Use of material for adsorption of compounds, and protective garment

Abstract

The present invention relates to the use of activated carbon fabrics in the adsorption of compounds such as aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs / aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs). Also described are garments including such fabrics, and a protective system comprising multiple garments.

Description

[0001] USE OF MATERIAL FOR ADSORPTION OF COMPOUNDS, AND PROTECTIVE GARMENT

[0002] Field of the Invention

[0003] The present invention relates to the adsorption of aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and polycyclic aromatic hydrocarbons (PAHs), and a protective garment for protection against such compounds.

[0004] Background

[0005] Many aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and polycyclic aromatic hydrocarbons (PAHs) are classed as chronic toxicants, with effects that are complex and long-term (such as the development of cancers, or cardiovascular problems). Specific examples include benzene and naphthalene. They exhibit carcinogenic, teratogenic and sensitising effects, causing long-term harm to reproductive, neurological, pulmonary, respiratory and haematological health. The risk of exposure to these compounds is present in many environments, and especially in environments where there is uncontrolled or controlled burning of materials.

[0006] Despite these huge risks to health, there is currently minimal or no control to limit the exposure of first- responders, such as firefighters, paramedics, and police officers, or military personnel, construction workers, workers in incineration plants, or indeed anyone or anything likely to be exposed to these compounds. Current personal protective equipment for those personnel contains no design to prevent these compounds from coming into contact with the skin. For example, in a recent study, the reported measurements on the concentration of benzene, toluene and naphthalene inside firefighters’ turn-out jackets matched those concentrations on the outside, and this corresponds with a growing body of evidence that firefighters are at increased risk of developing cancers and other diseases compared to the general population. Any person exposed to these compounds, either during their release or where they remain in the environment for a significant length of time after the initial release, is at risk of these negative long-term health effects.

[0007] There is therefore a significant need to reduce exposure to these compounds, whilst recognising that those at risk cannot avoid being in close proximity to the source when carrying out their essential roles.

[0008] Carbon has been used for decades for the filtration of toxic chemical vapours, and scientific advances aim towards more lightweight, air permeable and breathable activated carbon materials. However, the technology is still limited.

[0009] For example, activated carbon in the form of powders, granules or particulates is generally lacking in durability, being brittle and delicate. Most activated carbon is available loose in different forms such as powders, granules or as an unsupported textile which needs further processing to achieve a regular, consistent and physically stable form with passable durability. It is thus difficult to utilise in protective clothing which needs to have sufficient flexibility, weight, comfort and so on to be practical, while also retaining protective durable qualities, and garments containing these materials remain uncomfortable to wear, heavy, inflexible and expensive to produce.

[0010] In particular, current garments comprising activated carbon are not compatible with the high heat, high stress environments that are often associated with exposure to these compounds, and do not offer the user the flexibility and range of movement they require to carry out their roles. Their use could result in heat stress and fatigue, with immediate and acute negative health impacts that potentially outweigh any positive impact on long-term health. There is little motivation for those at risk of exposure to use these materials or garments which incorporate them.

[0011] Summary of the Invention

[0012] On considering this problem, the inventors have developed an activated carbon fabric. This material has significantly enhanced adsorption characteristics relative to a material of similar activated carbon weight that is not an activated carbon fabric, such as materials based on activated carbon in powdered, granular, spherical or particulate form.

[0013] Remarkably and surprisingly, the inventors have found this material performs excellently in the adsorption of aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and polycyclic aromatic hydrocarbons (PAHs). In combination with the lightweight, inexpensive, flexible properties of the activated carbon fabric, the material is ideal for the protection of users against these compounds.

[0014] A first aspect of the invention is the use of an activated carbon fabric for the adsorption of a compound selected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs). The adsorption of the compound prevents it passing freely through the fabric, and the concentration on the opposite side of the fabric to the source may be significantly reduced, or reduced to a level so small to be immeasurable, relative to a situation in which activated carbon fabric is not used. This effect may be observed over a significant time period. The invention can therefore limit or completely prevent exposure to the compounds over a period commensurate with the maximum length of time that a user is in the high-risk environment. The invention is therefore of significant benefit to preserving long-term health.

[0015] In some embodiments of the invention, the compound selected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is a fire effluent.

[0016] In some embodiments of the first aspect of the invention, the compound selected from aromatic semivolatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is at least one of naphthalene and benzene. Naphthalene and benzene exhibit carcinogenic, teratogenic and sensitizing properties, causing harm to reproductive, neurological, pulmonary, respiratory and haematological health. They are some of the most challenging compounds of these classes to limit exposure to, on account of their small size and relatively high volatility. Their adsorption is representative of the adsorption of other aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs / aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs).

[0017] In some embodiments of the first aspect of the invention, the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. The range of about 40 gsm to about 200 gsm provides good adsorption capacity and adsorption rate, whilst minimising the overall weight and the cost of the material.

[0018] In some embodiments of the first aspect of the invention, the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. The range of about 50 gsm to about 250 gsm provides good total adsorption capacity and sufficient robustness whilst minimising the overall weight and the cost of the material.

[0019] In some embodiments of the first aspect of the invention, the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm. The range of about 0.1 mm to about 2.0 mm provides good adsorption characteristics, slowing transport through the fabric, whilst maintaining usability, breathability and flexibility.

[0020] In some embodiments of the first aspect of the invention, the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. The range of about 50 mm / s to about 1000 mm / s is a good balance between adsorption performance and breathability.

[0021] In some embodiments of the first aspect of the invention, the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. The range of about 0.5 m2.Pa / W to about 10 m2.Pa / W is a good balance between adsorption performance and ability to maintain transmission of moisture for evaporative cooling.

[0022] In some embodiments of the first aspect of the invention, the activated carbon fabric is comprised within a garment (A). When the activated carbon fabric is in the form of a garment, the user’s skin surface area is protected most efficiently.

[0023] In some embodiments of the first aspect of the invention, the garment (A) forms part of a protective system, the protective system further comprising a garment (B), wherein the garment (A) is worn beneath a garment (B). For example, the garment (A) may be an inner garment such as an all-in-one body suit that is worn beneath an outer garment which is the garment (B). In this form, the garment (B) can offer additional protection or function that is not offered by garment (A) and can enhance the performance of the activated carbon fabric and / or protect it. Furthermore the garment (A) comprising the activated carbon fabric can be washed and regenerated without needing to wash the garment (B), which may be large and bulky. Furthermore, the garment (A) offers continued protection to the user during removal of the garment (B), which may be heavily contaminated.

[0024] Also described herein are embodiments wherein the garments (A) and / or (B) are formed of a single layer of fabric, or wherein the garments (A) and / or (B) are made up of more than one layer of fabric. Additional layers can provide additional function, such as thermal insulation, or can increase the comfort of the user, such as a layer of natural material such as cotton or silk.

