GB2609462A

GB2609462A - A curing tool

Info

Publication number: GB2609462A
Application number: GB2111127.3A
Authority: GB
Inventors: Dieudonne Addison; Myburgh Arno
Original assignee: Safran Seats GB Ltd
Current assignee: Safran Seats GB Ltd
Priority date: 2021-08-02
Filing date: 2021-08-02
Publication date: 2023-02-08
Also published as: GB202111127D0

Abstract

A curing tool 100 for curing a light-curable composite comprises a light passageway 141 partially enclosed by one or more internally facing light reflectors 132, a light source 111 at a first end of the light passageway for directing light through the light passageway, and a rigid and at least partially transparent tool head 151 at a second, opposite end of the light passageway, such that the tool is configured to, in use direct light from the light source through the light passageway to the tool head, transmit the light through the tool head, emit the light from the tool head to a light curable composite, and apply pressure to the light-curable composite through the tool head. The tool head may further be configured to focus light from the light passageway. The invention also provides a kit of parts, a method of curing a light-curable composite, a component and an aircraft seat.

Description

A CURING TOOL

BACKGROUND OF THE INVENTION

100011 The present disclosure relates to a curing tool.

100021 The present invention concerns curing tools. More particularly, but not exclusively, this invention concerns a curing tool including a light source. The invention also concerns a kit of parts, a method of curing a light-curable composite, a component and an aircraft seat.

100031 It is known that photopolymers can be cured by light, especially by UV light.

Tools for such curing, including use in dentistry, may use LEDs to provide the light over the area to be cured.

100041 However, such tools and curing methods are unsuitable for use with, for example, a number of layers of uncured composite (known as a lay-up) and/or where significant structural strength of the cured structure is required.

100051 The present invention seeks to mitigate the above-mentioned problems.

Alternatively or additionally, the present invention seeks to provide an improved curing tool.

SUMMARY OF THE INVENTION

100061 The present invention provides, according to a first aspect, a curing tool for curing a light-curable composite, the tool comprising a light passageway partially enclosed by one or more internally facing light reflectors, a light source at a first end of the light passageway for directing light through the light passageway, and a rigid and at least partially transparent tool head at a second, opposite end of the light passageway, such that the tool is configured to, in use, direct light from the light source through the light passageway to the tool head, transmit the light through the tool head, emit the light from the tool head to a light-curable composite, and apply pressure to the light-curable composite through the tool head.

[0007] Such a curing tool (and in particular the rigid and at least partially transparent tool head of the tool) allows curing light and pressure to both be applied to a composite in a single process. This may be by a user or by an actuation mechanism, such as a robotic arm.

[0008] This enables faster and more efficient curing of the composite. This means there is no need for the curing process to take place in an autoclave, for example, or another vessel for providing the pressure.

[0009] This may be especially advantageous when curing a layered composite, known as a lay-up. The curing tool is able to apply both light and compaction pressure to speed up the curing process, urge the layers together and provide a cured composite that has the desired strength. For example, the curing tool may be used to co-cure two or more composite plies together (on top of each other).

[0010] This may be especially advantageous for curing pre-impregnated products.

100111 The light-curable composite to be cured may be part of a component, for example a component of an aircraft interior, such as a component of an aircraft seat.

[0012] The light source may be a UV light source. The light source may comprise one or more (high power) LEDs.

[0013] The light reflectors are configured to reflect light internally such that the light does not escape through sides of the light passageway. In other words, substantially all light from the light source is directed through (and contained in) the passageway, for example to be emitted through the tool head, rather than "escape" through sides of the light passageway. The light reflectors may be configured to reflect TJV light. The light reflectors may comprise polished aluminium, foils, chrome coating and/or mirrors.

[0014] The tool head may be at least partially transparent to UV light. The tool head may be substantially transparent to light. The tool head may be substantially transparent to UV light. The tool head may comprise acrylic, polycarbonate and/or glass.

[0015] The rigid tool head is sufficiently rigid to be able to transmit a pressure force from the tool head to the composite. The pressure force applied to the composite may be 3-6 Bar (0.3 -0.6MPa). The tool head may have a compressive yield strength of greater than 500 Bar (50 MPa).

