitutes an impervious and resistant film, capable of protecting the material and the interior of a building against dust, rain, powder snow, etc. Said film therefore fulfills the functions of the films that are described as rain-cap roof-boarding screens.

Roof-boarding screens are known that are formed from a framework consisting of a batt which is coated on its two faces with a bitumen sprinkled with anti-adherent talc and which is possibly metallised on one face. Roof-boarding screens are also known that are formed from a reflective metallised film consisting of polyolefin, which is provided with a grille for mechanical reinforcement and which is coated with flame-retardant polymers. The known roof- boarding screens are intended for the protection of ventilated lofts or of closed lofts if they are microperforated (in order to be permeable to water vapour).

In a preferred version of the invention, the material therefore integrates a novel rain-cap roof-boarding screen and a novel multilayer insulator, the combination of which offers new advantages. Said combination imparts, in fact, a greater mechanical resistance to the roof- boarding screen and to the insulator at the same time, facilitates the laying of the insulator (the mechanical strength of which is enhanced by the presence of the screen), reduces considerably the laying-time and the corresponding costs, since a single product is laid offering imperviousness and insulation atthe same time, instead of two previously, etc. The thermal-insulation material according to the invention preferably comprises, moreover, an exterior film, a so- called finishing film, exhibiting an external face forming a front face of the material (a front face opposite that formed by the covering film) which is preferably intended to be oriented towards the interior of the building or of the part to be insulated. Advantageously, and according to the invention, said finishing film is similar or identical to the covering film. It is a question, in particular, of a nonwoven exhibiting a rupture strength greater than N. possibly impervious to water and permeable to water vapour, that is produced from a material chosen from among the polyesters, viscose rayon, the polyolefins and, in particular, the polypropylenes, mixtures of several of the aforementioned materials. The external face of said film is preferably covered by a reflective metallic facing.

Said face is advantageously embossed and/or calendered and/or finished, in order to impart a better rupture strength to the film. In a variant, the finishing film integrates a supple grille for mechanical reinforcement, such as a grille consisting of glass fibres, polyester fibres, polyamide fibres, etc., and exhibits an external face coated with a mechanical-reinforcement material chosen from among the polypropylenes. It should be noted that such a film may also be used by way of covering film.

Advantageously, and according to the invention, all the layers (film(s) and interposed layer(s)) of the material are fixed to one another by soldering or adhesion bonding at a restricted number of points, so-called coupling- points, which are isolated and distributed over the area of the material. It should be noted that the various layers of the insulator in the prior insulators are generally joined together by continuous stitching, producing thermal bridges over significant lengths, or are adhesion- bonded to one another over their entire surface, so that significant thermal exchanges between two adjacent layers appear by virtue of conduction. The various layers of the material according to the invention are, on the contrary, joined only at certain points, with a view to limiting the total surface over which they are in conductive contact, as well as the number of thermal bridges which are possibly generated by these contacts.

Advantageously, and according to the invention, the coupling-points are situated outside the insulation holes, in particular outside the resistive zones of each perforated batt (so that, at these coupling- points, the films remain separated by the insulating material constituting the batts).

The insulating material according to the invention takes the form of (supple) panels such as strips or approximately square pieces, so-called slabs. In all of the following, the expression "a panel of material" designates a piece of material exhibiting, when it is laid on an approximately plane surface, a smaller dimension orthogonal to said surface corresponding to a total thickness of the material, and more significant dimensions in a plane parallel to this surface, which delimit two front faces opposite the panel having any shape. The peripheral contour of a panel or of a layer of the panel (such as a film, a bats, or alternatively a series of films and batts) corresponds to the peripheral contour of a section of said panel or of said layer through a plane parallel to this surface, a so- called frontal plane of the panel or of the layer.

All the layers of a panel, with the exception of the covering film, exhibit approximately identical dimensions in frontal planes and form a multi-component thickness, a so-called insulating thickness. Advantageously, and according to the invention, the material exhibits, furthermore, a covering film which projects from this insulating thickness along at least one nominal portion of the peripheral contour of said insulating thickness in such a way as to form at least one overlapping band of an adjacent panel.

