Composite Material

Abstract

A composite material 100 for transport seating comprises a cover layer 110, a compressible layer 120 and a backing layer 130. The cover layer comprises a first fibrous material which is fire retardant

Description

TECHNOLOGICAL FIELD Examples of the disclosure relate to a composite material and a method of producing a composite material. Some relate to a composite material for aircraft seating. BACKGROUND Materials used for transport seating, such as train seating, car seating, aircraft seating or bus seating generally have a number of performance requirements, including low weight, comfort, aesthetics, fire retardancy, and durability. To meet these requirements, these seating materials typically comprise a foam, such as polyurethane foam or graphite foam. BRIEF SUMMARY According to various, but not necessarily all, examples there is provided a composite material for transport seating comprising: a cover layer, the cover layer comprising a first fibrous material, wherein the first fibrous material is fire retardant; a compressible layer, the compressible layer comprising a second fibrous material, wherein the compressible layer is configured to compress when a force is applied thereto; and a backing layer, the backing layer comprising a third fibrous material, wherein the third fibrous material is fire retardant, and wherein the compressible layer is located between the cover layer and the backing layer. The second fibrous material may be a non-woven or a spacer fabric. The second fibrous material may be a spacer fabric. The second fibrous material may be a knitted spacer fabric. The second fibrous material may be a warp-knitted spacer fabric. The second fibrous material may be a weft-knitted spacer fabric. The weight of the second fibrous material may be at least 200 gsm, and the density of the second fibrous material may be up to 400 kg / m3. The density of the second fibrous material may be up to 200 kg / m3. The third fibrous material may be a scrim fabric. The third fibrous material may be a woven fabric. Alternatively, the third fibrous material may be a non-woven. The weight of the third fibrous material may be from 50 gsm to 300 gsm. The first fibrous material may be a leather material, a textile material, or a fibrous hydroentangled material. The weight of the first fibrous material may be from 150 gsm to 1000 gsm. The first fibrous material may be a fibrous hydroentangled material, the fibrous hydroentangled material comprising: a reinforcing material; and a body of fibres, the body of fibres including fibres interlocked with each other by entanglement, and wherein at least some of the fibres of the body of fibres are mechanically bonded to the reinforcing material. The cover layer and the compressible layer may be lamination bonded. The compressible layer and the backing layer may be lamination bonded. According to various, but not necessarily all, examples there is provided a seat comprising the composite material of any of the preceding paragraphs. According to various, but not necessarily all, examples there is provided a vehicle comprising one or more of the seats of the preceding paragraph. The vehicle may be a train, a car, a van, a truck, a bus, a coach, a ferry and / or an aircraft. According to various, but not necessarily all, examples there is provided a method of forming the composite material of any of the preceding paragraphs, the method 3 comprising: securing the cover layer to the compressible layer; and securing the compressible layer to the backing layer. The first fibrous material may be a fibrous hydroentangled material, and the method may comprise forming the fibrous hydroentangled material, wherein forming the fibrous hydroentangled material comprises: forming fibres into a web; locating an arrangement comprising the web and a reinforcing material into a hydroentanglement apparatus, wherein the web defines a first layer of the arrangement and the reinforcing material defines a second layer of the arrangement; and subjecting the arrangement to successive hydroentanglement steps in the hydroentanglement apparatus to provide the fibrous hydroentangled material, wherein subjecting the arrangement to successive hydroentanglement steps causes the fibres of the web to entangle with each other and causes a mechanical bond to form between the fibres of the web and the reinforcing material. According to various, but not necessarily all, examples there is provided a method of forming a composite material for transport seating, the method comprising: securing a cover layer to a compressible layer; and securing the compressible layer to a backing layer, wherein: the cover layer comprises a first fibrous material, wherein the first fibrous material is fire retardant; the compressible layer comprises a second fibrous material, wherein the compressible layer is configured to compress when a force is applied thereto; and the backing layer comprises a third fibrous material, wherein the third fibrous material is fire retardant. The first fibrous material may be a fibrous hydroentangled material, and the method may comprise forming the fibrous hydroentangled material, wherein forming the fibrous hydroentangled material comprises: forming fibres into a web; locating an arrangement comprising the web and a reinforcing material into a hydroentanglement apparatus, wherein the web defines a first layer of the arrangement and the reinforcing material defines a second layer of the arrangement; and subjecting the arrangement to successive hydroentanglement steps in the hydroentanglement apparatus to provide the fibrous hydroentangled material, wherein subjecting the arrangement to successive hydroentanglement steps causes the fibres of the web to entangle with each other and causes a mechanical bond to form between the fibres of the web and the reinforcing material. According to various, but not necessarily all, examples there is provided examples as claimed in the appended claims. While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all of the features described in respect of other examples of the disclosure, and vice versa. BRIEF DESCRIPTION Some examples will now be described with reference to the accompanying figures in which: FIG. 1 shows an example composite material; FIG. 2 shows an image of a comparative example material following a 12-second