WO2025202497A1

WO2025202497A1 - Aerosol protection layer for cbrn suits

Info

Publication number: WO2025202497A1
Application number: PCT/EP2025/058633
Authority: WO
Inventors: Cem BAGIRAN; Filip GHEKIERE
Original assignee: SEYNTEX NV
Current assignee: SEYNTEX NV
Priority date: 2024-03-29
Filing date: 2025-03-28
Publication date: 2025-10-02
Anticipated expiration: 2026-09-29
Also published as: BE1032492A1; BE1032492B1

Abstract

The present invention relates to an aerosol protective layer comprising: (i) a nonwoven carrier layer, (ii) a nanofiber layer comprising electrospun nanofibers, and (iii) a nonwoven cover layer, wherein the nanofiber layer is made from materials such as polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), and polyvinylidene fluoride (PVDF). The nonwoven carrier layer and cover layer are made from materials such as polypropylene (PP), polyester (PET), polyethylene (PE), and polyamide (Nylon). The protective layer offers high filtration efficiency against aerosol particles and maintains its performance even after repeated washing. The lightweight design enhances user comfort and mobility. The invention also relates to a CBRN protective suit comprising of this aerosol protective layer, providing enhanced safety, durability, and adaptability against various CBRN threats.

Description

AEROSOL PROTECTION LAYER FOR CBRN SUITS

FIELD OF THE INVENTION

The field of the invention is related to the development of an aerosol protective layer for CBRN (Chemical, Biological, Radiological and Nuclear) protection. More specifically, it involves a multilayered system consisting of a nonwoven carrier layer, a nanofiber layer made of electrospun nanofibers, and a nonwoven cover layer. The invention also extends to the use of this aerosol protective layer in CBRN suits and other textile materials.

BACKGROUND

CBRN agents, which include Chemical, Biological, Radiological and Nuclear hazards, pose a significant threat to human health and safety. These agents can exist in various states and sizes, including aerosol particles that are particularly dangerous due to their small size (0,2-3 pm).

These particles can penetrate the skin through air-permeable suits and are not adequately captured by the outer fabric and active carbon layer of existing protective suits. This presents a significant problem, as these particles can carry toxic chemicals, biological agents, or radioactive dust.

Current protective layers, such as those made using melt-blown techniques, do not offer sufficient protection against these particles. Moreover, these layers often compromise breathability, comfort, and durability. They may also be heavy, reducing the wearer's mobility and increasing fatigue during prolonged use.

The current materials used in these layers may not provide sufficient filtration efficiency, and may not be resistant to washing or abrasion. Additionally, they may lack antibacterial and antiviral properties, which are crucial for protection against pathogens. Furthermore, existing layers may not provide selective permeability, allowing larger toxic molecules to pass through along with air.

Lastly, these layers may not provide sufficient protection against radiological particles, which are often scattered in aerosol form and have particle sizes lower than 0,5 pm. Therefore, there is a pressing need for an improved protective layer that addresses these issues. SUMMARY OF THE INVENTION

In an aspect, the invention provides an aerosol layer according to claim 1 designed to enhance protection against aerosols, particularly in the range of 0,2-3 pm. This aerosol layer is crafted using an electrospinning technique, which confers upon it several advantageous properties such as lightweight, air permeability, durability, and enhanced protective capabilities as compared to traditional melt-blown versions.

The aerosol layer comprises three distinct layers: a nonwoven carrier layer, a nanofiber layer made of electrospun nanofibers, and a nonwoven cover layer to shield against external impacts. The nanofiber layer serves as a fine mesh, capturing aerosol particles such as toxic chemicals, biological agents, or radioactive dust that may penetrate the outer fabric. The ultra-small pore size of the nanofiber layer ensures efficient filtration without compromising breathability.

The nanofiber layer exhibits high filtration efficiency due to its tiny pore sizes, allowing it to efficiently capture aerosol particles. It also maintains good air permeability, ensuring comfortable breathing during prolonged use. The nanofiber layer can optionally be functionalized with antimicrobial agents, providing an additional layer of protection against pathogens. Furthermore, nanofiber-based materials are robust and resistant to wear and tear, allowing them to withstand repeated use and washing without compromising performance.

In a second aspect, the invention relates to a CBR.N textile material in accordance with claim 14. This embodiment relates to a combination of the aerosol layer, an active carbon layer and a protective outer layer. These layers are finetuned to be complementary, resulting in a lightweight fabric, which is breathable yet provides robust protection against aerosols, chemical warfare agents, biological warfare agents and the like in a durable manner.

In a third aspect, the invention relates to a CBR.N suit comprising an aerosol layer in accordance with the first aspect or an CBR.N textile material in accordance with the second aspect of the invention. DETAILED DESCRIPTION OF THE INVENTION

In the present invention, the term "aerosol protective layer" or "aerosol layer" or "aerosol barrier" refers to a layer designed to protect against airborne particles, comprising three individual layers: a nonwoven carrier layer, a nanofiber layer comprising electrospun nanofibers, and a nonwoven cover layer.

The term "nonwoven" as used in this invention pertains to a sheet or web structure of fibers or filaments, randomly arranged or oriented in a particular direction, without the conventional weaving or knitting process. Examples of nonwoven techniques are melt blowing, needle felting, water fixing and spun bonding, wherein spunbond fibers are the most preferred.

The term "spunbond” refers to a type of manufacturing process for creating nonwoven fabric. The term "nanofiber" refers to fibers with diameters in the nanometer range, specifically between 100 nm to 500 nm in this invention, fibers that are interconnected by spun bonding are spunbound fibers.

