Patent Application
20240301588
The present invention relates to a water-repellent fibre, a yarn, plied yarn or garment comprising a water-repellent fibre and a method of manufacturing a water-repellent fibre.
Yarns used in making clothing fabrics such as sportswear fabric often require a number of properties including being water repellent and oil repellent, being anti-stain or stain resistant, being lightweight and being abrasion resistant.
Typically, water repellency, oil repellency and anti-stain properties are provided by using a repellent surface coating such as a durable water repellent (DWR) coating applied to a fabric surface, in line with industry standards. DWR surface coatings are often made from perfluorinated compounds (PFCs) such as perfluorinated sulfonic acids (PFOS) and perfluorinated carboxylic acids (PFOA), or a silicone-based material.
However, PFCs are toxic and therefore PFC-based DWR coatings based on PFCs are harmful to the environment. In addition, DWR coatings wear away due to abrasion during use, resulting in a decrease in water repellency, oil repellency and anti-stain properties over time.
The present invention has been devised with the foregoing in mind.
According to a first aspect, there is provided a water-repellent fibre for a yarn and/or a fabric or textile. The fibre may comprise a hydrophobic material. The fibre may have or comprise a shape or configuration comprising one or more micro and/or nano-sized structures.
One or more micro and/or nano-sized structures may enhance or amplify the inherent characteristics (e.g., physical and/or chemical properties) of a material. In the case of a hydrophobic material (which is due to a low surface energy of the material), the chemical property of hydrophobicity of the material may be enhanced by one or more micro and/or nano-sized structures. The one or more micro and/or nano-sized structures of the fibre may therefore enhance the inherent properties of the hydrophobic material of the fibre. In addition to hydrophobicity, other chemical properties that are commonly exhibited by materials with a low surface energy, such as oleophobicity, anti-stain properties and anti-fouling properties, may similarly be enhanced by one or more micro and/or nano-sized structures. That may result in a fibre having enhanced water repellent, oil repellent, anti-fouling and anti-stain properties without requiring a separate coating on a surface of the fibre. In addition, because the enhanced hydrophobic properties (and other enhanced properties such as oleophobicity, anti-stain and anti-fouling properties) of the fibre are not reliant on a surface coating which can be worn away due to abrasion, the enhanced hydrophobic properties of the fibre may be retained for an increased length of time. The fibre may be used to form fabrics and/or textiles and/or garments having enhanced hydrophobic performance without requiring a separate coating on the surface of the fabric and/or textile and/or garment. It will be appreciated that when referring to enhanced hydrophobic properties in this disclosure, reference is also made to other enhanced properties such as oleophobicity, anti-stain and anti-fouling properties.
The one or more micro and/or nano-sized structures may have or comprise a size of between substantially 10 nm and substantially 100 μm, or between substantially 50 nm and substantially 10 μm, or between substantially 100 nm and substantially 1 μm. In principle, the smaller the structure(s), the greater the enhancement of the hydrophobic properties. However, the above size ranges may be an optimal size range providing an optimal balance between enhancement of hydrophobic properties and manufacturability.
The one or more micro and/or nano-sized structures may form at least a part of, or be located on, an outer surface of the fibre. The structures forming part of or being located on an outer surface of the fibre may ensure the structures are easily able to provide the enhanced hydrophobic properties when the fibres are brought into contact with a liquid.
The fibre may have or comprise a cross-sectional shape or configuration that forms or provides the one or more micro and/or nano-sized structures. The cross-sectional shape or configuration may be substantially uniform along at least a part of a length of the fibre or substantially a full length of the fibre. The one or more micro and/or nano-sized structures may each extend partially or substantially fully along a length of the fibre.
The fibre may have or comprise a diameter of between substantially 100 nm and substantially 500 μm. In this disclosure, the term diameter also encompasses a width and/or thickness of substantially non-circular fibres. The small radius of curvature of the outer surface of a fibre having a size in that range may enable the outer surface of the fibre to act as or provide a micro and/or nano-sized structure. That may provide the fibre with enhanced hydrophobic properties.
The one or more micro and/or nano-sized structures may be or comprise one or more projections from and/or recesses in an outer surface of the fibre. The fibre may have or comprise a cross-sectional shape or configuration that forms or provides the one or more projections and/or recesses. A height and/or depth of the one or more projections and/or recesses may be between substantially 100 nm and substantially 10 μm. A height and/or depth of the one or more projections and/or recesses may be up to substantially 10% of a diameter or thickness of the fibre. A greater height and/or depth of the one or more projections and/or recesses may provide greater enhancement of the hydrophobic properties of the fibre. A fibre comprising an outer surface having a high radius of curvature in addition to one or more projections and/or recesses in the outer surface of the fibre may have a hierarchical surface structure that further enhances the hydrophobic properties of the fibre. The hierarchical surface structure may create one or more air pockets that prevent or inhibit water (or other liquids) from contacting the surface of the fibre.
