This invention relates to multi-layered and above all pre-assembled semiworked element, with the function of insulation against electromagnetic radiation and optionally also acoustic and/or thermal insulation: the semiworked element can be shaped according to various geometries and it can be used in building and/or civil works (such as, for example, living environments and the like) or also- depending on the needs - in terrestrial, aerial or naval vehicular applications .

As is known, the search for optimum performance in terms of stabilising and maintaining a certain temperature inside a domestic or work environment requires the adoption, during construction or reconstruction, of suitable thermo-insulating panelling which can be positioned against the outer or inner faces of the walls, floors and/or ceilings: the panelling normally comprise materials with a high capacity to prevent thermal flows, and they are installed in different ways.

Similarly, it may be necessary nowadays, for questions of safety or in order to avoid "electromagnetic pollution", to have a civil/building construction which defines spaces in which there is a substantial reduction (and a concurrent prevention) of magnetic fields deriving from radio transmissions and/or deriving from inductive phenomena (for example, from the electromagnetic induction developed around cables carrying electrical current) . The prior art described above, even though it is widely used in various application embodiments, has several drawbacks.

More specifically, the ever greater request for "thermal insulation" requires a considerable increase in the thickness of the thermo-insulating elements, which therefore take away space from within the rooms (if they are positioned on the inner faces of the building works) or increase the overall external dimensions of the building works; consequently, if a high performance is requested in terms of electromagnetic protection, it is necessary to use metal meshes.

At the same time, it should be noted that the thermal and/or electromagnetic insulation technologies currently most high-performing are very costly in terms of purchase and production of the semiworked elements: this in turn influences the overall cost of construction or reconstruction works.

It should also be noted that the prior art insulation products are usually installed with suitable connecting means which in general make any repositioning or recovery of the semiworked element very difficult, or practically impossible (for example, in the case of demolition of the masonry works) : this therefore results in a substantial limit in terms of operational flexibility.

In light of the above, the aim of this invention is to provide a semiworked element for electromagnetic shielding with a multi-layered structure and with insulating properties (at least in terms of electromagnetic radiation and, if so desired, also in terms of thermal and/or acoustic insulation) which is able to overcome the above-mentioned drawbacks.

More specifically, the aim of this invention is the implementation of a multi-layered, shielding semiworked element which allows extremely high "electromagnetic", "thermal" and/or "acoustic" performances to be achieved (according to the various requirements requested at the time of installation) and that above all is available for extremely easy and fast installation operations (that is, without requiring the placing alongside each other and the mechanical constraining of several layers which are separate and functionally independent from one another) .

The aim of this invention is also to provide a multi- layered and pre-assembled semiworked element that can provide high performance levels with very small thicknesses, with optimised costs with respect to the performance levels and, if requested, with a satisfactory degree of repositionability (whilst maintaining the possibility of making the semiworked element non-repositionable) during the steps for installation and/or demolition/dismantling of the semiworked element.

The technical purpose indicated and the aims specified are substantially achieved by a multi- layered and pre-assembled semiworked element having the features described in one or more of the accompanying claims, as well as having the features described below. A possible embodiment of the semiworked element according to this invention will now be described with reference to the accompanying drawings, without restricting the scope of the inventive concept, and in which:

Figures 1, 2 and 3 are schematic cross section views of of possible (but non-limiting) embodiments of the semiworked element according to this invention .

With reference to the accompanying drawings, the numeral 1 denotes the semiworked element, basically comprising a supporting layer 2 exposable to an environment (that is, in such a way that it is exposed and/or directly facing an environment during installation of the semiworked element) and a shielding layer 3 connected to the supporting layer 2.

Unlike the supporting layer, the shielding layer 3 is interposed, during installation of the semiworked element 1, between the supporting layer 2 and a wall defining the above-mentioned environment: in this way, the shielding layer 3 is neither visible nor even accessible after the semiworked element 1 is installed .

In order to guarantee the maximum speed and ease of use, the supporting layer 2 and the shielding layer 3 are connected to each other (when necessary, irreversibly) , and thus constitute the semiworked element integrally and cooperatively between them. Looking at the invention in more detail, it can be seen that, according to the needs of use/installation of the semiworked element, the supporting layer 2 can conveniently comprise various types of materials, such as, for example:

- a material designed to have a decorative/visual surface finish (for example, plasterboard, reinforcement fibres mixed with plaster, fibre cement and the like) ;

- a protective outer sheath;

- a breathable material;

- a material designed to slow down and/or retain vapours, gases or fumes.

