MULTILAYER HEATING TAPE AND FLUID PASSAGE PIPE COMPRISING SUCH TAPE

Abstract

The present invention relates to a multi-layer heating ribbon (3) comprising several superimposed layers including at least:- a first dielectric layer (52),- a heating film (6) above the first dielectric layer (52),- a second dielectric layer on the heating film (6),- a shielding layer on the second dielectric layer, and- a third dielectric layer on the shielding layer,in which the heating film comprises two electrically conductive strips (64, 66) between which PTC effect elements (62) extend,the ribbon is in the form of several multi-layer segments (32) each comprising a middle part (322) and two end parts (324, 326) between which the middle part extends, and the ribbon is cuttable to a desired length at the connections (320) between the multi-layer segments. Figure for abstract: Figure 9

Description

Title of the invention: MULTILAYER HEATING TAPE AND PASS-THROUGH PIPE OF FLUID COMPRISING SUCH A RIBBON Technical field of the invention

[0001] The invention relates to the field of heating systems for fluid passage pipes, in particular for the aeronautical industry (such as an aircraft).

[0002] More particularly, the invention relates to a multilayer heating tape, in particular for a fluid passage pipe, and a fluid passage pipe, in particular for the aeronautical industry, comprising such a multilayer heating tape. The invention also relates to a waste water evacuation circuit for an aircraft, comprising such a fluid passage pipe, and a method of manufacturing such a fluid passage pipe. Technical background

[0003] A heating system is generally necessary for the proper functioning of certain parts, such as fluid passage pipes, in particular for the aeronautical industry. The heating system can in particular prevent the freezing of the fluid circulating in a fluid passage pipe, in addition to temperature regulation.

[0004] For example, the fluid passage pipes in the aeronautical industry (such as in an aircraft) may be pipes for the evacuation of waste water, pipes for the conveyance of drinking water, coolant or any other liquid, etc. These pipes may therefore be heated in particular to maintain the temperature and / or prevent the freezing of a fluid (and in particular water) in these pipes.

[0005] It is known in the prior art that such a heating system can comprise several superimposed layers to form a multilayer heating ribbon. A possible solution for this type of ribbon comprises, for example, the following superimposed layers: - an adhesive layer, - a first dielectric layer above the adhesive layer, - a heating film above the first dielectric layer, - a second dielectric layer on the heating film, - a shielding layer on the second dielectric layer, and - a third dielectric layer on the shielding layer.

[0006] The multilayer heating tape can thus be bonded via the adhesive layer along the pipe, generally on a single longitudinal portion and / or a single side of the pipe. This tape can also be connected to an external electrical source via, in particular, wire-type electrical connectors which are connected to the dielectric layers and to the shielding layer. This tape configuration may have a small contact surface with the pipe and therefore not allow for homogeneous, regular heating without temperature differences on the pipe to be heated.

[0007] With reference to [Fig. 1], it is also known in the prior art to produce a heating cable 300 comprising two copper conductive wires and a PTC (Positive Temperature Coefficient) heating element located between these two conductive wires. The heating cable 300 is attached to one side of the pipe 1 by an adhesive A. This adhesive A is wound around the pipe 1 and the heating cable 300. However, this heating cable 300 is very thick, rigid and difficult to integrate around a pipe, in particular a wastewater evacuation circuit.

[0008] Furthermore, the multi-layer heating tape is generally oversized to be able to stick it along the entire length of the pipe. This can make the tape inflexible, heavy and bulky, particularly for the fluid passage pipe.

[0009] In this context, it is interesting to propose a new solution of reliable, flexible, modular and less bulky multi-layer heating tape for a fluid passage pipe. Summary of the invention

[0010] The present invention proposes a simple, effective and economical solution making it possible to remedy at least some of the aforementioned drawbacks.

[0011] To this end, the invention relates to a multilayer heating tape, in particular for a fluid passage pipe, this tape having an elongated shape and comprising several superimposed layers including at least: - a first dielectric layer, - a heating film above the first dielectric layer, - a second dielectric layer on the heating film, - a shielding layer on the second dielectric layer, and - a third dielectric layer on the shielding layer.

[0012] According to the invention, the heating film comprises two electrically conductive strips which extend along the ribbon and between which PTC (Positive Temperature Coefficient) effect elements extend.

