(19)
(11)EP 3 297 395 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
26.06.2019 Bulletin 2019/26

(21)Application number: 17192225.5

(22)Date of filing:  20.09.2017
(51)International Patent Classification (IPC): 
H05B 3/14(2006.01)
H05B 3/34(2006.01)
B64D 15/12(2006.01)

(54)

THERMALLY CONDUCTIVE, ELECTRICALLY INSULATING PROTECTION LAYER FOR DE-ICING HEATERS

WÄRMELEITENDE, ELEKTRISCH ISOLIERENDE SCHUTZSCHICHT FÜR ENTEISUNGSHEIZER

COUCHE DE PROTECTION ISOLANTE ÉLECTRIQUEMENT ET THERMIQUEMENT CONDUCTRICE POUR CHAUFFAGES DE DÉGIVRAGE


(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 MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 20.09.2016 US 201615271003

(43)Date of publication of application:
21.03.2018 Bulletin 2018/12

(73)Proprietor: Goodrich Corporation
Charlotte, NC 28217-4578 (US)

(72)Inventors:
  • HU, Jin
    Hudson, OH 44236 (US)
  • BOTURA, Galdemir Cezar
    Akron, OH 44313 (US)

(74)Representative: Dehns 
St. Brides House 10 Salisbury Square
London EC4Y 8JD
London EC4Y 8JD (GB)


(56)References cited: : 
EP-A1- 2 963 995
GB-A- 2 445 458
US-B1- 6 237 874
WO-A1-2012/015472
US-A1- 2014 014 640
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND



    [0001] An aircraft moving through the air is often subjected to ice formation, and anti-icing or de-icing devices must be used to remove or prevent ice from accumulating on exterior surfaces of the aircraft. For any type of electrical heaters or de-icing heaters, the closer the heater is to the skin of an airfoil, nacelle, nosecone, engine cowl, or other aircraft part, the less power it takes to heat or de-ice the aircraft element due to the proximity of the heater to the external surface. Thus, aerospace applications of de-icing heaters attempt to place those heaters as close to the external surface, as possible. However, heaters used for de-icing on aircrafts are often subject to foreign object damage (FOD), such as hail, bird strikes, and other debris, particularly when those heaters are placed too close to the surface. Ideally, the heater uses minimal power to accomplish de-icing but is protected from FOD.

    [0002] The materials used to protect heaters used for de-icing must be thermally conductive, allowing transfer of heat between the heater and the external surface of the aircraft element, but must also be electrically insulating to prevent shorting of the heater. Most thermally conductive materials are also electrically conductive, limiting the choice of materials.

    [0003] US6237874 describes a heating assembly. according to the preamble of the independent claims. GB2445458 describes a polymer film comprising boron nitride. WO2012/015472 describes boron nitride fabrics.

    SUMMARY



    [0004] A heating assembly includes a boron nitride nanotube fabric; a first adhesive; a heating element, wherein the boron nitride nanotube fabric is attached to the heating element by the first adhesive; a second adhesive; and a glass pre-preg fabric, wherein the glass pre-preg fabric is attached to the heating element by the second adhesive on a side of the heating element opposite the boron nitride nanotube fabric.

    [0005] A method for making a heating assembly includes obtaining a boron nitride nanotube fabric; bonding the boron nitride nanotube fabric to a heating element with a first adhesive; bonding the heating element to a glass pre-preg fabric with a second adhesive; and curing the assembly.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0006] 

    FIG. 1A is a schematic diagram of a thermally conductive, electrically insulated protected heater assembly.

    FIG. 1B is a schematic diagram of a thermally conductive, electrically insulated protected heater assembly in a different embodiment.

    FIG. 1C is a schematic diagram of a thermally conductive, electrically insulated protected heater assembly in a different embodiment.

    FIG. 1D is a schematic diagram of a thermally conductive, electrically insulated protected heater assembly in a different embodiment.

    FIG. 1E is a schematic diagram of a thermally conductive, electrically insulated protected heater assembly in a different embodiment.