The invention extends to a process for laying panels of material according to the invention opposite a surface to be insulated, characterized in that the panels of material, which are fixed to a support, are laid opposite said surface, so that each panel forms, with each panel adjacent to it, a covered junction of an overlapping band, along which junction the insulating thicknesses of said (adjacent) panels are juxtaposed, edge to edge, in order to form an approximately continuous insulating area.

Each overlapping band of a panel therefore comes to cover a portion (which is, by definition, of the same width as the band) of the covering film and of the insulating thickness of an adjacent panel. Advantageously, and according to the invention, each overlapping band of each panel is adhesion- bonded to the covering film of the adjacent panel which it partially covers. This operation may be realised by means of an adhesive film, such as an adhesive tape in the form of a roll, which is adhesion-bonded in straddling manner to the overlapping band and to the covering film of the adjacent panel. In a variant, the internal face of the overlapping band, which is intended to be applied to the covering film of the adjacent panel, is provided with a protected adhesive covering until such time as the panels are laid, by virtue of a detachable foil. In a variant, a double-faced adhesive tape is utilised which is adhesionbonded, on the one hand, to the internal face of the overlapping band and, on the other hand, to the covering film of the adjacent panel.

The presence of overlapping bands which are arranged in the covering film of the panels of material according to the invention permits satisfactory thermal-insulation performance to be preserved at the junctions of the panels, without it being necessary to provide a superposition of the panels at said junctions (which creates an undesirable excessive thickness). If the covering film creates a roof- boarding screen that is impervious to run-off water and to powder snow, the junction will also be impervious to run- off water and to powder snow, and the material will be preserved.

It should be noted that the expression "laying the panels opposite a surface to be insulated" employed above means either that said panels are applied against said surface, in which case the "support" to which the panels are fixed refers to the surface itself, or that the panels are laid out at a distance from the surface, approximately parallel to the latter, in which case the "support" comprises, for example, rafters and/or battens (the surface being that defined by the covering of a roof, for example) and/or cleats or lugs or other crosspieces consisting of plastic (for a surface such as a ceiling, a wall, etc.) etc. Furthermore, the expression "nominal portion" which was employed above makes reference to a portion of the peripheral contour of the insulating thickness of the panel that is adapted in such a way that, once the panels of the material have been laid in accordance with the invention, all the junctions between panels are normally (except for possible exceptions due to the geometry of the surface to be insulated) covered by overlapping bands.

In a first version of the invention, the panels take the form of strips (that is to say, bands of great length), and the covering film projects from the insulating thickness along a longitudinal lateral straight edge of said insulating thickness, a so-called overlapping edge, in such a way as to form a longitudinal lateral straight overlapping band. The longitudinal lateral straight edge of the insulating thickness, opposite the overlapping edge, is the so-called simple edge. In other words, the nominal portion, as previously defined, of peripheral contour of a strip of material corresponds to a longitudinal lateral edge of the strip.

In a second version of the invention, the panels take the form of slabs, and the covering film projects from the insulating thickness along two lateral straight edges, so- called overlapping edges, which are contiguous with or opposite said insulating thickness, in such a way as to form two contiguous or opposite lateral straight overlapping bands. The other two lateral straight edges of the insulating thickness are the so-called simple edges.

In other words, the nominal portion, as previously defined, of peripheral contour of a slab of material corresponds to two lateral edges of the slab.

In order to lay a strip or a slab, a so-called second panel, adjacent to a strip or a slab, a so-called first panel, which has already been laid and fixed to the support and which exhibits a free simple edge, an overlapping edge of the second panel is juxtaposed with the free simple edge of the first panel so that the overlapping band of said overlapping edge of the second panel comes to cover a portion of covering film and of insulating thickness of the first panel, starting form said simple edge. The second panel is then fixed to the support.

In order to lay a strip or a slab, a so-called second panel, adjacent to a strip or a slab, a so-called first panel, which has already been laid and fixed to the support and which exhibits a free overlapping edge, a simple edge of the second panel is inserted beneath the overlapping band of the free overlapping edge of the first panel in such a way as to juxtapose said simple edge of the second panel with said overlapping edge of the first panel, so that said overlapping band of the first panel comes to cover a portion of covering film and insulating thickness of the second panel, starting form said simple edge. The second panel is then fixed to the support.

