Structural panel with a metal fabric

The invention relates to a building panel with a metal mesh which forms an air-permeable surface on at least one side of the panel.

Since metal meshes do not have sufficient dimensional stability to form self-supporting building panels, these metal meshes are attached to load-bearing frames, whereby high tension forces have to be applied to the metal mesh in order to achieve an even mesh course, which, however, despite high tension forces with uneven heat loads on the metal mesh and frame cannot be ensured because of the different thermal expansions then. The high tension forces also require heavy frame constructions, which increase the effort considerably, so that despite the advantages of building panels with a surface made of an air-permeable metal fabric, especially in connection with cladding for sound insulation or with regard to air- and light-permeable wall elements, such building panels are hardly used .

To produce sound-absorbing composite panels, it is known to cover a honeycomb core on both sides with cover layers, one of which has sound passage openings. These sound-permeable covers can consist of multiple layers of fiber layers which are each embedded in synthetic resin and provided with through-holes (US Pat. No. 5,888,610 A). The multilayer structure of the synthetic resin-impregnated fiber layers results in a dimensionally stable cover layer which, after being coated with an adhesive, can be glued to the honeycomb core and hot-pressed with it. Instead of fiber layers, fiber fabrics made from fiber strands can also be impregnated with resin (US Pat. No. 4,390,584 A) in order to obtain a dimensionally stable cover layer for a honeycomb core. The inherent porosity of this resin-soaked fabric layer should ensure sufficient sound penetration. Since in this case too, in contrast to an air-permeable metal mesh, the synthetic resin embedding makes the cover layer an essentially closed surface, with the exception of the porosity, so the gluing of these resin-impregnated fiber layers to the honeycomb core does not pose any difficulties.

Finally, in order to be able to glue sound-permeable cover layers to a honeycomb core without having to worry about the sound passage openings of the cover layers being closed, it is known (US Pat. No. 4,284,457 A) to first apply a carrier provided with an adhesive layer to the honeycomb core, which The adhesive layer is removed from the honeycomb core again, so that adhesive adheres only in the area of ​​the end faces of the honeycomb core walls. The cover layer applied to a honeycomb core prepared in this way can then be connected to the honeycomb core with complete curing of the adhesive, without having to fear that the cover layer openings will stick in the area of ​​the honeycomb openings. However, such application of the adhesive to the honeycomb core is very expensive.

The invention is therefore based on the object of designing a building board with a metal mesh of the type described above so that, while avoiding complex frame structures, good dimensional stability can be ensured at a comparatively low weight without endangering the air permeability of the surface formed by the metal mesh.

The invention solves the problem in that the building board has, in a manner known per se, a honeycomb core open towards the two sides of the board between two glued-on cover layers, at least one of which consists of the metal fabric which is glued to the honeycomb core via an adhesive layer provided with openings is.

Since the metal mesh is glued onto a honeycomb core that is open towards the metal mesh, the metal mesh is supported by its surface on the end faces of the honeycomb walls of the honeycomb core, so that the surface profile of the honeycomb core determines the metal mesh profile and special tension forces for the metal mesh can be dispensed with. This enables the production of not only flat, but also curved building panels. The honeycomb core, which is open towards the metal mesh, ensures the air permeability of the surface formed by the metal mesh and enables a comparatively low construction panel weight without endangering the inherent strength of the construction panel, which for this purpose as a composite body requires an additional cover layer in addition to the cover layer made of the metal mesh. This additional cover layer, which is required for the inherent strength of the building board, can be designed differently depending on the application of the building board. Particularly advantageous design ver2

AT 408 007 B ratios result when both cover layers consist of possibly different metal fabrics, which can be important in particular with regard to air and light permeability.

Both for the optical effect and for the air permeability it is essential that the meshes of the metal fabric, which is also intended to include a braid or a metal lattice, are not covered by the adhesive layer between the metal fabric and the honeycomb core. In order to ensure such a gluing of the metal mesh, leaving the meshes free, with simple means, the metal mesh is affixed to the honeycomb core via an adhesive layer provided with perforations. The cohesive, but perforated adhesive layer can be easily inserted between the metal mesh and the honeycomb core before the metal mesh and the honeycomb core are glued together, with the perforations essentially only producing a bond in the area of ​​the contact surfaces, because during the curing process the adhesive layer is due to the perforations along the fabric threads or the front edges of the honeycomb core flow, even if the perforations do not match the meshes of the metal fabric.

A fabric or mesh could be used as the adhesive layer. Particularly simple conditions are, however, achieved by an adhesive layer made of a multiple slit or perforated adhesive film.

In order to support the flow of the adhesive layer along the threads of the metal fabric or the end faces of the honeycomb core and to concentrate the adhesive layer in the contact areas between the honeycomb core and metal fabric, the adhesive layer can have a shrinkage behavior during curing. Thermoplastic adhesive layers are therefore particularly suitable for this purpose.

The subject of the invention is shown in the drawing, for example. Show it

1 shows a section of a building board according to the invention in a partially torn plan view and

FIG. 2 shows this building board in a section along the line II-II in FIG. 1 on a larger scale.

According to the illustrated embodiment, a building board according to the invention has a honeycomb core 1, for example made of aluminum, the honeycombs 2 of which are open towards the two cover layers 3 and 4. These cover layers 3 and 4 each consist of a metal fabric 5 which is glued onto the end faces of the walls of the honeycomb 2, specifically with the aid of an adhesive layer 6. This adhesive layer 6 can consist of a multiple slit film, for example of a thermoplastic, which is inserted between the honeycomb core 1 and the respective metal fabric 5 and heated to harden. Because of the slots in the adhesive layer 6 distributed over the film, the adhesive layer 6 contracts along the threads of the metal fabric 5 and the end faces of the boundary walls of the honeycomb 2 of the honeycomb core 1, so that the meshes of the metal fabric 5 remain free after hardening. This means that the passage of air through the metal fabric 5 forming the plate surfaces is ensured despite their support by the honeycomb core 1. The support of the metal mesh 5 by the honeycomb core 1, which extends over the panel surface, makes the otherwise necessary tensioning of the metal mesh 5 superfluous, which on the one hand leads to a simple construction and on the other hand allows the production of curved building panels.

The building panels according to the invention can be trimmed in a simple manner. But it is also possible to fold the metal mesh 5 over the edges of the honeycomb core 1 against one another, as shown in FIG. 2 A mechanical connection of the metal mesh 5 of the two cover layers 3 and 4 is recommended whenever a loosening of the adhesive connection between the metal mesh 5 and the honeycomb core 1 must be expected in the event of a fire in order to prevent the building board from falling apart.

The invention is of course not limited to the illustrated embodiment. For example, the metal mesh 5 of the two cover layers 3 and 4 could be designed differently, for example to take into account the fact that the building board only needs to have one visible side when it is ζ. B. is used as wall cladding or suspended ceiling. Due to the air and light permeability, appropriately designed building panels are also advantageously suitable as partitions and partition walls, which are intended to prevent complete closure. Because

AT 408 007 B of air permeability, partition walls according to the invention can also be used advantageously in connection with sound-absorbing mats. Finally, it should be mentioned that the combination of a honeycomb core 1 with metal meshes 5 covering the end faces of the honeycombs makes it possible to achieve particularly optical effects which shape the appearance of the plate surfaces as a function of the viewing direction.