Life-saving appliances

Abstract

A life-saving appliance (10) has at least one sheet of flexible material (72, 74) that includes graphene. The sheet of material further may include a polyurethane, PU, or thermoplastic polyurethane, TPU. The life-saving appliance may include two sheets of material, one of which is provided to support the other and to form an inflatable bladder (58). The sheet of material may be formed from fibres, threads or yarn that contains graphene.

Description

LIFE-SAVING APPLIANCESTECHNICAL FIELD

[0001] The present invention relates to life-saving appliances .BACKGROUND TO THE INVENTION

[0002] It is known to form life-saving appliances , such as safety and survival equipment, using flexible polymer films (e . g . polyurethane, PU, or thermoplastic polyurethane, TPU) to create waterproof and air holding materials .SUMMARY OF THE INVENTION

[0003] According to one aspect of the invention, there is provided a life-saving appliance having at least one sheet of flexible material that includes graphene .

[0004] Graphene can be defined as a lattice of hexagonal carbon atoms having a single layer of atoms arranged in a honeycomb planar nanostructure . Graphene Nano Platelets (GNPs ) can be defined as platelet-shaped sheets of graphene stacked on top of one another . These graphitic stacks may have an average thickness of 1-2 nanometres . GNPs may possess many of the same properties as graphene . The graphene in the at least one sheet of flexible material, according to various embodiments of the invention, may be in the form of GNPs or other forms of graphene, including pure graphene .

[0005] The sheet of material may also include polyurethane, PU, and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs .

[0006] The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres, threads or yarn may be woven together to form the sheet of material . The fibres, threads or yarn may also include polyurethane, PU,and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs .

[0007] Embodiments of the invention may provide safety and survival equipment using flexible polymer films (e . g . PU or TPU) incorporating graphene to create waterproof and / or air holding materials . Such incorporation of graphene into the PU / TPU film may increase its strength and contributes to the overall performance of the equipment .

[0008] Embodiments of the invention may provide safety and survival equipment using one of more sheets of material, e . g . including PU or TPU, and incorporating graphene . Such incorporation of graphene into the sheet of material may increase its strength and flame retardance, and contributes to the overall performance of the equipment .

[0009] The sheet of material may be fluid impermeable . This allows the sheet of material to form a pressure holding inflatable item. Pressure holding inflatable items are normally referred to as "bladders" . Inflatable bladders can be inflated orally by mouth or from a compressed gas source such as a cylinder of compressed COp .

[0010] For example, life-saving appliances, such as safety and survival equipment, may utilise a film of a flexible polymer typically for example PU or TPU in order to provide a barrier against a pressurised gas in the creation of inflatable structures such as inflatable liferafts and lifeboats, escape slides and escape equipment, inflatable boats and lifebuoys, lifej ackets, other inflatable safety and survival equipment, inflatable anti-G garments , and other pressure garments .

[0011] A flexible polymer, typically for example PU or TPU, film incorporating graphene may also be used to create a flexible material which is waterproof and can be used to manufacture suits and other clothing which can be sealed against water ingress such as in immersion protection garments or dry suits .

[0012] The sheet of material may have a thickness of between 100 and 150pm - as this would typically be the film / sheet thickness for use in Life Preserver Unit (LPU) and anti G suit applications .

[0013] The sheet of material may include between 1 and 10% graphene (by weight ) , preferably 1.5% graphene by weight . Samples of a number of different percentages of graphene by weight ranging from 1% to 5% were tested in four ways - being breaking force, puncture resistance, weld strength and tear strength. The most effective percentage of GNPs within the TPU was found to be 1.5% .

[0014] The sheet of material may be moisture-vapour permeable . This may improve comfort of a garment and allow the passage of perspiration through the material .

[0015] The sheet of material may be flame retardant (e . g . it will be less damaged by fire than a non-graphene including sheet of material) .

[0016] The life-saving appliance may have at least one further non-graphene sheet of material (i . e . a sheet of material that does not contain graphene ) . The non-graphene sheet of material may support the sheet of flexible material that includes graphene . The sheet of flexible material that includes graphene may have a lower modulus of elasticity the non-graphene sheet of material . The non-graphene supporting sheet of material may limit the expansion or stretching of the sheet of flexible material that includes graphene (e . g . as a bladder incorporating the sheet of flexible material that includes graphene) . The non-graphene supporting sheet of material may protect the sheet of flexible material that includes graphene from abrasion or other damage . Alternatively, the supporting sheet of material may include graphene, and the sheet of material supported by the supporting sheet of material may or may not include graphene .

[0017] The sheet of material may form at least part of agarment .

[0018] The life-saving appliance may be a submarine escape suit, lifej acket, or single or multiple seater liferaft .

[0019] Life-saving appliances comprising conventional films or sheets of material (without graphene reinforcement ) have a number of disadvantageous features; these include limited tensile strength, limited resistance to impact damage, low modulus (modulus of elasticity) , low thermal stability and poor flame retardancy. Studies have shown that by incorporating graphene into a sheet or film (e . g . a PU / TPU film) it is possible to improve a number of characteristics of the sheet or film to the overall advantage of the equipment' s performance . For example see : "Chemical Engineering Journal" Vol 482 15thFebruary 2024 "The Reinforcement of Polyurethane by Mini-Sized Graphene with Superior Performances" . Such laboratory studies have indicated that the inclusion of graphene in PU material can provide the following benefits to the PU film and therefore to the equipment :Improved tensile strength by up to 80%Modulus by up to 126%Increased mechanical performanceIncreased shape memoryThe PU film can be fire retardant and generate limited smoke

[0020] Bladders incorporating graphene (and e . g . PU / TPU) , according to embodiments of the invention have been manufactured and tested and found to have the following improvements over the same non-Graphene bladders :Average breaking force increased by 40%Average puncture resistance improved by 10%Average weld strength improved by 39%Average tear strength improved by 10%

[0021] Reducing the weight of the product is very advantageous both for personal safety equipment (e . g .lifejackets and anti-G suits ) as well as multi-person liferafts etc . The thickness and therefore the weight of the PU film can be reduced while still achieving the same or better strength characteristics of the non-graphene PU film.

[0022] Additionally reducing the thickness of a grapheneincluding PU / TPU sheet or film may make it more flexible and therefore easier to pack into a more compact space thereby further saving space and weight .