vertical Bunsen burner test; FIG. 3 shows an image of a first face of two example composite materials following a 12-second vertical Bunsen burner test; and FIG. 4 shows an image of an opposite second face of the two example composite materials of FIG. 3 following the 12-second vertical Bunsen burner test. DETAILED DESCRIPTION In examples of the disclosure, a composite material for transport seating is provided. Transport seating includes, for example, train, car, van, truck, bus, coach, ferry or aircraft seating. The composite material may form part of a seat. The seat may be mounted to a vehicle, such as a train, a car, a van, a truck, a bus, a coach, a ferry, or an aircraft. A method of forming the composite material for transport seating is also provided. An example composite material 100 is shown in Fig. 1. The composite material comprises a cover layer 110, a compressible layer 120, and a backing layer 130. The composite material 100 may be a sheet material. Furthermore, each of the layers 110, 120, 130 may be a sheet material. The compressible layer 120 is located between the cover layer 110 and the backing layer 130. In other words, the compressible layer 120 is sandwiched between the cover layer 110 and the backing layer 130. The cover layer 110 comprises a first fibrous material, wherein the first fibrous material is fire retardant. The term fibrous material used herein is a material comprising fibres. The fibres may be intertwined. The fibrous material may comprise at least 50 % by weight of fibres, at least 70 % by weight of fibres, at least 90 % by weight of fibres, at least 95 % by weight of fibres, or at least 98 % by weight of fibres. Substantially all of the fibrous material by weight may be made from fibres. A fibre refers to a thread-like structure, i.e., an elongated solid material which is able to intertwine with another fibre. A fibre may have a length substantially greater than its diameter. For instance, the length divided by the width (i.e., the aspect ratio) of a fibre may be significantly greater than one. The aspect ratio may be greater than 50. The term fire retardant used herein refers to a material that substantially inhibits the onset of combustion and the rate of flame spread. The term fire retardant used herein may refer to a material that passes the 12-second vertical Bunsen burner test specified in Federal Aviation Regulation (FAR). 25.853. In particular, the material may pass the test specified in FAR 25.853 (a), Appendix F, Part I, (a) 1 (ii) and b(4). To carry out the test specified in FAR 25.853 (a), Appendix F, Part I, (a)1(ii) and b(4), the material is held in a vertical position and a Bunsen burner flame is applied from below for 12 seconds. Following 12 seconds, the flame is removed. The test is repeated at least 3 times and the results are averaged. To pass the test, the average burn length should not exceed 8 inches, the average flame time after removal of the flame source should not exceed 15 seconds, and drippings from the test specimen should not continue to flame for more than an average of 5 seconds after falling. The first fibrous material may include a fire retardant additive and / or a fire retardant coating. The fire retardant additive may comprise aramid fibres, glass fibres, brominated materials (e.g., ammonium bromide), phosphorus containing compounds (e.g., guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or melamine derivatives. The fire retardant coating may comprise a polymeric material, phosphorus containing compounds (e.g., red phosphorus, guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or intumescent graphite. In examples where the first fibrous material includes a polymeric coating, the polymeric coating may comprise polyurethane, polyacrylate and / or polyvinyl chloride. The polymeric coating may comprise fire retardant additives such as aluminium trihydrate and / or zinc compounds (e.g., zinc oxide, zinc borate, and zinc hydroxystannate). The first fibrous material may be a pliable fibrous material, such as a leather material, a textile material, or a fibrous hydroentangled material. In the example 100 of Fig. 1, the first fibrous material is a fibrous hydroentangled material. The fibrous hydroentangled material comprises a body of fibres 112 including fibres interlocked with each other by entanglement. The fibrous hydroentangled material further comprises a reinforcing material 114, wherein at least some of the fibres of the body of fibres 112 are mechanically bonded to the reinforcing material 114. The reinforcing material 114 forms an intrinsic part of the hydroentangled material (e.g., as opposed to being a backing layer). For example, it may be that the reinforcing material 114 and the fibres of the body of fibres 112 cannot be separated from each other without the use of one or more tools. The body of fibres 112 defines a first layer of the fibrous hydroentangled material, and the reinforcing material 114 defines a second layer of the fibrous hydroentangled material. The reinforcing material 114 is in the form of a sheet. The reinforcing material 114 could also be considered as a reinforcing structure or a second layer. The reinforcing material 114 may comprise a structure defined by a fabric. The fabric could be a woven fabric, a knitted fabric, a braided fabric or a non-woven. Alternatively, the reinforcing material 114 may comprise a structure defined by a combination of a woven fabric, a knitted fabric, a braided fabric, and / or a non-woven. The fabric of the reinforcing material 114 is preferably a durable fabric. A durable fabric may be suitable for multiple cycles of use and washing, as opposed to a disposable fabric, which is not suitable for repeated use and / or washing cycles. A durable fabric is suitable for use in clothing, footwear, accessories and / or upholstery. A durable fabric may be tear resistant (for instance greater than 10 N tear strength as measured by BS EN ISO 3377-2 2016 using a double edged tear) and may have high tensile strength (for instance a tensile strength of greater than 7 N / mm as measured by tensile strength test BS EN ISO 3376-2002). The fabric of the reinforcing material 114 could be a recycled fabric. The reinforcing material 114 may comprise virgin fibres and / or recycled fibres. The reinforcing material 114 may comprise natural, naturally derived and / or synthetic