The invention also concerns an insulating material that is characterized by all or some of the characteristics mentioned heretofore and hereinafter in combination.

Other aims, characteristics and advantages of the invention will become evident from the following description, which refers to the attached Figures representing preferential embodiments of the invention, which are given solely by way of non-limiting examples and in which: - Figure 1 is a perspective view of a strip of material according to the invention, a medial longitudinal band of which has been cut, and portions of which have been "pulled out" with a view to revealing certain layers (bats or film) of the material, - Figure 2 is a schematic top view of a portion of a perforated batt according to the invention.

The supple/material according to the invention which is represented in Figure 1 takes the form of a strip with a width of 1500 mm and a length of some tens of metres. In all of the following, the term "length" designates a dimension of an element in a longitudinal direction of the strip, and The term "width" designates a dimension of the element inn direction known as the transverse direction, which is orthogonal to said longitudinal direction and contained in a frontal plane of the strip. The strip is provided rolled up or folded, crumpled, when it is transported, and is unfurled as illustrated in Figure 1 when it is laid for the purposes of insulation.

The material comprises a succession of films and perforated batts, namely: a reflective covering film 1, a perforated bath 2, a reflective intermediate film 3, a perforated batt 4, a reflective intermediate film 5, a perforated batt 6, a reflective intermediate film 7, a perforated batt 8, a reflective intermediate film 9, a perforated bate 10, a reflective finishing film 11. The external face 12 of the covering film 1 constitutes a front face of the material, which is preferably intended to be oriented towards the exterior of the building to be insulated, the external face 14 of the finishing film 11 constituting the opposite front face of the material, which is preferably intended to be oriented towards the interior of the building.

Each intermediate film 9, 7 is made of polyether (in particular, polyester) and exhibits a thickness of the order of hundredths or tenths of a millimetre. Its faces 18, 19 are metallised, by vacuum deposition of aluminium for example, and therefore possess elevated reflectivity.

It should be noted that it is sufficient for a single face 18 or 19 to be metallised, in order to obtain the desired insulating effect, in summer as well as in winter (that is to say, whatever the side where the warm environment is situated).

The covering film 1 and the finishing film 11 are nonwovens consisting of polypropylene or polyether, having a mass per unit area of the order of 90 g/m2. The external face 12, 14 of said films is embossed over its entire surface (the embossing being represented only in places) and metallised by vacuum deposition of aluminium. The internal face 13, of each of these films preferably has no coating (outside the portion of internal face of the covering film 1 corresponding to the overlapping band 20, which may be covered by an adhesive coating); its emissivity varies, according to the polymer that has been chosen in order to produce the film, but remains very low. Such covering films and finishing films are impervious to run-off water and to powder snow, and are permeable to water vapour.

They both create rain-cap roof-boarding screens that are particularly resistant to tearing and to puncture.

The width of the covering film 1 is greater than that of the insulating thickness 35 formed by the other layers of the strip (baits, intermediate films and finishing film), and preferably measures 1600 mm. The covering film 1 therefore forms an overlapping band 20 with a width of 100 mm, along and projecting from a longitudinal lateral edge 21 of said insulating thickness 35.

Each batt 2, 4, 6, 8, 10 is pierced by insulation holes 17 which are evenly distributed over three resistive zones 24 (illustrated in Figure 2) in the form of continuous longitudinal bands, between which there extend solid (that is to say, free from insulation holes) longitudinal bands, also continuous, which are intended to receive the coupling-po-nts of the multilayer material. Such resistive zones in the form of continuous bands may easily be produced on a batt in strip- form moving past in its longitudinal direction, by means of simple cutting tools operating continuously (for example, a rotating cylinder fitted withcutting blades, and a counter-cylinder).

It should be noted that, in Figure 2, only a few insulation holes of a (central) resistive zone are represented. It will readily be understood that said zone is entirely pierced by insulation holes, and that this is also the case with the two other resistive zones 24 which are each delimited by a dashed line.