[0023] A life-saving appliance having at least one sheet of flexible material that includes graphene, according to embodiments of the invention, may, for example, be :• An inflatable Lifejacket• An Anti G Suit• An Immersion Protection Garment• An inflatable Liferaft, Boat or Marine Escape System (MES)

[0024] The invention may be applicable to any life-saving appliance as defined The International Life-Saving Appliance (LSA) Code . The invention may be applicable to safety and / or survival equipment in general .BRIEF DESCRIPTION OF THE DRAWINGS

[0025] For a better understanding of the present invention embodiments will now be described by way of example, with reference to the accompanying drawings , in which :Fig . 1 is a cross-section of an inflatable lifesaving appliance;Figs . 2 to 7 are partial views at points around the circumference of the inflatable lifesaving appliance of Fig . 1 - e . g . at points A, B or C - showing different forms of pieces of material that may be used to form the inflatable lifesaving appliance;Figs . 8 , 9 and 10 are partial views at points around the circumference of the inflatable lifesaving appliance showinghow two pieces of material and may be sealed at their seams in various different ways ;Fig . 11 shows a front view of a lifejacket;Fig . 12 is a cross-section taken along line X-X of Fig . 11;Fig . 12A shows an enlarged view of part of one piece of material of the lifej acket body of Figs 11 and 12 ;Fig . 12B shows an enlarged view of a seam between two pieces of material of the lifejacket body of Figs 11 and 12 ;Fig . 13 shows a front view of a lifejacket;Fig . 14 is a cross-section taken along line Y-Y of Fig . 13 ;Fig . 14A shows an enlarged view of part of one piece of material of the lifej acket body of Figs 13 and 14 ;Fig . 14B shows an enlarged view of a seam between two pieces of material of the lifejacket body of Figs 13 and 14 ;Fig . 15 is a front view of an aircrew ensemble;Fig . 16 is a cross-section taken along line Z-Z of Fig . 15 with an internal bladder deflated;Fig . 17 is a cross-section taken along line Z-Z of Fig . 15 with an internal bladder inflated;Fig . 18 is a front view of an Immersion Protection Garment; andFig . 19 is a perspective view of an inflatable liferaft .

[0026] In the drawings , like elements are generally designated with the same reference signs .DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0027] A life-saving appliance according to various embodiments has at least one sheet of flexible material that includes graphene . The sheet of flexible material may also include a flexible polymer - such as polyurethane, PU, and / or thermoplastic polyurethane, TPU.

[0028] The sheet of flexible material may be formed bydispersing graphene in the form of Graphene Nano Platelets (GNPs ) into PU / TPU at the melt stage . The sheet of material may have a thickness of between 100 and 150pm. The sheet of material may include between 1 and 10% graphene by weight, preferably 1.5% graphene by weight .

[0029] The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres, threads or yarn may be woven together to form the sheet of material . The fibres, threads or yarn may also include polyurethane, PU, and / or thermoplastic polyurethane, TPU . Graphene may be dispersed into PU / TPU at the melt stage in the form of GNPs to from the fibres , threads or yarn .

[0030] Embodiments of the im ention may provide safety and survival equipment using flexible polymer films (e . g . PU or TPU) incorporating graphene to create waterproof and / or air-holding materials . Such incorporation of graphene into the PU / TPU film may increase its strength and flame retardancy, and may contribute to the overall perform ance of the equipment .

[0031] The graphene-including sheet of material may be fluid impermeable . This allows the sheet of material to form a pressure-holding inflatable item and / or to form a waterproof garment / item.

[0032] Pressure-holding inflatable items are often referred to as "bladders" . Inflatable bladders can be inflated orally by mouth or from a compressed gas source such as a cylinder of compressed COp .

[0033] Embodiments of the invention may provide safety and survival equipment using one of more sheets of material . The sheet of material may be formed from fibres , threads or yarn that contains graphene . The fibres , threads or yarn may be woven together to form the sheet of material . The fibres , threads or yarn may include PU or TPU, and incorporate graphene . Such incorporation of graphene into the fibres, threads or yarn of the sheet of material may increase the strength of the sheet andflame retardancy, and contributes to the overall performance of the equipment .

[0034] A life-saving appliance may include inflatable structures such as inflatable liferafts and lifeboats, escape slides and escape equipment, inflatable boats and lifebuoys, lifejackets and other inflatable safety and survival equipment, inflatable anti-G garments , and other pressure garments . A lifesaving appliance may include suits and other clothing which can be sealed against water ingress such as in immersion protection garments or dry suits .

[0035] A graphene-including flexible sheet of material may be incorporated into a life-saving appliance in a number of ways . By way of example, an inflatable lifesaving appliance 10 is shown in Fig . 1. The inflatable lifesaving appliance 10 comprises two pieces of flexible material 12A and 12B . The pieces of flexible material 12A and 12B are connected to each other along opposite sides by a first seam 14A and a second seam 14B . The pieces of flexible material 12A and 12B form an inflatable bladder 16. The inflatable bladder 16 may be inflated, for example, by a gas inflation system 18 or by an oral inflation device 20. The inflatable bladder 16 may be circular in crosssection but may also have other cross-sectional shapes , such as elliptical .

[0036] Figs . 2 to 7 show different ways in which a grapheneincluding flexible sheet of material may be incorporated into the inflatable lifesaving appliance 10. Figs . 2 to 7 are partial views at any point around the circumference of the inflatable lifesaving appliance 10 of Fig . 1 - e . g . at points A, B or C .

[0037] In Fig . 2 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an inner face 24 of a supporting substrate 26 such as a woven textile (e . g . coated or laminated onto the entire inner face 24 of the supporting substrate 26 ) . The flexible sheet of material 22creates a barrier to gas when the bladder 16 is filled and pressurised with gas . The outer textile supporting substrate 26 provides strength, abrasion resistance and limits the elasticity of the bladder 16 to create a dimensionally stable structure . Such an arrangement may be used, for example, as part of a life jacket (e . g . the life preserver as described in WO-A-2020 / 079025 ) or anti G bladders (e . g . the aircrew ensembles as described in EP-A-2621804 or the submarine escape suit as described in GB-A-2441959) , etc . The supporting substrate 26 may be a non-graphene sheet of material ( i . e . a sheet of material that does not contain graphene) .

[0038] The supporting substrate 26 of Fig . 2 may be a graphene-containing sheet of material . The supporting substrate 26 may be formed by weaving together fibres , threads or yarn that contain graphene . In an arrangement where the supporting substrate 26 of Fig . 2 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a nongraphene sheet ( i . e . a sheet of material that does not contain graphene) .

[0039] In Fig . 3 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an outer face 28 of an inner supporting substrate 26A, such as a woven textile (e . g . coated or laminated onto the entire outer face 28 of the inner supporting substrate 26A) . The flexible sheet of material 22 creates a barrier to gas when the bladder 16 is filled and pressurised with gas . The inner supporting substrate 26A provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The inner supporting substrate 26A may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) . The flexible sheet of material 22 may protect the inner supporting substrate 26A from damage . The flexible sheet of material 22 may provide an outer surface onto which other items formed of PU / TPU may be readily attached - e . g . by high-frequency welding .