The term "electrospun" refers to a fiber production method that uses electric force to draw charged threads of polymer solutions or polymer melts up to fiber diameters in the order of some hundred nanometers.

The term "nanofiber" refers to a fiber with a diameter in the nanometer range. In the present invention, the nanofibers preferably have an average diameter between 100 nm and 500 nm, more preferably between 100 nm and 250 nm, as measured by scanning electron microscopy (SEM).

The term "ultrasonic welding" refers to a bonding technique wherein high-frequency ultrasonic vibrations are locally applied to bond materials under pressure. In a preferred embodiment, the carrier layer, nanofiber layer, and cover layer are bonded together by discrete ultrasonic welding points, with the spacing between adjacent welding points preferably ranging between 0.5 and 2.0 cm.

The term "antimicrobial agents" refers to substances that kill or slow the spread of microorganisms, including bacteria and viruses. The term "filtration efficiency" refers to the ability of a filter to remove particulate matter from the air, and is measured as a percentage of particles removed. In this invention, a filtration efficiency of over 95% against particles between 1-3 pm and over 85% of protection over 0,2 pm and 3 pm is achieved.

The term "air permeability" refers to the property of a fabric to allow air to pass through it, and is measured in l/m²sec at 100 Pa according to ISO 9237.

The term "active carbon layer" refers to a layer in a protective suit that contains active carbon, a processed form of carbon with small, low-volume pores that increase the surface area available for adsorption or chemical reactions.

The term "CBRN" refers to chemical, biological, radiological and nuclear materials that could potentially harm people or the environment.

The term "CBRN textile material" refers to a fabric designed to protect against CBRN threats. The term "CBRN protective suit" refers to a suit made to protect the wearer from CBRN threats.

First aspect - Aerosol protective layer

In an aspect, the invention provides an aerosol protective layer that significantly enhances filtration efficiency by effectively capturing harmful aerosol particles. The aerosol protective layer comprises a spunbound carrier layer, a nanofiber layer, and a nonwoven cover layer.

Preferably, the nanofiber layer is positioned between the carrier and cover layers. The trilayer arrangement provides both structural support and protection to the nanofiber layer, allowing it to act as an effective filtration medium while being shielded from mechanical damage during use.

The nanofiber layer is preferably sandwiched between two nonwoven layers. The nonwoven layers provide structural support to the nanofiber layer, protecting it from damage caused by external impacts. The nonwoven layers also contribute to the overall breathability of the aerosol layer, as they allow air to pass through while blocking larger particles. In a particular preferred embodiment, the nanofibers are produced by electrospinning and have an average diameter preferably between 100 and 250 nanometers, as measured by scanning electron microscopy (SEM). This fine diameter contributes to the high filtration efficiency of the aerosol layer while allowing sufficient air permeability for user comfort.

The aerosol protective layer preferably comprises a spunbound carrier layer, a nanofiber layer, and a nonwoven cover layer. Each of these layers may be made from a variety of materials, providing a range of properties and characteristics.

In the aerosol protective layer each layer has a weight between 0.1-40 g/m², preferably the aerial weight of this layer is between 1-25 g/m².

For instance, the nonwoven carrier layer may be made from materials such as polypropylene (PP), polyester (PET), polyethylene (PE), or polyamide (PA), or combinations thereof. Most preferably, the carrier layer is made from polypropylene (PP). Preferably, the carrier layer is a spunbound nonwoven, most preferably a PP spunbound nonwoven. The aerial weight of this layer is preferably between 5-35 g/m², more preferably between 6-25 g/m², more preferably between 7-20 g/m², more preferably between 8-20 g/m², more preferably between 10-20 g/m², more preferably between 12-20 g/m², and most preferably around 15 g/m².

The nanofiber layer, which serves as the main filtration medium, is preferably made from materials such as polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives, or mixtures thereof. Preferably, the nanofiber layer is made from polyurethane nanofibers; most preferably thermoplastic polyurethane (TPU) nanofibers. The aerial weight of this layer is preferably between 0.1-15 g/m², more preferably between 0.5-13 g/m², more preferably between 0.7-11 g/m², more preferably between 1-10 g/m², and most preferably around 5 g/m².

Finally, the nonwoven cover layer, which protects the nanofiber layer from external impacts, may be made from materials like polypropylene (PP), polyester (PET), polyethylene (PE), or polyamide (PA), or combinations thereof. The aerial weight of this layer is preferably between 10-25 g/m², more preferably between 12-23 g/m², more preferably between 14-21 g/m², more preferably between 16-19 g/m², and most preferably around 18 g/m². In a preferred embodiment, the aerosol protective layer is lightweight, contributing to the overall comfort of the user. The total aerosol protective layer, including the spunbound cover layer, nanofiber layer and spunbound carrier layer, may have a weight that ranges between 20-100 g/m², more preferably between 20-80 g/m², more preferably 30-60 g/m², more preferably between 35-55 g/m², even more preferably between 40-50 g/m², and most preferably around 45 g/m². The lightweight nature of the layer can significantly reduce physical stress or discomfort often typically associated with wearing protective gear. This comfort enhancement may lead to a higher rate of compliance with wearing these necessary safety measures, ultimately promoting better overall safety.