    FIG. 2 is a perspective view of heating assembly 10A shown in FIG. 1A.

    FIG. 3 is a flowchart depicting a method of making a thermally conductive, electrically insulated protected heater assembly.


    DETAILED DESCRIPTION



    [0007] A de-icing heater can be protected by strong, thermally conductive but electrically insulating material such as boron nitride nanotube (BNNT) fabric. BNNT fabric is strong enough to mitigate mechanical damage from bird strikes, hail, or other foreign object damage (FOD) when a heater is attached near an external surface of an aircraft. BNNT fabric additionally provides acoustic insulation, and can protect a de-icing heater on a breeze side of an airfoil or other aircraft structure from vibrational disturbances.

    [0008] FIG.s 1A-1E will be discussed together. FIG. 1A is schematic diagram of a thermally conductive, electrically insulated protected heater assembly 10A. Assembly 10A has breeze side 12 and bond side 14. Breeze side 12 faces an external environment and is subject to icing. Bond side 14 can be attached to part of an aircraft, such as an airfoil or other element. Assembly 10A includes metallic skin 16, third film adhesive 18, boron nitride nanotube (BNNT) pre-preg fabric 20, first film adhesive 22, electric heater 24, second film adhesive 26, and glass pre-preg fabric 28. Metallic skin 16 is attached to BNNT pre-preg fabric 20 by third film adhesive 18. BNNT pre-preg fabric 20 is attached to electric heater 24 through first film adhesive 22. Electric heater 24 is attached to glass pre-preg fabric 28 by second film adhesive 26. Glass pre-preg fabric 28 can be attached to an aircraft component (not pictured).

    [0009] On breeze side 12 of heating assembly 10A is metallic skin layer 16, which is connected to BNNT pre-preg fabric 20 by third film adhesive 18. Third film adhesive 18 can be a commercially available adhesive which is thermally conductive. Third film adhesive 18 can be the same or different from first and second adhesives 22, 26. Skin layer 16 is a metallic or alloy-based skin designed to prevent foreign object damage to electric heater 24. Because skin layer 16 is electrically conductive, it should not be directly adhered to electric heater 24. Instead, BNNT pre-preg fabric 20 is sandwiched between skin layer 16 and electric heater 24.

    [0010] BNNT pre-preg fabric 20 is a nontoxic, electrically insulating, and thermally conductive fabric material made of boron nitride nanotubes and an appropriate polymer resin. Its high strength is similar to the strength of carbon nanotubes (CNT), which have been used as a bullet-proof material and in a variety of aerospace applications.

    [0011] BNNTs are a type of one-dimensional nanostructure that are a close analogue to carbon nanotubes (CNTs), but are comprised of hexagonal B-N bond networks. BNNT bonds have partial ionic character due to the difference in electronegativity of nitrogen and boron. This causes BNNTs to be electrically insulating while CNTs are generally semiconductors. Moreover, BNNTs exhibit thermal conductivity, thermal stability, chemical stability and, when in fabric form, superhydrophobicity. Thus, BNNTs share mechanical properties of CNTs, but have additional advantages such as greater thermal and chemical stability, and optical and infrared transparency.

    [0012] To create the BNNT fabric, BNNT is grown in a laboratory. Several methods of synthesizing BNNTs can be used, including catalyst-based chemical vapor deposition, ball-milling and annealing methods, arc-discharge, plasma-enhanced pulsed laser deposition, laser vaporization, or other methods. The BNNTs are then impregnated with a polymer resin, such as an epoxy, a phenolic polymer or a bismaleimide. The fabric is then cured before being used. Alternatively, some BNNT fabrics are commercially available.

    [0013] BNNT pre-preg fabric 20 is connected to electric heater 24 by first film adhesive 22. First film adhesive 22 can be a commercially available adhesive. First film adhesive 22 can be the same or different from third adhesive 18. Electric heater 24 can be a nano-carbon heater or a resistive heater. Resistive heaters are comprised of metals or metal alloys, and are more cost-efficient, but higher weight than carbon alternatives. Nano-carbon heaters can be made of carbon nanotubes (CNTs), graphene, or graphene nanoribbons (GNTs). Carbon allotrope heaters are uniquely beneficial for de-icing because of their high efficiency, light weight, low cost, ability to be moulded into specific shapes, and durability.