[0013] According to the invention, the ribbon is in the form of several multi-layer segments which each have an elongated shape and which are connected end to end, the multi-layer segments being identical and each comprising: (a) a middle portion which extends over at least 50% of the length of the multi-layer segment and which comprises: - the first dielectric layer, - the heating film above the first dielectric layer, this heating film comprising portions of the strips and the PTC effect elements, - the second dielectric layer on the heating film, - the shielding layer on the second dielectric layer, this shielding layer comprising a shielding mesh, and - the third dielectric layer on the shielding layer, and (b) two end portions between which the middle portion extends, these end portions being identical and each comprising: - the first dielectric layer, - the heating film above the first dielectric layer, this heating film comprising portions of strips but no PTC elements, - the second dielectric layer on the heating film, - the shielding layer on the second dielectric layer, this shielding layer comprising a conductive track connected to the shielding mesh of the middle portion, and - the third dielectric layer on the shielding layer.

[0014] According to the invention, the ribbon can be cut to a desired length at the connections between the multilayer segments.

[0015] Thus, the multilayer heating tape according to the invention makes it possible to achieve the aforementioned objective.

[0016] In particular, the configuration of the heating film (in particular PTC effect elements interposed between two electrically conductive strips) makes it possible to heat, defrost and maintain the temperature of the fluid in a homogeneous and uniform manner throughout the pipe, while avoiding overheating in the event of any malfunction and thus protecting users (in particular in the event of a short circuit).

[0017] Furthermore, the tape is formed of several multilayer segments connected together end to end. Each multilayer segment thus comprises the specific arrangement of two end portions between which the middle portion extends. The middle portion comprising the heating element makes it possible to heat the pipe efficiently. Each end portion without the heating element is connected to another of the two end portions of an adjacent multilayer segment of the tape (and / or to an electrical connector when this end portion forms one of the free ends of the tape). The interface between the end portions of the adjacent multilayer segments thus forms a preferred and secure connection zone for cutting and adjusting the length of the tape relative to the actual dimensions of the pipe. In this way, the tape can be made and assembled on the pipe according to the functional need (i.e. according to the length of the pipe to be heated).

[0018] The invention therefore has the advantage of proposing a simple multilayer heating ribbon design, offering great reliability, and with little penalty in terms of cost and size, particularly in a fluid passage pipe.

[0019] The multilayer heating tape according to the invention may comprise one or more of the following characteristics, considered independently of one another or in combination with one another:

[0020] - at least part of the dielectric layers is made of polyimide;

[0021] - the strips are made of copper;

[0022] - the shielding layer, and in particular the shielding mesh and the tracks conductor of each multilayer segment, is made of copper;

[0023] - each of the layers or films has a thickness of between 10 and 100 pm, and the ribbon has a total thickness of between 100 and 900 pm;

[0024] - the ribbon has a width of between 10 and 100 mm, and preferably between 30 and 50 mm ;

[0025] - the strips each have an excess thickness on the two end parts;

[0026] - one of the free ends of the ribbon is connected to an electrical connector which comprises three terminals, a first terminal electrically connected to one of the strips, a second terminal which is electrically connected to the other of the strips, and a third terminal which is electrically connected to the shielding layer;

[0027] - the free end of the ribbon is formed by an end part of one of its multilayer segments, the first terminal being electrically connected to one of the strips of this end portion, the second terminal being electrically connected to the other of the strips of this end portion, and the third terminal being electrically connected to the conductive track of this end portion;

[0028] - the terminals of the electrical connector are connected to conductors of which ends are fixed on the free end of the ribbon;

[0029] - the tape further comprises at least one adhesive layer among the layers superimposed, and wherein the middle portion and the end portions comprise at least one adhesive layer;

[0030] - the first dielectric layer is above an adhesive layer;

[0031] - an adhesive layer is located between two superimposed layers of the tape among the first dielectric layer, the heating film, the second dielectric layer, the shielding layer and the third dielectric layer.

[0032] The present invention also relates to a fluid passage pipe, in particular for the aeronautical industry, comprising a tubular body and a ribbon multi-layer heating according to one of the features of the invention which is attached and assembled on the tubular body.

[0033] The fluid passage pipe according to the invention may comprise one or more of the following characteristics, considered independently of one another or in combination with one another:

[0034] - the multilayer heating tape is wound in a spiral around the tubular body;

[0035] - the ribbon is assembled either by gluing on the tubular body by means of its layer adhesive, or assembled by welding on the tubular body;

[0036] — the tubular body may comprise at least one rectilinear tubular portion and / or cubit;

[0037] — the tubular body can be made of plastic, polymer, thermoplastic (such as than in polyetheretherketone PEEK), etc.;

[0038] — the tubular body can be made of metal;

[0039] — the maximum diameter of the tubular body is approximately between 0.5 cm and 8 cm, preferably between 1 cm and 5 cm.

[0040] The present invention also relates to a waste water evacuation circuit for an aircraft, comprising a fluid passage pipe according to one of the particularities of the invention.