[0025] A second aspect of the invention is the provision of a protective garment comprising an outer fabric of limited flame spread material, wherein at least one of the following conditions is satisfied: a. the outer fabric has a residual tensile strength of at least 450 N, and / or b. the protective garment is heat resistant at 180 °C with shrinkage of <5%, and wherein the protective garment additionally comprises an activated carbon fabric.

[0026] In the second aspect of the invention, the activated carbon fabric has substantially the same benefits as described for the first aspect of the invention.

[0027] Where the outer limited flame spread material of the protective garment has a residual tensile strength of at least 450 N, the outer material is resistant to damage by flames and is durable and strong. Beyond offering additional protection to a user as a barrier, this offers an additional level of protection to the activated carbon fabric itself, and any other non-functional and functional layers, against damage, thereby maintaining performance.

[0028] Where the outer limited flame spread material of the protective garment is heat resistant at 180 °C with shrinkage of <5%, the outer material is resistant to damage by high temperature. Beyond offering additional protection to a user as a barrier, this again offers additional protection to the activated carbon fabric, and any other non-functional and functional layers, against damage by flames and high temperatures, thereby maintaining performance.

[0029] In some embodiments of the second aspect of the invention, the protective garment is a structural firefighting garment and / or a wildland firefighting garment. By the incorporation of an activated carbon fabric in a structural firefighting garment or a wildland firefighting garment, a firefighter is afforded protection from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) as described herein. Structural and wildland firefighting garments without the activated carbon material cannot offer this protection.

[0030] In some embodiments of the second aspect of the invention, the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. These ranges have substantially the same advantages as described for the first aspect of the invention.

[0031] In some embodiments of the second aspect of the invention, the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. These ranges have substantially the same advantages as described for the first aspect of the invention.

[0032] In some embodiments of the second aspect of the invention, the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm. These ranges have substantially the same advantages as described for the first aspect of the invention.

[0033] In some embodiments of the second aspect of the invention, the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. These ranges have substantially the same advantages as described for the first aspect of the invention.

[0034] In some embodiments of the second aspect of the invention, the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. These ranges have substantially the same advantages as described for the first aspect of the invention.

[0035] A third aspect of the invention is the provision of a protective system comprising a garment (A) and a garment (B), wherein the garment (A) comprises an activated carbon fabric.

[0036] The garment (A) may be located beneath the garment (B); that is, on the side of garment (B) where protection is wanted (for example, closer to the user). For example, the garment (A) may be an inner garment such as an all-in-one body suit beneath an outer garment which is the garment (B). In this form, the garment (B) can offer additional protection or function that is not offered by garment (A) and can enhance the performance of the activated carbon fabric and / or protect it. Furthermore, the garment (A) comprising the activated carbon fabric can be washed and regenerated without needing to wash the garment (B), which may be large and bulky. Finally, the garment (A) offers protection to the user on the removal of the garment (B), which may be heavily contaminated.

[0037] Also described herein are embodiments wherein the garments (A) and / or (B) are made up of a single layer of fabric, or wherein the garments (A) and / or (B) are made up of more than one layer of fabric. Additional layers can provide additional function, such as thermal insulation, or can increase the comfort of the user, such as a layer of natural material such as cotton or silk.

[0038] In some embodiments of the third aspect of the invention, the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. These ranges have substantially the same advantages as described for the first and second aspects of the invention.

[0039] In some embodiments of the third aspect of the invention, the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. These ranges have substantially the same advantages as described for the first and second aspects of the invention.

[0040] In some embodiments of the third aspect of the invention, the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm. These ranges have substantially the same advantages as described for the first and second aspects of the invention. In some embodiments of the third aspect of the invention, the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. These ranges have substantially the same advantages as described for the first and second aspects of the invention.

[0041] In some embodiments of the third aspect of the invention, the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. These ranges have substantially the same advantages as described for the first and second aspects of the invention.

[0042] The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

[0043] Summary of the Figures

[0044] Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures, where:

[0045] Figure 1 shows data from static diffusion tests corresponding to Examples 1 and 4.

[0046] Figure 2 shows data from static diffusion tests corresponding to Examples 2 and 5.

[0047] Figure 3 shows data from static diffusion tests corresponding to Examples 3 and 6.

[0048] Figure 4 shows data from static diffusion tests corresponding to Examples 7 and 10.

[0049] Figure 5 shows data from static diffusion tests corresponding to Examples 8 and 11 .

[0050] Figure 6 shows data from static diffusion tests corresponding to Examples 9 and 12.

[0051] Figure 7 shows data from dynamic convection tests corresponding to Examples 13 and 15.

[0052] Figure 8 shows data from dynamic convection tests corresponding to Examples 14 and 16.

[0053] Figure 9 shows data from dynamic convection tests corresponding to Examples 17 and 19.

[0054] Figure 10 shows data from dynamic convection tests corresponding to Examples 18 and 20.

[0055] Detailed Description of the Invention

[0056] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

[0057] A first aspect of the invention is the use of an activated carbon fabric for the adsorption of a compound selected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs). The highly efficient and high-capacity adsorption properties of the activated carbon fabric means that the transmission of the compound across the fabric is thwarted, or completely prevented, for a significant length of time and until the adsorption capacity is reached. The fabric can protect anyone or anything at risk from exposure to the compound over time periods commensurate with the maximum length of time that a user will be in the high-risk environment. Where the exposure is reduced, or fully prevented, the risks to long-term health, such as the risk of developing cancers, are reduced.

[0058] Activated carbon fabrics are known in the art.

[0059] Activated carbon fabrics are formed from yarns, fibres, knitted, woven or nonwoven fabrics that are typically formed from precursor materials such as polyacrylonitrile (PAN), pitch, cellulosic materials such as viscose rayon and acetates, poly(vinylidene chloride (PVDC), and phenolic resins.

[0060] These materials are subjected to a carbonisation and activation process to produce the activated carbon fabric.

[0061] For example, activated carbon fabrics may be formed from a suitable cellulosic or modified cellulose polymer and carbonising and activating the substrate in an oven or furnace in the absence of oxygen (and / or for a limited time) in order to prevent full combustion.

[0062] A starting material of the activated carbon fabric may, for example, be a viscose rayon fabric. The fabric may be woven, nonwoven, or knitted, formed from yarn or fibres. This fabric may be subjected to treatment with phosphoric acid before carbonisation and activation to form the activated carbon fabric.

[0063] A starting material of the activated carbon fabric may be polyacrylonitrile (PAN) tow (filament). The PAN tow may be processed via a tow to top conversion process, forming a continuous sliver or roving of continuous fibres. The roving may then be processed via a ring spinning process, in which the roving is drafted and spun, into a yarn format. In general, a yarn is a long continuous length of interlocked fibres. The yarn may then be further processed via a doubling process, in which two ring-spun yarns are combined with opposite twist) to produce a new yarn. This yarn may then be woven into a fabric. Then, the fabric may be carbonised and activated. For example, the fabric may be subject to continuous open width heat-based activation and carbonisation or the woven fabric at 1000 °C for a 10-minute periodicity.

