FR2591147A1 - Novel rigid laminated composite material - Google Patents

Abstract

The present invention relates to a rigid laminated composite material intended for the production of panels, especially large-sized panels. According to the invention, this material comprises an intermediate structure 4 of low density including elements having a multidirectional rigidity and a low deformation threshold, the said intermediate structure lying between two deformable external force-distributing layers 2, 3 chosen so that the said intermediate structure is not subjected to a localised force greater than the deformation threshold. The invention applies especially in the building industry, in particular for producing partitions for individual and/or communal dwelling-places.

Description

 The present invention relates to a new rigid laminated composite material intended for the production of panels, in particular of large dimensions.

 The invention can be used in particular in the building industry for the production of walls, partitions or roofs, but also in many other applications in particular for the production of decorative or advertising panels, screens, floating pontoons for example.

 Many laminate composite materials have been used to manufacture rigid panels of all sizes. The choice of thickness and composition of each layer of the material in fact makes it possible to advantageously impart to the panel the qualities of thermal, phonic and mechanical resistance sought.

 Thus already known composite laminate panels intended in particular for the realization of roofs, comprising an intermediate structure of expanded polystyrene chosen because of its well known insulation properties. In addition, in order to give its essential rigidity to the panels, this intermediate structure is comprised between two rigid external layers produced in the form of wooden panels, in particular agglomerated wood.

 There are also known multilayer panels entirely finished in the factory, of large area, intended in particular for the production of residential partitions. These panels have an insulating internal structure such as polystyrene, glass wool, polyurethane foam, with a wooden frame, and a laminated external structure made from reinforced polyester resin, on plywood with phenolic bonding. The rigidity of such a panel is obviously ensured by the plywood plate.

 Such a state of the art shows that it has been thought, until now, that in order to produce rigid panels of large dimensions, using laminated composite material it was absolutely essential that at least two layers of the material used have great rigidity, and are practically non-deformable.

 However, such a design requires the choice of relatively heavy materials which give the finished product a significant weight per square meter of about 25 to 35kg. This weight is responsible for a certain number of drawbacks, in particular when using residential panels for example. This is how it is necessary to use lifting equipment and specialized labor, the use of which considerably increases the cost price of the production.

 In the particular field of individual housing construction, we have recently moved towards an alternative formula based on the use of small and light weight panels. It is thus known to use in this application polystyrene panels obtained by molding.

 However, the size of such panels is limited on the one hand due to the limitation of the size of the molds that can be used for the manufacture of the panels, these molds being produced from very expensive materials, such as aluminum, and on the other hand due to the loss of rigidity correlative to the enlargement of the panels.

 In addition, when these panels are assembled to form walls or partitions, during construction, the overall rigidity is insufficient to be able to safely apply the necessary interior and exterior coatings. It has therefore been necessary to provide a stiffening structure, which is obtained by pouring concrete into cells provided in each panel for this purpose. However, to pour the concrete in these cells it is necessary to wedge and adjust the assembly beforehand, which requires the use of specialized equipment and labor.

 The present invention aims to solve the aforementioned problems by proposing a new rigid laminated composite material intended for the production of panels which can be easily executed in all dimensions, and produced from light and inexpensive materials.

 It has in fact been discovered that it is possible to obtain a rigid structure not surprisingly comprising elements that are substantially non-deformable ensuring overall rigidity.

 The solution proposed by the present invention, to solve the technical problem posed consists of a rigid laminated composite material, intended for the production of panels, in particular of large dimensions, characterized in that it comprises an intermediate structure of low density comprising elements having a multidirectional rigidity and a low deformation threshold, said intermediate structure being between two deformable external layers of distribution of the forces chosen so that said intermediate structure does not undergo any local force greater than said deformation threshold.

 A perfectly rigid material is thus obtained, although all of its constituent elements present an easily deformable structure. This completely unexpected effect is particularly advantageous, since, thanks to the possibility of using light materials, it is possible to obtain rigid panels of any size whose weight is such that they can be easily handled. In addition, these light materials are generally inexpensive and their use therefore reduces the cost price of the panels.