[0041] The present invention also relates to a method of manufacturing a fluid passage pipe according to one of the features of the invention, comprising the following steps of: (i) cutting a length of ribbon according to a length of pipe to be heated, the cutting being carried out at a connection between two consecutive segments, (iii) assembling the ribbon around the body, preferably in a helical manner.

[0042] Before step (iii) of assembling the ribbon, the method may comprise a step (ii) of fixing at least one electrical connector on the ribbon.

[0043] The assembly step (iii) can be carried out by gluing or by welding. Welding is preferably carried out by spots. Brief description of the figures

[0044] The invention will be better understood and other details, characteristics and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0045] [Fig.l] is a schematic partial side view of a prior art heating system comprising a heating cable attached to a pipe by an adhesive;

[0046] [Fig.2] is a schematic perspective and partial view of a waste water evacuation circuit, for example for an aircraft, comprising a fluid passage pipe according to the invention;

[0047] [Fig. 3] is a schematic view of an example of a fluid passage pipe of [Fig. 2], comprising a multilayer heating tape according to the invention;

[0048] [Fig.4] schematically represents a first example of the superimposed layers of the multilayer heating ribbon of [Fig.3];

[0049] [Fig.5] schematically represents a second example of the superimposed layers of the multilayer heating tape of [Fig.3];

[0050] [Fig.6] schematically represents a third example of the superimposed layers of the multilayer heating tape of [Fig.3];

[0051] [Fig.7] schematically represents a fourth example of the superimposed layers of the multilayer heating tape of [Fig.3];

[0052] [Fig.8a] is a schematic partial bottom view of a single multilayer segment of a fifth example of the multilayer heating ribbon of [Fig.3]

[0053] [Fig.8b] is a schematic and partial top view of the multi-layer segment of [Fig.8a];

[0054] [Fig.9] is a schematic and partial bottom view of several segments of the fifth example of multilayer heating tape of [Fig.8a];

[0055] [Fig. 10a] is another schematic and partial bottom view of the multi-layer heating tape of [Fig.9] which is connected to an electrical connector;

[0056] [Fig. 10b] is a schematic and partial bottom view of the multilayer heating tape connected to the electrical connector according to another embodiment variant to that of [Fig. 10a];

[0057] [Fig.l 1] is a schematic and partial top view of the multilayer heating ribbon of [Fig.9];

[0058] [Fig. 12] is a block diagram showing an example of a method of manufacturing the fluid passage pipe according to the invention.

[0059] Elements having the same functions in different implementations have the same references in the figures. Detailed description of the invention

[0060] In the following description, the invention applies in a non-limiting manner to a waste water evacuation circuit 10, for example for an aircraft 100. The invention can be applied to another fluid evacuation circuit in the aircraft or any other transport system (such as in an automobile), a drinking water delivery circuit, a coolant delivery circuit or any other fluid, etc.

[0061] With reference to [Fig. 2] and in a non-limiting manner, the wastewater evacuation circuit 10 may be arranged in a compartment 102 of the aircraft 100. This circuit 10 may comprise one or more drinking water tanks 12 and one or more waste tanks 14. The circuit 10 may comprise at least one pipe 1 of fluid passage. This pipe 1 can be connected to the waste tank 14 to convey the waste water to this waste tank 14. The pipe 1 can be fixed to a structure of the aircraft 100 (such as in the compartment 102) by collars equipped with fixing lugs for example.

[0062] The pipe 1 may comprise a tubular body 2 and at least one multi-layer heating tape 3. The pipe 1 and the tape 3 may be used without restriction for any fluid delivery circuit in the aircraft 100 or any other transport system.

[0063] The tubular body 2 may comprise at least one rectilinear and / or bent tubular portion. [Fig. 3] represents an example of a pipe 1 comprising a rectilinear portion of the tubular body 2.

[0064] The tubular body 2 may have a maximum diameter D2 of approximately between 0.5 cm and 8 cm, preferably approximately between 1 cm and 5 cm.

[0065] The tubular body 2 may have a first length L2. This first length L2 may correspond substantially to a total length of the pipe 1. The first length L2 may be of the order of ten meters.

[0066] The tubular body 2 may comprise one or more branch portions (visible in [Fig.l]). The tubular body 2 may have a section between the branch portion(s) which is between 1200 mm and 1600 mm.

[0067] The tubular body 2 can be made of plastic, polymer, thermoplastic (such as polyetheretherketone PEEK), etc. Alternatively, the tubular body can be made of metal.

[0068] With reference to [Fig. 3] and in a non-limiting manner, the ribbon 3 can be attached and assembled on the tubular body 2. The ribbon 3 can be wound in a spiral around the tubular body 2. This spiral winding makes it possible to reinforce the homogeneous and uniform heating of the entire pipe 1.