[0016] The light emitted from the tool head to the light-curable composite may occur at the same location (or locations) on the tool head, and hence the same location (or locations) of the light-curable composite, as the application of pressure to the light-curable composite. If the tool head is moved over the light-curable composite, in use, the receiving of light at a location (or locations) of the light-curable composite may occur at the same time as the receiving of pressure at the location (or locations) of the light-curable composite.

[0017] The location (or locations) of the application of pressure are known as compaction area (or areas)".

[0018] The tool head may be considered to be a compression tool head.

[0019] Preferably, the tool head is configured to focus light from the light passageway.

[0020] For example, the light from the passageway may be focused into a single location/area, or multiple locations/areas on the tool head. This enables even faster curing as the light can be provided more intensely (i.e. at a higher intensity) to the composite, compared to if it was "spread out" evenly over the whole of the tool head.

[0021] Preferably, the tool head comprises a first surface internal to the tool for receiving light from the light passageway and a second surface external to the tool for emitting light.

[0022] For example, the second surface may provide the more focused/intense light.

[0023] More preferably, the external surface extends past one or more side walls of the tool at the second end of the light passageway.

[0024] This provides a protruding external surface for providing the pressure to the light-curable composite. Hence, this makes positioning of the external surface of the tool on the composite easier.

[0025] Even more preferably, the tool head is held in place by the one or more side walls of the tool.

[0026] For example, the side walls may comprise a notch that holds a side protrusion of the tool head.

[0027] This provides a convenient way to secure the tool head without the need for additional parts.

[0028] Preferably, the external surface is substantially smooth.

[0029] This enables the tool head to be easily moved over the composite.

[0030] Preferably, the external surface is substantially flat.

[0031] This enables efficient curing of a substantially flat composite.

[0032] Alternatively, the external surface is curved.

[0033] This enables efficient curing of a curved composite.

[0034] The apex of the curve may be able to provide pressure (i.e. a compaction area) to the composite. The apex of the curve may be a focal point for the light. Such a curved external surface may provide an efficient way of focussing the light.

[0035] More preferably, the external surface is convex.

[0036] The apex of the convex curve may be able to provide pressure (i.e. a compaction area) to the composite. The apex of the convex curve may be a focal point for the light. Such a convex curved external surface may provide an efficient way of focussing the light.

[0037] Preferably, the internal surface is substantially flat.

[0038] This may aid focusing of the light, especially if the light from the light source is expected to be substantially perpendicular to the internal surface. For example, this could be if the light is not expected to be heavily reflected by the light reflectors prior to reaching the tool head.

[0039] Alternatively, the internal surface is curved, and preferably convex.

[0040] Such a curved internal surface may provide an efficient way of focussing the light.

[0041] Preferably, the tool further comprises one or more light focusing elements in between the light source and the light passageway. These may be adjacent or abutting the light source.

[0042] These may be thought of as the primary optics, with the tool head providing secondary optics.

[0043] Preferably, the tool further comprises a heat sink located behind the light source. The heat sink is able to dissipate excess heat from the curing tool. The heat sink may comprise aluminium alloy, for example.

[0044] In other words, the light source may be located in between the heat sink and the light passageway. This acts to prevent the tool from heating up due to the heat produced by the light source [0045] Preferably, the tool further comprises one or more mounting points for mounting the tool to an actuation mechanism.

[0046] The one or more mounting points may allow the tool to be rotationally mounted to the actuation mechanism. The actuation mechanism may be a robotic arm.

[0047] Preferably, the tool head has a compressive yield strength of greater than 500 Bar (50 MPa), more preferably greater than 600 Bar (60 MPa), 700 Bar (70MPa) or 800 Bar (80MPa).

[0048] According to a second aspect of the invention there is also provided a curing tool for curing a light-curable composite, the tool comprising a light source, and a rigid, at least partially transparent, compression head, through which the light source is arranged to emit light.

[0049] According to a third aspect of the invention there is also provided a kit of parts comprising a curing tool comprising a light passageway partially enclosed by one or more internally facing light reflectors and a light source at a first end of the light passageway for directing light through the light passageway, wherein the kit of parts further comprises a number of different rigid and at least partially transparent tool heads for mounting at a second, opposite end of the light passageway.

[0050] The different tool heads may be designed for applying pressure to different shaped composites, such as substantially flat or curved composite surfaces.

