GB2589555A

GB2589555A - Intumescent pocket

Info

Publication number: GB2589555A
Application number: GB1914898.0A
Authority: GB
Inventors: Hainsworth Ian; Coggon Rupert
Original assignee: Tenmat Ltd
Current assignee: Tenmat Ltd
Priority date: 2019-10-15
Filing date: 2019-10-15
Publication date: 2021-06-09
Also published as: GB201914898D0

Abstract

The intumescent pocket 1 is for thermally shielding an object 2 and comprises an intumescent material 3 and an encapsulating container 4 defining a cavity 5 for receiving said object 2. The intumescent material 3 is at least partly contained within the cavity 5 and is arranged to expand, in response to a heat source, into the cavity 5. An object 2 inside the pocket 1 may be insulated from external heat or an external environment may be shielded from a heat source within the pocket 1, such as a fire. The intumescent material 3 may be formed in two segments or a ring and may be 0-20% organic material by weight. The container 4 may be flexible or rigid. The object 2 may be electronic such as including a lithium ion battery or a radio frequency identification device, RFID. The pocket 1 may be securable to the object 2.

Description

INTUMESCENT POCKET

Field of the Invention

[1] The present invention relates to thermally insulating an object within an intumescent pocket. The present disclosure is particularly concerned with electronic objects, such as an electronic chip or a battery.

Background

[2] Electronic devices are highly susceptible to fire damage. For example, rising temperature in an electronic device may cause components to fail, thereby impairing function.

[3] Of particular interest to the present application are radio frequency identification (RFID) devices. These devices have particularly limited temperature resistance due in part to the soldered connections between the transmitter and antenna. Solder melts at approximately 180 degrees Celsius.

[4] One use of RFID's however is for the emergency services to track staff location, such as a firefighter, during dangerous situations. It is therefore desirable that the firefighter's RFID continues to function even while putting out a blaze.

[5] RFID's are also used for a plethora of other applications, including monitoring warehouse stock and tracking deliveries. While these RFID's are not normally exposed to fire, it is preferable that should an unfortunate fire incident occur, the RFID's continue to function. This is because the RFID's can be used to aid in recovery and clean up after the fire, as well as providing useful stock information to the insurance industry.

[6] Also of interest are lithium ion batteries. These batteries are used to power many electronic devices and so are manufactured and transported in large volumes. A risk with storing and transporting large volumes of batteries is that if one battery fails, and catches fire for any reason, then other nearby batteries simply provide further fuel for the fire, which can lead to a chain reaction effect. It is therefore highly desirable to be able to isolate an individual faulty battery, or perhaps group of batteries, from a surrounding area and prevent the spread of fire.

Summary

[7] It is an aim of the preferred embodiments of the present invention to overcome at least one of the aforementioned problems. In particular, it is an aim of the preferred embodiments to provide a mechanism for fire prevention which can either protect an object against external threats or protect an external environment from a combusting object.

[8] Accordingly, there is provided an intumescent pocket according to claim 1 and an object comprising an intumescent pocket according to claim 16. Additional features of the invention will be appreciated from the dependent claims and the discussion herein.

[9] In one aspect of the invention there is provided an intumescent pocket for thermally shielding an object. The intumescent pocket comprises an intumescent material component and an encapsulation component. The encapsulation component defines a cavity for receiving said object, and the intumescent material component is at least partly contained within the cavity and is arranged to expand, in response to a heat source, into the cavity. Suitably an object inside the pocket may be insulated from a heat source which is sufficient react the intumescent component. Alternatively the pocket may act to insulate an external environment from a sufficiently hot, e.g. burning, object.

[10] The intumescent material component may be positioned proximate to an outer edge of the object when received within the cavity, so as to minimise the distance the intumescent must expand in order to envelop the object.

[11] The intumescent material component may comprise at least two segments, The segments may be suitably provided on opposite sides of the object. In this way the intumescent material may expand to envelop the object from opposite directions, thereby increasing the speed at which the object becomes shielded.

[12] The intumescent material component may be arranged in a ring, with the object positioned within the ring, so as to more reliably ensure coverage of the object on all sides.

[13] The encapsulation component may comprise a flexible membrane, such as woven glass cloth. Suitably the encapsulation component may elastically expand in response to expansion of the intumescent component, so as to relieve expansion pressure on the object.

[14] The encapsulation component may comprise a rigid body such as gypsum board or mineral fibre board. Suitably the rigid body provides durability to the pocket and aids in protection of the object, for example during transportation of the object within the pocket.

[15] The intumescent pocket may comprise means for securing the pocket to the object so as to maintain the object securely in place whilst it resides in the pocket.

[16] The intumescent material component may comprise between 0% and 20% organic material by weight to reduce the effect of a temperature spike propagating from a hot surface of the intumescent material component to the cold surface. In this way enhanced insulation of the object is provided.