[0069] One or more ribbons 3 may be necessary when there are in particular one or more branch portions on the pipe 1.

[0070] The ribbon 3 may thus comprise several turns 30 forming the spiral winding around the tubular body 2. The turns 30 may be spaced from one another by a predetermined distance d30 which is measured in particular along the tubular body 2 and between two parallel planes separated by one spiral turn. This distance d30 may be between 5 mm and 25 mm. Preferably, the distance d30 may be approximately 15 mm. The distance d30 may be variable and adjustable as a function of the first length L2 of the tubular body 2 and / or of an electrical connector 8 described below.

[0071] The multilayer heating ribbon 3 has an elongated shape.

[0072] The ribbon 3 comprises several superimposed layers including at least: - optionally an adhesive layer 4, - a first dielectric layer 52, - a heating film 6 above the first dielectric layer 52, - a second dielectric layer 54 on the heating film 6, - a shielding layer 7 on the second dielectric layer 54, and - a third dielectric layer 56 on the shielding layer 7.

[0073] The first dielectric layer 52 may be above the adhesive layer 4. One of the adhesive layers 42, 44 may be located between two superimposed layers of the tape 3 among the first dielectric layer 52, the heating film 6, the second dielectric layer 54, the shielding layer 7 and the third dielectric layer 56.

[0074] Figures 4 to 7 illustrate in a non-limiting manner different examples of arrangement of the superimposed layers of the ribbon 3. Figures 4 to 7 are sectional views along a section plane passing through a patch (or in other words one of the transverse bars) of the PTC effect elements 62 of the heating film 6.

[0075] [Fig.4] represents a first example of the ribbon 3 comprising the following superimposed layers: - a first adhesive layer 4, - the first dielectric layer 52 above the first adhesive layer 4, - the heating film 6 above the first dielectric layer 52, - the second dielectric layer 54 on the heating film 6, - the shielding layer 7 on the second dielectric layer 54, and - the third dielectric layer 56 on the shielding layer 7.

[0076] [Fig.5] represents a second example of the ribbon 3 comprising the following superimposed layers: - the first dielectric layer 52, - the heating film 6 above the first dielectric layer 52, - a second adhesive layer 42 on the heating film 6, - the shielding layer 7 on the heating film 6, and - the third dielectric layer 56 on the shielding layer 7.

[0077] The second dielectric layer 54 and the first adhesive layer 4 are absent in this second example of tape 3. Thus, this second dielectric layer 54 and the first adhesive layer 4 can be optional in the tape 3.

[0078] [Fig.6] represents a third example of the ribbon 3 comprising the following superimposed layers: - the first adhesive layer 4, - the first dielectric layer 52 above the first adhesive layer 4, - the heating film 6 above the first dielectric layer 52, - the second adhesive layer 42 on the heating film 6, - the second dielectric layer 54 on the second adhesive layer 42, - the shielding layer 7 on the second dielectric layer 54, and - the third dielectric layer 56 on the shielding layer 7.

[0079] This third example of tape thus comprises the second additional adhesive layer 42 which is interposed between the heating film 6 and the second dielectric layer 54. This makes it possible to hold the heating film 6 and the second dielectric layer 54 in place.

[0080] [Fig.7] represents a fourth example of the tape 3 comprising the following superimposed layers: - a detachable layer 9, - the first adhesive layer 4 on the detachable layer 9, - the first dielectric layer 52 above the first adhesive layer 4, - the heating film 6 above the first dielectric layer 52, - a second adhesive layer 42 on the heating film 6, - the second dielectric layer 54 on the second adhesive layer 42, - the shielding layer 7 on the second dielectric layer 54, - a third adhesive layer 44 on the shielding layer 7, and - the third dielectric layer 56 on the third adhesive layer 44.

[0081] This fourth example of tape 3 thus comprises the third additional adhesive layer 44 which is interposed between the second dielectric layer 54 and the shielding layer 7. This makes it possible to hold the shielding layer 7 and the second dielectric layer 54 in place.

[0082] Advantageously, each of the aforementioned layers 4, 42, 44, 52, 54, 56, 7 may have a thickness of between 10 and 100 μm. The heating film 6 may have a thickness of between 10 and 100 μm.

[0083] The adhesive layer 4 makes it possible to stick the tape 3 around the tubular body 2. For example, the adhesive layer 4 may be a pressure-sensitive adhesive (known by the English acronym PSA for “Pressure-Sensitive Adhesive”). This adhesive layer 4 (and / or the second 42 and third 44 adhesive layers) may have a first thickness E4. This first thickness E4 may be between 10 and 30 μm. Preferably, the first thickness E4 may be approximately 10 μm.