The one or more micro and/or nano-sized structures may comprise a plurality of micro and/or nano-sized structures. The fibre may have or comprise a cross-sectional shape or configuration that forms or provides the plurality of structures. The fibre may have or comprise a multi-lobal cross-section (e.g., trilobal, quadlobal, pentalobal, hexalobal and so on). The fibre may have a star-shaped (e.g., a n-pointed star, where n is greater than or equal to 3) cross-section, a cross-shaped cross-section, a v-shaped cross-section, or a substantially flat or planar cross-section, although any suitable cross-sectional shape or configuration may be used. The cross-sectional shape or configuration (e.g., lobes, star points, cross arms, v arms) may at least partially form or define the micro and/or nano-sized structures, such as projections from and/or recesses in an outer surface of the fibre. The fibre may have between substantially 3 and substantially 50 micro and/or nano-sized structures, although any suitable number of structures may be used. In principle, the higher the number or density of micro and/or nano-sized structures, the greater the enhancement of the hydrophobic properties. However, that number of micro and/or nano-sized structures may provide an optimal balance between enhancement of hydrophobic properties and manufacturability.
A spacing between adjacent micro and/or nano-sized structures may be between substantially 100 nm and substantially 10 μm, or between substantially 100 nm and substantially 1 μm. A smaller spacing between adjacent structures may provide greater enhancement of the hydrophobic properties of the fibre. A cross-section of the fibre may have a substantially regular shape. The structures may be distributed around a cross-section of the fibre substantially uniformly or homogeneously. For example, a substantially uniform or similar spacing may be provided between adjacent structures. Alternatively, a cross-section of the fibre may have a substantially irregular shape. The structures may be concentrated at one or more locations around a cross-section of the fibre. A spacing between the structures may be variable or non-uniform.
The hydrophobic material may be or comprise an oleophobic material. Oleophobic materials are inherently hydrophobic, due to oleophobicity requiring a lower surface energy than hydrophobicity.
The hydrophobic material may be or comprise a hydrophobic or oleophobic polymeric material. A polymeric material may be simple to manufacture into a fibre having or comprising one or more micro and/or nano-sized structures.
The fibre may be or comprise a mixture of the hydrophobic polymeric material and one or more other polymeric materials. The one or more other polymeric materials may not be or comprise hydrophobic polymeric materials, or may be or comprise one or more polymeric materials that are less hydrophobic than the hydrophobic polymeric material. The one or more other polymeric materials may be included to improve one or more other properties of the fibre, for example one or more mechanical properties such as tensile strength, elongation at break, stiffness or flexibility, temperature resistance, and/or one or more aesthetic properties such as colour etc.
The mixture may comprise or be arranged in a core-sheath structure, an island-in-sea structure or a random blend structure. In a core-sheath structure, the hydrophobic polymeric material may be or comprise or form the sheath and substantially surround the non-hydrophobic or less hydrophobic polymeric material(s) to form an outer surface of the fibre. Similarly, in an island-in-sea structure, the hydrophobic polymeric material may be or comprise or form the sea and substantially surround the non-hydrophobic or less hydrophobic polymeric material(s) to form an outer surface of the fibre. In a random blend, the hydrophobic polymeric material may form a greater proportion of an outer surface of the fibre than the non-hydrophobic or less hydrophobic polymeric material(s). That arrangement may occur naturally during formation of the fibre, or during post-formation annealing of the fibre. In either case. the lower-surface energy of the hydrophobic polymeric material may cause the hydrophobic polymeric material in the random blend to diffuse towards an outer surface of the fibre. A random blend may comprise a higher proportion (e.g., by volume) of the hydrophobic polymeric material than the non-hydrophobic or less hydrophobic materials. Additionally or alternatively, the hydrophobic polymeric material and the one or more other polymeric materials in a random blend may have a similar melting point, or the hydrophobic polymeric material may have a lower melting point than the one or more other polymeric materials. One or more of those features may enable the lower surface energy hydrophobic polymeric material to more easily diffuse towards an outer surface of the fibre.
The mixture may comprise substantially 5% or more by volume of the hydrophobic polymeric material, or between substantially 60% and substantially 80% by volume of the hydrophobic polymeric material. The mixture may comprise up to substantially 95% by volume of the one or more other polymeric materials, or between substantially 20% and substantially 40% by volume of the one or more other polymeric materials.