[0040] The inner supporting substrate 26A of Fig . 3 may be a graphene-containing sheet of material . The inner supporting substrate 26A may be formed by weaving together fibres, threads or yarn that contain graphene . In an arrangement where the inner supporting substrate 26A of Fig . 3 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0041] In Fig . 4 each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 that is coated or laminated onto an inner face 24 of an outer supporting substrate 26B ( such as a woven textile ) and coated or laminated onto an outer face 28 of an inner supporting substrate 26A ( such as a woven textile ) . For example, the flexible sheet of material 22 is coated or laminated onto the entire inner face 24 of an outer supporting substrate 26B and coated or laminated onto the entire outer face 28 of an inner supporting substrate 26A. The flexible sheet of material 22 is sandwiched between an inner and outer supporting substrates 26A, 26B . The flexible sheet of material 22 creates a barrier to gas when the bladder 16 is filled and pressurised with gas . The inner supporting substrate 26A provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The outer supporting substrate 26B provides strength, abrasion resistance and limits the elasticity of the bladder 16 to create a dimensionally stable structure . Such an arrangement may be used, for example, as part of a large liferaft, inflatable slide or boats, etc (e . g . the survival craft as described in W02017 / 140890 ) . The inner supporting substrate 26A and / or the outer supporting substrate 26B may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) .

[0042] The inner supporting substrate 26A of Fig . 4 may be a graphene-containing sheet of material . The inner supportingsubstrate 26A may be formed by weaving together fibres, threads or yarn that contain graphene . Alternatively, or additionally, outer supporting substrate 26B of Fig . 4 may be a graphenecontaining sheet of material . The outer supporting substrate 26B A may be formed by weaving together fibres, threads or yarn that contain graphene . In an arrangement where the inner supporting substrate 26A and / or the outer supporting substrate 26B of Fig .4 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0043] In Fig . 5 each of the two pieces of flexible material 12A and 12B may be formed by an inner graphene-including flexible sheet of material 22 and an outer sheet 30 such as a woven textile (similar to the supporting substrate 26 of Fig . 2 ) . However, in this embodiment, the flexible sheet of material 22 is not attached to outer sheet 30 but is unsupported. The flexible sheet of material 22 may be within but completely separate from the outer sheet 30. The flexible sheet of material 22 may be connected to the outer sheet 30 at one or more points which form a minority of the surface area of the outer sheet 30. The outer sheet 30 forms a non-elastic outer "restrainer" which has smaller dimensions than the potential dimensions of the chamber formed by the flexible sheet of material 22 when expanded . The non-elastic outer "restrainer" retains its dimensional stability so that it does not expand when the chamber formed by the graphene-including flexible sheet of material 22 is inflated . Such an arrangement may be used, for example, as part of a lifej acket or small liferaft that need to be very compact when deflated and packed. The outer sheet 30 may be a non-graphene sheet of material (i . e . a sheet of material that does not contain graphene) .

[0044] The outer sheet 30 of Fig . 5 may be a graphenecontaining sheet of material . The outer sheet 30 may be formed by weaving together fibres, threads or yarn that containgraphene . In an arrangement where the outer sheet 30 of Fig . 5 is a graphene-containing sheet of material, the flexible sheet of material 22 may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0045] In Fig . 5 the chamber formed by the flexible sheet of material 22 may be made to be oversize or made from a material that can stretch and so that any join in the chamber (e . g . welds or seams between multiple flexible sheets of graphene-containing material ) never comes under tension . Although the chamber may be of generally the same shape as the non-elastic outer "restrainer", the chamber may be of generally larger size . The chamber may be made of a sufficiently large size so that, when inflated within the non-elastic outer "restrainer", the chamber fills the internal volume of the non-elastic outer "restrainer" without any stretching of the chamber occurring, and the tension is taken up by the non-elastic outer "restrainer" . If the chamber is made oversized, the chamber may be made of an inextensible and / or inelastic material . It is advantageous for the tension to be taken up by the non-elastic outer "restrainer", as it may generally be stronger than the chamber .

[0046] In Fig . 6 each of the two pieces of flexible material 12A and 12B is formed by a graphene-including flexible sheet of material 22. In this embodiment graphene-including flexible sheet of material 22 is not supported in any way and forms a single layer pressurised bladder (no sheet such as a woven textile or the like is provided) . The graphene-including flexible sheet of material 22 may provide an outer surface onto which other items formed of PU / TPU may be readily attached -e . g . by high-frequency welding .

[0047] In Fig . 7 each of the two pieces of flexible material 12A and 12B may be formed by two graphene-including flexible sheets of material 22A and 22B . Inner flexible sheet of material 22A is coated or laminated onto an inner face 24 (e . g . onto the entire inner face 24 ) of a supporting substrate 26 ( such as awoven textile) . Outer flexible sheet of material 22B is coated or laminated onto an outer face 28 (e . g . onto the entire outer face 28 ) of the supporting substrate 26. The supporting substrate 26 is "sandwiched" between the inner and outer flexible sheets of material 22A and 22B . The flexible sheets of material 22A and 22B create barriers to gas when the bladder 16 is filled and pressurised with gas . The supporting substrate 26 provides strength and limits the elasticity of the bladder 16 to create a dimensionally stable structure . The flexible sheets of material 22A and 22B provide redundancy, so that the gastight nature of the bladder may be maintained when one of the flexible sheets of material 22A and 22B is damaged. The supporting substrate 26 may be a non-graphene sheet of material ( i . e . a sheet of material that does not contain graphene ) . The outer flexible sheet of material 22B may protect the supporting substrate 26 from damage . The outer flexible sheet of material 22B may provide an outer surface onto which other items formed of PU / TPU may be readily attached - e . g . by high-frequency welding .

[0048] The supporting substrate 26 of Fig . 7 may be a graphene-containing sheet of material . The supporting substrate 26 may be formed by weaving together fibres , threads or yarn that contain graphene . In an arrangement where the supporting substrate 26 of Fig . 7 is a graphene-containing sheet of material, the flexible sheets of material 22A and 22B may be formed by a graphene-including flexible sheet or may be formed by a non-graphene sheet (i . e . a sheet of material that does not contain graphene) .

[0049] Although in the arrangements described above, each of the two pieces of flexible material 12A and 12B may be formed by a graphene-including flexible sheet of material 22 , it should be understood that only one of the pieces of flexible material 12A and 12B may formed by a graphene-including flexible sheet of material 22 (the other piece of flexible material may be gas-impermeable but not include graphene ) .

[0050] Other equipment may use a graphene-including flexible sheet of material 22 to create a barrier to water or other liquids when used for example in immersion survival suits . The graphene-including flexible sheet of material can be incorporated into the equipment structure in one of the six ways above in Figs . 2 to 7 .

