(19)
(11) EP 4 387 391 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
19.06.2024 Bulletin 2024/25

(21) Application number: 23216586.0

(22) Date of filing: 14.12.2023
(51) International Patent Classification (IPC): 
H05B 3/34(2006.01)
(52) Cooperative Patent Classification (CPC):
H05B 2203/003; H05B 2203/013; H05B 2203/017; H05B 3/347
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA
Designated Validation States:
KH MA MD TN

(30) Priority: 15.12.2022 IT 202200025662

(71) Applicants:
  • D'Amico, Piermatteo
    37023 Grezzana (IT)
  • ROSSO24 S.R.L.
    37121 Verona (IT)

(72) Inventor:
  • D'AMICO, Piermatteo
    37023 Grezzana (IT)

(74) Representative: Contadin, Giorgio et al
Notarbartolo & Gervasi S.p.A. Viale Achille Papa, 30
20149 Milano
20149 Milano (IT)

   


(54) COMPOSITE HEATING ELEMENT WITH VERY LOW VOLTAGE ELECTRIFICATION


(57) A thermally conductive and heating composite element (1; 50) comprising a laminar support layer (2; 51) provided with a first face (2a) adapted to remain facing towards the outside in application conditions, and with a second face (2b), opposite to the first face (2a), adapted to be coupled to a reference surface in application conditions, and a thermo-conductive and heating circuit (3; 52) of the electrical type, applied to the first face (2a) of the laminar support layer (2; 51), electrically connected to a very low voltage electrical power supply source comprised in the range of values from 3 Volts to 50 Volts, adapted to electrify the thermo-conductive circuit (3; 52) to produce heat. Particularly, in the thermally conductive and heating composite element (1; 50) of the invention, the thermo-conductive and heating circuit (3, 52) comprises at least one continuous resistive track (4) distributed on the first face (2a) of the laminar support layer (2; 51) and provided with a first end (4a), adapted to be coupled to a first electrical pole (P) of the electrical power supply source, and with a second end (4b) adapted to be coupled to a second electrical pole (N), having a polarity opposite to the polarity of the first electrical pole (P), of the electrical power supply source itself.




Description


[0001] The invention relates to a composite element (such as, for example and conventionally, a technical fabric, a flexible laminar film, a panel, a slab, an even rigid plane or the like) which is thermally conductive, radiant and heating due to a low voltage electrification thereof (not exceeding 50 Volts).

BACKGROUND ART



[0002] It is known that, at present, heating elements (commonly known as heating films) made on an insulating, flame-retardant, moderately flexible support (or substrate) made of PET (polyethylene terephthalate), having a very limited thickness, not exceeding a few millimeters (generally, from 0.5 mm to 2 mm), are being marketed.

[0003] On such insulating support (or substrate) made of plastic material of each heating element of the prior art, an electrically conductive circuit is laid, using screen printing technique, usually made of argentite, copper and carbon, following a classic pattern in the shape of a double track, which clearly limits the variation in shape of the heating element: not surprisingly, this is today only available in rolls.

[0004] A first track (or strip, or tape) made in copper - forming one of the electrodes of the electrical circuit - is positioned at a first lateral edge of the radiant element, while a second track (or strip or tape) - forming the other of the electrodes of the electrical circuit - is parallel to and spaced apart (therefore distinct) from the first track and is positioned at a second lateral edge, symmetrically arranged with respect to the first lateral edge, of the radiant element itself.

[0005] The carbon and argentite are, however, laid on a first face of the insulating support and mostly distributed on the surface of such face between the two tracks (electrodes) of the electrical circuit.

[0006] The film-shaped radiant elements of the prior art of the type briefly described above are rather rigid and difficult to shape, due to the very moderate mechanical flexibility thereof, and tolerate little bending during screen printing.

[0007] Furthermore, the radiant elements in the form of films of a known type, disadvantageously, do not have elastic memory (useful, for example, during installation, maintenance, repair and/or removal), they are not extensible, not very resistant to a prolonged contact with water and, above all, not effectively tolerate temperatures above approximately 60°C and they have sizes, shapes and powers which may not be customized, precisely because of how they are provided to users (rolls) and of the conventional production method thereof which, in addition, outputs a finished product with an elaborate construction concept.