[0064] Typically, the activated carbon layer is laminated with a support material, such as polyester, for structural integrity. This support material may be adhered to one or both surfaces, for example using a dot-printed thermoplastic polyamide adhesive, before lamination under heat and pressure. For example, the activated carbon fabric in the form of a laminated stack may have the structure: polyester / carbonised material / polyester.

[0065] Thus, an activated carbon fabric can exist as a layer of activated carbon fabric alone, or can exist as a laminated stack in which an activated carbon fabric layer is supported by one or more other materials. The term ‘activated carbon fabric’ refers to both scenarios.

[0066] Aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) include benzene, styrene, toluene, and phenol. Polycyclic aromatic hydrocarbons include naphthalene, benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, chrysene, and fluoranthene. These compounds are known to be carcinogenic, teratogenic, sensitising, and to have negative impact on reproductive, neurological, pulmonary, respiratory, and haematological health. Benzene is a known carcinogen and sensitiser, with negative impact on reproductive, neurological, pulmonary, respiratory, and haematological health. Naphthalene is a known carcinogen, with negative impact on neurological and haematological health. The adverse exposure to these compounds can occur via adsorption through the skin.

[0067] In some embodiments, the compound selected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is a fire effluent. A fire effluent is a gas and / or an aerosol, including suspended particles, created by combustion or pyrolysis in a fire. None of the embodiments of the invention are limited by the particular source of the compound which is adsorbed, but the adsorption of aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) through the skin is enhanced when the skin is at high temperature, which makes exposure to the compounds released as fire effluents particularly dangerous. Furthermore, the high stress and active environment that is associated with workers exposed to uncontrolled fires makes the use of a lightweight, flexible protective covering or garment particularly beneficial.

[0068] In some embodiments, at least one of the aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is benzene or naphthalene. Naphthalene is considered the smallest and most volatile PAH, and its adsorption is therefore representative of general PAH adsorption performance. Benzene is a highly volatile and small species which is the smallest building block of PAHs and is itself a significant combustion product. Its adsorption can be considered representative of general adsorption performance of other aromatic semivolatile and aromatic volatile organic compounds and polycyclic aromatic hydrocarbons.

[0069] The activated carbon fabric may have an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. The range of about 40 gsm to about 200 gsm provides a good balance between performance and weight. Below an activated carbon weight of about 40 gsm, the amount of activated carbon available for adsorption may be too low, and insufficient performance in the adsorption can be observed. Whilst the transmission of compounds will still be reduced, the time frame over which this occurs may be reduced before the material reaches its adsorption capacity. Above an activated carbon weight of 200 gsm the weight of the fabric as a whole may be too great, resulting in low comfort or portability for the user, as well as it being more expensive to produce. A fabric that is too heavy may reduce usability, especially in the context of a garment. A heavy garment is difficult to transport, wear, and perform energy intensive activities in, such as, but not limited to, firefighting, running, or carrying heavy objects.

[0070] The activated carbon fabric may have a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. The range of about 50 gsm to about 250 gsm provides good total adsorption capacity and sufficient robustness whilst minimising the overall weight and the cost. Below a weight of about 50 gsm, the fabric may not have sufficient robustness nor adsorption capacity. Above a weight of about 250 gsm, the same disadvantages as expressed above for high activated carbon weight are present. The activated carbon fabric may have a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm. The range of about 0.1 mm to about 2.0 mm provides good adsorption characteristics, slowing transport through the covering or garment, whilst maintaining usability, breathability and flexibility. At a thickness below about 0.1 mm, the material may not be robust and may demonstrate insufficient adsorption. At a thickness greater than about 2.0 mm, the material is more likely to be inflexible, more difficult to integrate as a layer of fabric within a layered material, and is also likely to be less breathable.

[0071] The activated carbon fabric may have an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. The minimum air permeability of about 50 mm / s is preferred so that the comfort and safety of the user is enhanced, because the air permeability is indicative of the breathability of the material. Where air permeability of the material is below about 50 mm / s, the user is more likely to suffer from heat stress and fatigue. However, an activated carbon fabric with an air permeability of greater than about 1000 mm / s may show reduced adsorption performance.

[0072] The activated carbon fabric may have a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. The maximum water vapour resistance of about 10 m2.Pa / W is preferred so that the comfort and safety of the user is not compromised. Where the water vapour resistance of the material is above about 10 m2.Pa / W, the rate of evaporative cooling from the skin is much reduced and the user is more likely to suffer from heat stress and fatigue. However, an activated carbon fabric with a water vapour resistance of below about 0.5 m2.Pa / W may show reduced adsorption performance.

[0073] The activated carbon fabric may be comprised within a garment (A). A garment is a piece of clothing, suitable to be worn alone, or beneath, on top of or in addition to another garment. Examples of garments may be an all-in-one bodysuit, a jacket, trousers, socks, shoes, a hat, gloves, a hood, or any other piece of clothing. In the form of a garment, the user’s skin is efficiently protected to the extent desired by the shape and size of the garment. The material of the garment is also used efficiently because its shape corresponds approximately to the surface area of skin to be protected.

[0074] The garment (A) may be formed of a single layer of fabric or of more than one layer of fabric. Where the garment (A) is formed of a single layer of fabric, this is the activated carbon fabric. Where the garment (A) is formed of more than one layer of fabric or material, the layers are further connected together; for example, by lamination, by adhesion, and / or by sewing.

[0075] For clarity, and as already expressed above, the activated carbon fabric layer may be a single layer of activated carbon fabric alone, or it may be in the form of a stack in which an activated carbon fabric is supported by one or more additional material layers such as polyester. In both forms it is referred to as the activated carbon fabric. For example, the activated carbon fabric in the form of a laminated stack may be in the form polyester / carbonised material / polyester. Within an activated carbon fabric in laminated form, and where more than one supporting layer is present, those supporting layers may all be formed of the same material or they may be formed of different materials. Examples of such supporting layers include those made of meta or para aramid, cotton, viscose, silk, polyester, polyamide or blends of different fibres. Other suitable choices include, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN) and poly(ethylene succinate). Polyethylene terephthalate (PET) is a particularly suitable choice, and especially polyethylene terephthalate (PET) woven in a plain or ripstop weave. The weight of such a layer can be chosen according to the intended use. The present inventors have found that using a material with a weight of 10 to 30 gsm, preferably 18 to 22 gsm and suitably about 20 gsm, is advantageous. It contributes to a lightweight and flexible layer while retaining the protective and comfort qualities associated with the material. On the other hand, such a woven material can be used as a durable, protective layer. Here, a heavier woven material can be used, for example with a weight of 150-250 gsm, suitably about 175 gsm.