fibres. A non-exhaustive list of example natural fibres includes: wool, cotton, leaf, flax, bast and silk fibres. A non-exhaustive list of example naturally derived fibres includes: bamboo, viscose and soybean fibres. A non-exhaustive list of example synthetic fibres includes: polyester, nylon, polypropylene, polyamide, elastane, and acrylic fibres. In some examples, the reinforcing material 114 comprises splittable fibres. The splittable fibres of the reinforcing material 114 may be splittable bicomponent fibres. Splittable bicomponent fibres comprise at least two different fibres arranged in distinct segments across the cross-section of the splittable fibre. For example, the at least two different fibres may comprise polyester fibres and polyamide fibres, which may be microfibres. The body of fibres 112 comprises fibres interlocked together by entanglement. The body of fibres 112 forms a first layer of the fibrous hydroentangled material. The body of fibres 112 may be interlocked together by hydroentanglement by subjecting an arrangement comprising a web of fibres to high pressure jets of liquid to interlock the fibres together by entanglement. At least some of the fibres of the body of fibres 112 are mechanically bonded to the reinforcing material 114. At least some of the fibres of the body of fibres 112 are mechanically bonded to the reinforcing material 114 through gaps in the reinforcing material 114. At least some of the fibres of the body of fibres 112 may be mechanically bonded to the reinforcing material 114 by being pushed by high-pressure jets of liquid into gaps in the reinforcing material 114. The body of fibres 112 may comprise synthetic, natural fibres and / or naturally derived fibres. A non-exhaustive list of example natural fibres includes: wool, cotton, leaf, flax, bast and silk fibres. A non-exhaustive list of example naturally derived fibres includes leather, soybean, viscose and bamboo fibres. A non-exhaustive list of example synthetic fibres includes: polyester, nylon, polypropylene, polyamide, elastane, and acrylic fibres. The synthetic fibres may be bi-composite fibres. In some examples, the body of fibres 112 may comprise synthetic and natural fibres in combination. The body of fibres 112 may comprise splittable fibres, which may be naturally derived or synthetic. The fibres of the body of fibres 112 may be in a non-woven arrangement. In some examples, the fibrous hydroentangled material comprises a further body of fibres 116. The example 100 of Fig 1 includes a further body of fibres 116. The further body of fibres 116 includes fibres interlocked with each other by entanglement. At least some of the fibres of the further body of fibres 116 are mechanically bonded to the reinforcing material 114. At least some of the fibres of the further body of fibres 116 are also mechanically bonded to the body of fibres 112 through gaps in the reinforcing material 114. The further body of fibres 116, when present, defines a third layer of the fibrous hydroentangled material. The second layer of the fibrous hydroentangled material is located between the first and third layers. The fibres of the body of fibres 112 and / or the further body of fibres 116 may be derived from leather waste and / or textile waste. Fibres derived from textile waste or leather waste can be prepared by shredding, granulating and milling the leather and / or textile waste. For illustrative purposes only, the fibre length resulting from disintegrating of waste leather in textile reclaiming equipment ranges from less than 1 mm with occasional fibres up to 20 mm. The fibre structure of natural leather before disintegration consists of closely entangled bundles of collagen fibres, which in turn consist of even finer fibrils, many of which become separated during the mechanical action. This results in a range of fibre diameters from about 100 microns for the bundles to very fine fibres below 1 micron for individual fibrils. In some examples, the first fibrous material is leather, such as top-grain leather, split leather or bonded leather. In some examples, the first fibrous material is a textile material. Textiles are materials formed by intertwining or interlocking fibres. The textile material may comprise a woven fabric, a knitted fabric, a braided fabric or a non-woven. A non-woven is defined as any fibrous material other than a woven fabric, a braided fabric or a knitted fabric, such as felt or a needle-punched structure. The fibres of the textile material may comprise natural fibres, naturally derived fibres and / or synthetic fibres. Examples of natural fibres include wool, cotton, flax, bast and silk fibres. Examples of naturally derived fibres include bamboo, viscose and soybean fibres. Examples of synthetic fibres include polyester, nylon, polypropylene, polyamide, elastane, and acrylic fibres. Some, but not all, natural and naturally derived textile fibres, such as cotton, flax, bast or viscose, are cellulosic textile fibres. Cellulosic textile fibres comprise cellulose. The textile material may be an artificial leather. The artificial leather may comprise a fabric first layer and a second coating layer. The coating layer may be made from PVC and / or polyurethane. In some examples, the weight of the first fibrous material is up to 1000 gsm, up to 850 gsm, or preferably up to 700 gsm. The first fibrous material may have a weight of at least 150 gsm, at least 300 gsm, or preferably at least 450 gsm. Preferably, the first fibrous material has a weight of from 150 gsm to 1000 gsm. Most preferably, the first fibrous material has a weight of from 450 gsm to 700 gsm. Gsm is the grammage or area density of the material, measured in grams per square metre of material. In some examples, the thickness of the first fibrous material is up to 2 mm, up to 1.7 mm, or preferably up to 1.5 mm. The thickness of the first fibrous material may be at least 0.7 mm, at least 0.9 mm, or preferably at least 1.0 mm. Preferably, the thickness of the first fibrous material is from 0.7 mm to 2 mm. Most preferably, the thickness of the first fibrous material is from 1.0 mm to 1.5 mm. The thicknesses described in the present disclosure are average (mean) thicknesses. The compressible layer 120 comprises a second fibrous material. The compressible layer 120 is configured to compress when a force is applied to the compressible layer 