[0008] As a negative consequence of these last two limitations, in the current state of the art, on the one hand users must inevitably adapt to the sizes and powers of the thermally conductive, radiant and heating elements (heating films) available on the market and, on the other hand, beyond the aforesaid temperature limit values (produced and bearable), the insulating support (or substrate), on and with which the radiant elements are made, deforms, generating downtimes and fire hazards.

[0009] The patent documents of the prior art published with US2005/082280 A1, US 2008/083743 A1 and KR20160131389 A show examples of radiant elements relevant to the present invention.

PURPOSES OF THE INVENTION



[0010] The present invention intends to overcome the drawbacks of the background art which have just been briefly highlighted.

[0011] In particular, it is main purpose of the invention to provide a thermally conductive and heating composite element, especially in the form of technical fabric, which has a simpler construction concept with respect to that of the radiant composite elements of the known type comparable thereto.

[0012] Within such object, it is a first task of the present invention to develop a thermally conductive and heating composite element that has a competitive production cost with respect to the one associated with the radiant composite elements of the prior art, with the other parameters involved in the calculation, such as, in particular, the cost of labor, having the same value.

[0013] It is a second purpose of the invention to indicate a thermally conductive and heating composite element that is capable of effectively generating, absorbing and withstanding operating temperatures with a value somewhat higher with respect to the one of the operating temperatures at which the known equivalent heating elements effectively operate.

[0014] It is another object of the invention to create a thermally conductive and heating composite element that is waterproof and mechanically resistant to traction, shear and bending, to an extent at least equivalent to the radiant composite elements of the electrical type of the prior art.

[0015] It is an additional purpose of the invention to create a thermally conductive and heating composite element that, contrary to the composite heating elements of the most recent prior art, is customizable in shape, size and electrical power delivered based on the needs of the user.

[0016] It is a further purpose of the invention to perfect a thermally conductive and heating composite element that is easily adaptable to various applications, also in this case, contrary to what is permitted by the composite elements of the prior art comparable thereto.

[0017] It is a further purpose of the invention to provide a non-continuous thermally conductive and heating composite element (preferably perforated to form a mesh) that may be used in the stratigraphic composition of construction systems and that is not a mechanically desolidarizing separating layer, as it negatively occurs in equivalent elements of the prior art. It is a not least object of the invention to create a thermally conductive and heating composite element that operates effectively even in the presence of critical outside environmental conditions, characterized by rather rigid temperatures, even considerably lower than 0°C.

[0018] Said purposes are achieved by means of a thermally conductive and heating composite element as in the accompanying claim 1, to which reference is made for brevity of exposition. Further detailed technical features of the thermally conductive and heating composite element are contained in the corresponding dependent claims.

[0019] The aforesaid claims, hereinafter specifically and practically defined, form an integral part of the present description.

ADVANTAGES



[0020] Advantageously, the thermally conductive and heating composite element of the present invention has a construction design and thermal efficiency in operating conditions that are improved with respect to those of the thermally conductive and heating composite elements of the prior art.

[0021] This is determined by the fact that, in the invention, the thermo-conductive and heating electrical circuit comprises at least one continuous resistive track distributed on the first face of the laminar support layer and provided with a first end, adapted to be coupled to a first electrical pole of the electrical power supply source, and a second end adapted to be coupled to a second electrical pole, having a polarity opposite to the polarity of the first electrical pole, of the electrical power supply source itself, the first end and the second end of the continuous resistive track being positionable so as to be effective for the intended use.

[0022] Equally advantageously, the thermally conductive and heating composite element of the invention may reach, by means of very low voltage electrification (in the 2-50 Volt value range) supplied by an electrical power supply source to which it is connected, surface temperatures that vary from 0 to 250°C, therefore rather higher, for a wide range of values, than the temperatures achievable with similar radiant composite elements of a known type (the well-known heating films of the prior art that do not exceed operating temperatures equal to 60°C): this without suitably undergoing deformation, damage, sparkling, incandescence, fire and, more generally, downtime, but remaining structurally and functionally intact in the use for which it is intended.

[0023] Still advantageously, the thermally conductive and heating composite element of the current invention provides a thermo-conductive and heating circuit of the electrical type which, thanks to the possibility of modulating the number of continuous resistive tracks thereof, allows to get the exact power useful for the intended use, thus determining a high customization capacity not found in any way in the radiant composite elements of the electrical type of the prior art.