[0051] Other equipment may use a graphene-including flexible sheet of woven material 26, 26A, 26B to improve strength, flame retardancy, and / or abrasion-resistance when used for example in immersion survival suits . The graphene-including flexible woven sheet of material can be incorporated into the equipment structure in one of the six ways above in Figs . 2 to 7 .

[0052] The graphene-including flexible sheet of material 22 can be made MVP (Moisture Vapour Permeable ) , termed "breathable", if required . For example, the graphene-including flexible sheet of material 22 may have a molecular structure that allows moisture vapour to pass through but that does not allow water to pass through .

[0053] Typically, such life-saving appliances are formed from a plurality of pieces of flexible material, such as the pieces of material 12A and 12B of the life-saving appliance 10 described above . The pieces of material may include (or consist of ) graphene-including flexible sheets of material, such as the graphene-including flexible sheet of material 22 and / or flexible sheet of woven material 26, 26A, 26B of the life-saving appliance described above . Edges of one or more pieces of material may be connected together to form a life-saving appliance .

[0054] Pieces of material 12A and 12B may be sealed at their seams ( such as the seams 14A and 14B described above) in various ways . Pieces of material may be sealed at their seams by being glued or welded (e . g . welded together by high frequency welding) . The seams can be "in shear", peel or peel and shear, as shown in Figs . 8 , 9 and 10, respectively.

[0055] By way of example, Fig . 8 shows a partial view of the life-saving appliance 10 described above in the region of the seam 14B . The two generally semicircular (in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B extending radially outwardly with respect to the generally circular (in cross-section) main body of the life-saving appliance 10 so that they lie adjacent to one another and in parallel . The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B . The weld (or adhesive ) between the edges 40A and 40B of the pieces of material 12A and 12B is designated 42. The seam 14A may be formed in the same way. Such seams as shown in Fig . 8 can be referred to as "in peel" .

[0056] By way of example, Fig . 9 shows a partial view of the life-saving appliance 10 described above in the region of the seam 14B . The two generally semicircular (in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B overlapping . The upper piece of material 12A has an outer surface 43A and an inner surface 43B . The lower piece of material 12B has an outer surface 45A and an inner surface 45B . The pieces of material 12A and 12B are connected at an edge region 40A and 40B of each of the pieces of material 12A and 12B so that the distal inner surface of one of the pieces overlaps the distal outer surface of the other one of the pieces . In the arrangement shown the distal outer surface 43A of the upper piece of material 12A is positioned to face the distal portion of the inner surface 45B of the lower piece of material 12B .

[0057] The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B . The weld (or adhesive) between the edges 40A and 40B of the pieces of material 12A and 12B is designated 42. The seam 14A may be formed in the same way. Such seams as shown in Fig . 9 can be referred to as "in shear" .

[0058] By way of example, Fig . 10 shows a partial view of the life-saving appliance 10 described above in the region of the seam 14B . The two generally semicircular (in cross-section) pieces of material 12A and 12B are brought together, with edges 40A and 40B of the pieces of material 12A and 12B extending radially inwardly with respect to the generally circular (in cross-section) main body of the life-saving appliance 10 so that they lie adjacent to one another and in parallel . The seam 14B is formed by welding or gluing (or otherwise fixing together) the edges 40A and 40B of the pieces of material 12A and 12B, and by welding or gluing (or otherwise fixing) a strip of material 47 over the outer surface of the life-saving apparatus 10 in the region where the pieces of material 12A and 12B meet . The weld (or adhesive) between the edges 40A and 40B of the pieces of material 12A and 12B, and between the strip of material 47 over the outer surface of the life-saving apparatus 10 in the region where the pieces of material 12A and 12B meet, is designated 42 . The seam 14A may be formed in the same way. Such seams as shown in Fig . 10 can be referred to as "in peel" and "in shear" .An Inflatable Lifejacket

[0059] Inflatable lifejackets are used to provide buoyancy to prevent a wearer drowning . An advantage of the use of inflatable lifejackets , as opposed to permanently buoyant lifej ackets using buoyant material rather than a gas, is that inflatable lifejackets can be of a small size prior to inflation, allowing them to be worn without encumbering the wearer or creating a thermal burden. However, the materials of the lifej acket, particularly any inflatable bladder, need to be robust and strong because these lifejackets will be donned and doffed frequently, kept in unclean conditions and roughly handled, used and stored in a range of extreme temperatures, and packed and repacked for maintenance and servicing . Additionally, the life j ackets may need to be flame and fire retardant and resistant to UV exposure and if used in an aircraft with an ejector seat system will need to be able to withstand wind blast .

[0060] Referring to Fig . 11, there is shown a life-saving appliance, such as a lifej acket 51. The lifejacket 51 comprises a body 52 that is generally horse-shoe shaped and is for fitting around a wearer ' s neck . The body 52 comprises first and second inflatable buoyancy sections 53 and 54 which form generally symmetrically disposed legs of the horse-shoe, arranged to lie on opposite sides of a wearer ' s torso . First ends of the first and second buoyancy sections 53, 54 are joined together by a neck portion 55 . The first and second buoyancy sections 53, 54 each extend from said first end to a second end, which is a free end . The first and second buoyancy sections 53, 54 , together with the neck portion 55 , define an aperture 56 for receiving a wearer ' s head and neck .

[0061] The lifejacket body 52 is formed from first and second pieces of material sealed together along a seam 57 , towards a peripheral edge, to define a body inflation chamber 58. The pieces of material protrude from the seam 57 to form an edge 60.

[0062] When inflated, each buoyancy section 53, 54 is an elongate member of generally oval cross section . The inflation chamber 58 is connected to an inflation cartridge 59, containing compressed gas, that can be manually or automatically actuated. Following actuation, the inflation cartridge inflates the body inflation chamber 58 .

[0063] Each buoyancy section 53, 54 is provided with a mouth-operable inflator in the form of a tube 62 connected to the interior of the body inflation chamber 58. This allows manual inflation of the body inflation chamber 58 in the event of failure of the inflation cartridge 59. Each tube 62 is provided with a non-return valve and a closure cap to prevent water flowing down the tube and into the body inflation chamber 58.

[0064] In use the first and second buoyancy sections 53, 54 lie on opposite sides respectively of a wearer ' s chest, in a side-by-side relationship .

[0065] Fig . 12 is a cross-section taken along line X-X of Fig . 11. Fig . 12A shows an enlarged view of part of one piece of material of the lifej acket body 52 . Fig . 12B shows an enlarged view of a seam between two pieces of material of the lifejacket body 52.