In a preferred embodiment, the carrier layer, nanofiber layer and cover layer are connected to one another. This can be achieved for example by seaming, sewing, welding or gluing. Most preferably, the three layers are connected at discrete points by welding, more preferably ultrasonic welding. This provides sufficient connection between the layers to avoid delamination, while minimizing the damage to both cover layers and particularly the nanofibers. To ensure durability and maintain structural integrity during use and after repeated washing, the three layers are preferably bonded to each other using ultrasonic welding. More preferably, the bonding is applied in discrete welding points, with a spacing between adjacent points of preferably 0.5 to 2.0 cm. This technique provides mechanical cohesion while minimizing localized damage to the nanofiber layer. Furthermore, discrete welding points allow a degree of movement between the layers and prevent delamination to occur and move through the layers during use and cleaning cycles.

The lightweight design of the aerosol protective layer does not compromise its protective capabilities. Despite its low weight, the aerosol protective layer is capable of providing high filtration efficiency, with over 95% of filtration efficiency in original and washed (lOx) form against particles between 1-3 pm and over 85% of protection over 0,2 pm and 3pm. This ensures that the aerosol protective layer is capable of providing effective protection against aerosol particles, while remaining lightweight and comfortable for the user. Filtration is preferably measured in accordance with ASTM F2299-03 (2010). The invention thus provides an aerosol layer that combines high protection, breathability, durability, and lightweight properties in a single design. Preferably, it offers over 95% of filtration efficiency in original and washed form against particles between 1.0-3.0 pm in diameter and over 85% of protection against particles between 0,2 pm and 3 pm in diameter.

In a preferred embodiment, the aerosol protective layer is resistant to laundering and abrasion. More preferably, the aerosol protective layer maintains its filtration efficiency after washing at least 10, more preferably at least 15, more preferably at least 25, most preferably at least 50 times in accordance with with ISO 6330-4N-F.

In the most preferred embodiment, the aerosol protective layer comprises, preferably consists essentially of :

(i) A spunbound carrier layer with an aerial weight of 5-35 g/m², wherein the spunbound carrier layer comprises a material selected from : polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof;

(ii) A nanofiber layer with an aerial weight of 0.1-15 g/m², said nanofiber layer comprising electrospun nanofibers from a material selected from : polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives; and mixtures thereof; and

(iii) A nonwoven cover layer with an aerial weight of 10-25 g/m², wherein the spunbound carrier comprises a material selected from : polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA).

In terms of dimensions, the spunbound carrier layers are preferably made of a material selected from polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (Nylon), each having a weight between 10-20 g/m². For a total weight of 30-60 g/m², the outer spunbound cover can have additional thickness. In a further embodiment, the aerosol protective layer has a layer: a spunbound carrier layer with an aerial weight of 5-15 g/m², a nanofiber layer with an aerial weight of 10-25 g/m², and a nonwoven cover layer with an aerial weight of 10-25 g/m². In a particularly preferred embodiment, the aerosol protective layer comprises three layers arranged in a defined sequence: a carrier layer, a nanofiber layer, and a cover layer. Each of these layers may be formed from various suitable materials and may exhibit a range of aerial weights. Preferred materials and weight ranges are described below for each component:

(i) Carrier layer:

The carrier layer is preferably a nonwoven fabric, more preferably a spunbound nonwoven. Suitable materials for this layer include polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA), or combinations thereof. The aerial weight of the carrier layer may range from 5 to 40 g/m², preferably between 10 and 35 g/m², more preferably between 20 and 35 g/m², and most preferably between 25 and 35 g/m². In the most preferred embodiment, the carrier layer consists of spunbound PP fibers with an aerial weight of about 30 g/m².

(ii) Nanofiber layer:

The nanofiber layer comprises electrospun nanofibers formed from one or more polymers selected from polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives, or mixtures thereof. The aerial weight of this layer may range from 0.1 to 10 g/m², preferably between 0.2 and 5.0 g/m², more preferably between 0.2 and 2.0 g/m², and most preferably between 0.3 and 1.5 g/m². In a preferred embodiment, the nanofibers are made of PU and exhibit an average diameter of 100 to 250 nm.

(iii) Cover layer:

The cover layer is preferably also a nonwoven fabric, more preferably a spunbound nonwoven. Suitable materials include polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA), or blends thereof. The aerial weight of the cover layer may range from 5 to 30 g/m², preferably between 10 and 25 g/m², more preferably between 10 and 20 g/m², and most preferably around 15 to 18 g/m². In a particularly preferred embodiment, the cover layer comprises spunbound PP fibers.

This trilayer configuration results in a total aerosol protective layer weight ranging from 20 to 80 g/m², preferably between 30 and 60 g/m², more preferably between 35 and 55 g/m², and most preferably around 45 g/m². This structure offers an optimal balance of filtration efficiency, breathability, mechanical stability, and comfort.

The aerosol protective layer is preferably suitable to provide effective filtration against both solid and liquid chemical warfare agents (CWAs) present in aerosol form, particularly in the particle size range of 1 to 10 micrometers. More preferably, the aerosol protective layer provides adequate protection against representative CWAs including sulfur mustard, which may form solid residues in the 2-10 pm range; riot control agents such as CS and CN, typically encountered as solid particles in the 0.5- 5 pm range; and liquid CWAs such as Sarin (GB) and Novichok agents, which are often aerosolized in the 0.5-5 pm range. In addition, the aerosol layer is preferably capable of capturing biological toxins such as ricin in liquid form (0.5-10 pm), and infectious droplets carrying viral agents such as Ebola or Marburg viruses (typically 0.8-5 pm). These particle sizes represent a critical window in which standard activated carbon layers alone may be insufficient. The combination of high-efficiency filtration and robust structural design makes the aerosol protective layer especially suited for use in protective systems targeting solid and liquid aerosol threats in both military and civilian CBR.N scenarios.