The hydrophobic polymeric material may be or comprise a polymethylpentene polymer or polymethylpentene based material. Polymethylpentene inherently has a low surface energy, meaning that polymethylpentene is strongly hydrophobic and oleophobic. Polymethylpentene is also a thermoplastic polymer, which may enable easy processing of the material to form a fibre. Polymethylpentene also has a low density, which may result in a lightweight water-repellent fibre. Polymethylpentene also has a high melting point and good chemical resistance, making it suitable for use in a wide variety of applications.
The polymethylpentene polymer may be or comprise a 4-methyl-1-pentene polymer. The polymethylpentene polymer may be or comprise a copolymer of 4-methyl-1-pentene with one or more α-olefins. The one or more α-olefins may each have or comprise between 2 and 20 carbon atoms.
Additionally or alternatively, the hydrophobic polymeric material may be or comprise one or more of an α-polyolefin (such as polypropylene, polyethylene, polybutylene, polybutene etc.), a polyester, a nylon, a thermoplastic polymer, a polysaccharide (such as cellulosic polymers, chitosan etc.) or a protein-based material.
According to a second aspect, there is provided a water-repellent yarn for a fabric or textile comprising at least one water-repellent fibre according to the first aspect. The yarn may be or comprise a plurality of fibres twisted together, wherein at least one of the fibres is a water-repellent fibre according to the first aspect.
The yarn may have or comprise a diameter of between substantially 200 nm and substantially 1000 μm. The yarn may have or comprise between substantially 15 twists/m and substantially 2000 twists/m.
According to a third aspect, there is provided a water-repellent plied yarn for a fabric or textile comprising at least one water-repellent yarn according to the second aspect. The plied yarn may be or comprise a plurality of yarns twisted together, wherein at least one of the yarns is a water-repellent yarn according to the second aspect.
The plied yarn may have or comprise a diameter of between substantially 400 nm and substantially 5000 μm. The plied yarn may have or comprise between substantially 15 twists/m and substantially 2000 twists/m.
According to a fourth aspect, there is provided a fabric or textile comprising at least one water-repellent fibre according to the first aspect, and/or at least one water-repellent yarn according to the second aspect and/or at least one waterproof plied yarn according to the third aspect.
The fabric or textile may be woven. The at least one water-repellent fibre, at least one water-repellent yarn and/or at least one water-repellent plied yarn may form or provide one or more warp threads and/or one or more weft threads of the fabric or textile. Alternatively, the fabric or textile may be knitted, or may be non-woven.
According to a fifth aspect, there is provided a garment comprising the fabric or textile of the fourth aspect. The garment may be or comprise a top such as a t-shirt, a vest, a shirt, a jumper, a sweatshirt, a hoodie or a coat. Alternatively or additionally, the garment may be or comprise a pair of shorts, a pair of trousers, a pair of tights, a pair of leggings, a sock or a shoe. The garment may be or comprise an item of personal protective equipment (PPE), for example an item of PPE for healthcare such as a mask.
According to a sixth aspect, there is provided an apparatus comprising the fabric or textile of the fourth aspect. The apparatus may be or comprise an item of outdoor equipment, for example camping equipment such as a tent, sleeping bag, or a geotextile. Alternatively, the apparatus may be an upholstered item, for example an item of furniture such as a chair or sofa, or a vehicle seat etc. The apparatus may be an interior textile product for a building (for example a house) such as a carpet, curtains etc., or for a vehicle (for example a car, train, aeroplane etc.) such as a vehicle floor, vehicle seat etc.
According to a seventh aspect, there is provided a method of manufacturing a fibre for a yarn and/or a fabric or textile. The method may comprise forming a fibre comprising a hydrophobic material. The method may comprise providing the fibre with a shape or configuration comprising one or more micro and/or nano-sized structures.
The method may comprise extruding a material comprising a hydrophobic material to form a fibre. Providing the fibre with a shape or configuration comprising one or more micro and/or nano-sized structures may comprise extruding the material through a nozzle. The nozzle may have or comprise a structure configured to impart one or more micro and/or nano-sized structures on an outer surface of the fibre (for example, during extrusion of the fibre).
The material may comprise a mixture of a hydrophobic material and a filler material. Providing the fibre with a shape or configuration comprising one or more micro and/or nano-sized structures may comprise removing the filler material after formation of the fibre. Removing the filler material may comprise dissolving the filler material.
Removing the filler may provide the fibre with one or more recesses and/or projections in an outer surface of the fibre.
