Patent Application
20070037461
This application claims priority from European Patent Application No. 05425587.2, filed on Aug. 9, 2005, the entire disclosure of which is incorporated herein by reference.
The invention relates to laminar covering materials that can be used, for example, for providing floorings such as floorings for civil applications, and in particular for “industrial” applications. The term “industrial” is here meant, in general, to refer to floorings that are exposed to conditions in which there is a lot of coming-and-going of people or that are subject to extensive wear (for example, airports, railway or bus stations, underground stations, commercial centres, etc.). In particular, the invention relates to a laminar covering material that can be made with a resilient material, such as a material for “resilient floorings”.
The term “resilient flooring” or “resilient floor covering” is intended to indicate the types of resilient flooring identified according to the CEN/TC134 Committee operating in the framework of the European Standards Committee, and in particular the types of flooring identified in the EN650 standard. It refers therefore, according to the current acceptation of the term, to resilient floorings made with materials comprising, for example, natural, synthetic, and artificial rubbers, artificial and synthetic resins (for example, polyolefin-based materials, PVC-based materials, and the like), as well as materials having a particular composition, such as for instance linoleum.
The known art regarding floor-covering materials of this type is extremely extensive, as certified, for example, by the documents Nos. U.S. Pat. No. 4,772,500, U.S. Pat. No. 5,217,554, U.S. Pat. No. 5,899,038, US-A-2003/006522, U.S. Pat. No. 6,391,381, U.S. Pat. No. 6,418,691, U.S. Pat. No. 6,809,144, US-A-2005/006809 and US-A-2005/065236, all assigned in ownership to the assignee of the present patent application.
In the production of covering materials (and in particular materials for floorings) of the type described herein, it is necessary to take into account requirements of various nature, which, in effect, frequently contrast with one another.
One of the most deeply felt requirements is that of providing covering materials that are able to combine an attractive aesthetic appearance with qualities of high resistance to wear, low deformation even under heavy loads, dimensional stability (in particular, conservation of the characteristics of planarity over time), absence of phenomena of detachment from the laying substrate, together with characteristics of tread that are completely satisfactory (good anti-slip performance, low noise).
The impossibility of satisfying all these requirements in an ideal way means that, at least for some applications, the choice of the users is oriented towards covering materials of a different type (in general, of a more traditional type) such as, for example, ceramic, marble and/or stone coverings and floorings, said covering materials in turn not, however, being without some major drawbacks, such as, for example, the weight (which renders far from readily proposable, for example, the use of said materials on board vehicles), the risk of failure and of cracking in the presence of possible deformations or vibrations of the laying substrates (which, once again, renders problematical the use of floorings of this kind on board mobile structures or also within civil structures in areas exposed to the risk of earthquake).
The object of the present invention is to provide a covering that is able to solve in an ideal way the problems linked both to the use of resilient materials and to the use of the alternative materials considered previously, the aim being to provide a covering material that is able to combine the characteristics of high aesthetic quality and of resistance to the stresses due to tread of some traditional materials with the qualities of performance (in particular, treading “comfort”) and of low weight traditionally recognized to coverings with a base of resilient materials.
According to the present invention, the object above is achieved thanks to a covering material having the characteristics referred to specifically in the ensuing claims.
Essentially, the solution described herein is based upon recourse to a combination between a metal material (in particular, in the form of a reticular structure) and a resilient material. This combination is not in itself new to the art; it is extensively used, for instance, in the production of conveyor belts, and in the automotive industry for making tyres and components such as sleeves, anti-vibrating elements and the like, in which an elastomer is combined with a structure of metal reinforcement, typically having a reticular structure.
The above “Technological” solutions usually contemplate, however, that the metal reinforcement structure is kept in a hidden (“embedded”) position with respect to the mass of elastomer material, seeking rather to contain as far as possible any risks of exposure of the metal structure with respect to the metal/elastomer composite material.