120. The compressible layer 120 may be configured to elastically deform when pressure is applied to the composite material 100 by a user, to improve the comfort of a user of the composite material 100. In some examples, the weight of the second fibrous material is at least 200 gsm, at least 250 gsm, or preferably at least 300 gsm. The weight of the second fibrous material may be up to 800 gsm, up to 700 gsm, or preferably up to 600 gsm. Preferably, the weight of the second fibrous material is from 200 gsm to 800 gsm. Most preferably, the weight of the second fibrous material is from 300 gsm to 600 gsm. In some examples, the thickness of the second fibrous material is at least 2 mm, at least 3 mm, or preferably at least 5 mm. The thickness of the second fibrous material may be up to 30 mm, upto 20 mm, or preferably up to 15 mm. Preferably, the thickness of the second fibrous material is from 2 mm to 30 mm. Most preferably, the thickness of the second fibrous material is from 5 mm to 15 mm. In some examples, the density of the second fibrous material is up to 400 kg / m3, up to 300 kg / m3, or preferably up to 200 kg / m3. The density of the second fibrous material may be at least 7 kg / m3, at least 20 kg / m3, or preferably at least 40 kg / m3. Preferably, the density of the second fibrous material is from 7 kg / m3 to 400 kg / m3. Most preferably, the density of the second fibrous material is from 40 kg / m3 to 200 kg / m3. In the example 100 of Fig. 1, the second fibrous material is a spacer fabric. A spacer fabric is a three-dimensional fabric. The spacer fabric comprises two outer layers 122, 126. The outer layers 122, 126 may be knitted. The two outer layers 122, 126 are joined to each other by spacer yarns 124. The outer layers 122, 126 are joined to each other by the spacer yarns 124 during the spacer fabric manufacturing process. The spacer yarns 124 permit air-flow through the spacer fabric, and the outer layers 122, 126 permit moisture release and heat dissipation. The spacer yarns 124 may be arranged in a vertical or zigzag pattern to provide the 3D structure of the spacer fabric. The spacer fabric may comprise synthetic fibres, such as polyester or nylon. Preferably, the spacer fabric is knitted. The spacer fabric may be a warp-knitted spacer fabric or a weft-knitted spacer fabric. The spacer yarns of a warp-knitted spacer fabric are interlooped vertically (i.e., along the length of the fabric). The spacer yarns of a weft-knitted spacer fabric are interlooped horizontally (i.e., along the width of the fabric). A warp-knitted spacer fabric may be knitted on a rib raschel machine with two needle bars. The outer layers of a warp-knitted spacer fabric may be bound together through pile yarns using stitches knitted on a rib raschel machine with two needle bars. A weft-knitted spacer fabric may be knitted on a double jersey circular machine with a rotatable needle cylinder and a needle dial, or may be knitted on a flat bed knitting machine. The weft-knitted spacer fabric may be a circular knitted spacer fabric. In some examples, the second fibrous material is a non-woven. The non-woven may be a laminated non-woven, a needle-punched non-woven, non-woven wadding, a thermal bonded non-woven, or a spray bonded non-woven. The non-woven may comprise synthetic fibres, such as polyethylene terephthalate (PET) fibres. In some examples, the second fibrous material is fire retardant. The second fibrous material may include a fire retardant additive and / or a fire retardant coating. The fire retardant additive may comprise aramid fibres, glass fibres, brominated materials (e.g., ammonium bromide), phosphorus containing compounds (e.g., guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or melamine derivatives. The fire retardant coating may comprise a polymeric material, phosphorus containing compounds (e.g., red phosphorus, guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or intumescent graphite. Where the second fibrous material includes a polymeric coating, the polymeric coating may comprise a polyurethane, a polyacrylate and / or polyvinyl chloride. The polymeric coating may comprise fire retardant additives such as aluminium trihydrate and / or zinc compounds (e.g., zinc oxide, zinc borate, and zinc hydroxystannate). In other examples, the second fibrous material is not fire retardant. The backing layer 130 comprises a third fibrous material, wherein the third fibrous material is fire retardant. The third fibrous material may include a fire retardant additive and / or a fire retardant coating. The fire retardant additive may comprise aramid fibres, glass fibres, brominated materials (e.g., ammonium bromide), phosphorus containing compounds (e.g., guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or melamine derivatives. The fire retardant coating may comprise a polymeric material, phosphorus containing compounds (e.g., red phosphorus, guanidine phosphate, ammonium polyphosphate, organic phosphates, or organic phosphonates), and / or intumescent graphite. Where the third fibrous material includes a polymeric coating, the polymeric coating may comprise a polyurethane, a polyacrylate and / or polyvinyl chloride. The polymeric coating may comprise fire retardant additives such as aluminium trihydrate and / or zinc compounds (e.g. zinc oxide, zinc borate, and zinc hydroxy stannate). The third fibrous material may be a pliable fibrous material, such as a textile material, or a fibrous hydroentangled material. In some examples, the weight of the third fibrous material is up to 300 gsm, up to 200 gsm, up to 170 gsm, or up to 100 gsm. The third fibrous material may have a weight of at least 50 gsm, at least 60 gsm, or at least 70 gsm. Preferably, the third fibrous material has a weight of from 50 gsm to 300 gsm. Most preferably, the third fibrous material has a weight of from 70 gsm to 170 gsm. The thickness of the third fibrous material may be up to 3 mm, up to 2.5 mm, up to 2 mm, or up to 1 mm. The thickness of the third fibrous material may be at least 0.3 mm, at least 0.5 mm, or at least 1 mm. Preferably, the thickness of the third fibrous material is from 0.3 mm to 3 mm. In some examples, the thickness of the third fibrous material is from 1 mm to 2 mm. In other examples, the thickness of the third fibrous material is from 0.3 mm to 1 mm. In the example 100 of Fig. 1, the third fibrous