[17] The intumescent pocket may be advantageously used in combination with an electronic object, such as a frequency identification device or a lithium-ion battery.

Brief Description of Figures

[18] For a full understanding of the present disclosure reference will now be made to the accompanying drawings, in which: [19] Figure 1 shows an example of an intumescent pocket; [20] Figure 2 shows another example of an intumescent pocket; [21] Figure 3 is a graph showing the temperature on a cold face of an intumescent material when the opposite or hot face is exposed to high temperature; and [22] Figure 4 shows a further example of an intumescent pocket. Detailed Description [23] Figure 1 shows an example intumescent pocket 1 which shields an object 2. That is, the intumescent pocket 1 may be generally regarded as encasing and protecting the object 2.

[24] In this context, the term 'shield' is used in the dual sense of either shielding the object from the outside world, or shielding the outside world from the object. The object 2 may be any object, but is particularly envisaged as an object for which there is a likelihood of exposure to fire. For example, the object 2 may be an electronic device or component thereof, such as a microchip board or an electronic battery, but is not limited thereto.

[25] The intumescent pocket 1 comprises an intumescent material component 3 and an encapsulation component 4. The encapsulation component 4 defines a cavity 5 into which the object 2 is received. In normal use, such as when the object 2 and pocket 1 are at room temperature, the intumescent material component 3 is inert, merely being present in the pocket 1. Importantly however the intumescent material component 3 is arranged to expand when exposed to a heat source, such as a fire.

[26] The intumescent material component 3 is arranged to expand into the cavity 5 defined by the encapsulation component 4. In this example, the cavity 5 includes a gap between an inner surface of the encapsulation component 4 and the object 2, and the intumescent material 3 expands in response to heat to expand into the gap and so fill the cavity 5. Put another way, expansion of the intumescent material component 3 in response to heat is restricted and contained by the encapsulation component 4. Suitably the intumescent material component 3 may be at least partly contained within the cavity 5 defined by the encapsulation component 4.

[27] In this way, the intumescent material 3 encloses the object 2 and thereby insulates the object 2 from the surrounding environment. Thus, if the surrounding environment is hot then heat is prevented from reaching the object 2. Conversely, if the object 2 is hot then heat (and fire) is prevented from escaping out of the intumescent pocket.

[28] Figure 1 shows one possible arrangement of the intumescent material component 3 whereby the intumescent material component 3 is positioned proximate to the edge of the object 2. More specifically, in this example the intumescent material component 3 surrounds the object in the x,y plane so as to provide a closed ring of intumescent material around the object 2. To ensure full enclosure of the object 2 the intumescent material component 3 may expand in all directions around the object 2 (barring of course into the object 2 itself).

[29] It will however be appreciated that other arrangements of the intumescent component are possible. For example, the intumescent material component 3 may be provided in a plurality of discrete sections surrounding the object 2; it is also not necessary for the intumescent material component 3 to fully surround the object 2, and instead one or more areas of intumescent material component 3 may be provided in strategic places in or around the object 2. In another example the intumescent material component 3 may entirely cover one or more surfaces of the object 2.

[30] The intumescent material component 3 is suitably comprised of an active (heat reactive) ingredient held within a polymeric matrix. Typically the active ingredient is graphite and the polymeric matrix is comprised at least partly of organic material.

[31] Current intumescent materials typically comprise an organic material content of over 50% of the mass of the intumescent by weight. Although the organic material may be considered inactive in comparison to the active graphite component, the organic material does also combust and create what is known as an 'organic temperature spike' throughout the intumescent. This spike lasts until all of the organic component of the intumescent material has been exhausted. The temperature spike transfers heat through the intumescent material from the hot surface to the cold surface. In the context of the present invention, whereby the intent is to prevent heat transfer, the organic temperature spike presents a problem.

[32] For example, where the intent is to shield the object 2 from an external fire within the pocket 1, then the organic temperature spike may cause damage to the object 2. Therefore, in order to better protect the object, it is desirable to lessen the effect of the temperature spike.

[33] Figure 3 is a graph showing the behaviour over time (x axis) of the temperature on the cold face of an intumescent material (y axis) when the opposite or hot face is exposed to fire or high temperature. The graph demonstrates the spike in temperature that can occur on the cold face of the intumescent material for materials with high organic component (e.g. over 50%) and low organic component (e.g. around 20%). As can be seen the effect of the temperature spike can be reduced by employing an intumescent material with low organic component.

[34] Investigations performed by the Applicant have found that reducing the organic component of the intumescent material to below 20% by weight dramatically reduces the effect of the temperature spike, and in some instances nullifies it entirely. Therefore it is preferable to use an intumescent material with less than 20% organic material by weight. This may be achieved for example by replacing the polymeric matrix with a largely mineral fibre matrix. Such mineral fibres are known in the art such as the Tenmat FF107 or FF104 intumescent materials, although not for the purpose of the present disclosure.

