Method for manufacturing a component for fitting out an aircraft cabin

Abstract

The invention relates to a method for manufacturing a component (12), in particular for fitting out an aircraft cabin, in particular for a seat of an aircraft cabin, comprising at least: a) a cutting step, in which a plurality of nonwoven layers (14), comprising fibre scraps with at least one binder, are cut and stacked, in order to form a stack of nonwoven layers, and b) a compression step, in which the stack of nonwoven layers is thermocompressed in a mould (16), so as to produce a component (12) having a non-planar shape.

Description

[0001] DESCRIPTION

[0002] TITLE: METHOD FOR MANUFACTURING A COMPONENT FOR FITTING OUT AN AIRCRAFT CABIN

[0003] Technical field of the invention

[0004] The invention relates to the technical field of components for fitting out an aircraft cabin, such components being intended, for example, to equip seats.

[0005] Technical background

[0006] The technical background includes in particular documents DE-A1 -102012003001 , US-A1 -2012 / 208419, US-A1 -2011 / 036481 , US-A1 -4,946,526 and JP-A-S63 125315.

[0007] The use of composite materials for the production of aircraft cabin fittings is well known. Such a material generally comprises fibers embedded in a polymer matrix. For example, it is known to use glass fibers, carbon fibers, etc. Other materials are known for the production of such components, such as aluminum or plastic.

[0008] Carbon fiber consumption has increased significantly over the past ten years. Production has adapted to meet growing demand.

[0009] Mainly used in composite structures, carbon fibers are widely used in the production of woven composite parts in the aeronautics field, particularly woven composite blades for turbojet engines. During their manufacture, the layers of warp and weft yarns are released as a preform of the composite part is created, in order to achieve the different desired thicknesses. When the preform is released from the loom, a cutting operation is carried out. The cut carbon yarns then become scraps from the weaving process.

[0010] Thus, carbon fiber waste represents a potentially significant volume across all production plants.

[0011] Furthermore, carbon fiber scraps have intact mechanical performance because they have not been stressed. They can therefore be reused to manufacture new composite reinforcements. However, until recently, carbon fiber scraps were practically not recycled. Indeed, although reprocessing channels for such carbon fiber scraps have developed, they are saturated with demand, particularly from the automotive industry.

[0012] Carbon fiber scraps are therefore not highly valued and outlets for reusing such fibers are still underdeveloped. They are mostly pyrolyzed and then ground into powder, which constitutes fillers for primers, paints or thermoplastic materials.

[0013] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states.

[0014] In particular, an ambitious standard applies to both new aircraft types and those already in operation, requiring the implementation of technological solutions to ensure their compliance with current regulations. Civil aviation has been mobilizing for several years now to contribute to the fight against climate change.

[0015] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft.

[0016] The research and development work supported focuses in particular on lightening the devices, particularly through the materials used and lightened on-board equipment.

[0017] It was therefore considered to recover carbon fiber scraps in order to set up a new sector. In this regard, research and development efforts have made it possible to develop a semi-finished recycling product based on carbon fiber scraps and a process for manufacturing such a product.

[0018] The product comes in the form of a roll of a strip or a non-woven layer containing carbon fiber scraps and a binder ensuring the cohesion of the fibers between them and the holding of the strip.

[0019] However, to date, no measures aimed at exploiting such a product have been undertaken. The invention therefore aims to provide a method for manufacturing a component for fitting out an aircraft cabin, by recycling carbon fiber scraps. To this end, the invention is the result of technological research aimed at very significantly improving the performance of aircraft and, in this sense, contributes to reducing the environmental impact of aircraft.

[0020] Summary of the invention

[0021] For this, the invention provides a method for manufacturing a component, in particular for fitting out an aircraft cabin, comprising at least: a) a cutting step, during which several non-woven layers, comprising fiber scraps advantageously having a random orientation with at least one binder, are cut and stacked, in order to form a stack of non-woven layers, and b) a compression step, during which the stack of non-woven layers is thermocompressed in a mold, so as to produce a component having a non-planar shape.

[0022] According to the invention, the non-woven layers may each comprise scraps of fibers, in particular carbon fibers, and thermoplastic fibers, in particular held punctually, with a binder, in particular thermoplastic, which ensures cohesion of the non-woven layer.

[0023] Furthermore, according to the invention, the non-woven layers may in particular have the same composition.

[0024] The invention thus proposes to recover fiber scraps, such as carbon fibers, and thus to recycle them. The invention therefore makes it possible to produce development components from recycled material, which is particularly advantageous from an environmental and economic point of view.