material is a textile material in the form of scrim fabric. The scrim fabric may be a woven fabric. The scrim fabric may be an open weave fabric. In some examples, the scrim fabric includes both a non-woven layer and a woven layer. The scrim fabric may be a light scrim fabric or a heavy scrim fabric. Light scrim fabric may be a woven material. Light scrim fabric may be made from cotton, flax and / or linen fibres. Heavy scrim fabric may be a non-woven material. Heavy scrim fabric may be made from nylon, polyester, rayon, glass and / or polypropylene fibres. In the example 100 of Fig. 1, the cover layer 110 and the compressible layer 120 are lamination bonded. Furthermore, in the example 100 of Fig. 1, the compressible layer 120 and the backing layer 130 are lamination bonded. The method of forming the composite material for transport seating comprises: securing the cover layer 110 to the compressible layer 120; and securing the compressible layer 120 to the backing layer 130. In some examples, the cover layer 110 is secured to the compressible layer 120 using lamination bonding. The lamination bonding may comprise flatbed lamination, calendar lamination, hotmelt lamination, powder lamination, spray adhesive lamination, and / or flame lamination. The lamination bonding may be roll-to-roll lamination or cut parts lamination. The cover layer 110 and / or the compressible layer 120 may comprise an adhesive coating for securing the cover layer 110 to the compressible layer 120. In some examples, the compressible layer 120 is secured to the backing layer 130 using lamination bonding. The lamination bonding may comprise flatbed lamination, calendar lamination, hotmelt lamination, powder lamination, spray adhesive lamination, and / or flame lamination. The lamination bonding may be roll-to-roll lamination or cut parts lamination. The compressible layer 120 and / or the backing layer 130 may comprise an adhesive coating for securing the compressible layer 120 to the backing layer 130. The fibrous hydroentangled material of the cover layer 110 of the example composite material 100 of Fig. 1 can be formed using the following hydroentanglement method. Fibres are formed into a web. The web may be in the form of a sheet. The web may be a non-woven web and the web can be formed by airlaying. In some examples, the web is needle punched once formed. Prior to (i.e., upstream of) forming the fibres into the web, the fibres for forming the web may be opened from a bale and / or a silo using a fibre opener. In some examples, the hydroentanglement method further comprises blending the fibres with additive fibres prior to (i.e., upstream of) forming the web. The inclusion of some additive fibres has been found to improve web stability during processing. In particular, these fibres can improve the stability of the web when forming the web into a roll, and therefore act as a process additive. In some examples, the additive fibres comprise bicomponent fibres, such as polylactic acid / polylactic acid bicomponent fibres, where each polylactic acid element has a different melting point, or polyethylene / polypropylene bicomponent fibres. The web may comprise 1 - 10 wt.% of the additive fibres. Preferably, the web comprises 2-5 wt.% of the additive fibres. Where the fibres are formed into a web using airlaying, the blending of the fibres with the additive fibres may be carried out by agitators in airlay forming heads. In examples where the fibres are formed into a web using airlaying, the fibres may be airlaid onto a support material. The support material is preferably a tissue material. The tissue material may have a weight per unit area (i.e., grammage) of 10 to 25 gsm, such as 18 gsm. In examples where the web comprises comprise synthetic bicomponent fibres, the formed web may be inserted into and heated in an oven to cause partial melting of the bicomponent fibres. In some examples, the formed web is heated to 140 °C - 170 °C in the oven. The formed web may be heated in the oven for 20 - 110 seconds. The heating of the web including synthetic bicomponent fibres has been found to stabilise the web. The stabilisation of the web enables the web to be processed more readily. Otherwise, the web is more likely to fall apart during processing, for example during winding of the web into a roll, during the formation of the web in an airlaying process, and / or during unwinding of the web roll prior to hydroentanglement. Following the formation of the web, the web may be formed into a roll. The hydroentanglement method further comprises locating an arrangement comprising the web and a reinforcing material into a hydroentanglement apparatus. The arrangement may be in the form of a sheet, and can be formed on a support by laying a sheet of the web onto a sheet of the reinforcing material. The web defines a first layer of the arrangement, and the reinforcing material defines a second layer of the arrangement The reinforcing material is in the form of a sheet. The reinforcing material could also be considered as a reinforcing structure. The reinforcing material may comprise a structure defined by a fabric. The fabric could be a woven fabric, a knitted fabric, a braided fabric, or a non-woven. Alternatively, the reinforcing material may comprise a structure defined by a combination of a woven fabric, a knitted fabric, a braided fabric, and / or a non-woven. The fabric of the reinforcing material is preferably a durable fabric. A durable fabric is suitable for multiple cycles of use and washing, as opposed to disposable fabric, which is not suitable for repeated use and / or washing cycles. A durable fabric is suitable for use in clothing, footwear, accessories and / or upholstery. A durable fabric may be tear resistant (for instance greater than 10 N tear strength as measured by BS EN ISO 3377-2 2016 using a double-edged tear) and may have high tensile strength (for instance a tensile strength of greater than 7 N / mm as measured by tensile strength test BS EN ISO 3376-2002). The fabric of the reinforcing material could be a recycled fabric. In some examples, the reinforcing material has a different weight per unit area to the web, and preferably has a lower weight per unit area than the web. In other examples, the reinforcing material has the same weight per unit area as the web. The reinforcing material may comprise virgin fibres and / or recycled fibres. The reinforcing material may comprise natural, naturally derived, and / or synthetic fibres. In some examples, the reinforcing material comprises splittable fibres. The splittable fibres of the reinforcing material may comprise at least two different fibres arranged in distinct segments across the cross-section of the splittable fibre. For example, the at least two different fibres may comprise polyester fibres and polyamide fibres, which may be microfibres. In some examples, the arrangement includes a further web on the opposite side of the reinforcing material to the web. In such examples, the web defines a first layer of the arrangement, the reinforcing material defines a second layer of the arrangement, and the further web defines a third layer of the arrangement. The second layer is between the first and third layers in this example (i.e., the further web is on the opposite side of the reinforcing material to the web). The further web may be the same as the web described above. Alternatively, the further web may have different weight per unit area to the web, a different structure to the web, and / or have a different composition to the web. The hydroentanglement method further comprises subjecting the arrangement to successive hydroentanglement steps in the hydroentanglement apparatus. The hydroentanglement steps include exposing the arrangement to high pressure jets of liquid over a surface of the arrangement. In some examples, the liquid is water. The jets may be directed firstly onto a first face of the arrangement, and subsequently onto a second opposite face of the arrangement. The jet pressure applied to the surface of the arrangement may be 180 - 380 bar. Subjecting the arrangement to successive hydroentanglement steps causes the fibres of the web to entangle with each other. Accordingly, the fibres of the web interlock with each other by entanglement. Subjecting the arrangement to successive hydroentanglement steps also causes a mechanical bond to form between the fibres of the web and the reinforcing material. This bond is caused by some of the fibres of the web being pushed by the high-pressure jets of liquid into gaps in the reinforcing material. Subjecting the arrangement to successive hydroentanglement steps may also dislodge non-fibrous particles from the fibres of the web to reduce the amount of non-fibrous material contaminants in the web. In some examples, in the hydroentanglement apparatus the arrangement is supported on a porous conveyor, which may be the support on which the arrangement is formed, and advanced through one or more treatment stations. In other examples, in the hydroentanglement apparatus the arrangement is supported on a porous drum, which may be the support on which the arrangement is formed, and advanced through one or more treatment stations. The one or more treatment stations comprise liquid outlets for subjecting the arrangement to high pressure jets of such liquid. In some examples, the hydroentanglement method comprises subjecting the arrangement to successive hydroentanglement steps, wherein in each such hydroentanglement step the arrangement is exposed to high pressure jets of liquid over a surface of one of the faces of the arrangement. In other examples, the method comprises subjecting the arrangement to successive hydroentanglement steps, wherein in each such hydroentanglement step the arrangement is exposed to high pressure jets of liquid over a surface of each of the respective faces. Each of the successive hydroentanglement steps on one or each face of the arrangement may be carried out at a different treatment station in the apparatus. In such examples, the conveyor or the drum is arranged to support and advance the arrangement through each of the respective treatment stations. The fibrous hydroentangled material may then be dried, for instance by heating the fibrous hydroentangled material in an oven. Examples Various example composite materials and comparative example materials were prepared and subjected to the 12-second vertical Bunsen burner test specified in Federal Aviation Regulation (FAR). 25.853. In particular, the test specified in FAR 25.853 (a), Appendix F, Part I, (a) 1 (ii) and b(4). To carry out the test specified in FAR 25.853 (a), Appendix F, Part I, (a) 1 (ii) and b(4), the material is held in a vertical position and a Bunsen burner flame is applied from below for 12 seconds. Following 12 seconds, the flame is removed. The test is repeated at least 3 times and the results are averaged. To pass the test, the average burn length should not exceed 8 inches, the average flame time after removal of the flame source should not exceed 15 seconds, and drippings from the test specimen should not continue to flame for more than an average of 5 seconds after falling. The examples are shown in Table 1 below, using the same layer structure as described previously (i.e., a cover layer and a backing layer, with a compressible layer sandwiched therebetween). Fig. 2 shows comparative example 7 of Table 1 following the 12-second vertical Bunsen burner test. Fig 3. shows a first ‘F’ face of examples 1 and 2 following the 12-second vertical Bunsen burner test (example 1 shown on the left and example 2 shown on the right). Fig 4. shows a second opposite face of examples 1 and 2 following the 12-second vertical Bunsen burner test (example 1 shown on the left and example 2 shown on the right) In comparative examples 4-7 and examples 1 - 5 of Table 1, the spacer fabric is a polyester warp-knitted spacer fabric. In comparative examples 1,3,6 and 7, along with examples 1, 2 and 5 of Table 1, the fire retardant fibrous hydroentangled material is E-leather ® Essence. E-leather ® Essence includes a body of fibres made from leather fibres on one side of a woven fabric reinforcing material made from fire retardant synthetic fibres, and a further body of fibres made from leather fibres on the other side of the reinforcing material. The fire retardant fibrous scrim fabric of examples 1 to 5 of 5 Table 1 includes a needle felt non-woven layer made from fire retardant synthetic fibres and oxidised polyacrylonitrile fibres, along with two woven fabric layers made from fire retardant synthetic fibres, wherein the two woven fabric layers are calendared on either side of the non-woven layer. The fire retardant fibrous scrim fabric of