[0066] As mentioned above, the lifejacket body 52 is formed from first and second pieces of material 64 , 66 sealed together along a seam 57 , towards a peripheral edge, to define a body inflation chamber 58. Each of the first and second pieces of material 64 , 66 consists of an outer textile supporting sheet 72 (for example nylon or polyester) coated or laminated on the inside with a sheet 74 of flexible, air impermeable material . The sheet 74 of flexible, air impermeable material may include graphene, as discussed above . The sheet 74 may also include a polymer such as neoprene, polyurethane or TPU, as discussed above . The outer textile supporting sheet 72 may include graphene fibres, threads or yarn, as discussed above . The sheet outer textile supporting sheet 72 may also include a polymer such as neoprene, polyurethane or TPU, as discussed above . Each of the first and second pieces of material 64 , 66 may have a structure and composition as described in relation to any of Figs . 2 to 7 .

[0067] The coated two pieces of material 64 , 66 are typically j oined at its edges by welding or gluing the material together to form a seam 57. The seam shown is "in peel" (see Fig . 8 ) , although it should be understood that the seam may be "in shear" ( see Fig . 9 ) or both "in peel" and "in shear" (see Fig . 10 ) .

[0068] Another type of life j acket has a bladder made with an outer "restrainer" which is not bonded onto the bladder . Fig .13 shows a front view of an example of such inflatable lifejacket 82 . Fig . 14 shows a cross-section taken along line Y-Y of Fig .13. Fig . 14A shows an enlarged view of part of one piece of material of the life jacket 52. Fig . 14B shows an enlarged view of a seam between two pieces of material of the lifejacket 82.The lifejacket 82 has an outer cover 83, which forms a cover over a bladder 84 which is packed tightly inside it . An inflation system 86, which comprises a compressed gas cylinder 85 and an activation mechanism 87 , is mounted directly onto the outer cover 83.

[0069] The bladder 84 is formed by one or more sheets 94A, 94B of air impermeable material . The one or more sheets 94A, 94B of air impermeable material may include graphene, as discussed above . The sheets 94 may also include a polymer such as neoprene, polyurethane or TPU. The outer cover 83 is the nylon outer "restrainer" . The outer cover 83 may include two (or more) pieces of material 83A, 83B that are joined together at a seam 99. The pieces of material 83A, 83B may be woven and include graphene fibres, threads or yarn, as discussed above . The pieces of material 83A, 83B may also include a polymer such as neoprene, polyurethane or TPU, as discussed above . A life acket made in this way can be folded and packed into a more compact cover because two layers (the outer "restrainer" and the bladder) are more flexible than a single layer made up of two sheets bonded together .

[0070] As shown in Figs . 14 , 14A and 14B, an outer textile outer layer 83 (for example nylon or polyester with or without graphene ) may be formed of two sheets of material 83A, 83B that are stitched together . An upper sheet of material 83A has an outer surface 97A and an inner surface 97B . The lower sheet of material 83B has an outer surface 98A and an inner surface 98B . The sheets 83A and 83B are connected at an edge region of each of the sheets so that the distal inner surface of one of the sheets overlaps the distal outer surface of the other one of the sheets, the distal surfaces being stitched together, as indicated at 88 to form the seam 99. In the arrangement shown, the distal inner surface 97B of the upper sheet of material 83A is positioned to face the distal portion of the outer surface 98A of the lower sheet of material 83B, these sheets being held in contact by the stitching 88 .

[0071] The bladder 84 is formed by two sheets 94A, 94B or flexible air impermeable material that may include graphene . The two sheets are joined by a weld 101 (or any other attachment technique ) .

[0072] In this embodiment the outer textile 83 is stitched ( in shear) around its edge and this creates a much stronger seam than the welding . The bladder 84 is made to be oversize or made from a material that can stretch and so the welded edge 101 never comes under tension, as shown in Figs . 14 , 14A and 14B . Although the bladder 84 may be of generally the same shape as the outer textile 83, the bladder 84 may be of generally larger size . The bladder 84 may be made of a sufficiently large size so that, when inflated within the outer textile 83 , the bladder 84 fills the internal volume of the outer textile 83 without any stretching of the bladder 84 occurring, and the tension is taken up by the outer textile 83. If the bladder 84 is made oversized, the bladder 84 may be made of an inextensible and / or inelastic material . It is advantageous for the tension to be taken up by the outer textile 83 , as it may be stronger than the bladder 84.

[0073] The outer textile layer 83 may be made from or include a lightweight "ripstop" material and is coated with a lubricant such as silicone . The outer textile layer 83 may be a lightweight material that includes graphene and is coated with a lubricant such as silicone . This may produce an extremely strong material with high tear strength, and also, because the surface has a very low surface friction, the inner polymer layer will slide easily over it which results in a very compact lifej acket .

[0074] Ripstop fabrics are woven fabrics, e . g . made of nylon, using a special reinforcing technique that makes them resistant to tearing and ripping . During weaving, relatively thick reinforcement threads are interwoven at regular intervals in a crosshatch pattern. The intervals are typically 5 to 8 mm. Thin and lightweight ripstop fabrics have a 3-dimensional structure due to the thicker threads being interwoven in thinner cloth . The ripstop fabric may be modified to include graphene-containing fibres , threads or yarn, as discussed above .

[0075] In the embodiment of Figs . 13 to 14B an inflatable chamber includes an inner layer and an outer layer, wherein the inner layer is separate from the outer layer . The outer layer comprises two sheets that are material that are stitched together "in sheer" . A low friction material may be provided between the inner layer and the outer layer (either or both of which may include graphene) . The outer layer may be substantially inelastic . In the embodiment of Figs . 13 to 14B the inner layer and the outer layer may be as described in relation to Figure 5 .

[0076] The inflatable bladder' s strength is determined by the tensile strength and puncture resistance as well as the strength of the seam 101 (weld strength) which is typically constructed by high frequency welding . The welding process can produce a weakness in the film of the bladder which will cause the bladder to burst if the pressure is increased significantly but this weakness is greatly reduced if the bladder is made with graphene in it .

[0077] Although these embodiments have been described in relation to a lifejacket as shown in Figs . 11 to 14 , it should be appreciated that least one sheet of flexible material that includes graphene may be advantageously incorporated into many other forms of lifej acket .An Anti G Suit .

[0078] An anti-G suit is worn by pilots and crew of high speed aircraft that subject them to a G force when turning, the effect of which is to drive the blood supply of the body towards the lower abdomen and legs resulting in a reduced supply of oxygenated blood to the brain which can lead to loss of consciousness (G LOG) and potentially the loss of the crew and aircraft . To counteract this effect pilots and crew wear an anti-G suit which consists of a close fitting suit which is adjusted to fit the wearer and has inflatable bladders withinit that when inflated apply a counter pressure to the lower abdomen and legs . This counter pressure reduces the blood volume by effectively compressing the lower abdomen and legs .