[0051] According to a fourth aspect of the invention there is also provided a method of curing a light-curable composite, the method including using the curing tool or kit of parts as described above.

[0052] According to a fifth aspect of the invention there is also provided a method of curing a light-curable composite, the method including the following steps emitting light -6 -from a light source, at a first end of a light passageway, reflecting light internally along the passageway, transmitting light through a rigid tool head at a second, opposite end of the light passageway, emitting light from the tool head to a light-curable composite, and applying pressure to the light-curable composite through the tool head.

[0053] The light emitted from the tool head to the light-curable composite may occur at the same location (or locations) on the tool head, and hence the same location (or locations) of the light-curable composite, as the application of pressure to the light-curable composite.

[0054] The method may also include the step of moving the tool head over the light-curable composite. Receiving of light at a location (or locations) of the light-curable composite may occur at the same time as the receiving of pressure at the location (or locations) of the light-curable composite.

[0055] According to a sixth aspect of the invention there is also provided a method of curing a light-curable composite, the method including the following steps: emitting light from a light source, transmitting light through a rigid, at least partially transparent, compression head, emitting light from the tool head to a light-curable composite, and applying pressure to the light-curable composite through the tool head.

[0056] According to a seventh aspect of the invention there is also provided a component including a light-curable composite cured by the method as described above.

[0057] Preferably, the component is a component of an aircraft interior, such as a component of an aircraft seat.

[0058] According to an eighth aspect of the invention there is also provided an aircraft seat including a component as described above.

[0059] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

DESCRIPTION OF THE DRAWINGS

[0060] Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which: [0061] Figure 1 shows a side sectional view of a curing tool according to a first embodiment of the invention; [0062] Figure 2 shows a side sectional view of a curing tool according to a second embodiment of the invention; [0063] Figure 3 shows a side sectional view of a curing tool according to a third embodiment of the invention; [0064] Figure 4 shows a side sectional view of a curing tool according to a fourth embodiment of the invention; [0065] Figure 5 shows a side sectional view of a composite being cured using the tool of Figure 4; and [0066] Figure 6 shows a side sectional view of a second composite being cured using the tool of Figure 4.

DETAILED DESCRIPTION

[0067] Figure 1 shows a side sectional view of a curing tool 100 according to a first embodiment of the invention.

100681 The tool 100 comprises a cylindrical housing 131 proving a top wall 132 and side walls 133. Mounted inside the casing against the top wall 131 is a high power LED 111 for emitting UV light. Abutting the LED 111 is a primary lens optic 113 to focus the light from the LED 111, such that light rays 112 project away from the top wall 132 and through a passageway 141 formed by the side walls 133.

[0069] The top wall 132 acts as a heat sink 121 to absorb heat emitted from the LED Ill. Alternatively, an additional heat sink could be provided and/or heat sink could be incorporated into the side walls 133 of the cylindrical housing 131.

[0070] The side walls 133 are provided with reflectors 134 on their inside to reflect any light rays 112 internally so they are not lost through the side walls 133.

100711 At a bottom end of the tool 100, the side walls 133 are provided with a notch and this notch 135 is used to mount a rigid tool head 151 [0072] The tool head 151 comprises a convex (domed) curved internal surface 152 (internal to the tool 100) and a convex (domed) external surface 153 (external to the tool). A side flange 156 extends around the circumference of the tool head 151 and this flange 156 fits into the side notch 135 of the side walls 133.

[0073] The tool head 151 is transparent and acts to focus the light rays 112 to a focal point 154 at the peak of the external surface 153. This same location 154 also provides a compaction point 155.

[0074] Hence, at location 154, 155 the tool head 151 can be urged against a surface to provide a compaction force and a focused light source. This allows for quick curing of a photopolymer (not shown).

[0075] The tool 100, and therefore the tool head 151 can be moved across, and also pushed into to provide pressure to, the photopolymer to cure it. Arrow 161 shows a rightwards direction of movement of the tool 100 and tool head 151. An uncured portion of the photopolymer (to the right of the compaction and focal point 154, 155) is shown by reference numeral 162. A cured portion of the photopolymer (to the left of the compaction and focal point 154, 155) is shown by reference numeral 163.

[0076] Such a curved tool head 151 is especially convenient for curing a curved photopolymer surface.

[0077] Figure 2 shows a side sectional view of a curing tool 200 according to a second embodiment of the invention.