    [0014] BNNT pre-preg fabric 20 protects electric heater 24 from foreign object damage (FOD), such as hail, bird strikes, or other events that may damage electric heater 24. BNNT is thermally conducting, so heat from electric heater 24 can still move to breeze side 12 and work to de-ice the aircraft part, but is electrically insulating, so electric heater 24 is not shorted. BNNT pre-preg fabric 20 helps to ensure electric heater 24 can still de-ice aircraft parts, but is more resistant to FOD.

    [0015] Electric heater 24 turns electric current received from a power source (not pictured) into heat, preventing ice formation on an aircraft element such as an airfoil, nacelle, nosecone, engine cowl, or other aircraft part. While electric heater 24 is de-icing an aircraft element, BNNT pre-preg fabric 20 protects electric heater 24 from FOD and electrically insulates electric heater 24. Additionally, BNNT pre-preg fabric 20 is acoustically insulating. Thus, the aircraft element and electric heater 24 are protected from acoustic vibrations during operation of aircraft.

    [0016] Glass pre-preg fabric 28 is attached to electric heater 24 by second film adhesive 26. Second film adhesive 26 is a commercially available adhesive, and can be the same or different from third and first adhesives 18 and 22. Glass pre-preg fabric 28 can be a commercially available glass pre-preg fabric. Glass pre-preg fabric 28 protects electric heater 24 on bond side 14 of heating assembly 10A. Glass pre-preg fabric 28 can be attached to an element of an aircraft (not pictured), such as an airfoil, nacelle, nosecone, engine cowl, or other aircraft part.

    [0017] The embodiments shown in FIG. 1B - 1E are variations on assembly 10A shown in FIG. 1A. All elements are the same except where otherwise noted. In FIG. 1B, metallic skin 16 is replaced with carbon fabric skin 30. Carbon pre-preg fabric skin 30 is lighter weight than metallic skin 16, and is durable. In FIG. 1C, carbon nanotube (CNT) pre-preg skin 32 replaces metallic skin 16. CNT pre-preg skin 32 is uniquely beneficial for de-icing because of its high efficiency, light weight, ability to be moulded into specific shapes, and durability. In FIG. 1D, CNT filled film skin 34 is used instead of metallic skin 16. Each of the carbon-based skins in FIG. 1B - 1D has unique properties and may be more useful in different parts of an aircraft, depending on the needs of that particular aircraft element.

    [0018] In FIG. 1E, there is no additional skin layer. Instead, BNNT pre-preg fabric 20 serves as the outermost skin layer in heating assembly 10E. This arrangement still provides FOD protection to electric heater 24 because of BNNT pre-preg fabric 20's strength and durability. But it also minimizes cost and weight by eliminating one layer of the heating assembly. This embodiment is useful in environments where a thicker skin is not needed.

    [0019] FIG. 2 shows a perspective view of heating assembly 10A, also pictured as a schematic diagram in FIG. 1A. Assembly 10A is shown as a bendable sheet, which can be formed to an aircraft element (not pictured). Heating assembly 10A is a thin sheet with breeze side 12, facing the external surface subject to icing, and bond side 14, which will be bonded to an aircraft element.

    [0020] FIG. 3 is a flowchart depicting method 40 of preparing a thermally conductive, electrically insulated protected heater assembly. Method 40 begins with steps 44 and 46, where the layers of the assembly are adhered together. The layers include a BNNT pre-preg fabric, an electric heater, a pre-preg glass fabric, and at least one adhesive.

    [0021] The BNNT pre-preg fabric can be commercially obtained or fabricated. If it is fabricated, a BNNT matrix is impregnated with a polymer, such as an epoxy, a phenolic polymer or a bismaleimide. The BNNT matrix impregnated with the polymer is then cured. The resulting BNNT fabric is very strong, thermally conductive and electrically resistant.