[0076] The supporting material is typically adhered to the carbonised layer using an adhesive. For example, they can be adhered using a thermoplastic polyamide adhesive that is dot-printed.

[0077] The layers which are not layers of activated carbon fabric within the garment (A) are not particularly limited. However, they may be functional or non-functional layers, they may act to enhance the performance of the activated carbon fabric, they may act to protect the activated carbon fabric, and they are incorporated only to the extent that they do not significantly limit the performance of the activated carbon fabric. It is noted also that the activated carbon fabric has been found advantageously not to negatively affect the functional performance or characteristics of any additional layers.

[0078] The garment (A) may include layers which increase comfort, especially in the case that the layer sits next to the skin. Suitable examples of materials to form the comfort layer are the same as described above for the supporting materials of the carbonised layer. Thus, examples of such layers include those made of meta or para aramid, cotton, viscose, silk, polyester, polyamide or blends of different fibres. Other suitable choices include, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN) and poly(ethylene succinate). Polyethylene terephthalate (PET) is a particularly suitable choice, and especially polyethylene terephthalate (PET) woven in a plain or ripstop weave.

[0079] Again, the weight of such a layer can be chosen according to the intended use. The present inventors have found that using a material with a weight of 10 to 30 gsm, preferably 18 to 22 gsm and suitably about 20 gsm, is advantageous. It contributes to a lightweight and flexible layer while retaining the protective and comfort qualities associated with the material.

[0080] The material may include layers which enhance function or add function. Functional layers may include, but are not limited to, a layer which filters particulates and / or wet and / or dry aerosols, a layer which increases the durability of the material and / or protects the activated carbon fabric layer, a layer which is thermally insulating, a layer which is flame-resistant and / or fire-resistant and / or fire-proof, and a breathable moisture barrier layer.

[0081] For example, a layer which filters particulates and / or wet and / or dry aerosols, or a layer which increases the durability of the material, may be formed of woven fabrics made from meta or para aramid, cotton, polyester, polyamide or blends of different fibres; nonwoven materials such as those spun from polyethylene, polypropylene, polyamide or polyester; or knitted materials made from meta or para aramid, cotton, polyester, polyamide or blends of different fibres. Nano fibre layers may also be used.

[0082] A layer which is thermally insulating may be a layer comprising meta or para aramid such as Nomex® and / or Kevlar®. It may be a layer of natural material such as wool or down, or a synthetic material such as polyester.

[0083] A layer which is flame-resistant and / or fire-resistant and / or fire-proof may be a layer comprising meta or para aramid such as Nomex® and / or Kevlar®, modacrylic, Polybenzimidazole fiber, or cotton.

[0084] A layer which is a breathable moisture barrier layer may be a layer comprising a hydrophilic, porous, semi-permeable or microporous polymer membrane. It may be woven or, more usually, nonwoven, or monolithic. Suitable materials include PTFE (polytetrafluoroethylene) or ePTFE (expanded polytetrafluoroethylene). Other suitable materials include polyurethane, polyesters, polyamide or blends of different polymers. Such a membrane is preferably an air-permeable or non-air-permeable membrane constructed from a fully or in-part moisture and / or vapour permeability polymer. For example, PTFE membranes are generally microporous, or alternatively can be used with an additional monolithic layer on one side, for example a polyurethane which may suitable be hydrophilic. Alternative, a semi-permeable or microporous membrane can be used. Examples include PTFE, microporous polyurethane, and some nonwoven materials in which the fibres are closely spaced, leaving fine pores between them. The membrane prevents toxic liquid and or particulate penetration.

[0085] The membrane may have a weight suitably selected according to the intended use or properties for the finished material, and depending on the membrane material itself. A useful membrane weight is, for example, 5 to 30 gsm, for example 8 to 15 gsm, suitably about 10 gsm.

[0086] Additional layers of any identity have been found to protect the activated carbon fabric from damage during use and during washing.

[0087] The garment (A) may comprise more than one layer of activated carbon fabric, and where there is more than one layer of activated carbon fabric they may be adjacent to each other or separated by other layers. Multiple layers of activated carbon fabric increase the total adsorption capacity of the material. Furthermore, having multiple layers of activated carbon fabric mitigates the risk of defects in one layer, arising in manufacture or from wear and tear, resulting in the transmission of the compounds through the material.

[0088] There is no particular limitation on the order in which the layers are arranged. Generally, there may be an outer flame-proof layer that is exposed to the environment and a comfort layer designed to sit closest to the user’s skin, and, between those layers, a particulate filter layer and / or a breathable moisture barrier layer, a layer of activated carbon fabric, and a thermally insulating layer, in any order. The layers may be arranged as follows: an outer flame-proof layer that is exposed to the environment, then a particulate filter layer or breathable moisture barrier layer, then a layer of activated carbon fabric, then a thermally insulating layer, then a comfort layer designed to sit closest to the user’s skin. Alternatively, the layers may be arranged as follows: an outer flame-proof layer that is exposed to the environment, then a particulate filter layer or breathable moisture barrier layer, then a thermally insulating layer, then a layer of activated carbon fabric, then a comfort layer designed to sit closest to the user’s skin.

[0089] In some embodiments, the garment (A) may form part of a protective system, the protective system further comprising a garment (B), wherein the garment (A) is worn beneath the garment (B). Typically, the garment (A) is not materially connected to the garment (B).

[0090] The garment (B) may be formed of a single layer or more than one layer. Where the garment (B) is formed of more than one layer, the layers are connected together; for example, by lamination, by adhesion, or by sewing. The garment (B) may comprise a layer of activated carbon fabric, as described for any of the embodiments of the garment (B), but this is not a requirement for garment (B).

[0091] The identity of the single layer or multiple layers in the garment (B) may be as described for the layers of the garment (A).

[0092] The inventors have found, surprisingly, that additional layers on top of or beneath an activated carbon fabric layer, in the garments (A) and / or (B), can remarkably enhance the performance of an activated carbon fabric layer in the garments (A) and / or (B).

[0093] When the garment (A) is beneath (that is, closer to the user) and separable from the garment (B), the weight and bulk of the garment (A) can easily be minimised whilst the garment (B) can provide the additional benefits of multiple non-functional and / or functional layers. The activated carbon fabric in the lightweight and non-bulky garment (A) may therefore be easily regenerated by separating from the garment (B) and washing, without the requirement to wash the garment (B) at the same time. Furthermore, the garment (A) still offers protection to the user during the removal of the garment (B), which may be heavily contaminated because of its direct exposure to the external environment.

[0094] A second aspect of the invention is the provision of a protective garment comprising an outer fabric of limited flame spread material, wherein at least one of the following conditions is satisfied: a. the outer fabric has a residual tensile strength of at least 450 N, and / or b. the protective garment is heat resistant at 180 °C with shrinkage of <5%, and wherein the protective garment additionally comprises an activated carbon fabric.