In a preferred embodiment, the aerosol protective layer does not comprise a meltblown layer, more preferably the aerosol protective layer does not comprise any meltblown layer. More preferably, the aerosol layer is entirely free of meltblown materials. Meltblown nonwovens, while commonly used in filtration applications, are generally not sufficiently durable for integration into reusable protective garments, particularly under conditions involving repeated laundering or mechanical stress. Meltblown layers tend to exhibit lower mechanical strength and are prone to degradation unless laminated to additional support fabrics, which adds weight and complexity. By excluding meltblown components, the aerosol protective layer of the present invention achieves superior wash resistance, mechanical flexibility, and longterm structural stability without compromising filtration efficiency and I or weight. The use of electrospun nanofibers, in combination with spunbound nonwoven support layers, offers a more robust and breathable construction, ensuring suitability for repeated use in demanding environments such as CBR.N suits.

Spunbound carrier layer

The spunbound carrier layer preferably has an aerial weight of 5-15 g/m². However, it is understood that the aerial weight of the spunbound carrier layer may range from 3-20 g/m², more preferably between 4-18 g/m², more preferably between 5-15 g/m², most preferably between 6-12 g/m². The spunbound carrier layer comprises a material selected from polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof. That is to say, the material that is spunbound preferably is selected from polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof.

The nonwoven carrier layer and cover layer may have an aerial weight ranging from 5 to 25 g/m². More preferably, the aerial weight is between 10 and 20 g/m². Even more preferably, the aerial weight is between 12 and 18 g/m². Most preferably, the aerial weight is around 15 g/m². This range of aerial weight provides an optimal balance between durability and weight, ensuring that the aerosol protective layer is robust yet lightweight. In an embodiment, the nonwoven carrier layer and the cover layer may have a similar aerial weight. In anther embodiment, the aerial weight of the cover layer is higher than that of the carrier layer. This is desirable to provide additional protection on the external side of the nanofiber layer, particularly additional abrasion and wear and tear resistance

Nanofiber layer

The nanofiber layer is preferably made using the electrospinning technique. This technique allows for the production of nanofibers with tiny pore sizes, which enhance the filtration efficiency of the nanofiber layer. The electrospinning process also allows for the production of nanofibers with a large surface area, which further enhances filtration performance.

The nanofiber layer preferably comprises electrospun nanofibers from a material selected from polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives, and mixtures thereof. The nanofibers are characterized by their tiny pore sizes that enable efficient capture of aerosol particles. The large surface area of the nanofibers enhances the filtration performance, thereby providing high protection against harmful aerosol particles, particularly those in the range of 0,2-3 pm.

In a preferred embodiment, the nanofiber layer is made from selected materials that enhance performance in several key areas. These materials are chosen for their durability, resistance to wear and tear, and filtration efficiency. They also retain their properties after washing, ensuring long-lasting performance. The nanofiber layer is preferably made from materials such as polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF) or mixtures thereof. These materials are selected for their unique properties that contribute to the overall performance of the nanofiber layer. In a preferred embodiment, the aerosol protective layer maintains its high filtration efficiency even after repeated washing, thereby ensuring long-term, reliable protection against aerosol particles. This requires a unique combination of materials that provide an exceptional balance between filtration efficiency and durability.

More preferably, the nanofiber layer is made from polyurethane (PU), polyacrylonitrile (PAN), or polycaprolactone (PCL). These materials are even more durable and resistant to wear and tear. They also have excellent filtration efficiency, capturing aerosol particles effectively. Most preferably, the nanofiber layer is made from polyurethane (PU) or polyacrylonitrile (PAN). These materials exhibit the highest durability and resistance to wear and tear, as well as superior filtration efficiency. In addition to the material selection, the weight of the nanofiber layer also contributes to its performance. The nanofiber layer preferably has an aerial weight of 5-30 g/m². More preferably, the nanofiber layer has an aerial weight of 10-25 g/m², more preferably 10-22 g/m², more preferably 10-20 g/m². This weight range ensures the nanofiber layer is lightweight yet durable enough to withstand wear and tear. Most preferably, the nanofiber layer has an aerial weight of 15-20 g/m². This weight provides the optimal balance between lightness, durability and high filtration efficacy.

In conclusion, the nanofiber layer in this preferred embodiment exhibits enhanced performance in terms of durability, wear and tear resistance, filtration efficiency, and long-lasting properties after washing. This is achieved through the selection of appropriate materials and the use of the electrospinning technique.

The nanofibers are made by the electrospinning technique. This technique allows for precise control over the diameter of the nanofibers, which is crucial for achieving the desired filtration efficiency and breathability. Moreover, the electrospinning technique enables the production of nanofibers with a uniform diameter, which contributes to the consistency of the aerosol layer's performance. In a preferred embodiment, the average nanofiber diameter range of the protective layer is between 10 and 1000 nm, more preferably between 50 and 750 nm, more preferably between 100 and 500 nm. This range is not a limitation but an optimal range that has been found to provide a balance between effective filtration of hazardous particles and breathability of the protective equipment. This results in both a high level of protection and comfort. The nanofiber diameter can be more preferably between 150 and 450 nm, even more preferably between 200 and 400 nm, and most preferably between 250 and 350 nm. A smaller diameter results in a larger surface area, which enhances the filtration Efficiency. In contrast, a larger diameter may reduce the air resistance, leading to improved breathability. A smaller diameter also reduces the durability of the fabric. Therefore, the selection of the nanofiber diameter is a trade-off between filtration efficiency and breathability.