[0078] This tool 200 is similar to tool 100 and only significant differences will be described. In the following, similar/corresponding elements will use the same reference numerals, preceded by a "2" instead of a "1".

[0079] Here, the reflectors 234 and side walls 233 are shaped so that the passageway 241 is a "lampshade" shape. A heat sink 221 is provided above the LED 211. The LED is flush with the reflectors 234 with the primary lens optic 213 sitting proud of the reflectors 234.

[0080] The tool head 251 is in the form of a planar lens and is held in place between the side walls 233 (not using a notch and flange arrangement).

[0081] Such a planar tool head 251 is especially convenient for curing a planar photopolymer surface.

[0082] Figure 3 shows a side sectional view of a curing tool 300 according to a third embodiment of the invention.

[0083] This tool 300 is similar to tool 100 and tool 200 and only significant differences will be described. In the following, similar/corresponding elements will use the same reference numerals, preceded by a "3" instead of a "1" or "2".

[0084] Here, the top wall 332 extends around above the heat sink 321.

[0085] The side walls 333 extend down and then angle in to the centre of the tool and provide a much smaller, spherical tool head 351. Reflectors are not shown in this figure for clarity.

[0086] The primary lens optic 313 is a convex lens with upper and lower surfaces to focus the light rays 312.

[0087] Such a small spherical tool head 351 is especially convenient for curing a photopolymer with complicated/fiddly geometry.

[0088] Figure 4 shows a side sectional view of a curing tool 400 according to a fourth embodiment of the invention [0089] This tool 400 is similar to tool 200 and only significant differences will be described. In the following, similar/corresponding elements will use the same reference numerals, preceded by a "4" instead of a "2".

[0090] Here, the top wall 432 extends around above the heat sink 421. The LED 411 sits abutting the heat sink 421 [0091] This tool 400 has a planar lens tool head 451 (shown by a single line in the figure) that is held in place between the side walls 433.

[0092] No reflectors are shown here, for clarity.

[0093] Such a planar tool head 451 is especially convenient for curing a planar photopolymer surface.

-10 - [0094] Figure 5 shows a side sectional view of a composite being cured using the tool of Figure 4.

[0095] Here, the tool 400 is mounted using a pivotal mounting point 1021 to a 6 axis robotic arm 1022, as part of a larger tool arrangement 1000.

[0096] The larger tool arrangement 1000 also comprises a tool base 1010 that provides a bed for a photopolymer component 2000, with a curved skin 2001 to be cured. The component 200 is for use as an aircraft seat (seat pan and seat back) structure.

[0097] The tool base 1010 has a corresponding flat portion 1012 and curved portion 1013 to provide the curved shape of the skin 2001. The tool base 1010 also comprises an edge bar 1011, to provide an abutment point for the photopolymer component 2000, and a datum point for the machinery operating the robotic arm I 022.

[0098] Arrow 461 demonstrates the movement of the tool 400 over the photopolymer component 2000 to cure it. The robotic arm 1022 also pushes the tool 400 downwards to provide downward pressure on the photopolymer during curing This pressure is applied across the planar external side of the tool head 451.

[0099] Figure 6 shows a side sectional view of a second composite 2000' being cured using the tool 400 of Figure 4.

1001001 The method demonstrated here is similar to that in Figure 5 and only significant differences will be described. In the following, different but corresponding elements will use the same reference numerals, followed by a '.

[001011 Again, the larger tool arrangement 1000 is used. However, here, the component 2000' to be cured has a skin 2001 and also a core 2002 and a corefill 2003. The tool 400 is used to cure the core and corefill (around the edge of the core) above the skin 2001.

1001021 Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. By way of example only, certain possible variations will now be described.

1001031 The larger tool arrangement 1000 could be used with any of the tools 100 to 400 described above, or any other suitable tool to provide a suitable shape tool head, for example 1001041 The various tools may be interchangeable so that different tools can be used with each larger tool arrangement.

1001051 The tools and larger tool arrangements could be used to cure/bond various different parts of components. For example, hardware (bonded by curing an adhesive between the insert and core), UV adhesive film (e.g. between a skin and core), z-pinning and inserts. For curing a skin, it is desirable to have the tool head in contact with the skin, s described above, but this may not be necessary for other elements being cured.