The solution described herein moves, instead, in the exactly opposite direction and is based upon the recognition of the fact that—in an altogether surprising and unexpected way—the, at least partial, exposure of the reinforcement metal structure on the outer surface of the covering bestows upon the covering material excellent characteristics of resistance to wear, low deformation even under heavy loads, dimensional stability (in particular, conservation of characteristics of planarity over time), absence of phenomena of detachment from the laying substrate, together with altogether satisfactory characteristics of tread (good anti-slip performance, low noise).
Added to the above is an appreciable high aesthetic quality without this having any adverse effect on the intrinsic qualities demonstrated by coverings with a base of resilient material. This regards in a particular, but not exclusive, way the possibility of altogether limiting undesirable phenomena of detachment between the metal reinforcement structure and the resilient material.
The invention will now be described, purely by way of non-limiting example, with reference to the annexed plate of drawings, in which:
FIGS. 1 to 3 illustrate successive steps of a method for the construction of a covering material of the type described herein; and
Even though this choice is not imperative, the choice of reticular structures consisting of a deformable metal material, i.e., structures presenting qualities of ductility and malleability, is believed to be amply preferable. A currently preferred material is represented by aluminium. The values of mass per unit area of the network, fabric or lattice-like structure range preferably between 250 and 1250 g/m2 approximately, a particularly preferred value being around 750 g/m2.
The expressions “approximately” and “around”, as used herein, are evidently intended to take into account the tolerances normally associated to the construction and to the measurement of the quantities each time considered.
The conformation of the meshes of the network or lattice does not in itself constitute a binding parameter. The choice currently preferred is that of networks with a flattened rhomboidal mesh (i.e., with each mesh having the shape of a rhombus) or a flattened hexagonal mesh.
Reticular metal structures of this type are commonly available in the art for various applications. A field in which extensive use of networks (grids or lattices) of this type is made is the automotive sector, where these networks are used, for example, to make protective grills for filters, ventilation intakes and openings or ducts of various nature. Networks or lattices of this type are widely used also in the building sector.
5The dimensions of the meshes of these structures are usually identified by two values (DL and DC), which correspond to the values of the maximum and minimum “diagonals” of the mesh. For the purposes of the solution described herein values of major diagonal DL approximately between 5 mm and 25 mm are considered preferable, the preferred range being between 10 mm and 15 mm approximately, a particularly preferred value being around 10 mm. Likewise values of minor diagonal DC of between 3 mm and 13 mm approximately are considered preferable, the preferred range being between 5 mm and 6.5 mm approximately, a particularly preferred value being around 5 mm. In a preferred way, the aforesaid ranges/values are to be considered co-ordinated with one another.
It will likewise be appreciated that the term “reticular structure” is herein used in its widest acceptation, and thus comprises within its scope also structures consisting of parallel filiform elements or else structures consisting of filiform elements that evolve according to volutes of various nature.
In the most typical form, which is that of a network consisting of regular meshes, these structures are usually obtained starting from a strip of sheet metal that is simultaneously undulated and notched so as to form a regular array (for example, a quincunx) of transverse slits and then stretched out so as to create the network structure.
In the majority of applications, this method means that the reticular structure obtained is not present exactly plane but is constituted by branches that extend, at least in part, in a direction at least marginally angled with respect to the general plane of extension of the reticular structure.
The plane reticular structure 2 thus obtained is then coupled, in the step schematically represented in
Before proceeding to said coupling operation, the metal reticular structure 2 subjected to flattening is treated, at least on the side that is to be coupled to the resilient material 3, with a so-called “primer”, i.e., with a material functioning as promoter of adhesion between the metal material of the structure 2 and the resilient material 3 to which said structure is to be coupled.
Promoters of adhesion that can be used in an altogether satisfactory way in the context described herein are available under the commercial name of CILBOND® produced by Chemical Innovations Limited of Bamber Bridge, England. Assuming, for example, that the metal material of the structure 2 is aluminium, and the resilient material 3 consists of rubber (either natural or synthetic, such as for example SBR) the aforesaid promoter of adhesion or primer, designated schematically by 4, may be the product CILBOND® 24.