In a preferred embodiment, the nanofiber layer of the aerosol protection system may be functionalized with antimicrobial agents. In a further preferred embodiment, the nanofiber layer may be functionalized with antimicrobial agents. This feature provides an additional layer of protection against pathogens, enhancing the effectiveness of the aerosol layer in CBR.N protection. This enhancement is expected to significantly increase the protective capacity of the aerosol layer against biological contaminants such as bacteria and viruses. The functionalized nanofiber layer can act as a powerful barrier, trapping and neutralizing harmful biological agents that may attempt to penetrate the protective suit. The nanofibers, due to their tiny pore sizes and large surface area, are already highly efficient at capturing aerosol particles. When these nanofibers are further functionalized with antimicrobial agents, their protective capacity is increased. These antimicrobial agents can be selected from a wide range of substances known for their antibacterial and antiviral properties. They may be incorporated into the nanofiber layer during the electrospinning process, or they may be added to the nanofiber layer post-production through a coating or impregnation process. The functionalization process preferably does not significantly affect the breathability, durability, or weight of the aerosol layer, maintaining the comfort and ease of use for the wearer.

The concentration of antimicrobial agents in the nanofiber layer may vary. It is preferably between 0.1 and 10 weight percent, more preferably between 0.5 and 5 weight percent, and most preferably between 1 and 3 weight percent. This range allows for effective antimicrobial activity without compromising the structural integrity of the nanofiber layer.

The protective capacity of the functionalized nanofiber layer against biological contaminants is preferably over 95 percent, more preferably over 97 percent, and most preferably over 99 percent, as tested by ISO 22196:2011 and/or EN ISO 20743:2021. This high level of protection ensures that wearers of protective suits incorporating this aerosol layer are adequately shielded from a wide range of biological threats. Suitable antimicrobial agents are known. Preferably, the antimicrobial agent is chosen from the list of : silver-based agents (e.g., nano-silver particles, silver nitrate), copper and its compounds (e.g., copper oxide, copper sulphate), triclosan, quaternary ammonium compounds (QACs) (e.g., benzalkonium chloride, cetrimonium bromide), zinc oxide (ZnO) (nano-sized ZnO particles), chitosan, polyhexamethylene biguanide (PHMB), permethrin or mixtures thereof.

Despite its high filtration efficiency, the nanofiber layer maintains good air permeability. This balance ensures comfortable breathing during prolonged use. The air permeability is preferably higher than 60 l/m²sec at 100 Pa according to ISO 9237. More preferably, the air permeability is higher than 80 l/m²sec at 100 Pa, more preferably higher than 100 l/m²sec at 100 Pa, more preferably higher than 120 l/m²sec at 100 Pa, most preferably higher than 150 l/m²sec at 100 Pa. More preferably, the air permeability is between 100-200 l/m²sec, and most preferably around 150 l/m²sec. As previously described, the air permeability is a trade-off between the weight of the fabric and the ability of the fabric to filter out small aerosols and large molecules.

In a preferred embodiment, the nanofiber layer of the aerosol protection system may be oil repellent as the nanofiber composite is engineered to have a rough surface texture. In a preferred embodiment, the nanofiber layer of the aerosol protection system has an oil repellence grade of at least 0.5 according to ISO 14419:2010; more preferably at least 1, more preferably at least 2, more preferably at least 3. The rough surface texture can be achieved through careful control of electrospinning parameters such as solution concentration and voltage. Preferably the solution concentration is between 5% to 25%, the percentage is a weight of polymer to volume of a solution to be electro spun. The voltage is preferably between 10 kV to 40 kV. The rough surface reduces the contact area between oil droplets and the nanofiber surface, thereby increasing oil repellency. Optionally, the electrospinning process may be adjusted to align the nanofibers in a preferred orientation. Aligned nanofiber structures in a fine closed network that make it more difficult for oil droplets to penetrate, further enhancing oil repellence.

Spunbound cover layer

In a preferred embodiment, the aerosol protective layer comprises a nonwoven carrier layer and a nonwoven cover layer. These layers are preferably made of a material selected from polypropylene (PP), polyester (PET), polyethylene (PE), or polyamide (PA), or mixtures thereof. These materials are preferred due to their superior resistance to deformation, tear, and abrasion, which results in a more durable and enduring aerosol protection system. The use of these materials extends the lifespan of the aerosol protective layer, providing long-term protection against hazardous aerosol particles.

The nonwoven cover layer preferably has an aerial weight of 10-25 g/m². However, it is understood that the aerial weight of the nonwoven cover layer may range from 5-30 g/m², more preferably between 7-28 g/m², more preferably between 10-25 g/m², most preferably between 12-22 g/m².

The nonwoven cover layer preferably comprises a material selected from polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof. The nonwoven carrier layer and cover layer may be made from a single material or a mixture of materials. The choice of material or mixture of materials may depend on the specific application and desired properties of the aerosol protective layer. For example, polypropylene (PP) may be preferred for its excellent chemical resistance, making it suitable for protection against chemical aerosols. On the other hand, polyamide (PA) may be preferred for its high strength and abrasion resistance, making it suitable for applications where the aerosol protective layer is subjected to physical stress.