 According to a particular characteristic of the invention, each external layer is produced in the form of a flexible sheet or plate, preferably cellular in extruded plastic, produced in particular on the basis of polypropylene, polyvinyl chloride, polycarbonate or polyester. Such materials provide great lightness to the finished panel.

 Advantageously, the intermediate structure comprises a certain number of open cavities or cells allowing, in particular by injection, the at least partial filling of the panel during its use.

The invention will be better understood and other objects, characteristics and advantages thereof will appear more clearly on reading the explanatory description which follows, made with reference to the appended schematic drawings given solely by way of nonlimiting examples illustrating several currently preferred embodiments of the invention and in which
- Figure 1 is a perspective view illustrating a panel according to a first embodiment of the invention;
- Figure 2 is a partial perspective view of a panel according to a second embodiment of the invention
- Figure 3 is a sectional view along line III-III of Figure 2; and
- Figures 4 and 5 are two perspective views similar to Figure 1 of two other embodiments of the invention.

 For the simplicity of the description, the material according to the invention will be described below with reference to a particular application, ie the production of large area panels intended in particular for the construction of residential walls or partitions, but this application is of course given only by way of nonlimiting example.

 With reference to the appended figures, the panel 1 according to the invention is substantially rectangular, but may be, due to the materials which constitute it, of any shape whatsoever. In particular, the thickness can be chosen according to the application, for example between 1 and 25 cm.

 Each outer layer 2, 3 is produced in the form of a flexible or deformable sheet or plate of plastic, in particular extruded material, or any other material that can be extruded or obtained in the form of a sheet produced in particular based on polypropylene, polyvinyl chloride, polycarbonate or polyester depending on the chosen application. Such a material is particularly advantageous, since it is possible to produce plates or sheets of any size and shape, the weight of which however remains low.

 Preferably, for the external layers 2, 3, a plastic material can be chosen which can be produced in the form of sheets, in particular cellular, of small thickness. In particular, plastic cardboard based on polypropylene was used in the invention. However, other materials can also be used with the same advantageous effects. The function of these external layers is to distribute the forces acting in particular locally on the surface on the intermediate structure.

 In addition, the plastic material gives the finished panels advantageous sealing and impermeability properties. Thus, unlike the structures of the prior art, it is not necessary to provide a specific means intended to waterproof the panel. Indeed, until now when using a plastic foam to achieve the intermediate structure, it was necessary, due to the sensitivity of the foam to humidity, to provide during construction, the establishment of '' a specific means intended to waterproof the panels.

 Figures 1, 4 and 5 show three embodiments of the invention in which the intermediate structure is produced, in a common manner, based on a plastic foam such as in particular polystyrene foam, polyurethane or phenolic foam. The choice of material is of course dependent on the use of the panel, and in the most common applications we will choose, in particular because of its low price, a polystyrene foam.

 However, in general, it is also possible to use other materials such as glass wool, expanded clay, beads of expanded glass, vermiculite and any light particles, in particular agglomerated, mineral or vegetable, to form the intermediate structure.

 As is known, plastic foams, and in particular of polystyrene, have a low density structure formed of individual grains having a certain multidirectional rigidity, but with low deformation threshold. Indeed, the polystyrene grains can be easily deformed by the application of a simple pressure of the fingers for example. This is why it is possible to obtain sheets of expanded polystyrene, although these sheets remain fragile and are easily deformable, in particular in bending.

 In FIG. 1, the intermediate layer 4 is produced in one-piece form.

 However, the embodiments shown in FIGS. 4 and 5 of the drawings are preferred, in which the intermediate structure is produced in the form of panels 5 juxtaposed with, in the case of FIG. 5, separation intervals forming a set of filling cavities. as will be described below.

 Advantageously, the intermediate structure is also produced in the form of multiple layers bonded.

 In fact, in order to carry out the present invention, use has been made of the least expensive materials. In this regard, blocks of polystyrene are preferably used which are cut into sheets according to use.

However, during cutting, there is a well-known effect of tiling of the polystyrene and the plates obtained have large flatness defects.

 It has been discovered that it is possible to ensure a certain flatness by producing the intermediate layer by means of cut and laminated plates.

(see figures 4 and 5). This design allows to effectively square the curling effect due to polystyrene.