[0095] An outer fabric is the layer of the protective garment which sits furthest away from the user’s skin and directly exposed to the external environment.

[0096] The limited flame spread property of a material is measured in accordance with ISO 15025:2016 (previously ISO 15025:2000). The outer fabric of limited flame spread material measured in accordance with this standard preferably has an after-flame time of a maximum of 2 seconds, with no hole formation in the material and no melt droplets, after exposure to a flame for 10 minutes. The after-flame time is the time that the flame on the fabric continues to burn after removal of the ignition flame and is determined by visual inspection. Alternatively, the limited flame spread material may have an after-flame time of greater than 2 seconds, but no hole formation or melt droplets must be observed, and the material must extinguish before the edge of the sample is reached.

[0097] The residual tensile strength of the outer fabric is measured in accordance with ISO 13934-1 :2013 (previously ISO 13934-1 :1999). Testing is preferably carried out after pre-treatment by washing, and the material is tested in both machine and cross direction. Testing according to ISO 13934-1 may also be performed after exposure to radiant heat, according to EN ISO 6942:2022 (previously EN ISO 6942:2002). The tensile strength of the outer fabric may be tested after exposure to radiant heat of 10 kW / m2. The outer fabric preferably has a residual tensile strength of at least 300 N, more preferably at least 450 N, or more preferably at least 600 N when measured according to this standard.

[0098] The heat resistance of the protective garment is measured in accordance with ISO 17493:2016 (previously ISO 17493:2000). The test is intended to determine physical changes in a material at a given exposure temperature in a hot air circulating oven, and the materials are evaluated for defined visible changes including the degree of shrinkage. The protective garment preferably shows a degree of shrinkage of <5% when exposed to 180 °C under the test and measurement conditions specified by this standard. The protective garment may additionally be tested at 260 °C, measured in accordance with ISO 17493-1 :2013 (previously ISO 17493:2000), and preferably shows a degree of shrinkage of <5%. Alternatively, the protective garment may show a degree of shrinkage of <10% when tested at 180 °C and / or 260 °C according to the same standard.

[0099] The activated carbon fabric is the same as described above for the any embodiment of the first aspect of the invention.

[0100] A protective garment with an outer fabric of limited flame spread material, wherein the outer fabric has a residual tensile strength of at least 450 N, and wherein the protective garment additionally comprises an activated carbon fabric, offers excellent protection to the user. The activated carbon fabric itself is protected from both fire and impact hazards and remains intact and functional. The same protection against flame and impact is also, of course, afforded to the user. In general, the addition of this outer layer, as described, means that the user can be protected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs), as described herein, in environments where there is also significant risk of fire and / or rupture of the outer fabric by impact, for example from falling debris.

[0101] A protective garment with an outer fabric of limited flame spread material, wherein the protective garment is heat resistant at 180 °C with shrinkage of <5%, and wherein the protective garment additionally comprises an activated carbon fabric, also offers excellent protection to the user. Again, the activated carbon fabric is protected from potential damage in a high temperature environment, and the user is afforded this protection also. In general, the addition of this outer fabric layer, as described, means that the user can be protected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs), as described herein, in environments where there is also significant risk of high temperatures. Where the outer layer both has a tensile strength of at least 450 N, and additionally is heat resistant at 180 °C with shrinkage of <5%, the benefits of both properties as described above are conferred to the protective garment.

[0102] An additional benefit of an outer layer as described for any embodiment of the second aspect of the invention is that because the outer layer itself is not compromised on exposure to flame and / or high temperatures and is durable and strong, the surprising enhancement in performance of the activated carbon fabric layer when in combination with another layer, as described above, is maintained.

[0103] The protective garment may be resistant to radiant heat, as measured according to ISO 6942:2022 (previously ISO 6942:2002, ISO 6942:1993). When measured according to that standard, the protective garment, or materials comprised in the protective garment, is preferably resistant to radiant heat such that when exposed to a 40 kW / m2energy source, a temperature rise of 24 °C (RHTI24), as measured on the opposite side to the heat source, takes at least 10 seconds. Additionally, RHTI24 - RHTI12 (where RHTI12 is the measured time for a temperature rise of 12 °C) is preferably at least 3 seconds. This represents the reaction time between the onset of second degree and first degree burns. For a higher level of protection, RHTI24 may be at least 11 seconds, or may be at least 18 seconds, and RHTI24 - RHTI12 may be at least 4 seconds.

[0104] The protective garment may additionally comprise seams with a tensile strength of at least 300 N, when measured according to ISO 13935-2:2014 (previously ISO 13935-2:1999).

[0105] The protective garment, or components of the protective garment, may also show a tear strength of at least 25 N, when measured according to ISO 13937-2:2000.

[0106] The protective garment, or materials comprised in the protective garment, may also show a dimensional change of no more than 3% for woven fabrics, and of no more than 5% for nonwoven and knitted fabrics, when tested according to ISO 5077:2007 (previously ISO 5077:1984) by subjecting to a combination of specified washing and drying procedures.

[0107] The protective garment, or materials comprised in the protective garment, may have a water vapour resistance of greater than 30 m2.Pa / W (but less than 45 m2.Pa / W), or less than or equal to 30 m2.Pa / W, when measured according to EN 11092:2014. Additionally, the protective garment may have a thermal resistance of less than or equal to 0.055 m2K / W, when measured according to EN 11092:2014.

[0108] The protective garment may show resistance to contact heat as determined by EN ISO 12127-1 :2015 (previously ISO 12127-1 :2007). When challenged by a contact temperature of 250 °C, according to this standard, the time taken for the temperature to rise by 10 °C inside the protective garment preferably takes a minimum of 10 seconds.

[0109] The protective garment may show resistance to convective heat when measured according to ISO 9151 :2016 (previously ISO 9151 :1995). When measured according to that standard, the protective garment, or materials comprised in the protective garment, is preferably resistant to convective heat such that when exposed to a 80 kW / m2energy source, a temperature rise of 24 °C (RHTI24), as measured on the opposite side to the heat source, takes at least 9 seconds. Additionally, RHTI24 - RHTI12 (where RHTIi2 is the measured time for a temperature rise of °C) is preferably at least 3 seconds. This represents the reaction time between the onset of second degree and first degree burns. For a higher level of protection, RHTI24 may be at least 13 seconds, or may be at least 18 seconds, and RHTI24 - RHTI12 may be at least 4 seconds.

[0110] The protective garment may additionally comprise zips designed such that they are locked when completely closed to avoid accidental opening. The protective garment may additionally comprise external pockets such that all external pocket flaps, excluding radio pockets, can be fastened shut, and wherein the flap extends at least 10 mm beyond each side of the pocket.

