MULTILAYER HEATING TAPE AND FLUID TRANSPORT PIPE CONTAINING SUCH A TAPE

Abstract

The present invention relates to a multilayer 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, wherein the heating film comprises two electrically conductive strips (64, 66) between which CTP effect elements (62) extend. The ribbon is in the form of several multilayer segments (32), each comprising a middle portion (322) and two end portions (324, 326) between which the middle portion extends. The ribbon can be cut to a desired length at the joints (320) between the multilayer segments. (See Figure 9 for abbreviations.)

Description

Title of the invention: MULTILAYER HEATING TAPE AND PASSAGE PIPE OF FLUID CONTAINING 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, especially for a fluid passage pipe, and to a fluid passage pipe, especially for the aeronautical industry, comprising such a multilayer heating tape. The invention also relates to a wastewater drainage circuit for an aircraft, comprising such a fluid passage pipe, and to a method for 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, particularly in the aeronautical industry. The heating system can, in particular, prevent the fluid flowing in a fluid passage pipe from freezing, in addition to regulating the temperature.

[0004] By way of example, fluid passage pipes in the aeronautical industry (such as in an aircraft) may be pipes for the evacuation of wastewater, 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 of 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 top of 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 section and / or one side of the pipe. This tape can also be connected to an external power source, notably via wire-type electrical connectors that are connected to the dielectric layers and the shielding layer. This tape configuration may have a small contact area with the pipe and therefore may not allow for homogeneous, even heating without temperature variations along the pipe to be heated.

[0007] With reference to [Fig. 1], it is also known in the prior art to make a heating cable 300 comprising two copper conductors and a PTC (Positive Temperature Coefficient) heating element located between these two conductors. The heating cable 300 is attached to one side of the pipe 1 by an adhesive A. This adhesive A is wrapped 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, particularly in a wastewater drainage system.

[0008] Furthermore, the multilayer heating tape is generally oversized to allow it to be glued along the entire length of the pipe. This can make the tape inflexible, heavy, and bulky, especially for the fluid passage pipe.

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

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

[0011] For this purpose, 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 extend elements with a PTC (Positive Temperature Coefficient) effect.

[0013] According to the invention, the ribbon is in the form of several multilayer segments, each having an elongated shape and connected end to end, the multilayer segments being identical and each comprising: a) a central portion extending over at least 50% of the length of the multilayer segment and comprising: - the first dielectric layer, - the heating film above the first dielectric layer, this heating film comprising portions of the strips and the CTP 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 top of the shielding layer, and b) two end parts between which the middle part extends, these end parts 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 having a conductive track connected to the shielding lattice 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 junctions 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 of CTP effect elements interposed between two electrically conductive strips) makes it possible to heat, thaw and maintain the temperature of the fluid homogeneously and uniformly 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 end to end. Each multilayer segment thus has a specific arrangement of two end portions between which the middle portion extends. The middle portion containing the heating element efficiently heats the pipe. Each end portion without the heating element is connected to one of the other 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 bonding zone for cutting and adjusting the length of the tape to the actual dimensions of the pipe. In this way, the The tape can be made and assembled onto 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 offering a simple multilayer heating tape design, offering high reliability, and little penalizing in terms of cost and bulk, particularly in a fluid passage pipe.

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

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

[0021] - the bands are made of copper;

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

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

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

[0025] - the strips each have an extra thickness on both end parts;

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

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

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

[0029] - the tape further comprises at least one adhesive layer among the layers superimposed, and in which the middle part and the end parts 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, particularly for the aeronautical industry, comprising a tubular body and a ribbon multilayer 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 features, considered independently of each other or in combination with each other:

[0034] - the multilayer heating tape is spirally wound around the tubular body;

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

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

[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 approximately between 1 cm and 5 cm.

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

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

[0042] Before step (iii) of assembling the ribbon, the method may include a step (ii) of attaching at least one electrical connector to the ribbon.

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

[0044] The invention will be better understood and other details, features and advantages of the invention will become more apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:

[0045] [Fig.1] is a schematic profile and partial 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 wastewater 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 tape 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 bottom and partial view of a single multilayer segment of a fifth example of the multilayer heating tape of [Fig.3]

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

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

[0055] [Fig. 10a] is another schematic view from below and partial of the multilayer heating tape of [Fig.9] which is connected to an electrical connector;

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

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

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

[0059] Elements having the same functions in the 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 way to a wastewater 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 supply circuit, a coolant supply circuit or any other fluid, etc.

[0061] With reference to [Fig. 2] and without limitation, the wastewater drainage circuit 10 may be arranged in a compartment 102 of the aircraft 100. This circuit 10 may include one or more potable water tanks 12 and one or more waste tanks 14. The circuit 10 may include at least one pipe 1 of fluid passage. This pipe 1 can be connected to the waste tank 14 to convey wastewater to this waste tank 14. The pipe 1 can be fixed to a structure of the aircraft 100 (such as in compartment 102) by means of clamps equipped with fixing tabs for example.