[0025] Recycling noble aeronautical materials such as carbon fibers makes it possible to have an isotropic or quasi-isotropic non-woven structure, particularly in the plane, with properties similar to those produced from woven structures, for example glass fibers, while significantly reducing the mass of the product.

[0026] In the present description, the term "furnishing component" must be understood as being a secondary structural component, in particular used to equip a seat, a piece of furniture, a storage chest or a trim panel for example. Such a component may have one or more functions chosen from: an aesthetic finish, a fixing, etc. In addition, in the present description, the term "non-woven layer" must be understood as being a layer composed of fibers, in particular carbon fibers, in particular with thermoplastic fibers, which are not woven together and which have a random orientation in the non-woven layer. The fibers of the non-woven layer are bound together by at least one binder, a binding material and / or a matrix, in particular a thermoplastic matrix, which ensures a certain cohesion of the non-woven layer.

[0027] The random orientation of the fibers is particularly advantageous because it allows the layer to have the same properties in all directions (isotropic or quasi-isotropic).

[0028] Thermocompression is a combination of heat treatment and compression treatment, which can, for example, be carried out in a press.

[0029] The heat treatment is carried out, in particular, at a temperature greater than or equal to the glass transition and / or melting temperature of the binder and / or thermoplastic fibers.

[0030] The present invention may include other features, described in the following, which may be considered independently or in combination with each other:

[0031] - the stack of non-woven layers is placed in a set of mold impressions in step b);

[0032] - the stack of non-woven layers is heated by conduction by the mold;

[0033] - the stack of non-woven layers is heated by convection (e.g. IR) or ceramic;

[0034] - the mold is configured to form at least one variable thickness, a rib, a groove and / or a hole;

[0035] - an insert intended to be fixed to the component is previously positioned in the mold before the compression step b);

[0036] - the binder is poly(phenylene sulfide) (PPS), polyetherimides (PEI), polyetheretherketone (PEEK), polycarbonate (PC), polyethersulfone (PESU) and / or polyphenylsulfone (PPSU);

[0037] - the compression step b) comprises and / or is followed by a step of overmolding the component;

[0038] - said fiber scraps have a random orientation; - the component is intended to equip a seat of an aircraft cabin or is a component of such a seat;

[0039] - during the compression step b) b1) the mold is heated from a first temperature to a plateau at a second temperature, then is cooled to a third temperature, and / or b2) the pressure in the mold increases from a first pressure to a plateau at a second pressure, then decreases to a third pressure,

[0040] - the mold: o is heated before the pressure in the mold increases, and / or o is cooled before the pressure in the mold decreases;

[0041] - the increase, respectively the reduction, of the temperature is linear;

[0042] - the increase, respectively the reduction, of the pressure is substantially instantaneous;

[0043] - the second temperature is greater than or equal to the glass transition and / or melting temperature of the binder, in particular greater than or equal to 350°C, and / or

[0044] - the second pressure is greater than or equal to 30 bars.

[0045] In particular, the first pressure, respectively the third pressure, is obtained either by evacuating the impression, in particular by mechanically closing the impressions and / or by pressurizing under pressure, in particular between 0.7 bar and 5 bar.

[0046] The present invention also relates to a component, in particular for fitting out an aircraft cabin, in particular for a seat of an aircraft cabin, manufactured by a manufacturing method as described above.

[0047] Furthermore, the manufacturing method according to the invention, which is particularly advantageous for the purpose of reducing the environmental impact of aircraft, relates to a fitting component for an aircraft cabin, such as a seat element, in particular a shell, a seat, a backrest, an armrest and / or a tablet obtained by a manufacturing method as described above.

[0048] The component is preferably a seat component of an aircraft cabin.

[0049] Brief description of the figures

[0050] The present invention will be better understood and other objects, characteristics and advantages of the invention will appear more clearly on reading the following description, comprising examples of embodiments of components for the arrangement presented as non-limiting examples which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition. This detailed description is made with reference to the appended figures, in which:

[0051] [Fig.1] Figure 1 is a schematic view of a pile of carbon fiber scraps; [Fig.2] Figure 2 is a schematic view of a non-woven layer of carbon fiber scraps;

[0052] [Fig.3] Figure 3 is a very schematic sectional view of a thermocompression mold used in the context of a manufacturing method according to the invention; [Fig.4] Figure 4 is a graph illustrating the evolution of the pressure and temperature in the mold, according to a first embodiment of the invention;

[0053] [Fig.5] Figure 5 is a graph illustrating the evolution of the pressure and temperature in the mold, according to a second embodiment of the invention; and

[0054] [Fig.6] Figure 6 includes schematic perspective views of a component for fitting out an aircraft cabin, manufactured by a manufacturing method according to the invention.