    [0022] The electric heater is typically a sheet heater, and can be a carbon-based or resistive type heater. The glass pre-preg fabric can be commercially obtained, or fabricated. The adhesive is typically a film adhesive which will be used between the layers of the assembly.

    [0023] The BNNT fabric is bonded to an electric heater with an adhesive. The BNNT fabric can serve as the external protection of the electric heater, or can be layered with a "skin," such as a metallic or carbon-based fabric, to create a tougher protection layer. The BNNT fabric protects the heating element from FOD. The glass pre-preg layer is adhered to the side of the electric heater opposite the BNNT fabric with another film adhesive. The heating element is "sandwiched" between the BNNT fabric and the glass pre-preg.

    [0024] Finally, in step 48, the assembly is cured to secure the adhesives. The assembly can then be applied to an external surface of an aircraft, such as an airfoil, nacelle, nosecone, engine cowl, or other aircraft part.

    [0025] The use of a BNNT fabric to protect an electrical heater used for de-icing has several benefits. Generally, for de-icing purposes, electrical heaters should be placed closer to the outside of an aircraft, so heating the surface takes less power. However, the closer a heater is to an external surface, the more likely it will be harmed by foreign object damage, including birds, hail and other surface damage. Thus, the best de-icing heaters are both close to the surface and well protected from FOD.

    [0026] The BNNT fabric is uniquely good at protecting de-icing heaters because it is both thermally conductive, allowing heat to pass through the BNNT fabric, and electrically insulating, preventing the heaters from being shorted. BNNT fabric is also very strong and capable of mitigating FOD. Additionally, BNNT fabric is acoustically damping, which allows the de-icing heaters to withstand vibrations and maintain longer lifespans. Thus, when BNNT is attached to an electric heater on an aircraft for de-icing, the heater is a low-power heater close to the surface, with an FOD-withstanding heating structure.

    Discussion of Possible Embodiments



    [0027] The following are non-exclusive descriptions of possible embodiments of the present invention.

    [0028] A heating assembly includes a boron nitride nanotube fabric; a first adhesive; a heating element, wherein the boron nitride nanotube fabric is attached to the heating element by the first adhesive; a second adhesive; and a glass pre-preg fabric, wherein the glass pre-preg fabric is attached to the heating element by the second adhesive on a side of the heating element opposite the boron nitride nanotube fabric.

    [0029] The assembly of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
    The assembly includes a skin, wherein the skin is attached to the boron nitride nanotube fabric by a third adhesive.

    [0030] The skin is comprised of a metal, an alloy, or a combination thereof.

    [0031] The skin is comprised of a carbon pre-preg fabric.

    [0032] The skin is comprised of a carbon nanotube pre-preg fabric.

    [0033] The skin is comprised of a carbon nanotube filled film.

    [0034] The heating element is a nano-carbon heater.

    [0035] The heating element is a resistive heating element.

    [0036] The boron nitride nanotube fabric is impregnated with a polymer chosen from the group consisting of an epoxy, a phenolic polymer, a bismaleimide, or combinations thereof.

    [0037] The assembly may further include one or more additional layers. The one or more additional layers may comprise pre-preg fabrics.

    [0038] A method for making a heating assembly (e.g. as herein described) includes obtaining a boron nitride nanotube fabric; bonding the boron nitride nanotube fabric to a heating element with a first adhesive; bonding the heating element to a glass pre-preg fabric with a second adhesive; and curing the assembly.

    [0039] The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
    The method includes adhering a first skin layer to the boron nitride nanotube fabric with a third adhesive.

    [0040] Obtaining a boron nitride nanotube fabric comprises impregnating a boron nitride nanotube matrix with a polymer and curing the boron nitride nanotube fabric.

    [0041] The boron nitride nanotube fabric is impregnated with a polymer chosen from the group consisting of an epoxy, a phenolic polymer, or bismaleimide, or combinations thereof.

    [0042] The heater is a nano-carbon heater.

    [0043] The heater is a resistive heater.

    [0044] The first skin is comprised at least one of a metal or an alloy.

