FR2813927A1 - PLASTIC INSULATING MULTILAYER PANEL - Google Patents

Abstract

The invention concerns an insulating multilayer panel comprising an expanded plastic material layer arranged between two unexpanded plastic material layers, characterised in that it comprises an integrated system for assembling in at least two spatial dimensions said panel and at least another matching panel.

Description

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The invention relates to insulating multilayer panels essentially made of plastic. The invention also relates to a manufacturing method for such panels and their use.

Many sectors of economic activity need insulating panels produced at low cost. For example, in the building and civil engineering sectors, the thermal insulation properties of panels used on the roof or for various partitions is essential. The same is true in the transport, refrigeration, etc. sectors. It is known practice to use multilayer panels for these applications, one layer of which provides thermal insulation. One or more other layers ensure the mechanical strength of the assembly and possibly make it possible to adapt its external appearance.

In many circumstances (near highways, airports, noisy machines, ...) sound insulation properties in addition to thermal insulation properties are sought.

US Patent US 5,842,315 describes a three-layer panel, the upper layer of which is made of plastic or metal is corrugated, the lower layer consists of a PVC film and the central layer is of injected polyurethane foam. The upper layer of these panels is extended beyond the foam layer to allow overlapping of the junction of different panels between them. During assembly, such panels are in fact simply juxtaposed. They must therefore be fixed to a supporting structure, using screws, bolts or nails which perforate the panel. This type of mounting has many disadvantages: risk of corrosion, handling necessary for their fixing, loss of tightness following the perforation of the panels, loss of insulating power following thermal bridges constituted by nails or bolts. In addition, due to mounting imperfections, there is a risk that the foam layers of adjoining panels are not perfectly contiguous. The insulation properties of the panels will then be greatly reduced.

The present invention aims to remedy these drawbacks by providing inexpensive multilayer insulating panels, suitable for many varied uses and provided with a reliable, fast and simple assembly system.

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 Consequently, the invention relates to a multilayer insulating panel comprising a layer of expanded plastic material located between two layers of unexpanded plastic material and comprising an integrated system making it possible to assemble said panel in at least two dimensions of space. minus one additional panel.

The multilayer panels according to the present invention are essentially planar. The word essentially refers in particular to the case where the panels have a surface relief. According to the embodiments, the panels will possibly have a certain flexibility which will make it possible to bend them when they are used.

 By expanded plastic is meant a plastic whose density has been reduced by the addition of additives known as foaming agents. Such additives are well known in the plastics industry. They can be of various types often grouped into two families: chemical foaming agents and physical foaming agents. You can also mix them. Information can be found on this subject in numerous technical works. The density reductions vary greatly depending on the foaming agent and the amount used. In the invention, by expanded plastic is meant a plastic whose density has been reduced by more than 5%, or even more than 10%, compared to its value without foaming agents, for identical pressure and temperature conditions. .

By unexpanded plastic is meant a plastic whose density is close to its value without foaming agents, for identical pressure and temperature conditions. It may or may not contain foaming agents. If it does, it must be in small quantities or the action of the foaming agent must have been prevented, for example by applying pressure. In the invention, by unexpanded plastic material means a plastic material whose density has been reduced by less than 5%, possibly less than 10%, compared to its value without foaming agents and for pressure and temperature conditions identical.

In the multilayer panels according to the invention, the transition between the expanded layer and the unexpanded layer can be very abrupt, that is to say that one passes directly from the density of the expanded material to that of the material unexpanded. It can also, depending on the technique used to produce the panels, be more progressive and present an area of intermediate density. This will often be the case if the unexpanded layers and the layer

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 foam are made of the same material, the expansion of the material having been able to occur, following the conditions of implementation, only in the expanded layer.

Depending on the case, an adhesive may be necessary to ensure adhesion between the different layers of the panel. It may constitute a separate layer between the expanded and unexpanded layers or else be an integral part of the latter. The unexpanded layers may or may not be reinforced by any well-known technique (for example fibers or fabrics of glass, polyester, etc.). They may include any type of additives well known in plastics to improve certain properties (such as impact resistance, fire resistance, etc.). They may also have undergone a surface treatment or even have been coated or covered with outer layers, for example protective thin layers, in particular protections against solar radiation. These thin layers may also have a decorative purpose.