[0055] Detailed description of the invention

[0056] Figure 1 is a schematic view of a cluster of carbon fiber scraps 10.

[0057] Carbon fiber scraps have a length less than or equal to 100mm and, in general, between 10mm and 50mm.

[0058] Rather than discarding carbon fiber scraps, the invention proposes to recycle them by producing components for fitting out an aircraft cabin. A component 12 of this type is illustrated in Figure 6. Component 12 is, for example, intended to equip an aircraft seat.

[0059] Figure 2 is a schematic view of a non-woven layer of carbon fiber scraps.

[0060] According to the invention, the component 12 is made from scraps of fibers, in particular carbon fibers, in the form of a layer or a non-woven strip 14, as illustrated in Figure 2.

[0061] More specifically, component 12 is made from a mixture of fiber scraps, thermoplastic fibers and a binder.

[0062] The thermoplastic fibers have a length less than or equal to 100 mm, and generally between 10 mm and 50 mm. The fiber scraps 10 are used to produce a non-woven layer 14, as shown in Figure 2.

[0063] The step of carrying out the manufacturing method, during which the non-woven layer 14 is produced, may comprise at least: i) a collection step, during which fiber scraps 10, in particular carbon fiber scraps, are recovered; ii) a disentangling step, during which the fibers 10, in particular the carbon fibers, are disentangled and may be mixed with a binder; iii) a dispersion step, during which a flow of dry air is used to disperse the fibers 10; iv) a manufacturing step, during which a fiber mat is produced, the fiber mat comprising the fibers 10, air and the binder; and v) a calendering step, during which the fiber mat is hot calendered to a temperature greater than or equal to the glass transition temperature of the binder, so as to produce a semi-finished recycling product in the form of a roll of non-woven strip or layer 14.

[0064] Advantageously, in the collection step i), the fiber scraps 10, in particular carbon fibers, result from the cutting of blanks of parts made of composite materials in the aeronautical field, such blanks being in particular obtained by three-dimensional weaving of carbon fibers using a loom as mentioned above.

[0065] The disentangling step ii) consists of disentangling the fibers 10 and, optionally, mixing them with a binder, in particular at low temperature. The binder may be in the form of particles and / or fibers, for example of a resin-based thermoplastic type, such as polyethylene (PE), polypropylene (PP) or in a PE-PP copolymer.

[0066] The disentangling step ii) may further comprise a mixture of the fibers 10, in particular carbon fibers, with thermoplastic fibers, such as polyetherimides (PEI), poly(phenylene sulfide) (PPS) or polycarbonate (PC). The thermoplastic fibers preferably have a glass transition temperature higher than that of the binder.

[0067] The calendering step iv) is carried out at the glass transition temperature of the binder and is intended not to soften the thermoplastic fibres intended to be softened during subsequent processing. In the presence of the thermoplastic fibres, the semi-finished product can be used to manufacture a finished product after further processing, in particular heating to the glass transition temperature of the thermoplastic fibres, such as hot moulding of the non-woven web.

[0068] The dispersion step iii) and the preparation step iv) of the manufacturing process make it possible, using a flow of dry air, to disperse the fibers 10 and to produce a fiber mat comprising the fibers 10, air and the binder.

[0069] The calendering step v) then makes it possible to produce the semi-finished recycling product in the form of a roll of non-woven strip 14.

[0070] The manufacturing method according to the invention essentially comprises at least: a) a cutting step, during which several non-woven layers 14 are cut and stacked, in order to form a stack of non-woven layers, b) a compression step, during which the stack of non-woven layers is thermocompressed in a mold, so as to produce a component having a non-planar shape.

[0071] Furthermore, the non-woven layers 14 respectively comprise scraps of fibres 10, in particular carbon fibres, held, at least occasionally, with a binder, in particular thermoplastic, ensuring cohesion of the non-woven layer 14. In addition, the non-woven layers 14 may also comprise thermoplastic fibres.

[0072] In particular, the non-woven layers 14 may have the same composition.

[0073] The fiber scraps 10 generally have a length less than or equal to 100mm, and in particular between 5mm and 50mm, in particular between 12.5mm and 25mm.

[0074] In the present description, the term “binder” must be understood as being an element making it possible to ensure cohesion of the non-woven layer 14, such as a binder material and / or a matrix.

[0075] The stack may consist of a non-woven mattress and / or non-woven flakes, which may be composed of cut pieces of non-woven mattress.