[0079] Referring first to Figure 15 , the aircrew ensemble includes a flight suit that comprises an upper suit portion 120 and lower suit portion 121. The upper suit portion 120 and the lower suit portion 121 are typically made from a fire-retardant textile which is stitched together, and preferably made from an inherently fireproof fabric such as NOMEX®. The upper suit portion 120 has a torso portion 122 , a waist 123, a neck opening 124 and left and right arm portions 125a, 125b, respectively. The upper suit portion also has a front opening 126 closed by, for example, a zipper 127. The lower suit portion 121 has a waist 128 and left and right leg portions 129a, 129b . The suit is completed by gloves 130 and boots 131.

[0080] The upper portion 120 and the lower portion 121 may be formed in one-piece with a front central longitudinal zip or may be formed as separate parts and connected at the waist .

[0081] The upper portion 120 carries a chest counter pressure assembly in the form of a jacket 132 containing a chest counter pressure bladder . The jacket 132 is formed of inner (not shown) and outer 135 layers of air permeable material that hold a bladder (not shown) between them located on the chest of a wearer . The inner layer and / or the outer layer 135 of the jacket 132 may be elastically deformable . The inner layer and / or the outer layer 135 of the jacket 132 may be inelastic and / or inextensible . Preferably at least the outer layer 135 of the j acket 132 is inelastic and / or inextensible .

[0082] The outer layer 135 is formed by front and rear portions 135a, 135b that are interconnected by two rows of side lacing 138 (only one of which can be seen in Fig . 15 ) located at respective opposite sides of the outer layer 135 to allow the circumferential length of the jacket 132 to be adjusted to thecorrect fit for a wearer, although such adjustment can be performed in other ways .

[0083] The bladder has an inlet 139 for connection to an inflation hose 137 that, in turn, is connected to an inflation system for supplying air under pressure to the bladder, in a manner to be described below . The inflation system may be part of a breathing system for the wearer . Both the inflation system and the breathing system may be part of the aircraft' s pressurisation system.

[0084] Referring to Fig . 15 , and also to Fig . 16, the lower portion 121 carries a lower G assembly 140 and a lower G bladder 141. The lower G assembly 140 is formed by inner and outer layers 142 , 143 of air-permeable material that hold the lower bladder 141 between them and located around the legs of a wearer (one of which is shown at 150 in Fig . 16 and 17 ) and over the abdomen of the wearer . The inner layer 142 and / or the outer layer 143 of lower G assembly 40 may be elastically deformable . The inner layer 142 and / or the outer layer 143 of lower G assembly 140 may be inelastic and / or inextensible . Preferably at least the outer layer 143 of lower G assembly 140 is inelastic and / or inextensible .

[0085] The outer layer 143 is formed with a side opening whose edges are interconnected by a row of side lacing 144 located to allow the circumferential length of the lower G assembly 140 outer layer 143 to be adjusted to the correct fit for a wearer, although such adjustment can be performed in other ways . The bladder 141 has an inlet 145 for connection to an inflation hose 148 that, in turn, is connected to an inflation system for supplying air under pressure to the bladder 141 , in a manner to be described below. The inflation system may be part of the breathing system for the wearer .

[0086] The lower G bladder 141 has also an outlet 146 at each ankle connected to respective bladders (not shown) in respective boots 131.

[0087] The bladder in the upper suit portion 120 may be arranged in a similar manner to the bladder 141 shown in Figs .16 and 17. The bladders , when inflated, apply a counter pressure to the chest or leg reduce the effects of high G forces on aircrew .

[0088] The bladder 141 (and the bladder in the upper suit portion 120 ) may be sized to extend exactly around the associated body part . However, this need not be the case . If the material of the bladder is inelastic, the bladder may be sized so that when uninflated (see Figure 16 ) the bladder is of greater diameter than the body part it encircles . Thus, when inflated (see Figure 17 ) , the bladder is not subj ect to hoop stress and the tension is taken up by the seams of the outer layer 143 and not by the welds 141a of the bladder 141 , which are weaker than the seams of the outer layer 143.

[0089] The inflatable bladders are filled and pressurised by an air supply from the aircraft' s power supply and supply the air under pressure through a special valve to the suit automatically as the aircraft experiences G force . The supply is regulated automatically to match the pressure to the G force . Additionally, pilots may also wear a close-fitting vest that also holds a bladder that can apply counter pressure to the chest if the pilot is breathing gas under pressure, termed a Chest Counter Pressure Vest . This prevents the chest over-expanding when breathing in and assists the lungs when exhaling .

[0090] The inflatable bladders in a G suit should preferably meet certain very demanding characteristics . The bladders which are conventionally made from TPU. The bladders may be inflated and deflated thousands of times and this weakens the bladder . The pressures that the bladders experience are four or five times greater than other inflatables . The bladders are subj ected to frequent washing as they are part of a worn garment, and this weakens the bladder over time . Additionally, the bladders within the G suit may need to withstand fire and flame exposure for example if ej ecting through a "fireball" . The suit mustpreferably also be capable of being stored or effectively functioning in a range of extreme temperatures from -40°C to +60°C, which requires exceptional performance from the TPU bladders .

[0091] According to this embodiment of the invention, the bladders may include at least one sheet of flexible material that includes graphene, of the type / composition as discussed above . The sheet of flexible material may also include a flexible polymer such as PU and / or TPU, as discussed above .

[0092] Conventional bladders made from TPU without graphene reinforcement may fail earlier in their lifetime than those with a graphene-including sheet and will not be flame retardant .

[0093] Bladders with a graphene-including sheet may be thinner, lighter and more flexible than conventional bladders while providing the same or better performance . As the bladders form part of the pilot' s worn suit, the lighter and more flexible the bladders with a graphene-including sheet will lead to a more comfortable and less obstructive garment which is helpful to achieve good pilot performance both in the air and on the ground . The thinner and lighter bladders with a graphene-including sheet will benefit this performance . The bladders with a grapheneincluding sheet material can also be made to be Moisture Vapour Permeable (MVP) which will further benefit the pilot by reducing thermal burden .

[0094] The inner layer and / or the outer layer 135 of the jacket 132 may be at least one sheet of flexible woven material that includes graphene, of the type / composition as discussed above . The sheet of flexible woven material may also include a flexible polymer such as PU and / or TPU, as discussed above .

[0095] Conventional jackets made without graphene reinforcement may fail earlier in their lifetime than those with a graphene-including woven sheet and will not be as flame retardant .

[0096] The inner layer 142 and / or the outer layer 143 of lower G assembly 40 may be at least one sheet of flexible woven material that includes graphene, of the type / composition as discussed above . The sheet of flexible woven material may also include a flexible polymer such as PU and / or TPU, as discussed above .

[0097] Conventional lower G assemblies made without graphene reinforcement may fail earlier in their lifetime than those with a graphene-including woven sheet and will not be as flame retardant .