According to the invention, the panels include an assembly system. This system is integrated into the panel. By this is meant that the component parts of the system are already part of the panel before it is attached to other panels. It is therefore not necessary to have additional separate parts. The assembly can therefore be done quickly and simply. Often, the assembly system will consist of two complementary parts, for example one of the male type and one of the female type. In general, the panels will be provided with this system on two of their opposite ends, each end carrying one of the two complementary parts. The complementary panels will therefore generally be similar. However, for certain applications it may prove useful to produce exceptional complementary panels having only one of the two parts on only one or two of their ends. Some panels may even include complementary parts of the assembly system on more than two of their ends. The additional panels may also be corner, edge, connection panels, etc. For the sake of simplicity, it will be understood below that reference is made to a panel carrying two complementary parts of the assembly system, and this on two of their opposite ends.

The assembly techniques can be very diverse. The panels can be pre-coated with glues or various adhesives, special attachment systems can be used such as for example those known under the

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 trademark VELCRO. Many other known mechanical assembly systems can be used.

The panels will be assembled in two or three dimensions of space. The word dimension is understood here in the geometric sense of directions perpendicular two by two: a plane has two dimensions and space has 3 dimensions. When the panels are assembled in two dimensions, these dimensions may be the two dimensions of the plane of the panels or a dimension in the plane of the panels and the dimension perpendicular to the panels. Preferably, this will be the dimension perpendicular to the panel and the dimension perpendicular to the assembly system. The panels will then be assembled in such a way that they cannot be separated from one another or lifted relative to each other in the dimension perpendicular to the plane of the panels.

The integrated assembly system can be made for example of metal (aluminum, in particular), of plastic material, etc. Plastics are preferred. Indeed, given the low thermal conductivity of these materials, thermal bridges are avoided. It is indeed well known in the field of thermal insulation that even a small element of the structure whose thermal conductivity is high can deteriorate the insulation properties of the entire structure. Preferably, the integrated assembly system consists of profiles. The concept of profile is well known in the art (parts defined geometrically by the translation of a two-dimensional contour). However, according to the invention, the profiles may possibly also include additional periodic patterns, such as notches or protuberances formed at regular intervals on the profile. The profile may consist of a part produced separately from the other elements of the panel and assembled during the manufacture of the latter. It can also consist of the ends of the layers of unexpanded material.

In an advantageous embodiment of the invention, the profiles have a grooved or ribbed shape provided with a self-locking cam. One end of the panel will be provided with the rib (male side) while its opposite end will be provided with a groove (female side). The penetration of the rib in the groove assembles the panels in the dimension which is perpendicular to them. The self-locking cam, on the other hand, prevents the panels from spreading when they are assembled.

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 In an alternative embodiment of the invention, the integrated system allows the said panel and at least one other complementary panel to be assembled in the three dimensions of the space. In the case where the assembly system consists of profiles provided with grooves, ribs and self-locking cams, the assembly will be obtained in the third dimension by providing the profiles with the additional periodic patterns mentioned above.

The integrated assembly system according to the invention makes it possible in most cases to avoid using additional fastening systems. However, it is possible to attach the panels additionally to an underlying supporting structure, for example a frame. To this end, locations may be provided in the assembly system for having there screws, nails or other well-known fixing device. Advantageously, these housings for additional fastenings will be arranged so as to be invisible after assembly of the panels together and to avoid thermal bridges. In a particular assembly of a set of panels, assembled according to the invention, one could for example fix some in this way. This will ensure the entire assembly exceptional stability, while greatly reducing the number of fasteners, compared to an assembly according to the prior art.

Many plastics are currently available to form foams: polyethylene, polypropylene, polyvinylidene fluoride, polyurethane. Polyurethane foam is preferred for its adhesion qualities on many supports (plastic materials, metals, wood, ...), its ease of implementation and its moderate cost. The layers of unexpanded material can be made of polyethylene, polypropylene or PVC, to cite only so-called convenience polymers. PVC is nevertheless preferred, given its widespread use, especially in the building sector, for which grades resistant to bad weather and solar radiation exist. Depending on the case, flexible or rigid PVC may be used. It is also very advantageous to combine these two materials, one non-expanded layer being made of flexible PVC, the other of rigid PVC. The use of flexible PVC as an outer layer (the layer which is subject to weathering) allows you to take advantage of the renovation possibilities offered by flexible PVC membranes. During a renovation, the entire panel should not be replaced. It will suffice to cover it by techniques well known for these products with a new layer of membrane.

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 The rigid PVC layer, placed on the inside of the panel, will ensure the rigidity of the panel.

It is also possible to provide the assembly system with seals.

In a preferred embodiment of the insulating multilayer panels according to the invention, the expanded plastic material is polyurethane and the two layers of unexpanded plastic material are made of flexible PVC and / or rigid PVC.