In a preferred embodiment, the aerosol protective layer is combined with an active carbon layer to provide a comprehensive barrier against a diverse range of CBR.N hazards. This combination may relate to the efficient capture of both aerosol particles and chemical vapors or gases. The aerosol protective layer, preferably made of nanofibers, exhibits high filtration efficiency due to its tiny pore sizes and large surface area. It can effectively trap aerosol particles, including toxic chemicals, biological agents, or radioactive dust, while maintaining good air permeability. This balance ensures comfortable breathing during prolonged use.

CRBN textile

The aerosol layer can be combined with other traditional layers in a CBR.N suit. A preferred embodiment would include an outer layer, the aerosol layer of the first aspect, and an active carbon layer.

The outer layer is preferably IR-reflectant, preferably camouflage printed, preferably flame retardant and durable. These functions are common in outer fabrics of CBR.N suits and protect the underlaying textile layers. More preferably, the outer layer is made from a material selected from : cotton, polyester-cotton mixture or polyamide- cotton mixture. More preferably, the outer layer has a surface weight of 170-230 g/m². The outer layer is preferably treated to be oil and I or water repellent.

The aerosol layer is as described in the first aspect of present invention.

The active carbon layer is a layer comprising active carbon particles. Preferably said active carbon is comprised in an amount of at least 50 g/m², preferably 80-120 g/m² of active carbon.

The active carbon aims to absorb volatile organic compounds (VOCs), chemical warfare agents (CWAs), smoke particles, heavy metals and some biological agents in particular. The aerosol layer is particularly designed to block small aerosols, particularly in the 0.1 to 5.0 pm range, more preferably the 0.2 to 3 pm range. These sizes of particles are not effectively absorbed in active carbon.

Overall, this preferred embodiment provides a high level of protection, breathability, durability, and lightweight characteristics, making it an ideal solution for a protective textile in CBR.N applications.

The areal weight of the aerosol protective layer preferably ranges from 20 to 100 g/m², more preferably from 30 to 60 g/m², and most preferably around 45 g/m². The active carbon layer, on the other hand, comprises active carbon in an amount of at least 50 g/m², preferably 80-120 g/m², more preferably around 100 g/m². The total weight of the combined layers is preferably between 80 and 250 g/m², more preferably between 100 and 180 g/m², and most preferably around 150 g/m². This lightweight design reduces strain on the wearer during extended wear and promotes comfort and mobility.

In a particular preferred embodiment, the CBR.N textile material comprises, more preferably consists essentially of : a) outer layer, preferably IR-reflectence, preferably camouflage printed, preferably from cotton, polyester-cotton mixture or polyamide-cotton mixture, preferably flame retardant, having a surface weight of 170-230 g/m²; b) the aerosol layer according to claim 1; and c) an active carbon layer, comprising active carbon in an amount of at least 50 g/m², preferably 80-120 g/m² of active carbon.

This combination results in a lightweight, durable textile material which shows both high filtration efficiency for small aerosol particles, yet remains breathable. In addition to providing high filtration efficiency and chemical absorption, the combination of the aerosol protective layer and the active carbon layer is also robust and resistant to wear and tear. It can withstand repeated use and washing without compromising performance. This durability is crucial for reusable CBRN suits and contributes to the longevity and cost-effectiveness of the protective clothing.

In a further particular preferred embodiment, the the CBRN textile material comprises:

- an outer layer that serves as a protective shell, typically imparting flame retardancy, camouflage properties, infrared reflectance, and water or oil repellency;

- an aerosol protective layer positioned beneath the outer layer, providing efficient filtration of aerosolized particles; and

- an active carbon layer, arranged beneath or adjacent to the aerosol layer, which adsorbs volatile chemical and biological agents.

The outer layer is preferably formed from woven or knitted textile materials, such as cotton, a polyester-cotton blend, or a polyamide-cotton blend. It may be treated with flame retardant, oil-repellent or water-repellent finishes. Preferably, this layer has a surface weight between 170 and 230 g/m².

The aerosol protective layer is as described in the first aspect and comprises, more preferably consists essentially of: a spunbound nonwoven carrier layer having an aerial weight of 25-35 g/m², preferably made of polypropylene (PP); a nanofiber layer comprising electrospun polyurethane (PU) nanofibers with an aerial weight of 0.2-2.0 g/m² and an average fiber diameter between 100 and 250 nm; and a spunbound nonwoven cover layer having an aerial weight of 10-20 g/m², preferably made of polypropylene (PP). The active carbon layer comprises activated carbon particles embedded in or supported by a textile matrix. The active carbon content is preferably at least 50 g/m², more preferably between 80 and 120 g/m², and most preferably around 100 g/m². This layer is designed to trap chemical warfare agents (CWAs), volatile organic compounds (VOCs), and other gaseous or vapor-phase toxins not effectively removed by the aerosol filter.

In this configuration, the CBRN textile material provides complementary and synergistic protection: the aerosol layer captures fine particulate hazards (including biological agents and radiological dust), while the active carbon layer adsorbs gaseous threats. The outer layer protects the underlying layers from mechanical, thermal, and environmental damage.

The resulting textile structure is lightweight, breathable, and mechanically robust, with excellent resistance to wear and laundering. This makes it highly suitable for incorporation into protective garments intended for extended operational use under demanding field conditions.

CRBN suit

The aerosol layer can be combined with traditional layers in a CBRN suit. In a third aspect, the invention relates to a CBRN suit comprising an aerosol protective layer in accordance with the first aspect of the invention, or a CBRN textile material in accordance with the second aspect of the invention.