[0111] In some embodiments of the second aspect of the invention, the protective garment is a structural firefighting garment or a wildland firefighting garment. A structural firefighting garment is a protective garment which conforms to EN 469:2020 (previously EN 469:2005). A wildland firefighting garment is a protective garment which conforms to EN ISO 15384:2018 (previously ISO 15384:2003), with amendments published in ISO 15384:2018 / Amd 1 :2021 . A structural firefighting garment is suitable for use in fighting fires in buildings or other enclosed structures. A wildland firefighting garment is suitable for use in fighting fires that occur outside.

[0112] By the inclusion of an activated carbon fabric in a structural or wildland firefighting suit, a firefighter gains the additional protection against aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs), as described herein, that is not otherwise offered in a firefighting garment which does not comprise the activated carbon fabric.

[0113] The product of the invention is suitable for use by first-responders, such as firefighters, paramedics, and police officers, and by military personnel, construction workers, workers in incineration plants, or indeed anyone or anything likely to be exposed to aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs). Substantially the same benefits as offered in the first aspect of the invention are offered.

[0114] The activated carbon fabric of the second aspect of the invention may have an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0115] The activated carbon fabric of the second aspect of the invention may have a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0116] The activated carbon fabric of the second aspect of the invention may have a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm.

[0117] The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention. The activated carbon fabric of the second aspect of the invention may have an activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0118] The activated carbon fabric of the second aspect of the invention may have a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0119] A third aspect of the invention is the provision of a protective system comprising a garment (A) and a garment (B), wherein the garment (A) comprises an activated carbon fabric.

[0120] The garments (A) and (B) may be as described for any embodiment of the first aspect of the invention. The activated carbon fabric is the same as described above for the any embodiment of the first aspect of the invention.

[0121] When the garment (A) comprising an activated carbon fabric is beneath (that is, closer to the user) and separable from the garment (B), the weight and bulk of the garment (A) can easily be minimised whilst the garment (B) can provide the additional benefits of multiple non-functional and / or functional layers. The activated carbon in the lightweight and non-bulky garment (A) may therefore be easily regenerated by separating from the garment (B) and washed, without the requirement to wash the secondary material at the same time. Furthermore, the garment (A) in use offers continued protection to the user on the removal of garment (B), which may be heavily contaminated.

[0122] The activated carbon fabric of the third aspect of the invention may have an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0123] The activated carbon fabric of the third aspect of the invention may have a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0124] The activated carbon fabric of the third aspect of the invention may have a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0125] The activated carbon fabric of the third aspect of the invention may have an activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention. The activated carbon fabric of the third aspect of the invention may have a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W. The benefits of this range are substantially the same as the benefits described above for the first aspect of the invention.

[0126] Described herein is a method for reducing or preventing the exposure of a person or animal or object to aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) by covering the person or animal or object with a material comprising an activated carbon fabric.

[0127] The aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) may be any as described in the first and second aspects of the invention. The activated carbon fabric may be any as described in the first and second aspects of the invention.

[0128] Also described herein is a method for reducing or preventing the exposure of a person or animal or object to cyclohexane by covering the person or animal or object with a material comprising an activated carbon fabric.

[0129] Also described herein is a method for reducing or preventing the transmission of aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) from an environment A to an environment B comprising placing a material comprising an activated carbon fabric between environment A and environment B.

[0130] The activated carbon weight can be measured in accordance with EN 12127:1998.

[0131] The activated carbon fabric weight can be measured in accordance with EN 12127:1998.

[0132] The activated carbon fabric thickness can be measured in accordance with EN ISO 5084:1997.

[0133] The activated carbon fabric air permeability can be measured in accordance with EN ISO 9237:1995.

[0134] The activated carbon fabric water vapour resistance can be measured in accordance with ISO 11092.

[0135] The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

[0136] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

[0137] For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0138] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0139] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example + / - 20%.

[0140] Examples

[0141] The resistance of activated carbon fabrics to the permeation of naphthalene and benzene, as well as cyclohexane, which is a standard model chemical used in adsorption studies, was determined. The tests were performed in accordance with standards EN 16523-1 and EN 16523-2.

[0142] Testing was performed on activated carbon fabric 1 (ACF-1); activated carbon fabric 2 (ACF-2); representative outer layer 1 (OL-1); ACF-1 in combination with OL-1 (herein described as OL-1 I ACF-1); and ACF-2 in combination with OL-1 (herein described as OL-1 I ACF-2). For the tests performed on OL- 1 I ACF-1 and OL-1 I ACF-2, the representative outer layer (OL-1) covered the activated carbon fabric layer; in other words, the representative outer layer was the layer closest to the source of the test chemical.

[0143] Activated Carbon Fabric 1 (ACF-1): ACF-1 is an activated carbon fabric in the form of a laminated stack of polyester / carbonised layer / polyester. The polyester layers are 18 to 20 gsm woven polyester, and the carbonised layer has an activated carbon weight of 80 gsm. The polyester layers are adhered to the carbonised layer with a dot printed thermoplastic adhesive of 2 to 4 gsm weight. The total weight of ACF- 1 is therefore about 120 gsm. It has a thickness of 0.4 mm, an air permeability of 584 mm / s, and a water vapour resistance of 2.4 m2.Pa / W.

[0144] Activated Carbon Fabric 2 (ACF-2): ACF-2 is an activated carbon fabric in the form of a laminated stack of polyester / carbonised layer / polyester. The polyester layers are 18 to 20 gsm woven polyester, and the carbonised layer has an activated carbon weight of 130 gsm. The polyester layers are adhered to the carbonised layer with a dot printed thermoplastic adhesive of 2 to 4 gsm weight. The total weight of the activated carbon fabric is therefore about 170 gsm. It has a thickness of 0.45 mm, an air permeability of 220 mm / s, and a water vapour resistance of 4.8 m2.Pa / W. The activated carbon fabrics ACF-1 and ACF-2 use polyacrylonitrile (PAN) as a precursor material. Polyacrylonitrile tow (filament) is processed into yarn, which is then woven into a fabric. This fabric then undergoes carbonisation and activation. This carbonised layer is then laminated with polyester into the format described above.

[0145] Representative Outer Layer 1 (OL-1 ): PGI Inc. FireLine firefighter protective suit (93% Nomex®, 5% Kevlar® aramid)

[0146] All samples were dried at 80°C for 4 hours, then sealed and stored in a dry environment and conditioned at 25°C prior to measurement.

[0147] The applied test substances were naphthalene, benzene and cyclohexane.

[0148] Naphthalene is the smallest and most volatile representative of polycyclic aromatic hydrocarbons. Testing the adsorption of naphthalene is therefore representative of performance for the adsorption of all polycyclic aromatic hydrocarbons.

[0149] Benzene is a volatile organic molecule which is a significant combustion product. It is small and highly volatile. Testing the adsorption of benzene is therefore representative of performance for the adsorption of many aromatic semi-volatile and aromatic volatile organic compounds.