BRIEF DESCRIPTION OF THE FIGURES



[0024] Further features and particularities of the present invention will become more evident from the following description, relating to preferred embodiments of the thermally conductive and heating composite element exclusively claimed herein, given for indicative and illustrative non-limiting purposes, with reference to the accompanying drawings in which:
  • figures 1 and 2 are two distinct assonometric views of a first possible executive variant of the thermally conductive and heating composite element of the invention;
  • figures 3 and 4 are two distinct partly exploded views of the composite element of figures 1 and 2;
  • figure 5 is the assonometric view from below of figures 3 and 4;
  • figure 6 is a partial and exploded view of the composite element of figures 1 and 2;
  • figure 7 is a partially exploded assonometric view of a second possible executive variant of the thermally conductive and heating composite element of the invention;
  • figure 8 is an assonometric view of a third possible executive variant of the thermally conductive and heating composite element of the invention.

DETAILED DESCRIPTION OF A FAVORITE


EMBODIMENT OF THE INVENTION



[0025] The thermally conductive and heating composite element with very low voltage electrification of the invention is described in a first embodiment in figures 1 and 2, where it's overall indicated with 1 and where, in this case, is shown as a technical fabric or flexible laminar film. The composite radiant element 1 of the invention is supplied and available ready for use, tailor-made for any environment and application, without requiring interventions on site to adapt it, in size, to the physical support for which it is intended.

[0026] It is observed that the thermally conductive, radiant and heating composite element 1 comprises:
  • a laminar support layer 2 provided with a first face 2a adapted to remain facing towards the outside in application conditions, and with a second face 2b, opposite to the first face 2a, adapted to be coupled to a reference surface (not shown) still in application conditions;
  • a thermo-conductive and heating circuit 3 of the electrical type, applied to the first face 2a of the laminar support layer 2 and adapted to be electrically connected to an electrical power supply source (not described except partially and diagrammatically in the electrical power supply cables C1 and C2 thereof) with a very low voltage within the range of values from 2 Volts to 50 Volts, adapted to electrify the thermo-conductive circuit 3 to produce heat by radiation.


[0027] In accordance with the invention, the thermo-conductive and heating circuit 3 of the electrical type comprises, in this case (and contrary to what is shown in the prior art document published as US2008/083743 A1), a single continuous resistive track 4 distributed on the first face 2a of the laminar support layer 2 and provided with a first end 4a, adapted to be coupled to a first electrical pole P of the electrical power supply source, and a second end 4b adapted to be coupled to a second electrical pole N, having a polarity opposite to the polarity of the first electrical pole P, of the electrical power supply source.

[0028] As it may be seen in figures 1-5, the continuous resistive track 4 is, in a suitable although not limiting manner, uniformly distributed on the first face 2a of the laminar support layer 2; preferably, but not necessarily, the continuous resistive track 4 is laid in the form of conductive ink or conductive paste (for example, made of silver with the addition of polymers with high adhesive capacity) on such first face 2a of the laminar support layer 2 itself, specifically by means ejection means, piezoelectric dispensers or volumetric dispensers that carry out a continuous deposition of microdrops.

[0029] Thereby, the entire first face 2a of the laminar support layer 2 emits heat due to the Joule effect in a homogeneous manner in a very rapid time (for example, a 24 Volt electrical power supply leads the composite element 1 of the invention to a temperature of 50°C in approximately fifteen seconds).

[0030] It is underlined in this regard that, contrary to the invention described herein, the previous document US2008/083743 A1 indicates that the formation of paste or ink (electrically conductive part) on the surface of at least one of the electrically insulating layers which laterally cover, by sandwiching, the four conductive and heating elements obtained due to such application, occurs by means of the so-called screen printing technique that disadvantageously does not allow the shape and power of the electrical circuit to be varied.

[0031] The four circuits mentioned above are also connected to the electrical power supply network by means of two common and opposed wiring cables or electrical conductors or electrical contacts (bus wires) that are completely absent in the thermally conductive, radiant and heating composite element 1 of the invention: each of such electrical conductors or electrical contacts consists of a braided or multiwire copper cable with a circular, flat or different shape, in cross section, and the ends thereof are provided with connectors for the connection to the electrical distribution network, by means of respective external electrical cables.

[0032] On its side, the specific heating element of the electrical circuit described in the previous document US2005/082280 A1 is not laid at all, as it occurs in the heating element of the invention, but it is obtained by photochemically etching with nickel, copper or steel a metallized fabric mesh that therefore gives little flexibility to the final product.