A preferred embodiment includes a CRBN suit formed from a layered textile material comprising:

An outer layer, preferably IR-reflectance, preferably camouflage printed, preferably flame retardant, preferably water and I or oil repellent, preferably from cotton, polyester-cotton mixture or polyamide-cotton mixture, having a surface weight of 170-230 g/m²; the aerosol layer as previously described; preferably with a weight of 30-60 g/m²; and an active carbon layer, comprising active carbon in an amount of at least 50 g/m², preferably 80-120 g/m² active carbon.

Preferably, all large textile sections of the coat are made from this material to ensure sufficient protection to all areas. These sections of the CBRN suit may be individual sections being sewn or otherwise permanently connected one to the other. Alternatively some or all sections may form an integral part of the same piece of textile fabric, being preferably said layered textile material.

EXAMPLES

The present invention will now be further exemplified with reference to the following examples. The present invention is in no way limited to the given examples.

Example 1

An aerosol protective layer was fabricated with a nonwoven carrier layer made of polypropylene (PP), a nanofiber layer made of polyurethane (PU) electrospun nanofibers, and a nonwoven cover layer made of polypropylene (PP). Each layer had a weight of 15 g/m². The nanofiber layer exhibited a high filtration efficiency of over 95% against particles between 1-3 pm and over 85% of protection over 0,2 pm and 3 pm with an air permeability of at least 100 l/m²sec at 100 Pa according to ISO 9237, demonstrating the enhanced filtration efficiency of the aerosol protective layer. Example 2

The aerosol protective layer from Example 1 was washed 10 times in accordance with ISO 6330-4N-F. The nanofiber layer maintained over 95% filtration efficiency after washing, showing the maintained performance and durability of the aerosol protective layer.

Example 3

An aerosol protective layer was fabricated with a nonwoven carrier layer made of polypropylene (PP), a nanofiber layer made of polyurethane (PU) electrospun nanofibers functionalized with antimicrobial agents, and a nonwoven cover layer made of polypropylene (PP). The nanofiber layer exhibited enhanced biological protection against bacteria and viruses due to the antimicrobial agents.

Example 4

An aerosol protective layer was combined with an active carbon layer, wherein the active carbon layer comprised active carbon in an amount of 80 g/m². The combination of the aerosol protective layer and the active carbon layer provided a comprehensive barrier against a diverse range of CBR.N hazards, including aerosol particles and chemical vapors or gases, demonstrating dual-protection.

Example 5 A CBR.N protective suit was fabricated using a CBR.N textile material comprising of an outer layer made of a polyamide-cotton mixture, the aerosol protective layer from Example 1, and an active carbon layer comprising active carbon in an amount of 80 g/m² of active carbon. The protective suit provided comprehensive protection against CBR.N threats while maintaining user comfort and mobility due to the lightweight and breathable aerosol protective layer.

It is supposed that the present invention is not restricted to any form of realization described previously and that some modifications can be added to the presented example of fabrication without reappraisal of the appended claims. For example, the present invention has been described referring to specific materials for the nanofiber layer, but it is clear that the invention can be applied to other suitable materials for electrospinning nanofibers, such as polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), and polyvinylidene fluoride (PVDF).

Example 6

An aerosol protective layer was constructed using three distinct layers arranged in a defined sequence. The carrier layer consisted of a spunbound polypropylene (PP) nonwoven fabric with an aerial weight of 30 g/m². The nanofiber layer was positioned directly on top of the carrier layer and comprised electrospun polyurethane (PU) nanofibers, having an aerial weight of 1.5 g/m². The average fiber diameter of the nanofibers was between 150 and 200 nanometers, as determined by scanning electron microscopy (SEM). Over the nanofiber layer, a spunbound polypropylene (PP) cover layer was applied, having an aerial weight of 15 g/m².

The three layers were bonded together by ultrasonic welding using a discrete point pattern, with approximately 1 cm spacing between adjacent welding points. The total weight of the trilayer structure was approximately 46.5 g/m².

The resulting material was lightweight and flexible, and the bonded structure showed good cohesion and handling stability.

Example 7

The aerosol protective layer prepared in Example 6 was tested for both filtration efficiency and mechanical durability. The layer was subjected to 10 laundering cycles in accordance with ISO 6330-4N-F. Filtration efficiency was tested before and after laundering using an aerosol challenge in the 1-3 micrometer size range, and air permeability was measured at a pressure differential of 100 Pa in accordance with ISO 9237. Prior to laundering, the filtration efficiency exceeded 99.5%, and after 10 washing cycles, the efficiency remained at or above 99%. Air permeability was consistently measured at approximately 150 liters per square meter per second, both before and after laundering.

In addition, bending resistance was evaluated in accordance with ISO 7854, Method C. The bending test was performed both before and after the 10 laundering cycles to assess any potential degradation of mechanical integrity. In both cases, the layer withstood cyclic flexing without delamination, cracking, or structural failure. SEM analysis confirmed that the nanofiber structure remained intact and showed no signs of deformation. These results indicate that the aerosol protective layer possesses a high degree of mechanical robustness suitable for use in flexible protective garments.

Example 8

A multilayered CBR.N textile material was prepared by combining an outer fabric, an aerosol protective layer according to Example 6, and an active carbon layer. The outer fabric was a 200 g/m² polyamide-cotton blend, printed with camouflage and treated to provide flame retardance as well as oil and water repellency. The aerosol protective layer was positioned beneath the outer fabric. Below the aerosol layer, an active carbon layer was added, containing 100 g/m² of activated carbon distributed in a suitable carrier textile.