The method of the seventh aspect may be used to produce a fibre according to the first aspect. The method of the sixth aspect may be particularly suitable for producing a fibre according to the first aspect comprising a hydrophobic polymeric material.
Features which are described in the context of separate aspects and embodiments of the invention may be used together and/or be interchangeable wherever possible. Similarly, where features are described in the context of a single embodiment for brevity, those features may also be provided separately or in any suitable sub-combination. Features described in connection with the fibre of the first aspect may have corresponding features definable with respect to one or more of the yarns of the second and third aspects, the fabric or textile of the fourth aspect, the garment of the fifth aspect, the apparatus of the sixth aspect or the method of the seventh aspect, and vice versa, and these embodiments are specifically envisaged.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
Like reference numerals in different Figures may represent like elements.
By combining a hydrophobic material with one or more micro and/or nano-sized structures, the fibre 300 has enhanced hydrophobic performance relative to the inherent hydrophobic properties of the hydrophobic material. Incorporating the fibre 300 into a yarn for a fabric or textile, or directly into a fabric or textile, may provide a yarn, fabric or textile having enhanced water repellent, oil repellent, anti-fouling and anti-stain properties without requiring a separate coating. The improved properties of the yarn, fabric or textile may be more durable and longer lasting than those provided by a separate coating. A separate coating is susceptible to contamination and abrasion during use of the yarn, fabric or textile, leading to reduced hydrophobic performance over time. In contrast, because the hydrophobic properties of the fibre 300 are integral to the fibre 300 itself, the hydrophobic performance of the yarn, fabric or textile is also integral to the yarn, fabric or textile and is not dependent upon a coating that can be removed from the yarn, fabric or textile.
The star-shaped cross-section may alternatively have any suitable number of micro and/or nano-sized structures 310 that each form a point or arm of the star, for example three or more structures 310. The fibre 300 may alternatively have any suitable diameter, for example between substantially 100 nm and substantially 500 μm. Each structure 310 may alternatively have any suitable height or depth, for example between substantially 10 nm and substantially 100 μm, or up to substantially 10% of the diameter or thickness of the fibre 300. Adjacent structures 310 may be spaced any suitable distance apart, for example between substantially 10 nm and substantially 100 μm apart.
It will be appreciated that a fibre 300 may comprise both internal and external (e.g., on an outer surface) micro and/or nano-sized structures 310. For example, the annular fibre 300 of
In the embodiments shown, the hydrophobic polymeric material 312 is a polymethylpentene polymer substantially as described above, although that is not essential. In the embodiment shown, the one or more other polymeric materials 314 is or comprises a different hydrophobic polymer such as an α-olefin polymer, a polyester, a nylon, a thermoplastic polymer etc. For example, the one or more other polymeric materials 314 may be or comprise polypropylene. Polypropylene may improve the mechanical properties of the fibre 300 without substantially reducing the hydrophobic properties of the fibre 300 (because polypropylene is also hydrophobic). However, that is not essential, and any other suitable polymeric material 314 may alternatively be used, hydrophobic or not.
In the embodiment shown, the mixture (e.g., the fibre 300) comprises substantially 60% by volume of the hydrophobic polymeric material 312. The mixture (e.g., the fibre 300) comprises substantially 40% by volume of the one or more other polymeric materials 314. However, that is not essential, and any mixture ratio of the two may alternatively be used.
The yarn 320 is formed by twisting a plurality of fibres together using conventional techniques. One of the fibres is a fibre 300 comprising a hydrophobic material and having a shape or configuration comprising one or more micro and/or nano-sized structures, as described above. By incorporating at least one fibre 300 in the yarn 320, the enhanced hydrophobic properties of the fibre 300 are also incorporated into the yarn 320, thereby making the yarn 320 water-repellent. In the embodiment shown, the fibre 300 is an eight-pointed star as described above with respect to
The plied yarn 330 is formed by twisting a plurality of yarns together using conventional techniques. One of the yarns is the yarn 320 described above. By incorporating at least one water-repellent yarn 320 in the plied yarn 330, the plied yarn 330 is also water-repellent (by virtue of the enhanced hydrophobic properties of the at least one fibre 300 in one or more of the yarns 320). Alternatively, the plied yarn 330 may comprise a plurality of yarns 320 twisted together, optionally with one or more other yarns. The plied yarn 330 may have a diameter or thickness of between substantially 400 nm and substantially 5000 μm, depending on a diameter or thickness of each yarn and the number of yarns in the plied yarn 330.