examples 1 to 5 of Table 1 has a thickness of 1.6 mm ± 0.6 mm under 0.5 Kpa. 10 Table 1 Example Cover Layer Compressible Layer Backing Layer 12-Second Vertical Bunsen Burner Test Pass / Fail Comparative example 1 Fire retardant fibrous hydroentangled material Fire retardant graphite polyurethane foam None Pass Comparative example 2 Fire retardant traditional leather Fire retardant graphite polyurethane foam None Pass Comparative example 3 Fire retardant fibrous hydroentangled material None None Pass Comparative example 4 None 6mm thickness fibrous spacer fabric None Pass Comparative example 5 None 10mm thickness spacer fabric None Pass Comparative example 6 Fire retardant fibrous hydroentangled material 6mm thickness fibrous spacer fabric None Fail Comparative example 7 Fire retardant fibrous hydroentangled material 10mm thickness fibrous spacer fabric None Fail Example 1 Fire retardant fibrous hydroentangled material 6mm thickness fibrous spacer fabric Fire retardant fibrous scrim fabric Pass Example 2 Fire retardant fibrous hydroentangled material 10mm thickness fibrous spacer fabric Fire retardant fibrous scrim fabric Pass Example 3 Fire retardant traditional leather 10mm thickness fibrous spacer fabric Fire retardant fibrous scrim fabric Pass Example 4 Fire retardant woven fabric comprising wool and nylon fibres 10mm thickness fibrous spacer fabric Fire retardant fibrous scrim fabric Pass Example 5 Fire retardant fibrous hydroentangled material Fibrous polyester non-woven Fire retardant fibrous scrim fabric Pass Comparative examples 1 and 2 include polyurethane foam, which is commonly used in transport seating applications. However, polyurethane foam is non-fibrous and thus comparative examples 1 and 2 are not readily recyclable to form new fibrous materials. 5 The relatively poor fire retardancy of fibrous materials, such as spacer fabrics or non-wovens, means that they are typically considered unsuitable as a compressible layer for transport seating applications. Indeed, as demonstrated by comparative examples 6 &7, use of a fibrous material as a compressible layer, which is more readily recyclable, does not provide adequate fire retardance according to the 12-second 10 vertical Bunsen burner test. It has however been found that the addition of a backing layer comprising a third fibrous material which is fire retardant provides a significant improvement in the fire retardancy of the composite material, such that a fibrous material can be utilized in the compressible layer. This is demonstrated by examples 1 to 5 of Table 1. Examples 1 to 5 of Table 1 are made up of fibrous materials and thus can be readily recycled to provide new fibrous materials for use in, for instance, seating, clothing, footwear, accessories or upholstery. The composite materials for transport seating described herein therefore provide greatly enhanced sustainability whilst providing effective fire retardancy. The example composite materials described herein may have a fibrous material content by weight of at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.%, or at least 98 wt.%. The example composite materials described herein may have a non-fibrous material content by weight of up to 2 wt.%, up to 5 wt.%, up to 10 wt. %, up to 20 wt.%, or up to 30 wt.%. Non-fibrous material is any solid material that is present within the composite material which is not a fibre or is not made from fibres. A non-fibrous material may have a length to diameter ratio (i.e., aspect ratio) of less than 10. The non-fibrous material may be a coating, lamination, foam and / or a treatment applied to the composite material or a layer of the composite material. The recyclable content of the composite material can be increased by maximising the fibrous material content in the composite material and minimising the non-fibrous material content. Fibrous material can be broken down into individual fibres at the end of its life, by for example shredding, granulating and milling the fibrous material. These individual fibres can be formed into new fibrous materials, for example by using the hydroentanglement method described herein. These new materials can be used, for instance, in seating, clothing, footwear, accessories or upholstery. Thus, the example composite materials described herein can readily be recycled into new fibrous materials, which can again be recycled into new fibrous materials. The example composite materials described herein therefore provide a circular economy solution. Furthermore, where the fibrous hydroentangled material described herein is used in the composite material, waste fibres from textile waste and / or leather waste can be incorporated into the fibrous hydroentangled material, and thus into the composite material. The composite materials described herein can also provide a reduced weight seat cover, which can reduce fuel / energy usage by a vehicle in which the seat cover is transported / installed. The seat cover can also be readily replaced, provide a wrinkle free seat surface, and increase passenger comfort. There is thus described a composite material for transport seating and a method of forming a composite material for transport seating with a number of advantages as described above. Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one...” or by using “consisting”. In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’, ‘can’ or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example. Features described in the preceding description may be used in combinations other than the combinations explicitly described above. Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not. The term ‘a,’ ‘an’ or ‘the’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a / an / the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use ‘a’, ‘an’ or ‘the’ with an exclusive meaning then it will be made clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning. The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result. In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described. The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such 5 alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure. Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the applicant may seek 10 protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and / or shown in the drawings whether or not emphasis has been placed thereon.