Each resistive zone 24 extends over a width of 400 mm and over the entire length of the strip of material. The distance (in the transverse direction) between each of the edges 21, 22 and the nearest resistive zone 24 is of the order of 100 mm. The distance separating two resistive zones in the transverse direction is also of the order of 100 mm.

In the example illustrated, each insulation hole is circular and exhibits a diameter of the order of 20 mm.

The distance in the transverse direction between two successive insulation holes is of the order of 10 mm. The transverse rows of insulation holes are realised in staggered manner: the holes of two successive transverse rows are not opposite in the longitudinal direction.

Each perforated batt has a thickness, at rest (that is to say, without any pressure exerted on either side of the bats), of the order of 8 mm. It should be noted that, in Figure 1, the ratio of the diameter of the insulation holes to the thickness of the batt has not been observed. The batts are preferably textile waddings made of polyester, having a mass per unit area between 80 g/m2 and 120 g/m2.

The various films and batts are fixed to one another by ultrasonic soldering at a few coupling-points 25, 26 which are distributed over the area of the strip outside the resistive zones 24. The coupling-points 25, which are situated in the two lateral solid longitudinal bands 27, 28, are the so-called lateral coupling-points; the coupling-points 26, which are situated in the two central solid longitudinal bands 29, 30, are the so-called central coupling-points. The lateral coupling-points 25 are realised in the middle of the lateral solid bands 27, 28, that is to say, 50 mm away from the edges 21, 22. In similar manner, the central coupling-points 26 are realised in the middle of the central solid bands 29, 30, that is to say, 50 mm away from each of the neighbouring resistive zones 24. The distance separating two lateral coupling- points 25 in the longitudinal direction is of the order of 200 mm. The distance separating two central coupling- points 26 in the longitudinal direction is of the order of 400 mm. The two rows of lateral coupling-points 25 are realised in such a way that said lateral points 25 are aligned in the transverse direction. The two rows of central coupling-points 26 are realised in such a way that said central points 26 are staggered (that is to say, not aligned) in the transverse direction, and in such a way that they are also staggered - in the transverse direction - with the lateral coupling-points 25.

At each coupling-point the thickness of the material is of the order of a few millimetres, on account of the compressionof the batts by the soldering. At a distance from the aeupling-points the thickness of the material varies, at-rest (that is to say, when the material is laid unstretched on a plane surface and is not subjected to any pressure force) , between 40 mm and 60 mm. These values are greater than the sum of the thicknesses of all the layers (films and.batts) constituting the material. In fact, as they are not adhesion-bonded to one another, two successive layers touch only in zones of small dimension around the coupling-points. At a distance from said coupling-points, when the material is at rest, the two successive layers are separated by a more or less thick air space which contributes to the thermal-insulation performance of the material. In the course of laying of the material, it is advisable not to stretch the material in forced manner, so as to fix it in a state that is as close as possible to its state of rest, and in this way to preserve air spaces between the various layers of the material. It should be noted that, in the stretched state (that is to say, when tensile forces are exerted on either side of the strip in the transverse and/or longitudinal directions), the material exhibits a thickness which is capable of varying from 20 mm to 40 mm, and thermal-insulation properties which remain entirely satisfactory and prove to be better than those of the prior materials.

The external face 12 of the covering film 1 is preferably orientated towards the exterior of the building in all applications in which the material is liable to be subjected to accidental run-offs of rainwater or of slush.

In this way, the overlapping bands 20 prevent the run-off water from infiltrating into the junctions between strips, and protect not only the interior of the building but also the insulating thickness 35 of the material.

In any case, the strips of material according to the invention are normally laid in such a way that the external face of the covering film are oriented towards the person who is laying the material, in order to facilitate the operation of adhesion bonding each overlapping band to the covering film of the adjacent strip. When the strips are laid on rafters or on laths, the covering film 1 is therefore advantageously oriented towards the exterior of the building. It should be noted that, for the insulation of a roof or of a vertical partition wall, the strips may be arranged vertically or horizontally.