[0098] Garment layers with a woven graphene-including sheet may be thinner, lighter and more flexible than conventional garment layers while providing the same or better performance . As the garment layers form part of the pilot' s worn suit, the lighter and more flexible the garment layers with a grapheneincluding sheet will lead to a more comfortable and less obstructive garment which is helpful to achieve good pilot performance both in the air and on the ground.

[0099] Although this embodiment has been described in relation to an anti-G suit as shown in Figs . 15 to 17 , it should be appreciated that least one sheet of flexible material that includes graphene may be advantageously incorporated into many other forms of anti-G suit .Immersion Protection Garment (IPG)

[0100] IPGs are worn when there is the possibility of the wearer deliberately or accidentally entering the water . The IPG (or Survival Suit) provides an effective barrier against the water and is typically fitted with a waterproof zipper, neck and wrist seals or other methods of preventing water entering the suit . Keeping the wearer dry is vital in preventing hypothermia and drowning .

[0101] Fig . 18 shows an example of an IPG, a submarine escape suit . The submarine escape suit would conventionally be formed from a waterproof flexible material e . g . a textile such as a nylon or polyester which is coated on the internal face with a waterproof layer such as TPU. The suit is formed with a body portion 210 , leg and right leg portions 211a, 211b and left and right arm portions 212a, 212b .

[0102] In addition, the suit includes a hood 213 provided with translucent panels 214 . The hood 213 would conventionally also be made of the same material with TPU as the suit itself .

[0103] A central zip 215 allows access to the suit and releasable side connections 216a, 216b that allow a central face panel 217 to be lifted away from the face of a wearer . The suit is completed by foot coverings in the form of left and right boots 226a, 226b .

[0104] The suit may also include a liferaft shown in broken line at 231. The liferaft is for use by a wearer on reaching the sea surface, when the liferaft is inflated and deployed before being boarded by the wearer . Such liferafts are known from, for example, EP-A-0444400 .

[0105] The suit also includes a strap 221 is formed from a band of inflexible material . The strap 221 extends from a first point on the back of the body portion towards an upper end of the back portion through the crotch region between the left and right legs to a second point 233 on the front of the body portion towards the lower end of the hood 213. This strap 221 includes an adjustment buckle 234 .

[0106] IPGs, such as a submarine escape suit, are typically conventionally made from a textile such as a nylon or polyester which is coated on the internal face with a waterproof layer such as TPU. The TPU in some cases may be MVP to provide greater comfort to the wearer and reduce thermal burden.

[0107] The suits may be subj ected to heavy wear and use particularly if they are within a working environment and can be subj ected to damage and excessive wear which will damage the conventional TPU layer leading to leakage and failure of the suit to protect the wearer . The suits may also be laundered frequently leading to deterioration of the TPU layer .

[0108] The suit preferably complies with a number of requirements to meet Regulations as well as user demands including durability, ability to withstand the high pressures as a consequence of escaping at depth from the submarine, to not be affected by a range of possible contaminants within the submarine including engine fumes, resistance to flame and fire, able to withstand a range of temperatures , resistant to damage during the escape and on the surface, requirement not to create too great a thermal burden on the wearer . The suit is very tightly packed within a valise to save space and must be able to withstand compression and also must be as light as possible to be accommodated within the submarines weight allowances .

[0109] The suit is unpacked and donned within the submarine in an emergency prior to the escape from the submerged submarine .

[0110] According to this embodiment of the invention, the suit and / or hood 213 include at least one sheet of flexible material that includes graphene, of the type / composition as discussed above . The sheet of flexible material may also include a flexible polymer such as PU and / or TPU, as discussed above . The sheet of flexible material that includes graphene may be a woven sheet formed of graphene-including fibres , threads or yarn . The sheet of flexible material that includes graphene may provide improved performance and resistance to wear and damage .

[0111] Although this embodiment has been described in relation to a suit as shown in Fig . 18 , it should be appreciated that least one sheet of flexible material that includes graphene may be advantageously incorporated into many other forms of garment .An Inflatable Boat, Liferaft and Marine Escape Systems (MESs)

[0112] Conventionally, inflatable liferafts, inflatable boats and inflatable MESs are manufactured from a material which is the supporting textile such as nylon of polyester coated with a TPU layer which provides the seal against internal air pressure and external water pressure .

[0113] As shown in Figure 19, the structure made be made using an inflatable tubular system or can be made also in combination using an inflatable "drop thread" or "spacer" material which consists of two layers of textile spaced apart by threads which keep the internal space between the layers uniform. The external faces of the textiles and the side walls are coated with a TPU.

[0114] Referring first to Fig . 19, a survival craft comprises a hull 310 and a superstructure 311 carried on the hull 310. The structure may be as described in WO-A-2015 / 107019 .

[0115] The hull 310 is formed by port and starboard inflatable tubes 312 , 313 that extend along the gunwales of the hull 310 and extend upwardly while converging to meet at a shaped bow 314 . At the stern 315 , the tubes 312 , 313 are spaced by a stern member 316. A floor 317 extends between the gunwale tubes 312 , 313 and the stern member 316 and is formed by spaced sheets of air-impervious fabric forming an inflatable chamber . The spaced sheets may be formed by a drop thread material . In addition two longitudinal inflatable floor tubes 342 , 343 may extend from the stern 215 to the bow 314 . These tubes 342 , 343 may also be formed of a drop thread material to give these tubes 342 , 343 increased rigidity.

[0116] The floor 317 carries a powered propulsion system for the survival craft . This may be an electrical system with a generator (not shown) , which may be a diesel power unit, mountedwithin the survival craft and electrical connections to fore and aft thrusters located beneath the floor 317 .

[0117] The superstructure 311 is formed by a roof and port and starboard sidewalls . Each sidewall is formed by an upper elongate inflatable tube 325 , 326 extending along the length of the hull 310 generally parallel to the associated gunwale tubes 312 , 313 with the upper tubes converging and meeting above the bow 314 . At the stern 315 , the upper tubes 325 , 326 are separated by an upper stern spacer 327 . The upper tubes 325 , 326 are spaced by lateral inflatable spacer tubes 344 at spaced intervals along the upper tubes 325 , 326. A sheet 328 of flexible water-impervious material (only half of which is shown, so as not to obscure the internal parts of the survival craft) extends between the upper tubes 325 , 326 and forms a roof . Again, any or all of the tubes may be made from a drop thread material .