The two layers of unexpanded plastic material of the insulating panel according to the invention may have various reliefs. These reliefs can be the well-known undulations (rounded, of Greek form, etc.), or any periodic form which can be obtained by hot forming techniques. It is in fact known that such reliefs increase the overall rigidity of the panel. All combinations between these reliefs are possible for the two layers. One can thus combine by way of example two greca undulations or a greca undulation and a thermoformed relief. It is also possible to use layers whose outer face is flat and the inner face has a relief, for example ribbed, or even the opposite situation. Depending on the technique for producing the panel, it may be that the foam layer follows these various reliefs or that, on the contrary, it remains flat.

It is however advantageous that at least one of the two layers of unexpanded plastic material is planar. Indeed, thanks to the good performance of the assembly system according to the invention and thanks to the rigidity provided by the foam layer, a panel of which one of the layers of unexpanded material is planar will already be sufficiently rigid for many applications. All other things being equal, such a panel will require less material, will be lighter and simpler to produce, a forming operation being able to be avoided. It will also be easier to install.

In a particularly advantageous manner, the two layers of unexpanded plastic material will be flat.

In addition to the advantages mentioned above, such panels can be more easily bent, in order to obtain rounded shapes.

It should be noted that the concepts of relief, undulation, plane plastic layer which we are talking about here are understood at the centimeter scale and do not concern the surface condition of the materials. The surface condition also concerns reliefs but which have a smaller characteristic size.

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 The surface condition of a layer of flat plastic can therefore have reliefs intended to improve, for example, its adhesion to the foam or the adhesion of a finishing layer which would be applied to the panel. An example of such relief is the graining which is often given to plastic sheets and plates.

The invention also relates to a method for manufacturing a multilayer insulating panel according to the invention as defined above, according to which the layer of expanded plastic is injected.

The panels according to the invention can be produced by numerous techniques well known in the plastics industry. For example, when the assembly system consists of plastic profiles, the panel can be coextruded directly as a block, by means of a coextrusion die whose different segments are supplied with the different necessary materials (expanded, unexpanded , material for the profiles). However, in this case, the extrudate must be cut periodically at the outlet of the die. To obtain panels of very good finish, this step will be delicate.

According to the invention, the expanded plastic material is injected. If the panel is made of a single material, the well-known techniques of structured foams can be advantageously used. We will then find ourselves in the situation mentioned above, in which the interface between the expanded and unexpanded layers is of the progressive type. Several well-known implementation techniques are available in this context in order to release the action of the foaming agent present in the material only in the desired layer of the panel. We can also coinject the different layers of the panel.

If the layers of unexpanded material are produced separately, the method of manufacturing the panel according to the invention will advantageously include the following steps - two layers of unexpanded plastic are provided in a mold, leaving an interior space between them - injection is carried out expanded plastic in the interior space defined during the first operation - the panel is extracted from the mold.

In many cases, the injection of: foam will cause the different layers to adhere to each other. When the integrated assembly system is produced separately, it will be introduced into the mold together with the layers of unexpanded material. The interior space in which

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 the foam is injected will be that formed between the unexpanded layers on the one hand and the assembly system, arranged at the ends, on the other hand. This panel production technique is simple and quick.

The integrated system for assembling the panel according to the invention can be produced by any implementation technique (molding, overmolding, thermoforming, compression, extrusion, etc.). When it is made up of profiles, the system will advantageously be produced by extrusion. If the profiles are provided with additional periodic patterns, such as notches or protuberances provided at regular intervals, the extrusion die will be provided with a mobile device, actuated periodically.

It is however particularly advantageous for the assembly system of said panel to be produced by molding or thermoforming the ends of at least one of the two layers of unexpanded plastic. By thermoforming is meant any forming technique during which the material undergoes heating. The thermoforming of the assembly system may be carried out separately or else when the panel itself is made up. A panel produced in the latter way will be particularly economical.

 Finally, the invention also relates to the use of the insulating multilayer panel according to the invention as defined above, for the insulation of premises or parts of vehicles whose interior temperature is controlled.

The multilayer insulating panels according to the invention can be used for extremely varied applications, such as: production of refrigerated warehouses, cold rooms, storage of food products, construction of operating theaters for hospitals, production of vehicle cases for transport, insulation of swimming pools, construction of light and inexpensive housing, ....

The multilayer insulating panels according to the invention will advantageously be used for the insulation of premises or parts of vehicles whose interior temperature is controlled. The excellent thermal and sound insulation properties, the sealing, the corrosion resistance, the ease of assembly (and disassembly) and finally the economic nature of the panels according to the invention allow a particularly competitive use in these applications. In addition, the assembly system ensures that the panels according to the invention keep these properties for a long period of use.