1001061 The tools and larger tool arrangements could be used to cure components for any suitable use or application.

1001071 The photopolymer components being cured may be formed of any suitable photopolymer material. The material may comprise a resin. It may include obligimers which define matrix structural properties. It may include monomers to decrease viscosity and increase flexibility and adhesion. It may comprise one or more additives. It may comprise a photo initiator.

1001081 The tool heads may be any suitable shape to provide the light focused in a suitable way and location. The tool heads may comprise shapes such as Biconvex, Plano-convex, Positive meniscus, Negative meniscus, Plano-Concave and Biconcave.

1001091 The tool heads may be interchangeable in the tools.

1001101 Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some -12 -embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

1001111 It should be noted that throughout this specification, "or" should be interpreted as "and/or".

Claims

-13 -CLAIMSA curing tool for curing a light-curable composite, the tool comprising: i) a light passageway partially enclosed by one or more internally facing light reflectors, ii) a light source at a first end of the light passageway for directing light through the light passageway, and iii) a rigid and at least partially transparent tool head at a second, opposite end of the light passageway, such that the tool is configured to, in use: direct light from the light source through the light passageway to the tool head, transmit the light through the tool head, emit the light from the tool head to a light-curable composite, and apply pressure to the light-curable composite through the tool head.
2. A curing tool as claimed in claim I, wherein the tool head is configured to focus light from the light passageway.
3. A curing tool as claimed in claim 1 or claim 2, wherein the tool head comprises a first surface internal to the tool for receiving light from the light passageway and a second surface external to the tool for emitting light.
4. A curing tool as claimed in claim 3, wherein the external surface extends past one or more side walls of the tool at the second end of the light passageway.
A curing tool as claimed claim 4, wherein the tool head is held in place by the one or more side walls of the tool.
6. A curing tool as claimed in any of claims 3 to 5, wherein the external surface is substantially smooth.
-14 - 7. A curing tool as claimed in any of claims 3 to 6, wherein the external surface is substantially flat.
8. A curing tool as claimed in any of claims 3 to 6, wherein the external surface is curved.
9 A curing tool as claimed in claim 8, wherein the external surface is convex.
10. A curing tool as claimed in any of claims 3 to 9, wherein the internal surface is substantially flat.
11. A curing tool as claimed in any of claims 3 to 9, wherein the internal surface is curved, and preferably convex.
12. A curing tool as claimed in any preceding claim, wherein the tool further comprises one or more light focusing elements in between the light source and the light passageway.
13. A curing tool as claimed in any preceding claim, wherein the tool further comprises a heat sink located behind the light source.
14. A curing tool as claimed in any preceding claim, wherein the tool further comprises one or more mounting points for mounting the tool to an actuation mechanism.
15. A curing tool as claimed in any preceding claim, wherein the tool head has a compressive yield strength of greater than 500 Bar.
16. A curing tool for curing a light-curable composite, the tool comprising a light source, and a rigid, at least partially transparent, compression head, through which the light source is arranged to emit light.
-15 - 17. A kit of parts comprising a curing tool comprising a light passageway partially enclosed by one or more internally facing light reflectors and a light source at a first end of the light passageway for directing light through the light passageway, wherein the kit of parts further comprises a number of different rigid and at least partially transparent tool heads for mounting at a second, opposite end of the light passageway.
18. A method of curing a light-curable composite, the method including using the curing tool or kit of parts of any preceding claim.
19. A method of curing a light-curable composite, the method including the following steps: i) emitting light from a light source, at a first end of a light passageway, ii) reflecting light internally along the passageway, iii) transmitting light through a rigid tool head at a second, opposite end of the light passageway, iv) emitting light from the tool head to a light-curable composite, and v) applying pressure to the light-curable composite through the tool head.
20. A method of curing a light-curable composite, the method including the following steps: i) emitting light from a light source, it) transmitting light through a rigid, at least partially transparent, compression head, iii) emitting light from the tool head to a light-curable composite, and iv) applying pressure to the light-curable composite through the tool head.
-16 - 21. A component including a light-curable composite cured by the method of claim 18, 19 or 20.
22. A component a claimed in claim 21, wherein the component is a component of an aircraft interior, such as a component of an aircraft seat.
23. An aircraft seat including a component as claimed in claim 22.