[0118] The side walls (only one of which, 323, can be seen) are formed by inflatable side spacer tubes 329a - 329i that extend between the gunwale tubes 312 , 313 and the associated upper tubes 325 , 326. The side spacer tubes 329a - 329i are arranged in a zigzag configuration along the gunwale tubes 312 , 313 with successive side spacer tubes 329a - 329i being inclined in respective opposite directions relative to the gunwale tubes 312 , 313. In addition, two inflatable stern tubes 330a, 330b extend in a V-conf iguration between the stern member 316 and the upper stern spacer 327 . The inflatable side spacer tubes 329a -329i may be formed by consecutive sections of a single tube or by separate tubes . The tubes 329a - 329i may be formed of a drop thread material . Sheets of flexible water-impervious material (not shown, so as not to obscure the internal parts of the survival craft ) cover the sides of the superstructure 311 and the end of the superstructure 311 and are provided with door and window openings .

[0119] In this way, the superstructure 311 forms a truss structure carried by the hull 310 that provides the hull 310with increased longitudinal rigidity, resisting any tendency of the hull 310 to bow. In addition, it forms a protective shelter for occupants of the survival craft .

[0120] In use, the survival craft is deflated and packed in a container (not shown) that may be rigid or flexible . The container includes an inflation system (not shown) of any suitable known type . The container is carried by a deployment system that is for mounting on a marine structure such as a rig or a ship . The system may carry more than one such container .

[0121] When required for use, the system releases the container into the water . On reaching the water, the inflation system commences inflation of the survival craft and the container opens, so allowing the survival craft to complete inflation and deploy. People from the marine structure can then enter the survival craft .

[0122] As mentioned above, conventionally, inflatable liferafts, inflatable boats and inflatable MESs are manufactured from a material which is the supporting textile such as nylon of polyester coated with a TPU layer which provides the seal against internal air pressure and external water pressure . Such a material may be used for the floor, panels and tubes .

[0123] The systems using these structures rely on the TPU coating to be extremely strong and robust as this not only provides the air pressure retention but also must be sufficiently strong and durable to withstand the possible damage caused during boarding and use where multiple impacts and scraping of the structure may occur . Additionally, the material has to withstand extended sea trials , UV and saltwater exposure and hot and cold temperature extremes .

[0124] According to this embodiment of the invention, the inflatable liferafts, inflatable boats and / or inflatable MESs include at least one sheet of flexible material that includes graphene, of the type / composition as discussed above . The sheetof flexible material that includes graphene may be a woven sheet formed of graphene-including fibres, threads or yarn. The sheet of flexible material may also include a flexible polymer such as PU and / or TPU, as discussed above . Such a material may be used for the floor, panels and tubes .

[0125] Although this embodiment has been described in relation to a craft as shown in Fig . 19, it should be appreciated that least one sheet of flexible material that includes graphene may be advantageously incorporated into many other forms of craft .

[0126] Conventional inflatable liferafts, inflatable boats and inflatable MESs made from TPU without graphene reinforcement may fail earlier in their lifetime than those with a grapheneincluding sheet .

[0127] The sheet of flexible material that includes graphene may be on the outside face of the structures of the survival craft, as in Figs . 3 and 8 , and sealed as in Fig . 10. Such a sheet of material may be air impermeable and / or waterproof .

[0128] The sheet of flexible material that includes graphene may be formed of graphene-including fibres, threads or yarn may be an internal part of the structures of the survival craft, as in Figs . 3 , 7 and 8.

[0129] Although the invention has been described with reference to embodiments that relate to particular devices, it should be appreciated that the principles could be applied any other type of device . The device may be a lifesaving appliance such as a submarine escape suit, lifej acket, or single or multiple seater liferaft . The device may have another application that is not lifesaving . The device may be any lifesaving appliance as defined The International Life-Saving Appliance (LSA) Code . The device may be safety and / or survival equipment in general .

[0130] The invention is also applicable to devices / lif e-saving appliances (or parts thereof ) that are not inflatable . For example, the roof 328 in Fig . 19 is not inflatable but may be formed of a sheet of flexible material that includes graphene .

[0131] In the description references to the use of air or COp are examples only. It should be understood that any suitable gas may be applicable instead of, or in addition to, air or CO2 . For example, the bladders may be inflated by any suitable gas; a material this is described as air-impermeable or air-permeable may instead, or additionally, be gas-impermeable or gas-permeable, etc .

Claims

CLAIMS1 . A life-saving appliance having at least one sheet of flexible material that includes graphene .2 . The life-saving appliance of claim 1, wherein the graphene included in the sheet of flexible material comprises the graphene nano platelets .

3. The life-saving appliance of claim 1 or 2 , wherein the sheet of material further includes a flexible polymer .4 . The life-saving appliance of claim 1 , 2 or 3 , wherein the sheet of material includes polyurethane, PU .5 . The life-saving appliance of any one of claims 1 to 4 , wherein the sheet of material includes thermoplastic polyurethane, TPU.

6. The life-saving appliance of any one of claims 1 to 5 , wherein the sheet of material includes between 1 and 10% graphene by weight, preferably 1.5% graphene by weight .7 . The life-saving appliance of any one of claims 1 to 6, wherein the sheet of material has a thickness of between 100 and 150pm.8 . The life-saving appliance of any one of claims 1 to 7 , wherein the sheet of material is fluid impermeable .

9. The life-saving appliance of any one of claims 1 to 8 , wherein the sheet of material is moisture-vapour permeable .

10. The life-saving appliance of any one of claims 1 to 9, wherein the sheet of material is formed from fibres , threads or yarn that contains graphene .

11. The life-saving appliance of claim 10, wherein the fibres, threads or yarn are woven together to form the sheet of material .12 . The life-saving appliance of any one of claims 1 to 11 , including first and second sheets of material, one of which is said at least one sheet of flexible material that includes graphene .

13. The life-saving appliance of claim 12 , wherein the first sheet of material is arranged to support the second sheet of flexible material .14 . The life-saving appliance of claim 12 or 13, wherein the second sheet of flexible material has a lower modulus of elasticity than the first sheet of material .15 . The life-saving appliance of claim 12 , 13 or 14 , wherein the second sheet of flexible material is bonded to the first sheet of material .

16. The life-saving appliance of claim 12 , 13 or 14 , wherein the second sheet material is separate from the first sheet of material .17 . The life-saving appliance of any one of claims 12 to 16, wherein the second sheet of material flexible material forms at least part of an inflatable bladder .18 . The life-saving appliance of claim 17 when dependent on claim 15 or 16, wherein first sheet of material is configured to limit the expansion of the inflatable bladder .

19. The life-saving appliance of any one of claims 12 to 18 , wherein the first and / or second sheet of flexible material includes graphene .20 . The life-saving appliance of any one of claims 1 to 19, wherein the sheet of flexible material that includes graphene forms at least part of a garment .21 . The life-saving appliance of any one of claims 1 to 20 , wherein the sheet of flexible material that includesgraphene forms at least part of an inflatable device having a drop stitch structure .22 . The life-saving appliance of any one of claims 1 to 21 , wherein the sheet of flexible material that includes graphene is connected to another sheet of material by an in shear and / or in peel connection .

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