The first strip is laid in the customary manner and is evenly stapled to the support (laths, rafters, dormer- window trusses, cleats, floor, etc.). If need be, the longitudinal extremities of the strip are cut with the aid of a conventional cutter. The following strip, the so- called second strip, is laid in such a way that its overlapping edge 21 comes into contact with the simple edge (such as 22) of the first strip, and in such a way that its overlapping band 20 covers the covering film (such as 1) of the first strip. In a variant, the second strip is laid in such a way that its simple edge 22 comes into contact with the overlapping edge (such as 21) of the first strip, and in such a way that the overlapping band (such as 20) of the first strip covers its covering film 1. The second strip is then evenly stapled to the support against which it is applied. The overlapping band 20 of the second strip (or, in a variant, of the first strip) is then adhesion-bonded to the first strip (respectively, the second strip). To this end, the internal face 13 of the covering film 1 is coated with an adhesive coating in the region of the overlapping band 20 (and solely in this zone), protected by a detachable foil. Once the second strip has been stapled, the foil is removed and the overlapping band of the second strip (or of the first) is laid against the front face of the first strip (respectively, of the second strip). It should be.n-oted that, bearing in mind the suppleness of the covering film 1, the overlapping band 20 of a strip is easily folded over with a view to adjusting the relative position of the corresponding overlapping edge and of the simple edge of the adjacent strip, or with a view to detaching the foil protecting the adhesive coating of said band.

It goes without saying that the invention may be the subject of numerous variants in relation to the embodiments described previously and represented in the Figures. In particular, the number of batts and films of the material is not limited to that of the embodiment illustrated. The invention extends notably to the particular case of a material constituted by a single perforated batt covered on each side by a reflective film, or even covered on one side only by such a film. It should be noted, however, that the superposition of several reflective films permits the exchanges between two environments by radiation to be reduced in more effective manner.

The invention also extends to the case of a material comprising one or more interposed layers of any type (bubble films, batts consisting of foam or of fibrous material, etc.), as long as one at least of these interposed layers is a perforated batt as previously defined.

Furthermore, the invention is not limited to a thin material (of thickness less than 10 cm). Said invention may be applied to a thicker material, although the thin materials are preferred for their slight bulkiness.

On the other hand, the materials cited in the description for creating the films and batts are given by way of non-

limiting examples.

The shape, number and arrangement of the resistive zones and of the insulation holes of a perforated batt are not limited to those of the embodiment illustrated in Figure 2.

However, according to the invention the insulation holes are devoid of sharp corners, which excludes polygons. The dimensions of each insulation hole are, moreover, adapted so that the films facing one another do not touch across the hole under normal conditions of utilization and use of the material.

In particular, the insulation holes may exhibit a cross section that is elliptical, oblong or of more complex shape. The perimeter of the hole may possibly exhibit one or more rectilinear portions, which, however, may not be consecutive (these portions are separated by curved portions in such a way as not to form any sharp corner).

Furthermore, the successive transverse rows of insulation holes may be aligned in the longitudinal direction, with a view to simplifying the production thereof. Transverse bands of solid batt may, in addition, be provided between successive resistive zones in the longitudinal direction.

Consistory Clauses In one aspect, the present invention provides a flexible thermal-insulation material comprising at least one batt and at least one flexible film, which are superposed, characterized in that said material comprises at least one flexible perforated bats, wherein the batt is: À covered on at least one side by the flexible film, the film exhibiting at least one face that is reflective, barely emissive, or both; À provided with at least one insulation aperture, the aperture extending through the batt from the at least one covered side of the batt to the other side; the aperture containing a volume of gas which normally comes into contact with a portion of film covering the insulation aperture, each insulation aperture having a frontal cross-section devoid of sharp corners.

Preferably, the perforated batt comprises at least one resistive zone of greater thermal resistance, in which there are arranged insulation apertures defining a total area of opening greater than half of the area of the resistive zone, the totality of said resistive zones extending over more than half of the area of the perforated bats.

More preferably, the perforated batt is made of a non- woven, thermobonded and/or needled and/or adhesion-bonded fibrous material.