[0076] The non-woven layer 14 preferably has a thickness of between 0.1 mm and 0.6 mm, and preferably of between 0.2 mm and 0.4 mm.

[0077] The non-woven layer 14 may be associated with a binder, in particular a thermoplastic or a thermoset. The thermoplastic binder may, for example, be poly(phenylene sulfide) (PPS), polyetherimides (PEI), polyetheretherketone (PEEK), polycarbonate (PC), polyethersulfone (PESU) and / or polyphenylsulfone (PPSU).

[0078] Thermoplastic fibers preferably have a glass transition or melting temperature higher than that of the binder.

[0079] The non-woven layer 14 may have a surface density of between 100g / m 2 and 1000g / m 2 , especially between 200g / m2 and 600g / m 2 .

[0080] Figure 3 is a very schematic sectional view of a thermocompression mold used in the context of a manufacturing method according to the invention. More particularly, Figure 3 illustrates very schematically the implementation of the compression step b) of the manufacturing method according to the invention.

[0081] For this purpose, as shown in Figure 3, two presses 16 are arranged next to each other and each receiving a set of impressions 20a and 20b with a stack of non-woven layers 14 for the production of two components 12.

[0082] Conventionally, the press 16 comprises two parts, respectively an upper part 16a and a lower part 16b, between which the stack of non-woven layers 14 is arranged. The upper part 16a and the lower part 16b comprise imprints 20a and 20b for the formation of the component 12.

[0083] The prints 20a and 20b may be fixed, removable or movable in the upper part 16a and the lower part 16b of the press 16.

[0084] A stack of non-woven layers 14 is arranged in each set of prints 20a and 20b of the presses 16, so as to best fill the volume of a material chamber defined inside the prints 20a and 20b.

[0085] In particular, the stacking is mass controlled, in order to obtain the required mass, dimensions and thicknesses of the components 12.

[0086] The set of impressions 20a and 20b is equipped with a compression chamber allowing the stack of non-woven layers 14 to be encapsulated, in particular very swollen when cold.

[0087] In a particular embodiment, the impressions 20a and 20b have a limited thickness, so as to be heated quickly, and sufficiently thick, so as to be sufficiently rigid for compliant dimensioning. In particular, the impressions 20a and 20b have a thickness of between 5mm and 20mm.

[0088] In addition, the sets of impressions 20a and 20b may be equipped with a closing system, in particular by vacuum and / or mechanical. Figure 6 includes schematic perspective views of a component for fitting out an aircraft cabin, manufactured by a manufacturing method according to the invention. As can be seen in Figure 6, the component 12 has a non-planar shape, in particular a complex three-dimensional shape.

[0089] For this purpose, the stack of non-woven layers 12 is heated, in particular by conduction, by the mold 16.

[0090] Heating is preferably carried out at a temperature above the glass transition and / or melting temperature of the binder, impregnating the fibers, in particular carbon fibers.

[0091] The mold 16 is preferably configured to form at least one variable thickness, rib, groove, and / or hole in the component 12.

[0092] In a particular case, an insert may be intended to be fixed to the component 12. For this purpose, the insert is previously positioned in the mold 16.

[0093] According to the invention, two methods of managing the temperature and pressure in the mold 16. More particularly, figures 4 and 5 are graphs illustrating the evolution of the pressure and the temperature in the mold, respectively, according to a first and a second embodiment of the invention.

[0094] The graphs in Figures 4 and 5 show,

[0095] - on the one hand, the evolution of the temperature T(°C) in the mold 16 over the time T(min) according to a curve C1, and

[0096] - on the other hand, the evolution of the pressure P(bar) in the mold 16 over time T(min) according to a curve C2.

[0097] As illustrated in the graphs in Figures 4 and 5:

[0098] - b1) the mold 16 is heated from a first temperature T1 to a plateau at a second temperature T2, then is cooled to a third temperature T3; and

[0099] - b2) the pressure in the mold 16 increases from a first pressure P1 to a second pressure P2, then decreases to a third pressure P3.

[0100] Additionally, the mold 16 may be heated prior to increasing the pressure in the mold 16. Furthermore, the mold 16 may be cooled prior to decreasing the pressure in the mold 16.

[0101] The increase and / or decrease in temperature T, respectively during heating and cooling, can be linear. The increase and decrease in pressure can each be instantaneous, quasi-instantaneous or substantially instantaneous.

[0102] Especially :

[0103] - the first pressure P1 is between 0.5 bar and 5 bar,

[0104] - the second pressure P2 is greater than or equal to 30 bars, in particular between 30 bars and 70 bars, and / or

[0105] - the third pressure P3 is between 0.5 bar and 5 bar.