The composite textile material was tested for performance both before and after 10 laundering cycles in accordance with ISO 6330-4N-F. Filtration efficiency was tested against both liquid and solid aerosols in the 1-3 micrometer range. Penetration remained below 1% throughout all tests. Air permeability remained comfortably within the desired range, at values exceeding 100 liters per square meter per second.

Bending resistance of the full composite was tested before and after laundering using ISO 7854, Method C. The textile retained its structural integrity after cyclic flexing, with no cracking, delamination or visual degradation. SEM examination showed that the nanofiber structure remained stable, even in zones subjected to repeated flexing. These results confirm that the CBR.N textile material provides a high level of mechanical and functional durability, and is suitable for incorporation into protective garments subject to frequent movement and reuse. The present invention is in no way limited to the embodiments described in the examples. On the contrary, methods according to the present invention may be realized in many different ways without departing from the scope of the invention.

Claims

1. An aerosol protective layer comprising: (i) a nonwoven carrier layer, (ii) a nanofiber layer comprising electrospun nanofibers, and (iii) a nonwoven cover layer.

2. The aerosol protective layer according to claim 1, wherein the nanofiber layer (ii) is wedged between the nonwoven carrier layer (i) and the nonwoven cover layer (iii).

3. The aerosol protective layer according to any one of claims 1 or 2, comprising:

(i) spunbound carrier layer with an aerial weight of 5-35 g/m², wherein the spunbound carrier layer comprises a material selected from : polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof;

(ii) nanofiber layer with an aerial weight of 1-15 g/m², said nanofiber layer comprising electrospun nanofibers from a material selected from : polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives; and mixtures thereof; and

(iii) nonwoven cover layer with an aerial weight of 10-25 g/m², wherein the spunbound carrier comprises a material selected from: polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA).

4. The aerosol protective layer according to any one of claims 1 or 2, comprising:

(i) spunbound carrier layer with an aerial weight of 25-35 g/m², wherein the spunbound carrier layer comprises a material selected from : polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA) or mixtures thereof; preferably polypropylene (PP);

(ii) nanofiber layer with an aerial weight of 0.2-5.0 g/m², preferably 0.2-2.0 g/m², said nanofiber layer comprising electrospun nanofibers from a material selected from : polyurethane (PU), polyacrylonitrile (PAN), polycaprolactone (PCL), polyethylene terephthalate (PET), polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), chitosan, cellulose and cellulose derivatives; and mixtures thereof; preferably polyurethane (PU); and (iii) nonwoven cover layer with an aerial weight of 10-20 g/m², wherein the spunbound carrier comprises a material selected from: polypropylene (PP), polyester (PET), polyethylene (PE), polyamide (PA); preferably polypropylene (PP).

5. The aerosol protective layer according to claim 4, comprising:

(i) spunbound nonwoven carrier layer with an aerial weight of 25-35 g/m², wherein the spunbound carrier layer comprises polypropylene (PP) fibers;

(ii) nanofiber layer with an aerial weight of 0.2-5.0 g/m², preferably 0.2-2.0 g/m², said nanofiber layer comprising electrospun nanofibers comprising polyurethane (PU); wherein said electrospun nanofibers have an average diameter of 100 to 250 nm; and

(iii) a spunbound nonwoven cover layer with an aerial weight of 10-20 g/m², wherein the spunbound carrier comprises polypropylene (PP) fibers.

6. The aerosol protective layer according to any one of claims 1-5, wherein the carrier layer (i), nanofiber layer (ii), and cover layer (iii) are bonded to each other by ultrasonic welding.

7. The aerosol protective layer according to claim 6, wherein the carrier layer (i), nanofiber layer (ii), and cover layer (iii) are bonded to each other by ultrasonic welding points, wherein the distance between two adjacent welding points is between 0.5 and 2.0 cm.

8. The aerosol protective according to any one of claims 1-7, wherein the nanofibers have diameters in the range of 100 nm to 500 nm, more preferably the nanofibers have an average diameter of 100 to 250 nm; as measured by scanning electron microscopy (SEM).

9. The aerosol protective layer according to any one of claims 1-8, wherein the nanofiber layer provides a filtration efficiency of over 95% against particles between 1-3 pm and over 85% of protection over 0,2 pm and 3 pm with an air permeability of at least 100 l/m²sec at 100 Pa according to ISO 9237.

10. The aerosol protective layer according to any one of claims 1-9, wherein the nanofiber layer maintains over 95% filtration efficiency after being washed 10 times in accordance with ISO 6330-4N-F.

11. The aerosol protective layer according to any one of claims 1-10, wherein the total weight of the aerosol protective layer is between 30-60 g/m².

12. The aerosol protective layer according to any one of claims 1-11, combined with an active carbon layer, wherein the active carbon layer comprises active carbon in an amount of at least 50 g/m², preferably 80-120 g/m² active carbon.

13. A CBRN textile material comprising of at least two layers, wherein one layer is an aerosol protective layer according to any one of claims 1-12.

14. CBRN textile material of claim 13, comprising : a) outer layer, preferably IR-reflectance, preferably camouflage printed, preferably from cotton, polyester-cotton mixture or polyamide-cotton mixture, preferably flame retardant, having a surface weight of 170-230 g/m²; b) the aerosol layer according to any one of claims 1-12; and c) an active carbon layer, comprising active carbon in an amount of at least 50 g/m², preferably 80-120 g/m² of active carbon.

15. A CBRN protective suit comprising of a CBRN textile material according to claim 14.