[0084] The dielectric layers 52, 54, 56 make it possible to electrically insulate the heating film 6 from the rest of the strip 3 (and consequently the strip 3).

[0085] At least a portion of the first dielectric layer 52 and / or of the second dielectric layer 54 and / or of the third dielectric layer 56 may be made of polyimide or any other material making it possible to electrically insulate the heating film 6.

[0086] Each of these dielectric layers 52, 54, 56 may have a second thickness E5. This second thickness E5 may be between 20 and 60 μm. Preferably, the second thickness E5 may be approximately 50 μm.

[0087] The shielding layer 7 may comprise a shielding mesh 70. The shielding mesh provides protection against electromagnetic interference (EMI).

[0088] The shielding layer 7 may comprise a conductive track 72 connected to the shielding mesh. The conductive track 72 may be configured to be connected to the electrical connector 8.

[0089] The shielding layer 7 may be made of copper or any other metallic material suitable for providing EMI protection (acronym for electromagnetic shielding). The electromagnetic shielding makes it possible to reduce the electromagnetic field in the vicinity of the ribbon. More particularly, the shielding mesh 70 and the conductive tracks 72 may be made of copper or any other metallic material suitable for providing EMI protection.

[0090] The shielding layer 7 may have a third thickness E7. This third thickness E7 may be between 35 and 90 μm. Preferably, the third thickness E7 may be approximately 70 μm.

[0091] The detachable layer 9 can be configured to be removed in order to be able to stick the tape 3 on the pipe 1. The detachable layer 9 can be made of silicone.

[0092] One of the particularities of the invention is that the heating film 6 comprises two electrically conductive strips 64, 66, respectively first strip 64 and second strip 66, which extend along the ribbon 3 and between which extend PTC effect elements 62 (acronym designating a Positive Temperature Coefficient or known as "Positive Temperature Coefficient"). As mentioned below, the heating film 6 according to this configuration makes it possible to heat, thaw and maintain the temperature of the fluid in a homogeneous and uniform manner throughout the pipe 1, while avoiding overheating in the event of any malfunction.

[0093] Figures 8a to 11 partially represent the ribbon 3 with a non-limiting arrangement of the heating film 6.

[0094] The CTP effect elements 62 may each be formed from a CTP effect ink that is printed in the form of crossbars.

[0095] The PTC effect elements 62 may extend (in particular overlap) over at least a portion of the first 64 and second 66 bands (as illustrated in FIGS. 4 to 6).

[0096] The first 64 and second 66 strips may be made of copper or any other electrically conductive material.

[0097] The heating film 6 (in particular the first 64 and second 66 strips and / or the PTC effect element 62) may have a fourth thickness E6. This fourth thickness E6 may be between 35 and 90 μm. Preferably, the fourth thickness E6 may be approximately 70 μm.

[0098] The heating film 6 can be connected to the electrical connector 8 (Figures 10a and 10b). In this way, the heating film 6 can be connected to an external electrical source, for example via conductors (such as electrical wires), to supply it with electrical energy. For this, the electrical connector 8 can comprise a first terminal 82 and a second terminal 84 which can be connected to the external electrical source. The first terminal 82 can be electrically connected to one of the first 64 and second 66 strips, and the second terminal 84 can be electrically connected to the other of the first 64 and second 66 strips of the heating film 6.

[0099] The shielding layer 7 may also be connected to the electrical connector 8 (Figures 10a and 10b). In this way, the shielding layer 7 may be connected to an electrical ground, for example via a conductor (such as an electrical wire). For this purpose, the electrical connector 8 may further comprise a third terminal 86 which may be connected to the electrical ground. This third terminal 86 may be electrically connected to the conductive track 72 of the shielding layer 7. The third terminal 86 may therefore be distinct from the first 82 and second 84 terminals.

[0100] Advantageously, the electrical connector 8 can be connected to the heating film 6 on the one hand, and to the shielding layer 7 on the other hand. In this configuration, the first 82 and second 84 terminals can be connected, respectively, to the first 64 and second 66 strips of the heating film 6, and the third terminal 86 can be connected to the shielding layer 7.

[0101] Furthermore, the ribbon 3 is in the form of several multilayer segments 32 which each have an elongated shape and which are connected end to end (figures 7 and 11).

[0102] These multilayer segments 32 are identical to each other and each comprise: a) a middle part 322 which extends over at least 50% of a second length L32 of the multilayer segment 32, and b) two end portions 324, 326, respectively first 324 and second 326 portions, between which the middle portion 322 extends.

[0103] The ribbon 3 can be cut to a desired length at the connections 320 between the multilayer segments 32.