It is also preferred that the perforated batt exhibits insulation apertures of circular cross-section or oval or elliptical cross-section.

It is preferred that the dimensions of each insulation aperture, the thickness of the perforated batt and the flexibility of each film that covers it are adapted so as to avoid any untimely contact, across said aperture, between the reflective film and a film or a partition wall opposite the other side of the perforated bats.

Preferably, each insulation aperture exhibits a maximal dimension less than ten times the thickness of the perforated bats.

The perforated batt preferably exhibits a thickness between 1 mm and 12 mm, and in that each insulation aperture exhibits a maximal dimension between 10 mm and mm.

Preferably, the insulation apertures of a resistive zone are aligned in a longitudinal direction and in a transverse direction of the material. It is also preferred that the insulation apertures of a resistive zone are arranged in staggered manner.

Preferably, the resistive zone or zones forms one or more longitudinal.or transverse bands in the perforated bats.

The total thickness of the material is preferably less than 10 cm.

It is preferred that each perforated batt is covered on each side byea reflective flexible film.

Preferably, each perforated batt is a wadding or a felt or a flannelette consisting of a non-woven fibrous material that is produced from a material chosen from among the synthetic materials made of polyester, polyamide, chlorofibres, polyolefin, the artificial materials such as viscose rayon, the natural materials of vegetable origin, such as cotton, hemp, flax, the natural materials of animal origin, such as sheep's wool, mixtures of several of the aforementioned materials.

It is preferred that the material comprises a covering film exhibiting an external face forming a front face of the material, and in that said covering film is impervious to water and permeable to water vapour, and exhibits a rupture strength greater than 150 N. Preferably, the covering film is a non-woven produced from a material chosen from among the polypropylenes, the polyesters, viscose rayon, mixtures of several of the aforementioned materials, and in that its external face is embossed and/or calendered and/or finished and is covered by a reflective metallic facing.

It is preferred that the material is formed from layers which are fixed to one another by soldering or by adhesion bonding at a restricted number of coupling- points which are isolated and distributed over the area of the material.

Preferably, the coupling-points are situated outside the resistive zones of each perforated bats.

It is also preferred that the material is formed from layers which, with the exception of a covering film, exhibit approximately identical dimensions in frontal planes and form a multi-component insulatingthickness and in that the covering film projects from the insulating thickness along at least one nominal portion of the peripheral contour of said insulating thickness in such a manner as to form at least one overlapping band of an adjacent panel.

Preferably, the covering film projects from the insulating thickness along a longitudinal lateral straight overlapping edge of said insulating thickness, in such a manner as to form a longitudinal lateral straight overlapping band.

More preferably the covering film projects from the insulating thickness along two lateral straight overlapping edges, which are contiguous with or opposite said insulating thickness, in such a way as to form two contiguous or opposite lateral straight overlapping bands.

In another aspect, the present invention provides A supple thermalinsulation material comprising at least one supple batt (10) and at least one supple film (9), which are superposed, characterized in that said material comprises at least one supple batt (10), a so-called perforated tats, that is À covered Ion one side at least by a supple film (9), a so-called reflective film, exhibiting a face that is, attache same time, reflective and hardly emissive, and/or two hardly emissive faces, and/or two reflective faces, À and provided with at least one through-hole (17), a so-called insulation hole, containing a volume of gas which normally comes into contact with each portion of film opposite the insulation hole, each insulation hole (17) having a frontal cross-section devoid of sharp corners.

Preferably, the perforated batt (10) comprises at least one zone (24), a so-called resistive zone, of greater thermal resistance, in which there are arranged insulation holes (17) defining a total area of opening greater than half of the area of the resistive zone, the totality of said resistive zones extending over more than half of the area of the perforated bats.

More preferably, the perforated batt exhibits insulation holes (17) of circular cross-section.

Even more preferably, the perforated batt exhibits insulation holes of oval or elliptical cross-section.

It is also preferred that the dimensions of each insulation hole (17), the thickness of the perforated batt (10) and the suppleness of each film (9, 11) that covers it are adapted so as to avoid any untimely contact, across said hole, between the reflective film (9) and a film (11) or a partition wall opposite the other side of the perforated bats.