[0033] Finally, it is highlighted that the previous document KR20160131389 A describes heat supply means which, unlike the object of the invention claimed herein, comprise an electrical cable applied by means of stitching or tacking to the basic insulating substrate.

[0034] In addition, in the invention, the continuous resistive track 4 has an extremely reduced thickness, with a value from 1 µm to 200 µm.

[0035] Furthermore, the continuous resistive track 4 consists of a conductive material that emits electromagnetic radiation when electrified by the very low voltage electrical power supply source.

[0036] The electromagnetic radiations are preferably infrared rays, with electrical powers developed from 50 W/m2 to 1,000 W/m2, varying in particular from 1 W/m2 to 400 W/m2 with a 24 Volt power supply (the highest among the heating films with very low voltage existing on the market), or from 20 W/m2 to 400 W/m2 with power supplies from 1 Volt to 48 Volt; the frequency variation of the infrared rays is given by the type of combination of the conductive materials with which the continuous resistive track is made (inks and/or pastes) and by the electrical power supply.

[0037] With regard to the conductive material of the continuous track 4, it is any one of the electrifiable thermo-conductive materials selected from the group consisting of silver, copper, carbon, carbon nanotubes, graphene, gold, nickel and/or combinations thereof.

[0038] Preferably, the laminar support layer 2 consists of a technical fabric, generally flexible and continuous which, unlike the thermal insulation layer defined in the document of the prior art KR20160131389 A, is made of any one of the materials selected from the group consisting of glass fiber, carbon fiber and/or combinations thereof.

[0039] In a preferred but non-binding manner, such flexible and moderately elastic technical fabric has a flat weave, to make (by means of an ejection system in the case of conductive inks, or by means of piezoelectric dispensers, piezoelectric dispensers with pressurized valves, contact volumetric dispensers and pressurized jet volumetric dispensers in the case of conductive pastes) the laying or application of the thermo-conductive and heating circuit 3 (such as, for example, the continuous track 4) on the first face 2a of the laminar support layer 2 more uniform and balanced.

[0040] More in detail, the flexible technical fabric presents a weight value from 50 g/m2 to 500 g/m2.

[0041] It follows, essentially, that the thermally conductive and heating composite element 1 of the invention, shown in the accompanying figures 1-6, is configured as a heating fabric capable of producing and undergoing temperatures of up to 250°C, without being damaged and without the constructive and functional stability thereof and safety of use thereof being compromised.

[0042] The thermally conductive and heating composite element 1 of the invention in the form of a technical fabric is resilient, provided with elastic memory, resistant to UV rays and has high dielectric strength.

[0043] The elastic memory makes the thermally conductive and heating composite element 1 of the invention moldable to create protection systems for intense cold (up to -60°C), so that to cover and protect engines, mechanical parts, tanks or reservoirs of fuel and oil, tensile structures, tents, roofs and storage batteries for vehicles, allowing safe uses that are not achievable with the radiant composite elements of the electrical type of the prior art involved herein.

[0044] In essence, by virtue of the technical features of the flexible technical fabric which, preferably, forms the laminar support layer (or substrate) 2, the applications of the thermally conductive and heating composite element 1 of the invention are rather numerous: the soft consistency thereof allows, in fact, to cover the most complex shapes, conforming thereto, and to be integrated into a multitude of products, especially if intended for protective applications from the cold, from frost due to snow and ice, of plants, animals, human beings, energy storage batteries, tents, roofs, heat engines, tanks and reservoirs, aircraft wings, take-off runways, sloped accesses in mountain places, just to name a few applications.

[0045] The deformability and workability of the thermally conductive and heating composite element 1 of the invention are unlimited: even when folded several times it does not become damaged and the thermo-electrical capacities of the flexible technical fabric which, preferably, characterizes it, are not interrupted, conversely with respect to what happens with the majority of electrified heating films on the market or shown in the patent documents cited above, not least the one published as US2005/082280 A1.

[0046] Last but not least, the modeling capacity of the thermally conductive and heating composite element 1 of the invention, in the form of a technical fabric, allows adaptability to the most varied finished and final shapes, for example to cover and protect any object from frost.

[0047] However, this does not exclude that, in other embodiments of the invention, the laminar support layer consists of a rigid, three-dimensional and/or extensible component, so that the thermo-conductive and heating composite element of the invention may be configured as a panel, a support surface, a slab, a decorative body and so on.