[0150] Cyclohexane is a standard model chemical used in adsorption studies. It is small and highly volatile. Testing the adsorption of cyclohexane is therefore representative of performance for the adsorption of many aromatic semi-volatile and aromatic volatile organic compounds.

[0151] Testing was conducted in two primary modes: static and dynamic. The static mode represents the basic setup where the vapours of the test chemical permeate the test material solely through diffusion. In contrast, the dynamic mode involves the forced convective flow of the challenge chemical vapor through the material. Dynamic tests are similar to the real conditions experienced by breathable protective clothing, taking into account factors such as wind flow effects, air suction under the garment during movement (pumping), and the stack effect.

[0152] Test methodology

[0153] Static - diffusion test:

[0154] The tested material was placed inside the permeation cell. An LDPE (Low Density Polyethylene) film was placed on top of the sample, and the specimen was then contaminated with the test chemical at a given challenge concentration (Co). The LDPE film prevented the penetration of the liquid or solid phase when measuring permeable samples and served as a stable vapor source for the test chemical. From that moment, the permeation time of the test chemical through the material was measured. The collecting gas was passed through the sampling compartment of the permeation cell and carried the sample to the open sampling loop, from which the sample was periodically transferred into the GC system for analysis and determination of the breakthrough time. The BT (breakthrough time) was the time when the first measurable breakthrough of the test chemical occurred. To enhance the informational value, the BT was also recorded when the breakthrough concentration (C10), corresponding to 10% of the nominal challenge concentration (Co), was reached. The methodology was in accordance with standards EN 16523-1 and EN 16523-2.

[0155] Conditions for static - diffusion test:

[0156] Temperature: 25 ± 1 °C

[0157] Exposed area: 4.9 cm2

[0158] Collecting gas: synthetic air 100 mL / min

[0159] Test chemicals: naphthalene, benzene, cyclohexane (purity >99.5%)

[0160] Vapour concentrations under LDPE film (at 25 °C): naphthalene 0.5 mg / L; benzene 2.3 mg / L; cyclohexane 2.7 mg / L.

[0161] Volume of collecting cell: 14.7 cm3

[0162] Sampling time: 30 s under gas flow 50 mL / min

[0163] Volume of sampling loop: 250 pL

[0164] Detection: GC-FID

[0165] Dynamic - convection test:

[0166] The tested material was placed inside the permeation cell. A precisely prepared vapor concentration (Co) of the test chemical was introduced over the sample and allowed to pass through the sample at a defined rate (Q). From that point, the permeation time of the test chemical through the material was measured. The permeating mixture was carried to an open sampling loop, from which the sample was periodically transferred into the GC system for analysis and determination of the breakthrough time. The BT was the time when the first measurable breakthrough of the chemical occurred. To enhance the informational value, the BT was also recorded when the breakthrough concentration (C10), corresponding to 10% of the nominal challenge concentration (Co), was reached. The methodology was in accordance with standards EN 16523-1 and EN 16523-2. Practical limitations prevented the use of naphthalene (which is solid at 25 °C) in the dynamic convection tests.

[0167] Conditions for dynamic - convection test:

[0168] Temperature: 25 ± 1 °C

[0169] Exposed area: 4.9 cm2

[0170] Test chemical vapour flow (Q): 300 mL / min

[0171] Sample face velocity: ~ 1 cm / s

[0172] Chemical vapor challenge concentration Co: 250 pg / L

[0173] Test chemicals: benzene, cyclohexane (purity >99.5%)

[0174] Sampling time: 30 s under gas flow 50 mL / min

[0175] Volume of sampling loop: 250 pL Detection: GC-FID

[0176] Under each testing regime (static and dynamic), and for each test chemical:

[0177] The measurements on Activated Carbon Fabrics 1 and 2 (ACF-1 and ACF-2) were repeated three times; the measurements on Activated Carbon Fabrics 1 and 2 in combination with the representative outer layer 1 (OL-1 I ACF-1 and OL-1 I ACF-2) were performed once; the measurements on the Representative Outer Layer 1 (OL-1) were performed once.

[0178] Adsorption Capacity

[0179] The adsorption capacity of the material, denoted as We, was calculated from the dynamic adsorption curves.

[0180] This calculation relies on the assumption of an ideally symmetric adsorption curve and utilizes the stoichiometric time (tsto), which is the time at which half of the challenge concentration (Co / 2) has permeated the material. However, real measurements are often influenced by various factors, such as material inhomogeneity, which is more pronounced in the case of measurements on a single layer of textile compared to a sorption bed in a canister mask filter, for instance.

[0181] Another significant factor that affects the shape of the adsorption curve is the presence of residual moisture in the activated carbon material. While the moisture itself does not have a major impact on the residence time (BT) or the total adsorption capacity, it influences the kinetics of sorption, i.e. , the rate at which sorption occurs. Therefore, when performing calculations, it is important to consider that the calculated sorption capacity should be regarded as an estimate or indication rather than an absolute value.

[0182] Calculations were carried out for benzene and cyclohexane, specifically for samples ACF-1 and ACF-2, using the following simplified relationship:

[0183] Wtot = Q. Co. tsto (gram)

[0184] To calculate the effective adsorption capacity (We), the total adsorbed amount (Wtot) is divided by the total amount of adsorbent (W), which here is the activated carbon.

[0185] We = Wtot I W (gram / gram)

[0186] This ratio provides an indication of the effective uptake of the adsorbate by the activated carbon material.

[0187] The average Wevalue was calculated for samples ACF-1 and ACF-2 for both benzene and cyclohexane:

[0188] We = 160 mg / g (mg of adsorbate per gram of activated carbon)

[0189] List of Examples and Comparative Examples

[0190] The Examples and Comparative Examples are described below. Note that the data for the Comparative Examples in Tables 1 and 2 is not shown in the Figures; OL-1 exhibited no or negligible resistance to the challenge chemicals in any testing regime, as illustrated by the very low breakthrough times for Comparative Examples.

[0191] Example 1 : Static; naphthalene; ACF-1 ; Figure 1. Example 2: Static; benzene; ACF-1 ; Figure 2.

[0192] Example 3: Static; cyclohexane; ACF-1 ; Figure 3.

[0193] Example 4: Static; naphthalene; OL-1 / ACF-1 ; Figure 1.

[0194] Example 5: Static; benzene; OL-1 / ACF-1 ; Figure 2.

[0195] Example 6: Static; cyclohexane; OL-1 I ACF-1 ; Figure 3.

[0196] Example 7: Static; naphthalene; ACF-2; Figure 4.

[0197] Example 8: Static; benzene; ACF-2; Figure 5.

[0198] Example 9: Static; cyclohexane; ACF-2; Figure 6.

[0199] Example 10: Static; naphthalene; OL-1 I ACF-2; Figure 4.

[0200] Example 11 : Static; benzene; OL-1 / ACF-2; Figure 5.