 For the bonding of the polystyrene plates 5 to one another and with the external layers 2, 3, any conventional adhesive will be used, which remains flexible over time.

 In the embodiment shown in FIGS. 2 and 3 of the drawings, the intermediate structure is produced in the form of strips 6, preferably formed from the same material as the external layers 2 and 3. These strips are arranged transversely between said external layers 2 and 3, and extend in any direction and with any density. In FIG. 2, the bands extend in waves or in a zigzag in substantially parallel directions. In general, a distribution of the strips will be chosen so that they form between them a set of cells intended to receive a filling material.

 In the embodiments of Figures 2, 3 and 5, the intermediate structure therefore comprises a number of open cavities or cells allowing at least partial filling of the panel, for example during its use. Preferably, concrete will be injected into these cavities, but the conformation of the panels is advantageous, since it allows, by simply cutting out the panels of the intermediate structure, to use any desired filling material such as wood, or metal insert by example, regardless of its form or nature.

 We will use a filling material whenever we want to give the panels a self-supporting structure. In the realization of individual housing, we will use concrete for the realization of load-bearing walls. However, unlike the prior art, the panels are sufficiently rigid and self-supporting to allow by simple suitable bonding on the foundation concrete plate, the establishment of the panel prior to its filling. In this case, it is not necessary to use specific timing and adjustment means.

 As will be understood, the present invention finds its originality in the production of rigid rigid panels, in particular of large surface area, of solid or honeycomb structure, the lightness of which allows easy handling. We obtain for panels with a thickness of about 15 cm a weight per square meter of the order of 3 to 5 kg. Thus, in the case of individual housing construction, a panel with a surface of 25 m2, intended for the realization of a partition or a wall can be handled by two people only.

 The panel according to the invention has a self-supporting, insulating, waterproof structure, which can be reinforced in particular by injection or filling, and adaptable to all styles. In addition, by simple manual cutting, panels of any shape and size can be obtained. In addition, the panel according to the invention can easily receive interior and / or exterior coatings making it particularly rot-resistant, hard and even more rigid.

 Finally, thanks to the use of inexpensive materials, the panels according to the invention are capable of advantageously replacing a large number of already existing panels, in particular in the field of advertising and decoration.

 Finally, the lightness and the tightness make it possible to envisage applications of the invention to floating pontoons or to the production of swimming pool partitions, or even cold room partitions.

Claims (7)

 1. rigid laminated composite material, intended for the production of panels, in particular of large dimensions, characterized in that it comprises an intermediate structure (4) of low density comprising elements having a multidirectional rigidity and with low threshold of deformation, said intermediate structure (4) being between two deformable external layers (2,3) of distribution of the forces chosen so that said intermediate structure does not undergo a local force greater than said threshold of deformation.  2. Material according to claim 1, characterized in that each said outer layer (2,3) is produced in the form of a deformable sheet or plate, preferably cellular, of extruded plastic material produced in particular on the basis of polypropylene, polyvinyl chloride, polycarbonate or polyester.  3. Panel according to claim 1 or 2, characterized in that the aforementioned intermediate structure (4) comprises a number of open cavities or cells to allow in particular by injection, the at least partial filling of the panel during its use.  4. Panel according to claim 1, 2 or 3, characterized in that the above-mentioned intermediate structure (4) is made from plastic foam such as in particular polystyrene foam, polyurethane or phenolic foam, in the form of juxtaposed panels preferably with separation intervals forming the aforementioned filling cavities.  5. Panel according to claim 4, characterized in that the above-mentioned intermediate structure is produced in the form of multiple layers laminated.  6. Panel according to claim 2 or 3, characterized in that the above-mentioned intermediate structure (4) is produced in the form of strips (6) preferably formed from the same material as the above-mentioned outer layers, arranged transversely between said outer layers, said strips (6) extending substantially in any directions to form between them a set of cells intended to receive the aforementioned filling material.  7. Panel according to claim 6, characterized in that the aforementioned transverse bands are made of a material, in particular plastic and cellular, such as in particular plastic cardboard, and in that said bands have a certain number of folds, and extend in waves or in zigzag in cross section.