[0048] According to the preferred embodiment described herein of the invention, the thermally conductive and heating composite element 1 further comprises stabilization means, overall numbered with 5, applied to the second face 2b (opposed to the one in which the thermo-conductive and heating circuit 3 of the electrical type is applied) of the laminar support layer 2 and adapted to give greater stability and protection to the latter 2, a particularly useful aspect during the step of applying the thermo-conductive and heating circuit 3 of the electrical type.

[0049] In particular, the stabilization means 5 comprise, by way of a preferred example, a layer (or film) of elastomeric resin 6, shown in figure 6 in an augmented and accentuated manner (for explanatory purposes only), spread over the entire second face 2b of the laminar support layer 2.

[0050] Preferably but not limitedly, the layer of elastomeric resin 6 has a weight value from 10 g/m2 to 500 g/m2 (for example, equal to 100 g/m2) and a thickness not exceeding 110 µm, determined according to the final use of the composite radiant element 1 of the invention.

[0051] Still preferably but not exclusively, the elastomeric resin 6 is silicone applied by means of a surface finishing treatment carried out in a high temperature oven.

[0052] In other embodiments of the thermally conductive and heating composite element of the invention, not accompanied by reference drawings, the stabilization means may comprise a layer (or film) made of aluminum having a weight value still from 10 g/m2 to 500 g/m2 (for example, equal to 200 g/m2) and a thickness still not exceeding 110 µm.

[0053] What has just been indicated in relation to the stabilization means 5, which the composite element 1 of the invention is provided with, contrasts with what is highlighted in the previous document KR20160131389 A, in which the internal layer (or the external layer) is a sheet with a certain thickness (up to 2 mm), described only according to the insulating properties thereof and made of any of the materials selected from the group consisting of Teflon-coated non-woven fabric, carbon fiber, aramid fiber, silica fiber, glass fiber or E-PTFE fiber.

[0054] It should be noted that the laminar support layer 2, the thermo-conductive and heating circuit 3 of the electrical type and the stabilization means 6 form a structural assembly having a very limited thickness, not exceeding 1 mm, in any case provided with high resistance to traction, shear and bending.

[0055] Figures cited so far also highlight the advantageous system for connecting the continuous resistive track 4 of the thermo-conductive and heating circuit 3 to the electrical power supply cables C1 and C2 of the very low voltage electrical power supply source, which occurs without the interposition of intermediate physical electrical contacts (bus wires) of the type described in the previous document US2008/0083743 A1, but it's obtained exclusively and solely by means of a press-fit connector 7 that presses from opposite sides onto the laminar support layer 2.

[0056] More specifically, the press-fit connector 7 comprises a first shaped bracket 8, to which the electrical power supply cable C1 is coupled, and a second shaped bracket 9, completely identical in shape to the first shaped bracket 8, from which it is slightly spaced apart, to which the power supply cable C1 is coupled.

[0057] Each of the aforesaid shaped brackets 8, 9 preferably but not necessarily comprises:
  • a first flat plate 10 that first identifies a horizontal plane (see figures 3-5) and, subsequently (i.e., when it contacts the respective ends 4a and 4b of the continuous resistive track 4 at the top and is in the operating position, see figures 1 and 2), a horizontal plane after being folded by 90°;
  • a second flat plate 11, monolithic or coupled by means of junction means (such as, for example, a welding section) to said first flat plate 10 and identifying a horizontal plane distinct and parallel with respect to the horizontal plane identified by the first plate 10 in the operating position: the entire upper surface 11a of the second flat plate 11 contacts the lower face 2b of the laminar support layer 2, or rather, in this case, the lower surface of the layer of elastomeric resin 6 of the stabilization means 5.


[0058] To allow such form of coupling of the press-fit connector 7 to the laminar support layer 2 and to the thermo-conductive and heating circuit 3, the first plate 10 and the second plate 11 of each shaped bracket 8, 9 define a longitudinal slot 12 therebetween that accommodates a pre-established section (not numbered for simplicity) of the laminar layer 2 at a perimeter segment of the latter: it is precisely such pre-established section of the laminar layer 2 that is pressed by the press-fit connector 7 when it is coupled to the structural assembly identified above.