Special features and details of the invention will emerge from the following description of the appended figures, given without limitation.

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 Figure 1 Figure 1 shows an embodiment of the panel according to the invention.

It comprises a flexible PVC membrane 1, a rigid PVC plate 2, a layer of polyurethane foam 3, a section 4 comprising a rib 6 and a section 5 comprising a groove 7. The sections 4 and 5 are made of rigid PVC. The profile 4 is also provided with a housing 9. The profile 5 is provided with a self-locking cam 8 and a housing for fixing 10. The polyurethane foam, which adheres both to the membrane 1, to the plate 2 and on profiles 4 and 5, ensures the cohesion of the whole.

Figures 2a, 2b, 2c Figures 2a, 2b, 2c illustrate the operation of the assembly system according to the invention in the case of the panel illustrated in Figure 1. Figure 2a shows the assembly systems of the panels before their coupling , in particular the sections 4 and 5. It can be seen that the self-locking cam 8 prevents the panels from being brought together completely by translation. FIG. 2b illustrates the inclination or the bending which it is necessary to give to the panel provided with the male part of the assembly system so that it can penetrate into the groove of the complementary part. Figure 2c shows the assembled system. The self-locking cam 8 assembles the panels in the X dimension of the space. The penetration of the rib 6 in the groove 7 assembles the panels in the dimension Y of the space. The X and Y dimensions are perpendicular. By way of illustration, a screw 11 has been placed in the housing 10 provided for this purpose. The presence of this screw is optional. The housing for fixing 10 makes the screw 11 invisible after assembly of the panels. The space provided above the screw 11 by this housing 10 also prevents the screw from forming a thermal bridge. The contact surfaces 12a and 12b seal the assembly. They can be covered with a seal, not shown. The presence of the screw 11 will therefore not affect the tightness of the assembled panels.

Figure 3 Figure 3 shows an embodiment of the panel according to the invention, particularly suited to the case where these must be bent: The panel comprises a flexible PVC membrane 13, a rigid PVC plate 14, a layer of foam polyurethane 15, part

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 upper 16 of the assembly system according to the invention and its lower complementary part 17.

The figure illustrates the two perpendicular dimensions X and Y.

The cutting of the two parts of the assembly system is such that the vertical sides 19 to 24 have an angle 18 relative to the dimension Y. Figures 4a and 4b Figures 4a and 4b illustrate the operation of the assembly system according to invention, in the case of a panel well suited to bending. Figure 4a shows the positioning of the panels before their assembly. Figure 4b illustrates the relative arrangement of the panels after assembly. We note that thanks to the angle 18 made by the sides 19 to 24 with the dimension Y, the panels are assembled in the two perpendicular dimensions X and Y.

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Claims (1)

CLAIMS 1. - Multilayer insulating panel comprising a layer of expanded plastic material located between two layers of unexpanded plastic material, characterized in that it comprises an integrated system making it possible to assemble said panel in at least two dimensions of space at least one other additional panel. 2. - Multilayer insulating panel according to claim 1, characterized in that the integrated system consists of profiles. 3. - Multilayer insulating panel according to the preceding claim, characterized in that the profile has a grooved or ribbed shape provided with a self-locking cam. 4. - Multilayer insulating panel according to any one of the preceding claims, characterized in that the integrated system allows said panel and at least one other complementary panel to be assembled in three dimensions of space. 5. - Multilayer insulating panel according to any one of the preceding claims, characterized in that the expanded plastic material is polyurethane and in that the two layers of unexpanded plastic material consist of flexible PVC and / or rigid PVC. 6. - Multilayer insulating panel according to any one of the preceding claims, characterized in that at least one of the two layers of unexpanded plastic is flat. 7. - Multilayer insulating panel according to any one of the preceding claims, characterized in that the two layers of unexpanded plastic are flat. 8. - A method for manufacturing a multilayer insulating panel according to any one of the preceding claims, characterized in that it comprises the following three operations - there are in a mold two layers of unexpanded plastic material sparing between them an interior space - we inject expanded plastic into the interior space defined during the first operation - we extract the panel from the mold. 9. - A method for manufacturing a multilayer insulating panel according to the preceding claim, characterized in that the system <Desc / Clms Page number 12>  assembly of said panel is carried out by molding or thermoforming the ends of at least one layer of unexpanded material. 10. - Use of the multilayer insulating panel according to any one of claims 1 to 7 for the insulation of premises or parts of vehicles whose interior temperature is controlled.