It is preferred that each insulation hole (17) exhibits a maximal dimension less than ten times the thickness of the perforated batt (10).

Preferably, the perforated batt (10) exhibits a thickness between 1 mm and 12 mm, and in that each insulation hole exhibits a maximal dimension between 10 mm and 30 mm.

More preferably, the insulation holes of a resistive zone are aligned in a longitudinal direction and in a transverse direction of the material.

More preferably, the insulation holes (17) of a resistive zone (24) are arranged in staggered manner.

Furthermore, it is also preferred that the resistive zone(s) forms/form one or more longitudinal or transverse bands in the perforated bats.

The material preferably exhibits a total thickness of less than 10 cm.

It is preferred that each perforated batt (2, 4, 6, 8, 10) is covered on each side by a reflective supple film (1, 3, 5, 7, 9, 11).

Preferably, -teach perforated batt (2, 4, 6, 8, 10) is a wadding or a felt or a flannelette consisting of a non- woven fibrous material that is produced from a material chosen from among the synthetic materials made of polyester,tpolyamide, chlorofibres, polyolefin, the artificia lmaterials such as viscose rayon, the natural 38; materials of vegetable origin, such as cotton, hemp, I flax, the natural materials of animal origin, such as sheep's wool, mixtures of several of the aforementioned materials.

It is also preferred that the material comprises a film (1), a so-called covering film, exhibiting an external face (12) forming a front face of the material, and in that said covering film (1) is impervious to water and permeable to water vapour, and exhibits a rupture strength greater than 150 N. Preferably, the covering film is a non-woven produced from a material chosen from among the polypropylenes, the polyesters, viscose rayon, mixtures of several of the aforementioned materials, and in that its external face (12) is embossed and/or calendered and/or finished and is covered by a reflective metallic facing.

It is preferred that the material is formed from layers (1, 3, 5, 7, 9, 11; 2, 4, 6, 8, 10) which are fixed to one another by soldering or by adhesion bonding at a restricted number of points (25, 26), so-called coupling- points, which are isolated and distributed over the area of the material.

Preferably, the coupling-points (25, 26) are situated outside the resistive zones (24) of each perforated bats.

Furthermore, it is also preferred that the material is! formed from layers (1, 3, 5, 7, 9, 11; 2, 4, 6, 8, 10) which, with the exception of a film (1), a so-called covering film, exhibit approximately identical dimensions in frontal planes and form a multi-component insulating l9 3' thickness (35) and in that the covering film (1) projects I from the insulating thickness (35) along at least one nominal portion of the peripheral contour of said insulating thickness in such a manner as to form at least one overlapping band (20) of an adjacent panel.

Preferably, the covering film (1) projects from the insulating thickness (35) along a longitudinal lateral straight edge (21) of said insulating thickness, a so-called overlapping edge, in such a manner as to form a longitudinal lateral straight overlapping band (20).

More preferably, the covering film projects from the insulating thickness along two lateral straight edges, so-called overlapping edges, which are contiguous with or opposite said insulating thickness, in such a way as to form two contiguous or opposite lateral straight overlapping bands.

The terms insulation aperture referred to herein may be any hole, as discussed above, or bore, gap, chasm, cleft, or tunnel that preferably passes from one side of the batt to the other, although it is also envisaged that this need not necessarily be the case, as the aperture may extend from one side of the batt into the body of the bats, but net pass all the way to the other side of the bats.

Claims

1. A flexible thermal-insulation material comprising at least one batt and at least one flexible film, which are superposed, characterized in that said material comprises at least one flexible perforated bats, wherein the batt is: À covered on at least one side by the flexible film, the film exhibiting at least one face that is reflective, barely emissive, or both; À provided with at least one insulation aperture, the aperture extending through the batt from the at least one covered side of the batt to the other side; the aperture containing a volume of gas which normally comes into contact with a portion of film covering the insulation aperture, each insulation aperture having a frontal cross- section devoid of sharp corners.