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

[0063] The tubular body 2 may include at least one straight and / or angled tubular portion. Figure 3 shows an example of a pipe 1 comprising a straight portion of the tubular body 2.

[0064] The tubular body 2 can 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 on the order of ten meters.

[0066] The tubular body 2 may include one or more branch portions (visible in [Fig. 1]). The tubular body 2 may have a cross-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 without limitation, the ribbon 3 can be attached and assembled onto the tubular body 2. The ribbon 3 can be wound spirally around the tubular body 2. This spiral winding helps to enhance the homogeneous and uniform heating of the entire pipe 1.

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

[0070] The ribbon 3 can thus comprise several turns 30 forming a spiral winding around the tubular body 2. The turns 30 can be spaced from each other 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 can be between 5 mm and 25 mm. Preferably, the distance d30 can be approximately 15 mm. The distance d30 can be variable and adjustable according to the first length L2 of the tubular body 2 and / or an electrical connector 8 described below.

[0071] The 3-layer multilayer heating tape 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 can be above the adhesive layer 4. One of the adhesive layers 42, 44 can 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 the arrangement of the superimposed layers of the ribbon 3. Figures 4 to 7 are cross-sectional views along a cutting plane passing through a patch (or in other words one of the cross bars) of the CTP effect elements 62 of the heating film 6.

[0075] Figure 4 represents a first example of 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] Figure 5 represents a second example of 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 tape 3.

[0078] Figure 6 represents a third example of 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 includes the additional second adhesive layer 42 which is interposed between the heating film 6 and the second dielectric layer 54. This allows the heating film 6 and the second dielectric layer 54 to be held in place.

[0080] Figure 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 removable 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 includes the additional third adhesive layer 44 which is intercalated between the second dielectric layer 54 and the shielding layer 7. This makes it possible to keep 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 can have a thickness between 10 and 100 µm. The heating film 6 can have a thickness between 10 and 100 µm.

[0083] The adhesive layer 4 allows the tape 3 to be bonded around the tubular body 2. For example, the adhesive layer 4 may be a pressure-sensitive adhesive (PSA). 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 allow the heating film 6 to be electrically isolated from the rest of the ribbon 3 (and consequently the ribbon 3).

[0085] At least a part of the first dielectric layer 52 and / or the second dielectric layer 54 and / or the third dielectric layer 56 may (or may) be made of polyimide or any other material enabling electrical insulation of 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 pm. Preferably, the second thickness E5 may be about 50 pm.

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

[0088] The shielding layer 7 may include 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 can be made of copper or any other suitable metallic material to provide EMI protection (an acronym for electromagnetic shielding). Electromagnetic shielding reduces the electromagnetic field in the vicinity of the tape. More specifically, the shielding mesh 70 and the conductive tracks 72 can be made of copper or any other suitable metallic material to provide 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 about 70 µm.

[0091] The detachable layer 9 can be configured to be removed so that the tape 3 can be glued onto the pipe 1. The detachable layer 9 can be made of silicone.

[0092] One of the features of the invention is that the heating film 6 comprises two electrically conductive strips 64, 66, respectively the first strip 64 and the second strip 66, which extend along the ribbon 3 and between which extend PTC effect elements 62 (acronym for Positive Temperature Coefficient). As mentioned below, the heating film 6 in this configuration makes it possible to heat, thaw, and maintain the fluid at temperature homogeneously and uniformly throughout the pipe 1, while preventing 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 can each be formed from a CTP effect ink which is printed in the form of crossbars.

[0095] The CTP effect elements 62 can extend (in particular cover) over at least a portion of the first 64 and second 66 bands (as illustrated in Figures 4 to 6).

[0096] The first 64 and second 66 bands can 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 CTP 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 about 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 power source, for example via conductors (such as electrical wires), to supply it with electrical energy. For this purpose, the electrical connector 8 may include a first terminal 82 and a second terminal 84 which can be connected to the external power 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 can also be connected to the electrical connector 8 (Figures 10a and 10b). In this way, the shielding layer 7 can 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 include a third terminal 86 which can be connected to the electrical ground. This third terminal 86 can be electrically connected to the conductive track 72 of the shielding layer 7. The third terminal 86 can therefore be separate 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. 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] Moreover, 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 comprises: a) a central portion 322 which extends over at least 50% of a second length L32 of the multilayer segment 32, and b) two end parts 324, 326, respectively first 324 and second 326 parts, between which extends the middle part 322.

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

[0104] As mentioned above, the ribbon 3 in the form of multilayer segments 32 and cuttable at the connection 320 between these multilayer segments 32 allows the length of the ribbon 3 to be adjusted to the dimensions of the pipe 1.