[35] Expansion of the intumescent material component 3 is controlled by the encapsulation component 4. In other words, without the presence of the encapsulation component 4, the intumescent material would be free to expand in any direction and there would be no guarantee that the intumescent material component 3 would enclose the object 2. Thus the encapsulation component 4 aids in achieving the purpose of covering the object 2 in the intumescent material in orderto provide a shield against heat. Expansion of the intumescent material component 3 may also be controlled by providing the intumescent material component 3 with an outer edge 6 which is solid, or at least not made from an intumescent material. That is, the outer edge 6 may provide a shell which prevents expansion of the intumescent in a direction away from the object 2 [36] In the example of Figure 1 the encapsulation component 4 extends from the outer edge 6 of the intumescent material component 3 to cover the object 2. Here the encapsulation component 4 extends both above and below the object 2 such that the object 2 is fully enclosed in the x, y, & z dimensions. It will however be appreciated that other configurations are possible.

[37] In one example (not shown) the encapsulation component 4 may extend from a different part of the intumescent material component 4, such as an inner edge, provided that expansion of the intumescent material is directed into the cavity 5. In another example (not shown) the encapsulation component 4 may not be attached directly to a surface or edge the intumescent material component 3 at all, and may suitably be thought of as a case surrounding the intumescent material component 3 (and ultimately surrounding the object 2).

[38] In yet another example (not shown), if the object 2 has an insulating or fire retarding surface then it may not be necessary for the intumescent material to expand to cover that surface. In such an example the intumescent material component 3 and associated encapsulation component 4 would only be required on the non-fire resistant surface. In other words, if we suppose the object 2 has an insulating base extending in the x,y plane at z=0, such that the object extends only in the positive z direction, then it may be appropriate for the intumescent pocket 1 to only encapsulate the object 2 in the positive z direction and not the negative z direction; that is, the intumescent pocket 1 may extend above the object 2 but not below it.

[39] The encapsulation component 4 may comprise flexible and/or rigid parts. That is, the encapsulation component 4 may have elastic or deforming properties such that it is notionally flexible, or the encapsulation component 4 may have in-elastic or solid properties such that it is notionally rigid.

[40] Where the encapsulation component 4 is flexible it may be provided as a flexible membrane. Such a membrane may be suitable for objects 2 with irregular surfaces, such as electronic chips, in order to minimise the volume of the cavity 5 required to be filled by the intumescent material. Such a membrane has the additional benefit of further protecting the object from particulates/contaminants. Further beneficially, if the flexible membrane is elastic, then pressure from expansion of the intumescent will cause stretching of the flexible membrane rather than applying pressure to the object and potentially damaging it. Preferably a flexible membrane would be provided by a woven glass cloth.

[41] In one example, not shown, the flexible membrane may be initially dimensioned so as to be in contact with the object 2 received into the cavity 5. That is, once the object 2 is received into the cavity 5 then the cavity 5 may be regarded as completely filled by the object 2, or filled by a combination of the object 2 and the intumescent component 3; in other words it may be considered that there is no cavity 5 remaining after receipt of the object 2. Expansion of the intumescent component 3 in response to heat would then cause the encapsulation component to bulge outwards. Suitably, such an arrangement would allow for the overall size of the intumescent pocket 1 to be reduced compared to other described examples.

[42] Where the encapsulation component 4 is rigid it may be provided by a rigid body such as gypsum board or mineral fibre-based board. A rigid encapsulation component 4 would provide additional durability to the intumescent pocket 1, and may be particularly appropriate for transporting lithium ion batteries.

[43] The intumescent pocket 1 may be installed around the object 2 in situ, or may be provided as an individual entity into which the object is inserted. For example, the intumescent pocket 1 may be secured to the object 2 using securing means 7, may be formed as an integral part of the object 2, or may provide a container for the object 2.

[44] Figure 2 shows an example whereby the intumescent pocket 1 comprises opening and closing means such that the intumescent pocket 1 may be opened to receive the object 2 and close around the object 2.

[45] In this example the intumescent material component 3 is divided into 2 halves. Along one edge where the two halves meet is provided a hinge mechanism 8, whilst on another edge is provided a lock mechanism 9. In this way the intumescent pocket 1 is advantageously reusable for different objects, provided of course that the intumescent material has not been activated.

[46] In another example, not shown, the hinge 8 and securing mechanism 9 are positioned between the intumescent material component 3 and a part of the encapsulation component 4, thereby leaving the intumescent material component 3 as a single entity rather than divided.