2. A material according to Claim 1, characterized in that the perforated batt comprises at least one resistive zone of greater thermal resistance, in which there are arranged insulation apertures defining a total area of opening greater than half of the area of the resistive zone, the totality of said resistive zones extending over more than half of the area of the perforated bats.

3. A material according to one of Claims 1 or 2, characterized in that the perforated batt is made of a non woven, thermobonded and/or needled and/or adhesion-bonded fibrous material.

4. A material according to one of Claims 1 to 3, characterized in that the perforated batt exhibits insulation apertures of circular cross- section.

5. A material according to one of Claims 1 to 4, characterized in that the perforated batt exhibits insulation apertures of oval or elliptical cross-section.

6. A material according to one of Claims 1 to 5, characterized in that the dimensions of each insulation aperture, the thickness of the perforated batt and the flexibility of each film that covers it are adapted so as to avoid any untimely contact, across said aperture, between the reflective film and a film or a partition wall opposite the other side of the perforated bats.

7. A material according to one of Claims 1 to 6, characterized in that each insulation aperture exhibits a maximal dimension less than ten times the thickness of the perforated bats.

8. A material according to one of Claims 1 to 7, characterized in that the perforated batt exhibits a thickness between 1 mm and 12 mm, and in that each insulation aperture exhibits a maximal dimension between 10 mm and 30 mm.

9. A material according to one of Claims 2 to 8, characterized in that the insulation apertures of a resistive zone are aligned in a longitudinal direction and in a transverse direction of the material.

10. A material according to one of Claims 2 to 8, characterized in that the insulation apertures of a resistive zone are arranged in staggered manner.

11. A material according to one of Claims 2 to 10, characterized in that the resistive zone or zones forms one or more longitudinal or transverse bands in the perforated bats.

12. A material according to one of Claims 1 to 11, characterized in that it exhibits a total thickness of less than 10 cm.

13. A material according to one of Claims 1 to 12, characterized in that each perforated batt is covered on each side by a reflective flexible film.

14. A material according to one of Claims 1 to 13, characterized in that each perforated batt is a wadding or a felt or a flannelette consisting of a non-woven fibrous material that is produced from a material chosen from among the synthetic materials made of polyester, polyamide, chlorofibres, polyolefin, the artificial materials such as viscose rayon, the natural materials of vegetable origin, such as cotton, hemp, flax, the natural materials of animal origin, such as sheep's wool, mixtures of several of the aforementioned materials.

15. A material according to one of Claims 1 to 14, characterized in that it comprises a covering film exhibiting an external face forming a front face of the material, and in that said covering film is impervious to water and permeable to water vapour, and exhibits a rupture strength greater than 150 N.

16. A material according to Claim 15, characterized in that the covering film is a non-woven produced from a material chosen from among the polypropylenes, the polyesters, viscose rayon, mixtures of several of the aforementioned materials, and in that its external face is embossed and/or calendered and/or finished and is covered by a reflective metallic facing.

17. A material according to one of Claims 1 to 16, characterized in that it is formed from layers which are fixed to one another by soldering or by adhesion bonding at a restricted number of coupling-points which are isolated and distributed over the area of the material.

18. A material according to Claim 17, characterized in that the couplingpoints are situated outside the resistive zones of each perforated bats.

19. A material according to one of Claims 1 to 18, taking the form of panels, characterized in that it is formed from layers which, with the exception of a covering film, exhibit approximately identical dimensions in frontal planes and form a multi-component insulating thickness and in that the covering film projects from the insulating thickness along at least one nominal portion of the peripheral contour of said insulating thickness in such a manner as to form at least one overlapping band of an adjacent panel.

44 1

20. A material in strip-form according to Claim 19, characterized in that the covering film projects from the insulating thickness along a longitudinal lateral straight overlapping edge of said insulating thickness, in such a manner as to form a longitudinal lateral straight overlapping band.

21. A material in slab-form according to Claim 20, : characterized in that the covering film projects from the insulating thickness along two lateral straight overlapping edges, which are contiguous with or opposite said insulating thickness, in such a way as to form two contiguous or opposite lateral straight overlapping bands.

22. A material as substantially described herein, with I reference to the accompanying description and/or figures.