[0104] As mentioned above, the tape 3 in the form of multilayer segments 32 and cuttable at the level of the connections 320 between these multilayer segments 32 makes it possible to adjust the length of the tape 3 to the dimensions of the pipe 1.

[0105] The middle part 322 comprises: - optionally the adhesive layer 4, - the first dielectric layer 52 which may optionally be above the adhesive layer 4, - the heating film 6 above the first dielectric layer 52, this heating film 6 comprising portions of the strips 64, 66 and the PTC effect elements 62, - the second dielectric layer 54 on the heating film 6, - the shielding layer 7 on the second dielectric layer 52, this shielding layer 7 comprising the shielding mesh 70, and - the third dielectric layer 56 on the shielding layer 7.

[0106] The first 324 and second 326 end portions are identical and each comprise: - optionally the adhesive layer 4, - the first dielectric layer 52 which may optionally be above the adhesive layer 4, - the heating film 6 above the first dielectric layer 52, this heating film 6 comprising portions of strips 64, 66 but no PTC effect elements 62, - the second dielectric layer 54 on the heating film 6, - the shielding layer 7 on the second dielectric layer 54, this shielding layer 7 comprising the conductive track 72 connected to the shielding mesh 70 of the middle portion 322, and - the third dielectric layer 56 on the shielding layer 7.

[0107] Thus, the first and second strips 324, 326 differ from the middle portion 322 by the absence of the PTC effect elements 62 and the shielding layer 7 comprising only the conductive track 72 without the shielding mesh 70 (figures 8a, 8b, 9 and H).

[0108] The arrangement of the layers 4, 42, 44, 52, 54, 56 and / or the heating film 6 may vary at the middle portion 322 and the first 324 and second 326 end portions. For example, with reference to [Fig. 5], the second dielectric layer 54 may be absent from the middle portion 322 and the first 324 and second 326 end portions. Referring to [Fig. 6], the middle portion 322 and first 324 and second 326 end portions may comprise the second adhesive layer 42 interposed between the heating film 6 and the second dielectric layer 54. Referring to [Fig. 7], the middle portion 322 and first 324 and second 326 end portions may comprise the second adhesive layer 42 interposed between the heating film 6 and the second dielectric layer 54, and the third adhesive layer 44 interposed between the shielding layer 7 and the third dielectric layer 56.

[0109] Advantageously, at least one of the free ends of the ribbon 3 can be connected to the electrical connector 8. More particularly, the first terminal 82 can be connected electrically to one of the first 64 and second 66 strips, the second terminal 84 can be electrically connected to the other of the first 64 and second 66 strips, and the third terminal 86 can be electrically connected to the shielding layer 7.

[0110] The free end of the strip 3 which is connected to the electrical connector 8, can be formed by an end portion 324, 326 of one of the multilayer segments 32. The first terminal 82 can be electrically connected to one of the first 64 and second 66 strips of this end portion 324, 326, the second terminal 84 can be electrically connected to the other of the first 64 and second 66 strips of this end portion 324, 326, and the third terminal 86 can be electrically connected to the conductive track 72 of the shielding layer 7. In the example of [Fig. 10a] or [Fig. 10b], the second end portion 326 can be connected to the electrical connector 8.

[0111] Each of the terminals 82, 84, 86 can be connected to conductors in particular of the electrical connector 8. Ends 820, 840, 860 of these conductors can be fixed to the free end of the strip 3, such as on the first end part 324 and / or the second end part 326. For this, each end 820, 840, 860 can comprise a terminal allowing the electrical connection between the conductor of the electrical connector 8 and the free end of the strip 3 (for example at the level of the first 64 and second 66 strips of the heating film 6 and the conductive track 72 of the shielding layer 7).

[0112] [Fig. 10a] illustrates in a non-limiting manner connection plates individually fixed to the ends 820, 840, 860 of the conductors of the electrical connector 8. These connection plates make it possible to connect these ends 820, 840, 860 of the conductors to the free end of the strip 3.

[0113] The fixing of the ends 820, 840, 860 of the conductors can be carried out by crimping, gluing and / or overmolding, for example, of an electrical insulator.

[0114] As an example, [Fig. 10b] illustrates an overmolded part 800 connecting the ends 820, 840, 860 of the conductors of the electrical connector 8 to the free end of the ribbon 3. The overmolded part 800 can be made of silicone.

[0115] Advantageously, the first 64 and second 66 bands may have an excess thickness on the first 322 and second 324 end portions (Figures 8a and 9).

[0116] Each multilayer segment 32 may therefore have the second length L32. This second length L32 may be between 5 and 50 cm. Preferably, the second length L32 may be between 10 and 30 cm. The ribbon 3 may have multilayer segments 32 of identical or different second lengths L32.