Claims

1. A composite material for transport seating comprising:a cover layer, the cover layer comprising a first fibrous material, wherein the first fibrous material is fire retardant;a compressible layer, the compressible layer comprising a second fibrous material, wherein the compressible layer is configured to compress when a force is applied thereto; anda backing layer, the backing layer comprising a third fibrous material, wherein the third fibrous material is fire retardant, andwherein the compressible layer is located between the cover layer and the backing layer.

2. The composite material of claim 1, wherein the second fibrous material is a non-woven or a spacer fabric.

3. The composite material of claim 2, wherein the second fibrous material is a spacer fabric.

4. The composite material of claim 3, wherein the second fibrous material is a knitted spacer fabric.

5. The composite material of claim 4, wherein the second fibrous material is a warp-knitted spacer fabric.

6. The composite material of claim 4, wherein the second fibrous material is a weft-knitted spacer fabric.

7. The composite material of any of the preceding claims, wherein the weight of the second fibrous material is at least 200 gsm, and the density of the second fibrous material is up to 400 kg / m3.

8. The composite material of any of the preceding claims, wherein the density of the second fibrous material is up to 200 kg / m3.

9. The composite material of any of the preceding claims, wherein the third fibrous material is a woven fabric.

10. The composite material of any claims 1 to 8, wherein the third fibrous material is a non-woven.

11. The composite material of any of the preceding claims, wherein the third fibrous material is a scrim fabric.

12. The composite material of any of the preceding claims, wherein the weight of the third fibrous material is from 50 gsm to 300 gsm.

13. The composite material of any of the preceding claims, wherein the first fibrousmaterial is a leather material, a textile material, or a fibrous hydroentangled material.

14. The composite material of any of the preceding claims, wherein the weight of the first fibrous material is from 150 gsm to 1000 gsm.

15. The composite material of any of the preceding claims, wherein the first fibrous material is a fibrous hydroentangled material, the fibrous hydroentangled material comprising:a reinforcing material; anda body of fibres, the body of fibres including fibres interlocked with each other by entanglement, and wherein at least some of the fibres of the body of fibres are mechanically bonded to the reinforcing material.

16. The composite material of any of the preceding claims, wherein the cover layer and the compressible layer are lamination bonded.

17. The composite material of any of the preceding claims, wherein the compressible layer and the backing layer are lamination bonded.

18. A seat comprising the composite material of any of the preceding claims.

19. A vehicle comprising one or more of the seats of claim 18.

20. The vehicle of claim 19, wherein the vehicle is an aircraft.

521. A method of forming a composite material for transport seating, the method comprising:securing a cover layer to a compressible layer; andsecuring the compressible layer to a backing layer, wherein:10 the cover layer comprises a first fibrous material, wherein the firstfibrous material is fire retardant;the compressible layer comprises a second fibrous material, wherein the compressible layer is configured to compress when a force is applied thereto; and15 the backing layer comprises a third fibrous material, wherein the thirdfibrous material is fire retardant.

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