[0059] Figure 7 shows a first possible embodiment of the invention in which the thermally conductive and heating composite element, now overall indicated with 50, differs from the one described above and numbered with 1 due to the profile of the structural assembly formed by the laminar support layer 51, by the thermo-conductive and heating circuit 52 of the electrical type and, also in this case but preferably, by the stabilization means 54: the profile, rather than being rectangular as in figures 1-6, is, indeed, circular.

[0060] This last figure shows how the thermally conductive and heating composite element of the invention may be produced in different shapes and sizes, thus adapting to the most diverse customer requests and various types of applications, without any constraints, as it occurs instead with the heating films of the type available on the market.

[0061] Figure 8 highlights a further possible embodiment of the invention in which the thermally conductive and heating composite element, now overall indicated with 100, differs from those already described, numbered with 1 and 50, due to the fact that the flexible technical fabric that forms the laminar support layer 101 is perforated, presenting a plurality of through holes 104 obtained in the thickness of the laminar layer 101 and between which the continuous resistive track 103 forming the thermo-conductive and heating circuit 102 extends tortuously. In this regard, it is specified that a continuous fabric, such as that of the most relevant prior art described above, is an element which may not be used in stratigraphic construction systems (furniture, walls, doors, etc.) since it is a separating element that does not allow mechanical continuity between the various layers forming the artefacts. In fact, it is a disjunctive element that does not allow the passage of the adhesive part between the support layer and the finishing layer.

[0062] The innovative solution shown in the thermally conductive and heating composite element 100, by virtue of the presence of holes, allows mechanical continuity between the various layers, allowing the passage of glues and mutual mechanical anchoring (for example, between support/substrate and finishing, of the type: masonry and plaster or MDF (acronym of Medium-density fiberboard) or solid wood and veneer of furniture and so on).

[0063] It is therefore not a mesh on which a cable or an electrical element is applied, by means of various methodologies, but rather a technical fabric on which the thermo-conductive and heating electrical circuit 102 is first laid, which is then carefully perforated to give mechanical stability to the mesh that in fact is at the same time thermo-emissive, in a thickness of less than a millimeter.

[0064] The description just provided therefore allows to highlight how the thermally conductive and heating composite element of the present invention, resulting from very low voltage electrification, meets the objects and achieves the advantages mentioned above.

[0065] During the implementation step, modifications may be made to the thermally conductive and heating composite element of the current invention, consisting, for example, of a number of continuous resistive tracks different from that described above and visible in the accompanying figures, such number varying according to construction choices and/or application needs, starting from one.

[0066] In particular, in the case in which the thermally conductive and heating composite element of the invention comprises a plurality of continuous resistive tracks (multi-track), these are generally and preferably parallel to each other (even if they follow an articulate path) and allow to ensure a longer duration of the operation of the radiant product claimed herein, since they make up for any damage to any of such continuous tracks.

[0067] The innovative radiant composite element of the invention is encapsulated or integrated into several materials, products for improving personal indoor and outdoor thermal comfort, such as furniture, windows, cushions, mirrors, paintings, vertical ceramic coverings and more, as well as for space heating.

[0068] It is reiterated that the composite radiant, thermo-conductive and heating element of the invention may also be used, with high safety standards, for protecting people, plants, animals, engines (especially thermal engines), reservoirs, energy storage batteries (for vehicles, airplanes, boats, trains, buildings) from cold and frost.

[0069] In fact, one of the preferred applications of the thermally conductive and heating composite element of the invention is the protection of energy storage batteries for cars and buildings (residential, public, industrial, housing). In this regard, it should be noted that several studies have shown that the load capacity and autonomy of batteries significantly drops with temperatures below zero. The values of capacity and autonomy loss of the aforesaid batteries drop by 41% at -6°C and continue to decrease at lower temperatures.

[0070] The systems in use for heating the batteries appear to be energy-intensive (from 5 to 7 Kwh, a value which, although contained, still reduces the autonomy of the energy storage batteries) and incapable of operating at temperatures below -20°C.

[0071] Furthermore, size, weight and costs of the heating systems must also be considered: by means of the thermally conductive and heating composite element of the invention it is possible to maintain the temperature of the batteries in cold months and places, with an energy consumption between 0.3 and 1 Kwh (depending on the size of the battery pack to be protected) thus ensuring an effective recharging thereof and the maintenance of the operating autonomy.

[0072] It's clear that several other changes could be made to the thermally conductive and heating composite element concerned, falling within the scope limited by the accompanying claims.