After application of the primer 4 (performed in a station designated by B, operating according to known techniques), the metal structure 2 and the resilient material 3 are coupled to one another according to one of the typical methods used for the production of laminar covering materials with a base of resilient materials.
For example, the resilient material 3 may be of a stratified type and comprise two or more layers 3a, 3b, for instance of a rubber-based mix with different formulation, for example for optimizing the ratio of connection/adhesion with the adjacent layers.
The method of coupling in question can be performed by resorting to known technologies that envisage the simultaneous application of pressure and heat to the composite material constituted, in the specific case considered herein (see
In the case in point, in
The construction of the composite material described herein involves in a preferred way the application, on the side of the layer of the resilient material 3 opposite to the plane metal structure 2, of one or more stabilization layers.
A typical example of such a stabilization layer consists of a network 5 made of glass fibre (with mass per unit area, for example, of from 25 to 100 g/m2 approximately, with a preferred value of around 50 g/m2), the function of which, in the context of the composite product obtained, is to create a balanced metal/resistant-material/reinforcement-fabric structure that can minimize undesirable phenomena of deformation of the structure thus obtained.
Combined with the network 5, on the outer side with respect to the composite material, there may be a further layer of material 6, such as for example a geotextile material and/or a material in the form of felt (with mass per unit area, for instance, of 80 to 300 g/m2 approximately, with a preferred value of around 200 g/m2). A felt of this type, made for example with a base of polyester and/or polypropylene, is able to facilitate application of glues for laying of the flooring and the firm connection of the covering material thus obtained (designated as a whole by 7) on an application substrate.
As already mentioned in the introductory part of the present description, the material 7 takes the form of a composite metal material/resilient material in which the reinforcement metal structure, instead of being embedded within the composite material, is completely exposed or else at least marginally emerging from the outer surface of the composite material 7, i.e., the surface exposed to severe treatment during use: in the case of a flooring, said outer surface is evidently constituted by the upper surface of the flooring, which is exposed to tread.
The degree of exposure/surfacing of the metal structure 2 with respect to the aforesaid outer surface can be conveniently adjusted—all other process parameters being equal—by adjusting the pressure applied to the composite material during its formation in the equipment designated by RC in
The material 7 obtained with the method just described is configured then as schematically represented in
Albeit without wishing to be tied down to any specific theory in this connection, the present applicant has reasons to believe that the (complete or partial) surfacing of the metal structure 2 on the outer surface of the composite material thus obtained means that the metal structure 2 amply absorbs the stresses that, in a resilient flooring of a traditional type, tend to be discharged on the resilient material. From this fact there derive the characteristics of resistance to wear demonstrated by a covering material of the type described above.
At the same time, the material in question presents good characteristics of compliance, i.e., of resilience. This also in view of the fact that the metal structure 2 is not completely rigid and has, instead, above all in the case where it is made with a material such as aluminium, good characteristics of deformability and of resistance to vibration and to the stresses possibly linked to a deformation of the laying substrate.
The material may be made in a laminar form with small thicknesses (for example, with thicknesses typically of between 1.8 mm and 4 mm, typical of coverings made of resilient material) with a containment of the weight per unit surface to values considerably smaller than the homologous values of materials, such as ceramic or stone materials. It will, on the other hand, be appreciated that the solution described herein is suited also to the creation of the laminar material 7 with larger thicknesses (thicknesses of around one centimetre), with the possibility of making the material available in the form of tiles.
Added to these considerations of a technical nature are also considerations of an aesthetic nature: the emerging metal structure 2 is able to contribute, with its colouring (and its typical metallic appearance), to the high aesthetic quality of the flooring, it being also possible, for the purposes of the overall colouring of the covering, to play on the range of chromatic choices—which are practically infinite—allowed for the resilient material.
Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may widely vary with respect to what is described and illustrated herein, without thereby departing from the scope of the present invention, as defined by the annexed claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| EP 05422587.2 | Aug 2005 | EP | regional |