[0117] The ribbon 3 may have a fifth total thickness E3 of between 100 and 900 μm.

[0118] The ribbon 3 may have a width 13 of between 10 and 100 mm, and preferably between 30 and 50 mm.

[0119] The PTC heating elements 62 may have a width 162 of between 2 and 10 mm. The width 162 is measured between the first 64 and second 66 strips with reference to [Fig.8a], in a direction perpendicular to these strips.

[0120] The present application will now describe a method of manufacturing the fluid passage pipe 1 (as described above with reference to FIGS. 2 and 3). The steps of the method are summarized in [Fig. 12].

[0121] According to the invention, the method comprises the following steps: (i) cutting a length of ribbon 3 according to a length of the pipe 1 to be heated, the cutting being carried out at a connection 320 between two consecutive multi-layer segments (32), (iii) assembling the ribbon 3 around the tubular body 2, preferably in a helical manner.

[0122] Step (i) can be carried out manually using a cutting tool O320, such as a suitable chisel ([Fig. 11]).

[0123] After cutting the ribbon 3, in particular at the connection 320, the first 64 and second 66 strips and the shielding layer 7 of the cut multilayer segment 32 can be exposed, for example, by mechanical treatment (such as a cutting tool of the stripping pliers type which is flat and adjustable to remove one or more layers), chemical treatment (such as by a solvent for dissolving the shielding layer 7) or thermal treatment (such as laser ablation). Exposure at this connection 320 consists of locally removing the different layers located above the heating film 6 and the shielding layer 7. This makes it possible to fix the ends 820, 840, 860 of the conductors of the electrical connector 8, respectively, on the first strip 64, the second strip 66 and the shielding layer 7 of one of the multilayer segments 32, thus forming the free end of the ribbon 3.

[0124] Before step (iii) of assembling the ribbon 3, the method may comprise a step (ii) of fixing the electrical connector 8 on the ribbon 3.

[0125] Advantageously, a first electrical connector 8 is positioned and fixed firstly at a first free end of the tape 3. Then, the tape 3 can be wound manually or automatically around the tubular body 2. The distance d30 between the consecutive turns 30 can be adjusted by a manual guide. A second electrical connector 8 can be positioned and fixed at a second free end of the tape 30. The distance d30 can be adjusted according to the length of the pipe 1 to be heated and / or the position of the first and second electrical connectors 8.

[0126] More particularly, the ends 820, 840, 860 of the conductors of each of the first and second electrical connectors 8 can be fixed, respectively, on the first and second free ends of the strip 3. For this, these ends 820, 840, 860 can be crimped and / or glued on the first and second free ends of the strip 3. According to another variant, the ends 820, 840, 860 can be crimped on the first and second free ends of the strip 3 and overmolded by the electrical insulation.

[0127] In step (iii), the ribbon 3 is assembled around the tubular body 2. For this, the ribbon 3 can be fixed around the tubular body 2 by helical (or spiral) winding.

[0128] The assembly step (iii) can be carried out by gluing, in particular using the adhesive layer 4, the tape 3 around the tubular body 2.

[0129] According to another variant, the assembly step (iii) can be carried out by welding. The welding can be carried out by plastic fusion and the energy necessary for the fusion can be provided by a laser. For example, the tubular body 2 can be melted and welded onto the strip 3 and / or the strip 3 (in particular at the level of the polyimide dielectric layers 52, 54, 56) can be melted and welded onto the tubular body 2. Advantageously, the welding can be carried out by points, for example either along the entire edges of the strip 3, or in the middle of the strip 3, for example at the cutting connections 320. Welding makes it possible to simplify step (iii) by simultaneously positioning the strip 3 on the tubular body 2 and fixing it by welding.

Claims

Claims

1. Multilayer heating tape (3), in particular for a fluid passage pipe (1), this tape (3) having an elongated shape and comprising several superimposed layers including at least: - a first dielectric layer (52), - a heating film (6) above the first dielectric layer (52), - a second dielectric layer (54) on the heating film (6), - a shielding layer (7) on the second dielectric layer (54), and - a third dielectric layer (56) on the shielding layer (7), characterized in that the heating film (6) comprises two electrically conductive strips (64, 66) which extend along the tape (3) and between which elements (62) with a PTC (Positive Temperature Coefficient) effect extend, in that the tape (3) is in the form of several multilayer segments (32) which each have an elongated shape and which are connected end to end,the multilayer segments (32) being identical and each comprising: a) a middle portion (322) which extends over at least 50% of the length of the multilayer segment (32) and which comprises: - the first dielectric layer (52), - the heating film (6) above the first dielectric layer (52), this heating film (6) comprising portions of the strips (64, 66) and of the PTC effect elements (62), - the second dielectric layer (54) on the heating film (6), - the shielding layer (7) on the second dielectric layer (54), this shielding layer (7) comprising a shielding mesh (70), and - the third dielectric layer (56) on the shielding layer (7), and b) two end portions (324, 326) between which the middle portion (322) extends, these end portions (324, 326) being identical and each comprising: - the first dielectric layer (52),