[47] Figure 4 shows a further example of a closable/openable intumescent pocket 1. In this example, the intumescent material component is provided as two distinct segments 3a and 3b. The object 2 is received by the pocket 1 through an opening 10 such that the object 2 resides between the two segments 3a, 3b. Preferably the object 2 is positioned substantially central in the pocket 1, which may be suitably achieved under friction, e.g. by dimensioning the object 2 slightly larger than a distance 11 between the two segments 3a, 3b. The pocket 1 comprises closing means, such as a flap 12, which covers the opening 10 to close the object 2 inside the pocket 1. Here the flap 12 forms part of the encapsulation component 4.

[48] When closed, the flap 12 is suitably secured to the pocket 1 such that expansion of the intumescent material is contained by the flap 12. For example, the flap 12 may be securable to a side wall 13 of the pocket 1. In one example, the flap 12 may be secured by a lock mechanism 9, analogous to Figure 2, such that the object 2 may be easily removed without damaging the pocket 1 and so the pocket 1 may be reused. In another example, the flap 12 may be secured by strong adhesive to create a seal between the flap 12 and side wall 13, so that the object 2 is only removable after breaking the seal. This arrangement may be particularly appropriate where evidence of any tampering with the object 2 during e.g. transit in the pocket 1 is desired.

[49] Optionally, the closing means 12 may be provided as a different material to other parts of the encapsulation component 4. That is, the closure means 12 may be rigid while other areas of the encapsulation component 4 are flexible (e.g. an end 14), or the pocket 1 may be primarily rigid while the closure means 12 is flexible.

[50] This principle of variable material for the encapsulation component may also be applied more generally. For example, the closing means 12 and the end 14 of the pocket 1 (opposite the opening 10) may be formed as a flexible membrane, while side walls 13 of the pocket 1 may be formed from rigid board [51] It will of course be appreciated that the intumescent pocket 1 is not restricted to protecting only one object 2, but may shield a plurality of objects depending on the size of the objects and the size of the pocket 1.

[52] In summary, exemplary embodiments of an intumescent pocket which creates an insulating shield around an object have been discussed. The described examples provide the benefit of shielding an object inside the pocket from external fires whilst simultaneously shielding the outside environment from a fire from within the pocket. In other words the intumescent pocket provides a shield regardless of the source of the fire.

[53] The described exemplary embodiments are convenient to manufacture industrially and straight forward to use. An industrial application of the example embodiments will be clear from the discussion herein.

[54] All of the features disclosed in the specification (including any accompanying claims, abstract, and drawings) may be combined in any combination except combinations where at least some of such features and / or steps are mutually exclusive [55] Each feature disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature discloses one example only original series or equivalent or similar features.

[56] Although preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made without departing from the scope of the invention as defined in the claims.

Claims

CLAIMS: 1. An intumescent pocket forthermally shielding an object, the intumescent pocket comprising an intumescent material component and an encapsulation component, wherein the encapsulation component defines a cavity for receiving said object, and wherein the intumescent material component is at least partly contained within the cavity and is arranged to expand, in response to a heat source, into the cavity.
2. The intumescent pocket according to claim 1, wherein the intumescent material component is positioned proximate to an outer edge of the object when received within the cavity.
3. The intumescent pocket according to claim 1 or 2, wherein the intumescent material component comprises at least two segments.
4. The intumescent pocket according to claim 3, wherein the segments are provided on opposite sides of the object
5. The intumescent pocket according to any preceding claim, wherein the intumescent material component is arranged in a ring.
6. The intumescent pocket according to any preceding claim, wherein the encapsulation component comprises a flexible membrane.
7. The intumescent pocket according to claim 6, wherein the flexible membrane comprises
8. The intumescent pocket according to any of claims 1 to 5, wherein the encapsulation component comprises a rigid body.
9 The intumescent pocket according to claim 8, wherein the rigid body comprises gypsum.
10. The intumescent pocket according to claim 8, wherein the rigid body comprises mineral fibre.
11. The intumescent pocket according to any preceding claim, wherein the intumescent pocket comprises means for securing the pocket to the object.
12. The intumescent pocket according to any preceding claim, wherein the intumescent material component comprises between 0% and 20% organic material by weight.
13. The intumescent pocket according to any of claims 1 to 12 wherein the object being shielded is electronic.
14. The intumescent pocket according to claim 13, wherein the electronic object is a radio frequency identification device.
15. The intumescent pocket according to claim 13, wherein the electronic object is a lithium-ion battery.
16. An object comprising an intumescent pocket according to any one of claims 1-12.
17. The object according to claim 16, wherein the object is electronic.
18. The object according to claim 17, wherein the electronic object comprises a radio frequency identification component.
19. The object according to claim 17, wherein the electronic object comprises a lithium-ion battery.