[0105] The median portion 322 comprises: - optionally, 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 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 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 parts are identical and each comprises: - optionally, 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 bands 324, 326 differ from the middle portion 322 by the absence of the CTP 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 midsection 322 and the first 324 and second 326 end sections. For example, with reference to [Fig. 5], the second dielectric layer 54 may be absent from the midsection 322 and the first 324 and second 326 end sections. With reference to [Fig. 6], the middle portion 322 and the first 324 and second 326 end portions may include the second adhesive layer 42 intercalated between the heating film 6 and the second dielectric layer 54. With reference to [Fig. 7], the middle portion 322 and the first 324 and second 326 end portions may include the second adhesive layer 42 intercalated between the heating film 6 and the second dielectric layer 54, and the third adhesive layer 44 intercalated 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 bands, the second terminal 84 can be electrically connected to the other of the first 64 and second 66 bands, and the third terminal 86 can be electrically connected to the shielding layer 7.

[0110] The free end of the ribbon 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 bands of this end portion 324, 326, the second terminal 84 can be electrically connected to the other of the first 64 and second 66 bands 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. The ends 820, 840, 860 of these conductors can be fixed to the free end of the tape 3, such as to the first end part 324 and / or the second end part 326. For this purpose, each end 820, 840, 860 can have a lug allowing the electrical connection between the conductor of the electrical connector 8 and the free end of the tape 3 (for example at 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 allow these ends 820, 840, 860 of the conductors to be connected to the free end of the ribbon 3.

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

[0114] By way of example, [Fig. 10b] illustrates an overmolded portion 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 portion 800 can be made of silicone.

[0115] Advantageously, the first 64 and second 66 bands may have an overthickness on the first 322 and second 324 end parts (figures 8a and 9).

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

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

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

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

[0120] The present application will now describe a method for manufacturing the fluid passage pipe 1 (as described above with reference to Figures 2 and 3). The steps of the process 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 pipe 1 to be heated, the cutting being carried out at a connection 320 between two consecutive multilayer segments (32), (iii) assembly of the ribbon 3 around the tubular body 2, preferably in a helical manner.

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

[0123] After cutting the ribbon 3, particularly at the joint 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 stripping tool that is flat and adjustable for removing one or more layers), chemical treatment (such as by a solvent to dissolve the shielding layer 7), or thermal treatment (such as laser ablation). Exposure at this joint 320 consists of locally removing the various layers located above the heating film 6 and the shielding layer 7. This allows the ends 820, 840, and 860 of the conductors of the electrical connector 8 to be fixed, respectively, to 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 process may include a step (ii) of attaching the electrical connector 8 to the ribbon 3.

[0125] Advantageously, a first electrical connector 8 is initially positioned and fixed at a first free end of the ribbon 3. Then, the ribbon 3 can be wound manually or automatically around the tubular body 2. The distance d30 between 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 ribbon 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 tape 3. For this purpose, these ends 820, 840, 860 can be crimped and / or glued onto the first and second free ends of the tape 3. According to another embodiment, the ends 820, 840, 860 can be crimped onto the first and second free ends of the tape 3 and overmolded by the electrical insulator.

[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] 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 embodiment, assembly step (iii) can be carried out by welding. The welding can be performed by plastic fusion, and the energy required for fusion can be supplied by a laser. For example, the tubular body 2 can be melted and welded onto the strip 3, and / or the strip 3 (particularly at the polyimide dielectric layers 52, 54, 56) can be melted and welded onto the tubular body 2. Advantageously, the welding can be performed by spot welding, for example, either along the entire edges of the strip 3 or in the middle of the strip 3, for example, at the cut joints 320. Welding simplifies step (iii) by simultaneously positioning the strip 3 on the tubular body 2 and securing it by welding.

Claims

Demands

1. Multilayer heating tape (3), in particular for a fluid passage pipe (1), said 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) extending along the tape (3) and between which extend PTC (Positive Temperature Coefficient) elements (62), in that the tape (3) is in the form of several multilayer segments (32) each having an elongated shape and which are connected end to end,the multilayer segments (32) being identical and each comprising: a) a middle portion (322) extending over at least 50% of the length of the multilayer segment (32) and comprising: - 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 the CTP 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 layer dielectric (52),

2.

3.

4.

5.

6.

7.

8.

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

10. 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 on the free end of the tape (3).

11. Multilayer heating tape according to any 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 part (322) and the end parts (324, 326) comprise at least one adhesive layer (4, 42, 44).

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

13. 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. Fluid passage pipe (1), in particular for the aeronautical industry, comprising a tubular body (2) and a multilayer heating ribbon (3) according to any one of claims 1 to 13, the ribbon (3) being attached and assembled onto the tubular body (2).

15. Fluid passage pipe according to claim 14, in which the multilayer heating tape (3) is spirally wound around the tubular body (2).

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

17. Wastewater drainage circuit (10) for an aircraft, comprising a fluid passage pipe (1) according to any one of claims 14 to

18. 10. Method of manufacturing a fluid passage pipe (1) according to any 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 joint (320) between two consecutive multilayer segments (32), (iii) assembling the ribbon (3) around the tubular body (2), preferably in a helical manner.

19. A manufacturing method according to claim 18, characterized in that prior to step (iii) of assembling the ribbon (3), the method includes a step (ii) of attaching at least one electrical connector (8) to the ribbon (3).

Images