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9. - the heating film (6) above the first dielectric layer, this heating film (6) comprising portions of strips (64, 66) but no elements (62) with a PTC effect, - the second dielectric layer (54) on the heating film (6), - the shielding layer (7) on the second dielectric layer (54), this shielding layer (7) comprising a conductive track (72) connected to the shielding mesh (70) of the middle portion (322), and - the third dielectric layer (56) on the shielding layer (7), and in that the ribbon (3) is cuttable to a desired length at the connections (320) between the multilayer segments (32). Multilayer heating ribbon according to claim 1, in which at least a portion of the dielectric layers (52, 54, 56) is made of polyimide. A multi-layer heating tape according to claim 1 or 2, wherein the strips (64, 66) are made of copper. Multilayer heating tape according to one of claims 1 to 3, in which the shielding layer (7), and in particular the shielding mesh (70) and the conductive tracks (72) of each multilayer segment (32), is made of copper. Multilayer heating tape according to one of claims 1 to 4, in which each of the layers (4, 42, 44, 52, 54, 56, 7) or film (6) has a thickness of between 10 and 100 pm, and the tape (3) has a total thickness (E3) of between 100 and 900 pm. Multilayer heating tape according to one of claims 1 to 5, in which it has a width (13) of between 10 and 100 mm, and preferably between 30 and 50 mm. Multilayer heating tape according to one of claims 1 to 6, in which the strips (64, 66) each have an excess thickness on the two end portions (324, 326). Multilayer heating tape according to one of claims 1 to 7, wherein one of the free ends of the tape (3) is connected to an electrical connector (8) which comprises three terminals, a first terminal (82) electrically connected to one of the strips (64, 66), a second terminal (84) which is electrically connected to the other of the strips (64, 66), and a third terminal (86) which is electrically connected to the shielding layer (7). Multilayer heating tape according to claim 8, wherein the free end of the tape (3) is formed by a part end (324, 326) of one of its multilayer segments (32), the first terminal (82) being electrically connected to one of the strips (64, 66) of this end portion, the second terminal (84) being electrically connected to the other of the strips (64, 66) of this end portion, and the third terminal (86) being electrically connected to the conductive track (72) of this end portion.

10. A multilayer heating tape according to claim 8 or 9, wherein the terminals (82, 84, 86) of the electrical connector (8) are connected to conductors whose ends are fixed to the free end of the tape (3).

11. A multilayer heating tape according to one of claims 1 to 10, wherein the tape (3) further comprises at least one adhesive layer (4, 42, 44) among the superimposed layers, and wherein the middle portion (322) and the end portions (324, 326) comprise the at least one adhesive layer (4, 42, 44).

12. A multi-layer heating tape according to claim 11, wherein the first dielectric layer (52) is above an adhesive layer (4).

13. A multilayer heating tape according to claim 11 or 12, wherein an adhesive layer (42, 44) is located between two superimposed layers of the tape (3) among the first dielectric layer (52), the heating film (6), the second dielectric layer (54), the shielding layer (7) and the third dielectric layer (56).

14. Pipe (1) for passing fluid, in particular for the aeronautical industry, comprising a tubular body (2) and a multi-layer heating tape (3) according to one of claims 1 to 13, the tape (3) being attached and assembled on the tubular body (2).

15. A fluid passage pipe according to claim 14, wherein the multi-layer heating tape (3) is spirally wound around the tubular body (2).

16. A fluid passage pipe according to claim 14 or 15 in combination with claim 12, wherein the tape (3) is assembled either by gluing to the tubular body (2) by means of its adhesive layer (4), or assembled by welding to the tubular body (2).

17. Waste water evacuation circuit (10) for an aircraft, comprising a fluid passage pipe (1) according to one of claims 14 to

18. 10. Method for manufacturing a fluid passage pipe (1) according to one of claims 14 to 16, comprising the following steps of: (i) cutting a length of ribbon (3) according to a length of pipe (1) to be heated, the cutting being carried out at a connection (320) between two consecutive multilayer segments (32), (iii) assembling the ribbon (3) around the tubular body (2), preferably in a helical manner.

19. Manufacturing method according to claim 18, characterized in that before step (iii) of assembling the ribbon (3), the method comprises a step (ii) of fixing at least one electrical connector (8) on the ribbon (3).

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