On the other hand, according to this invention, the shielding layer 3 can advantageously be made from a multiplicity of fibres of electrically conductive material (for example, carbon fibres) and be designed to provide an electromagnetic shielding to radiation with a frequency of 50 Hz, 100 MHz and between 900 MHz and 1800 MHz.

In order to achieve the above-mentioned quantitative results, the shielding layer 3 can conveniently be made from a fabric (formed by a multiplicity of mutually twisted load-bearing weft and warp wires) , and by a predetermined number of electrically conductive thread-like elements, and preferably made from carbon fibres, interposed in weft and/or warp with the wires making up the fabric (or, in other words, with the above-mentioned load-bearing wires) : in a particular, but non-limiting, embodiment of this invention, this fabric being made from a weave of viscous polyester and polyester mixed with carbon, with an overall weight of 100 g/m ² . From the point of view of the shielding capacity, this invention is able to provide the following quantitative performance levels:

- surface resistivity = 79 kOhm.m;

- shielding efficiency at the (mean) frequency of 50 Hz = 30 dB;

- shielding efficiency at the (mean) frequency of 100 Hz = 29 dB; and

- shielding efficiency at frequencies of between 900 and 1800 MHz = 30 dB.

If further insulating properties are to be granted to the semiworked element 1, it is advantageously possible to prepare at least one supplementary layer 4, which is designed to exercise a function of thermal and/or acoustic insulation: the supplementary layer 4 is in turn associated in an irreversible manner with the supporting layer 2 and/or the shielding layer 3 and can be made from various combinations of materials and/or fibres and/or binding substances.

In an embodiment of this invention, the supplementary layer 4 comprises a non-woven fabric (or, as it is known in the jargon of the trade, a so-called "felt") of composite fibres, preferably made of carbon (possibly, in combination with pre-oxidized polyacrylonitrile fibres) , with low overall thermal conductivity: in this way it is possible to obtain an extremely high capacity of interrupting the conductive heat exchanges across the semiworked element 1, whilst maintaining an extremely small overall thickness. Again, in order to guarantee easy, fast and error- free installation, this invention can comprise an adhesive layer 5 associated with the supplementary layer 4 and/or the shielding layer 3 and/or the supporting layer 2: the adhesive layer 5 is designed to allow a reversible engagement of the semiworked element 1 relative to the wall and can also be coupled, from the functional point of view, with a removable protection layer 6.

In other words, the removable protection layer 6 associated with the adhesive layer 5 and reversibly configurable, by simple operations for manual separation of the semiworked element 1 by a user, between a protection condition (wherein it prevents adhesions of the adhesive layer 5) , and a removable condition (wherein it allows adhesions of the adhesive layer 5) .

In order to guarantee adequate mechanical consistency of the various layers of the semiworked element according to this invention, there are conveniently suitable connecting means: the latter are active between the supplementary layer 4, the shielding layer 3 and the supporting layer 2 and can be made with various technologies, also of prior art type (for example, they can comprise a predetermined quantity of adhesive and/or joining substance) .

From the geometrical point of view, thanks to the features described above and the appended claims, it is possible to obtain a pre-assembled semiworked element with extremely high insulation properties and with very small thicknesses: typically, the overall thickness of the semiworked element 1 can be between 10 and 50 mm, and preferably between 15 and 40 mm (for example, in an embodiment of this invention the thickness can be equal to 20 mm) .

The invention achieves numerous advantages.

In fact, thanks to the particular structure of the semiworked element 1, it is possible to maintain extremely low overall thicknesses, guaranteeing advantageous production costs (both of the semiworked element and of the construction or reconstruction operations) : this can be particularly appreciable in those applications of the invention comprising electromagnetic insulation, thermal improvement or sound-proofing of one or more rooms intervening on the internal faces of the walls.

At the same time, it should be noted that the suitable selection of the construction materials for the various layers (and in particular of the pre- oxidized polyacrylonitrile felt, of the mixed fabric of electro-conducting polymeric and carbon fibres, of the extreme variety of supporting/cover materials on view and, lastly, of the adhesive) makes a much more flexible operation possible, especially in terms of adjustment/repositioning.

Lastly, it should be noted that this invention can be used extremely easily by any user, regardless of high professional specialisation requirements and is able to position itself in a wide market segment ideally accessible also to "unskilled" operators.