    [0045] The first skin is comprised of a carbon pre-preg fabric.

    [0046] The method may further include attaching a second skin to the first skin with a film adhesive.

    [0047] The method may further include attaching a second pre-preg fabric to the glass pre-preg fabric with an adhesive.

    [0048] The method may include more than one curing step.

    [0049] The method includes curing the assembly after adhering the boron nitride nanotube fabric to the electric heater.

    [0050] The method includes curing the assembly after adhering the glass pre-preg fabric to the electric heater.

    [0051] The method includes curing the assembly after adhering the skin to the boron nitride nanotube fabric.

    [0052] While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.


    Claims

    1. A heating assembly comprising:

    a boron nitride fabric (20);

    a first adhesive (22);

    a heating element (24), wherein the boron nitride fabric is attached to the heating element by the first adhesive (22);

    a second adhesive (26); and

    a glass pre-preg fabric (28), wherein the glass pre-preg fabric (28) is attached to the heating element (24) by the second adhesive (26) on a side of the heating element (24) opposite the boron nitride fabric (20), characterised in that the boron nitride fabric (20) is a boron nitride nanotube fabric.


     
    2. The assembly of claim 1 further comprising a skin (16, 30, 32), wherein the skin (16, 30, 32) is attached to the boron nitride nanotube fabric by a third adhesive (18).
     
    3. The assembly of claim 2, wherein the skin (16, 30, 32) comprises a material selected from the group consisting of a metal, an alloy, a carbon pre-preg fabric, a carbon nanotube pre-preg fabric, and a carbon nanotube filled film.
     
    4. The assembly of any preceding claim, wherein the heating element (24) is a nano-carbon heater, or a resistive heating element.
     
    5. The assembly of any preceding claim, wherein the boron nitride nanotube fabric (20) is impregnated with a polymer selected from the group consisting of an epoxy, a phenolic polymer, a bismaleimide, and combinations thereof.
     
    6. The assembly of any preceding claim, further comprising one or more additional layers.
     
    7. The assembly of claim 6, wherein the one or more additional layers comprise pre-preg fabrics.
     
    8. A method for making a heating assembly, the method comprising:

    bonding a boron nitride fabric (20) to a heating element (24) with a first adhesive (22);

    bonding the heating element (24) to a glass pre-preg fabric (28) with a second adhesive (26); and

    curing the assembly, characterised in that the boron nitride fabric (20) is a boron nitride nanotube fabric (20).


     
    9. The method of claim 8, wherein the boron nitride nanotube fabric (20) is formed by the steps of:

    impregnating a boron nitride nanotube matrix with a polymer; and

    curing the boron nitride nanotube matrix impregnated with the polymer.


     
    10. The method of claim 9, wherein the boron nitride nanotube matrix is impregnated with a polymer selected from the group consisting of an epoxy, a phenolic polymer, a bismaleimide, and combinations thereof.
     
    11. The method of any one of claims 8 to 10, further comprising adhering a first skin (16, 30, 32) layer to the boron nitride nanotube fabric with a third adhesive (18).
     
    12. The method of claim 11, wherein the first skin (16, 30, 32) comprises at least one of a metal, an alloy, or a carbon pre-preg fabric.
     
    13. The method of claim 11 or claim 12, further comprising attaching a second skin to the first skin (16, 30, 32) with a film adhesive.
     
    14. The method of any one of claims 8 to 13, further comprising attaching a second pre-preg fabric to the glass pre-preg fabric (28) with an adhesive.
     
    15. The method of any one of claims 8 to 14, wherein curing the assembly includes more than one curing step.
     


    Ansprüche

    1. Heizanordnung, umfassend:

    ein Bornitridgewebe (20);

    einen ersten Klebstoff (22);

    ein Heizelement (24), wobei das Bornitridgewebe mit dem Heizelement durch den ersten Klebstoff (22) befestigt ist;

    einen zweiten Klebstoff (26); und

    ein vorimprägniertes Glasgewebe (28), wobei das vorimprägnierte Glasgewebe (28) mit dem zweiten Klebstoff (26) auf einer dem Bornitridgewebe (20) gegenüberliegenden Seite des Heizelements (24) am Heizelement (24) befestigt ist, dadurch gekennzeichnet, dass das Bornitridgewebe (20) ein Bornitrid-Nanoröhrengewebe ist.