[0073] Where the constructional features and techniques mentioned in the following claims are followed by reference signs or numerals, such reference signs were introduced for the sole purpose of increasing the intelligibility of the claims themselves, and therefore have no limiting effect on the interpretation of each element identified, by way of example only, by such reference signs.


Claims

1. A thermally conductive and heating composite element (1; 50; 100) comprising:

- a laminar support layer (2; 51; 101) provided with a first face (2a) adapted to remain facing towards the outside in application conditions, and with a second face (2b), opposite to said first face (2a), adapted to be coupled to a reference surface in application conditions;

- a thermo-conductive and heating circuit (3; 52; 012) of the electrical type, applied to said first face (2a) of said laminar support layer (2; 51; 101), electrically connectable to a very low voltage electrical power supply source comprised in the range of values 2 Volts to 50 Volts, adapted to electrify said thermo-conductive circuit (3; 52; 102) to produce heat,

characterized in that said thermo-conductive and heating circuit (3; 52; 102) comprises at least one continuous resistive track (4; 103) distributed on said first face (2a) of said laminar support layer (2; 51; 101) and provided with a first end (4a), adapted to be coupled to a first electrical pole (P) of said electrical power supply source, and a second end (4b) adapted to be coupled to a second electrical pole (N), having a polarity opposite to the polarity of said first electrical pole (P), of said electrical power supply source.
 
2. Element (1; 50; 100) according to claim 1), characterized in that said continuous resistive track (4; 103) is uniformly distributed on said first face (2a) of said laminar support layer (2; 51; 101).
 
3. Element (1; 50; 100) according to 1) or 2), characterized in that said continuous resistive track (4; 103) is laid, by means of ejection means, piezoelectric dispensers or volumetric dispensers, in the form of conductive ink or conductive paste on said first face (2a) of said laminar support layer (2; 51; 101).
 
4. Element (1; 50; 100) according to claim 1), 2) or 3), characterized in that said continuous resistive track (4; 103) has a thickness value from 1 µm to 200 µm.
 
5. Element (1; 50; 100) according to any of the preceding claims, characterized in that said continuous resistive track (4; 103) consists of a conductive material that emits electromagnetic radiations when electrified by said electrical power supply source.
 
6. Element (1; 50; 100) according to claim 5), characterized in that said electromagnetic radiations are infrared rays.
 
7. Element (1; 50; 100) according to claim 5) or 6), characterized in that said conductive material is any one of the electrifiable thermo-conductive materials selected from the group consisting of silver, copper, carbon, carbon nanotubes, graphene, gold, nickel and/or combinations thereof.
 
8. Element (1; 50; 100) according to any of the preceding claims, characterized in that said laminar support layer (2; 51) consists of a technical fabric made of any of the materials selected from the group consisting of glass fiber, carbon fiber and/or combinations thereof.
 
9. Element (1; 50) according to claim 8), characterized in that said technical fabric has a flat weave to make the laying of said thermo-conductive and heating circuit (3; 52) on said first face (2a) of said laminar support layer (2; 51) more uniform.
 
10. Element (1; 50) according to claim 8) or 9), characterized in that said technical fabric has a weight value from 50 g/m2 to 500 g/m2.
 
11. Element (100) according to claim 8), characterized in that said technical fabric is perforated.
 
12. Element (1; 50; 100) according to any of the preceding claims, characterized in that it comprises stabilization means (5; 54) applied to said second face (2b) of said laminar support layer (2; 51; 101) and adapted to give greater stability to said laminar support layer (2; 51; 101).
 
13. Element (1; 50; 100) according to claim 12), characterized in that said stabilization means (5; 54) comprise at least one layer of elastomeric resin (6) spread on said second face (2b) of said laminar support layer (2; 51; 101).
 
14. Element (1; 50; 100) according to claim 13), characterized in that said layer of elastomeric resin (6) has a weight value from 10 g/m2 to 500 g/m2.
 
15. Element (1; 50; 100) according to claim 13) or 14), characterized in that said elastomeric resin (6) is silicone.
 
16. Element (1; 50; 100) according to claim 12), characterized in that said laminar support layer (2; 51; 101), said thermo-conductive and heating circuit (3; 52; 102) of the electrical type and said stabilization means (5; 54) form a structural assembly having a thickness not exceeding 1 mm.
 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description