[0106] Moreover,

[0107] - the first temperature T1 is in particular between 20°C and 60°C,

[0108] - the second temperature T2 is in particular greater than or equal to the glass transition or melting temperature of the binder, in particular greater than or equal to 350°C, in particular between 350°C and 400°C, and / or

[0109] - the third temperature T3 is in particular between 20°C and 60°C.

[0110] Moreover,

[0111] - the duration of the temperature level is in particular between 5 min and 15 min, in particular approximately 10 min,

[0112] - the heating time, i.e. the increase from the first temperature T1 to the second temperature T2, is in particular between 3 min and 30 min, and / or

[0113] - the cooling time, i.e. the reduction from the second temperature T2 to the third temperature T3, is in particular between 5 min and 20 min.

[0114] In an alternative embodiment of the invention, the mold 16 may comprise a consolidation press regulated at a fourth temperature T4, lower than the solidification temperature of the binder with upper part 16a and lower part 16b of the mold 16.

[0115] Furthermore, the heating of the manufacturing process according to the invention is carried out by a heating means, of the conduction type, of the convection type, in particular infrared, or of the ceramic type.

[0116] In addition, the imprints 20a and 20b, in which the stack of non-woven layers 14 is arranged for the formation of the component 12, are mobile, in particular mounted on a carriage, so as to be able to pass between different stations, such as, in particular, a stack loading station, a heating station, a consolidation station and an unloading station.

[0117] The present invention provides several advantages including: - a reduction in material losses (particularly carbon fibers) during the composite manufacturing cycle in the aeronautical field,

[0118] - recycling of this material for the interior fittings of an aircraft, such as aircraft seats, - a reduction in the mass of these fittings thus obtained and, consequently, a reduction in the carbon footprint linked to air transport,

[0119] - etc.

Claims

CLAIMS 1. Method for manufacturing a component (12), in particular for fitting out an aircraft cabin, in particular for a seat of an aircraft cabin, comprising at least: a) a cutting step, during which several non-woven layers (14), comprising scraps of fibers having a random orientation with at least one binder, are cut and stacked, in order to form a stack of non-woven layers, and b) a compression step, during which the stack of non-woven layers is thermocompressed in a mold (16), so as to produce a component (12) having a non-planar shape.

2. Manufacturing method according to claim 1, in which the stack of non-woven layers is heated by conduction by the mold (16), by convection or ceramic.

3. A manufacturing method according to any one of the preceding claims, wherein the mold (16) is configured to form at least one variable thickness, a rib, a groove and / or a hole.

4. Manufacturing method according to any one of the preceding claims, in which an insert intended to be fixed to the component (14) is previously positioned in the mold (16) before the compression step b).

5. A manufacturing method according to any one of the preceding claims, wherein the binder is poly(phenylene sulfide) (PPS), polyetherimides (PEI), polyetheretherketone (PEEK), polycarbonate (PC), polyethersulfone (PESU) and / or polyphenylsulfone (PPSU).

6. Manufacturing method according to any one of the preceding claims, in which the compression step b) comprises and / or is followed by a step of overmolding the component (12).

7. Manufacturing method according to any one of the preceding claims, in which, during compression step b): - b1) the mold (16) is heated from a first temperature T1 to a plateau at a second temperature T2, then is cooled to a third temperature T3, - b2) the pressure in the mold increases from a first pressure P1 to a second pressure P2, then decreases to a third pressure P3.

8. Manufacturing method according to claim 7, in which the mold (16): - is heated before increasing the pressure in the mold (16), and / or - is cooled before the pressure in the mold (16) decreases.

9. Manufacturing method according to claim 7 or 8, wherein the increase, respectively the reduction, of the temperature is linear.

10. Manufacturing method according to any one of claims 7 to 9, in which the increase, respectively the reduction, of the pressure is substantially instantaneous.

11. Manufacturing method according to one of claims 7 to 10, in which the second temperature T2 is greater than or equal to the glass transition and / or melting temperature of the binder, in particular greater than or equal to 350°C, and / or the second pressure P2 is greater than or equal to 30 bars.

12. A manufacturing method according to any one of the preceding claims, wherein the component is a seat component of an aircraft cabin.

13. Manufacturing method according to any one of the preceding claims, in which the stack of non-woven layers is placed in a set of mold impressions in step b).

14. Component (12) in particular for fitting out an aircraft cabin, characterized in that the component (12) is obtained by a manufacturing method according to one of the preceding claims.

15. Component (12) according to the preceding claim, in which the component is a seat component of an aircraft cabin.

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