     
    2. Anordnung nach Anspruch 1, ferner umfassend eine Haut (16, 30, 32), wobei die Haut (16, 30, 32) durch einen dritten Klebstoff (18) an dem Bornitrid-Nanoröhrengewebe befestigt ist.
     
    3. Anordnung nach Anspruch 2, wobei die Haut (16, 30, 32) ein Material umfasst, das aus der Gruppe ausgewählt ist, die aus einem Metall, einer Legierung, einem vorimprägnierten Kohlenstoffgewebe, einem vorimprägnierten Kohlenstoff-Nanoröhrengewebe und einem mit Kohlenstoff-Nanoröhren gefüllten Film besteht.
     
    4. Anordnung nach einem vorhergehenden Anspruch, wobei das Heizelement (24) ein Nano-Kohlenstoff-Heizer oder ein Widerstandsheizelement ist.
     
    5. Anordnung nach einem vorhergehenden Anspruch, wobei das Bornitrid-Nanoröhrengewebe (20) mit einem Polymer imprägniert ist, das aus der Gruppe ausgewählt ist, die aus einem Epoxid, einem phenolischen Polymer, einem Bismaleimid und Kombinationen daraus besteht.
     
    6. Anordnung nach einem vorhergehenden Anspruch, ferner umfassend eine oder mehrere zusätzliche Schichten.
     
    7. Anordnung nach Anspruch 6, wobei die eine oder die mehreren zusätzlichen Schichten vorimprägniertes Gewebe umfassen.
     
    8. Verfahren zum Herstellen einer Heizanordnung, wobei das Verfahren Folgendes umfasst:

    Verbinden eines Bornitridgewebes (20) mit einem Heizelement (24) mit einem ersten Klebstoff (22);

    Verbinden des Heizelements (24) mit einem vorimprägnierten Glasgewebe (28) mit einem zweiten Klebstoff (26); und

    Aushärten der Anordnung, dadurch gekennzeichnet, dass das Bornitridgewebe (20) ein Bornitrid-Nanoröhrengewebe (20) ist.


     
    9. Verfahren nach Anspruch 8, wobei das Bornitrid-Nanoröhrengewebe (20) durch die folgenden Schritte gebildet wird:

    Imprägnieren einer Bornitrid-Nanoröhrenmatrix mit einem Polymer; und

    Aushärten der mit dem Polymer imprägnierten Bornitrid-Nanoröhrenmatrix.


     
    10. Verfahren nach Anspruch 9, wobei die Bornitrid-Nanoröhrenmatrix mit einem Polymer imprägniert ist, das aus der Gruppe ausgewählt ist, die aus einem Epoxid, einem phenolischen Polymer, einem Bismaleimid und Kombinationen daraus besteht.
     
    11. Verfahren nach einem der Ansprüche 8 bis 10, ferner umfassend das Aufkleben einer ersten Haut-(16, 30, 32)-schicht auf das Bornitrid-Nanoröhrengewebe mit einem dritten Klebstoff (18).
     
    12. Verfahren nach Anspruch 11, wobei die erste Haut (16, 30, 32) zumindest eines von einem Metall, einer Legierung oder einem vorimprägnierten Kohlenstoffgewebe umfasst.
     
    13. Verfahren nach Anspruch 11 oder Anspruch 12, ferner umfassend das Befestigen einer zweiten Haut an die erste Haut (16, 30, 32) mit einem Filmkleber.
     
    14. Verfahren nach einem der Ansprüche 8 bis 13, ferner umfassend das Befestigen eines zweiten vorimprägnierten Gewebes an dem vorimprägnierten Glasgewebe (28) mit einem Klebstoff.
     
    15. Verfahren nach einem der Ansprüche 8 bis 14, wobei das Aushärten der Anordnung mehr als einen Aushärtungsschritt beinhaltet.
     