[0201] Example 12: Static; cyclohexane; OL-1 / ACF-2; Figure 6.

[0202] Example 13: Dynamic; benzene; ACF-1 ; Figure 7.

[0203] Example 14: Dynamic; cyclohexane; ACF-1 ; Figure 8.

[0204] Example 15: Dynamic; benzene; OL-1 I ACF-1 ; Figure 7.

[0205] Example 16: Dynamic; cyclohexane; OL-1 / ACF-1 ; Figure 8.

[0206] Example 17: Dynamic; benzene; ACF-2; Figure 9.

[0207] Example 18: Dynamic; cyclohexane; ACF-2; Figure 10.

[0208] Example 19: Dynamic; benzene; OL-1 / ACF-2; Figure 9.

[0209] Example 20: Dynamic; cyclohexane; OL-1 / ACF-2; Figure 10.

[0210] Comparative Example 1 : Static; naphthalene; OL-1 .

[0211] Comparative Example 2: Static; benzene; OL-1 .

[0212] Comparative Example 3: Static; cyclohexane; OL-1 .

[0213] Comparative Example 4: Dynamic; benzene; OL-1.

[0214] Comparative Example 5: Dynamic; cyclohexane; OL-1 . able 1

[0215] able 2

[0216] Summary of Examples and Comparative Examples

[0217] Both ACF-1 and ACF-2, when tested alone (Examples 1-3, Examples 7-9, and Examples 13, 14, 17, 18)), demonstrated much improved breakthrough times (BT and BT at C10) as compared to measurements performed on OL-1 alone (Comparative Examples 1 - 5).

[0218] This was the case in both static and dynamic regimes and for all test chemicals naphthalene, benzene and cyclohexane. The improved protection against naphthalene exhibited by both ACF-1 and ACF-2 over OL-1 alone was particularly good.

[0219] Similarly, the combination of ACF-1 and OL-1 , and the combination of ACF2 and OL-1 (Examples 4-6, Examples 10 - 12, and Examples 15, 16, 19, 20) also demonstrated improved breakthrough times (BT and BT at C10) as compared to measurements performed on OL-1 alone (Comparative Examples 1 - 5).

[0220] This was the case in both static and dynamic regimes and for all test chemicals naphthalene, benzene and cyclohexane. Again, the improved protection against naphthalene exhibited by both ACF-1 and ACF- 2 in combination with OL-1 over OL-1 alone was particularly good.

[0221] The combinations of ACF-1 or ACF-2 with OL-1 demonstrated surprisingly improved breakthrough times relative to ACF-1 or ACF-2 alone, despite the fact that the breakthrough time of OL-1 alone was negligible. In other words, the combination of the ACF material with OL-1 demonstrated enhanced protection against naphthalene, benzene and cyclohexane to a much greater extent than expected based on a simple additive effect. For example, compare Examples 1-3 vs. Examples 4-6; Examples 7-9 vs. Examples 10-12; Examples 13, 14 vs. Examples 15, 16; Examples 17, 18 vs. Examples 19, 20.

[0222] There was, in general, a significant improvement in breakthrough time when the activated carbon weight was increased moving from ACF-1 to ACF-2.

[0223] The breakthrough times BT measured for the activated carbon fabrics, and the activated carbon fabrics in combination with the representative outer layer, are at least comparable with and, in the majority of cases, significantly longer than the typical length of time that a user would be exposed to the high-risk environment. Not only is the exposure of the user to these compounds therefore significantly reduced, but in many cases it can be eliminated entirely. Given that the breakthrough times measured for the representative outer layer alone are negligible, or zero, any reduction in exposure represents a significant improvement.

Claims

Claims:1 . Use of an activated carbon fabric for the adsorption of a compound selected from aromatic semivolatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs).

2. Use according to claim 1 , wherein the compound selected from aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is a fire effluent.

3. Use according to claim 1 or claim 2, wherein at least one of the aromatic semi-volatile and aromatic volatile organic compounds (aromatic SVOCs I aromatic VOCs) and / or polycyclic aromatic hydrocarbons (PAHs) is benzene or naphthalene.

4. Use according to any of claims 1 to 3 wherein the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm.

5. Use according to any of claims 1 to 4, wherein the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm.

6. Use according to any of claims 1 to 5, wherein the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm.

7. Use according to any of claims 1 to 6, wherein the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s.

8. Use according to any of claims 1 to 7, wherein the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W.

9. Use according to any of claims 1 to 8, wherein the activated carbon fabric is comprised within a garment (A).

10. Use according to claim 9, wherein the garment (A) forms part of a protective system, the protective system further comprising a garment (B), and wherein the garment (A) is worn beneath the garment (B).11 . A protective garment comprising an outer fabric of limited flame spread material, wherein at least one of the following conditions is satisfied: a. the outer fabric has a residual tensile strength of at least 450 N, and / or b. the protective garment is heat resistant at 180 °C with shrinkage of <5%, and wherein the protective garment additionally comprises an activated carbon fabric.

12. A protective garment according to claim 11 , wherein the protective garment is a structural firefighting garment and / or a wildland firefighting garment.

13. A protective garment according to claim 11 or claim 12, wherein the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm.

14. A protective garment according to any of claims 11 to 13, wherein the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm.

15. A protective garment according to any of claims 11 to 14, wherein the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm.

16. A protective garment according to any of claims 11 to 15, wherein the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s.

17. A protective garment according to any of claims 11 to 16, wherein the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1.5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W.

18. A protective system comprising a garment (A) and a garment (B), wherein the garment (A) can be worn beneath the garment (B), and wherein garment (A) comprises an activated carbon fabric.

19. A protective system according to claim 18, wherein the activated carbon fabric has an activated carbon weight of about 40 gsm to about 200 gsm, preferably about 60 gsm to about 160 gsm, more preferably about 80 gsm to about 130 gsm.

20. A protective system according to claim 18 or claim 19, wherein the activated carbon fabric has a weight of about 50 gsm to about 250 gsm, preferably about 70 gsm to about 200 gsm, more preferably about 120 gsm to about 170 gsm.21 . A protective system according to any of claims 18 to 20, wherein the activated carbon fabric has a thickness of about 0.1 mm to about 2.0 mm, preferably about 0.2 to about 1 .0 mm, more preferably about 0.4 to about 0.45 mm.

22. A protective system according to any of claims 18 to 21 , wherein the activated carbon fabric has an air permeability of about 50 mm / s to about 1000 mm / s, preferably about 100 mm / s to about 800 mm / s, more preferably about 200 mm / s to about 600 mm / s.

23. A protective system according to any of claims 18 to 22, wherein the activated carbon fabric has a water vapour resistance of about 0.5 m2.Pa / W to about 10 m2.Pa / W, preferably about 1 .5 m2.Pa / W to about 6.0 m2.Pa / W, more preferably about 2.4 m2.Pa / W to about 4.8 m2.Pa / W.

Images