    Revendications

    1. Ensemble chauffant comprenant :

    un tissu de nitrure de bore (20) ;

    un premier adhésif (22) ;

    un élément chauffant (24), dans lequel le tissu de nitrure de bore est fixé à l'élément chauffant par le premier adhésif (22) ;

    un deuxième adhésif (26) ; et

    un tissu préimprégné de verre (28), dans lequel le tissu préimprégné de verre (28) est fixé à l'élément chauffant (24) par le deuxième adhésif (26) sur une face de l'élément chauffant (24) opposée au tissu de nitrure de bore (20), caractérisé en ce que le tissu de nitrure de bore (20) est un tissu de nanotubes de nitrure de bore.


     
    2. Ensemble selon la revendication 1, comprenant en outre une peau (16, 30, 32), dans lequel la peau (16, 30, 32) est fixée au tissu de nanotubes de nitrure de bore par un troisième adhésif (18).
     
    3. Ensemble selon la revendication 2, dans lequel la peau (16, 30, 32) comprend un matériau choisi dans le groupe composé d'un métal, d'un alliage, d'un tissu préimprégné de carbone, d'un tissu préimprégné de nanotubes de carbone et d'un film rempli de nanotubes de carbone.
     
    4. Ensemble selon une quelconque revendication précédente, dans lequel l'élément chauffant (24) est un chauffage au nanocarbone ou un élément chauffant résistif.
     
    5. Ensemble selon une quelconque revendication précédente, dans lequel le tissu de nanotubes de nitrure de bore (20) est imprégné d'un polymère choisi dans le groupe composé d'un époxy, d'un polymère phénolique, d'un bismaléimide et de combinaisons de ceux-ci.
     
    6. Ensemble selon une quelconque revendication précédente, comprenant en outre une ou plusieurs couches supplémentaires.
     
    7. Ensemble selon la revendication 6, dans lequel les une ou plusieurs couches supplémentaires comprennent des tissus préimprégnés.
     
    8. Procédé de fabrication d'un ensemble chauffant, le procédé comprenant :

    la liaison d'un tissu de nitrure de bore (20) à un élément chauffant (24) avec un premier adhésif (22) ;

    la liaison de l'élément chauffant (24) à un tissu préimprégné de verre (28) avec un deuxième adhésif (26) ;

    le durcissement de l'ensemble, caractérisé en ce que le tissu de nitrure de bore (20) est un tissu de nanotubes de nitrure de bore (20).


     
    9. Procédé selon la revendication 8, dans lequel le tissu de nanotubes de nitrure de bore (20) est formé par les étapes de :

    imprégnation d'une matrice de nanotubes de nitrure de bore avec un polymère ; et

    durcissement de la matrice de nanotubes de nitrure de bore imprégnée de polymère.


     
    10. Procédé selon la revendication 9, dans lequel la matrice de nanotubes de nitrure de bore est imprégnée d'un polymère choisi dans le groupe composé d'un époxy, d'un polymère phénolique, d'un bismaléimide et de combinaisons de ceux-ci.
     
    11. Procédé selon l'une quelconque des revendications 8 à 10, comprenant en outre l'adhésion d'une première couche de peau (16, 30, 32) au tissu de nanotubes de nitrure de bore avec un troisième adhésif (18).
     
    12. Procédé selon la revendication 11, dans lequel la première peau (16, 30, 32) comprend au moins l'un d'un métal, d'un alliage, ou d'un tissu préimprégné de carbone.
     
    13. Procédé selon la revendication 11 ou la revendication 12, comprenant en outre la fixation d'une seconde peau à la première peau (16, 30, 32) avec un adhésif en film.
     
    14. Procédé selon l'une quelconque des revendications 8 à 13, comprenant en outre la fixation d'un second tissu préimprégné au tissu préimprégné de verre (28) avec un adhésif.
     
    15. Procédé selon l'une quelconque des revendications 8 à 14, dans lequel le durcissement de l'ensemble comporte plus d'une étape de durcissement.
     




    Drawing


























    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description