The yarn 320 may have between substantially 15 and substantially 2000 twists/m. The plied yarn 330 may have between substantially 15 and substantially 2000 twists/m. Increasing twists/m of the yarn 320 and/or the plied yarn 330 generally increases mechanical properties of the yarn 320 and/or plied yarn 330 such as tensile strength and stiffness. The twists/m may be varied in order to provide the yarn 320 and/or plied yarn 330 with suitable mechanical properties for an intended application of the yarn 320 and/or plied yarn 330.
Each of the fibre 300, the yarn 320 and/or the plied yarn 330 may be incorporated into or used to form a fabric or textile, for example woven or knitted into a fabric or textile or incorporated into or used to form a non-woven fabric or textile. Incorporating one or more fibres 300, yarns 320 and/or plied yarns 330 into a fabric or textile may provide a substantially waterproof fabric or textile, due to the water-repellent or enhanced hydrophobic properties of the fibre(s) 300, yarn(s) 320 and/or plied yarn(s) 330.
For a woven fabric or textile, the fibre(s), yarn(s) 320 and/or plied yarn(s) 330 may form one or warp threads and/or one or weft threads of the fabric or textile. The twists/m of a yarn 320 or plied yarn 320 may be higher for a warp thread than a weft thread, because typically warp threads require greater strength and stiffness than weft threads during weaving. One or more other fibres or yarns may be incorporated into the fabric or textile to provide the fabric or textile with additional functional properties. For example, silver or copper fibres or yarns may be incorporated into the fabric or textile to provide anti-bacterial and anti-viral properties.
The fabric or textile may be used in a variety of applications. For example, it may be used to form substantially waterproof garments such as for outdoor pursuits including walking, hiking, climbing, mountaineering etc., or personal protective equipment (PPE) such as masks and gowns for healthcare. Similar, the fabric or textile may be used to form substantially waterproof apparatus such as tents, hammocks, sleeping bags, umbrellas, bags, rucksacks etc., or upholstered items such as chairs, sofas, vehicle sets etc., or an interior textile product such as for a house (e.g., carpet, curtains) or a car (e.g., a car floor) The fabric or textile may also be used for construction or landscaping purposes, for example as a geotextile or geomembrane to prevent water from travelling through an area or retain water in a specific location.
At step 405, the method 400 comprises forming a fibre 300 comprising a hydrophobic material. At step 410, the method 400 comprises providing the fibre 300 with a shape or configuration comprising one or more micro and/or nano-sized structures.
In the embodiment shown, the method 400 comprises extruding a material comprising a hydrophobic material to form the fibre 300. The apparatus 500 comprises a vessel 505 configured to contain a polymer feedstock (for example, a melt or solution). The apparatus 500 includes a metering pump 505a is included to control feed of the polymer feedstock, but that is not essential. The apparatus 500 a spinneret 510 configured to form one or more fibres 300 from the polymer feedstock. In the embodiment shown, the spinneret 510 comprises one or more nozzles (not shown) through which the polymer feedstock passes. In the embodiment shown, one or more of the nozzles comprises a structure configured to provide the formed fibres 300 with one or more micro and/or nano-sized structures. In the embodiment shown, steps 405 and 410 therefore take place substantially simultaneously. For example, the nozzle may be shaped (e.g., have a cross-sectional shape) or configured to impart one or more micro and/or nano-sized structures on an outer surface of the fibre 300 during extrusion of the fibre. Examples of such nozzles are shown in
The apparatus 500 comprises a filter 508 to filter the polymer feedstock prior to passing through the spinneret 510, although that is not essential. A flow of cooling air F is provided to solidify the fibres 300 following exit from the spinneret, although that is not essential. A series of spools 512a-c are then provided to capture the fibres 300, although that is not essential.
The method 400 described above comprises a conventional melt-spinning process in combination with one or more specific nozzles configured to produce a fibre 300 comprising one or more micro and/or nano-sized structures. It will be appreciated that any suitable manufacturing technique may alternatively be used to form the fibre 300, for example melt-blowing, dry-spinning, wet-spinning, dry-jet wet-spinning etc. It will also be appreciated that similar techniques may be used to form fibres 300 having multi-material compositions, for example core-sheath structures, island-in-sea structures and random blend structures.
If the polymer feedstock comprises a random blend of a hydrophobic material and one or more other materials, an annealing step may be performed after formation of the fibre 300. The reason for that is to cause the hydrophobic material to diffuse towards an outer surface of the fibre 300. The low surface energy of the hydrophobic material makes it energetically favourable for the hydrophobic material to be located at an outer surface of the fibre 300. Annealing may provide a sufficient temperature to enable the hydrophobic material to diffuse towards an outer surface of the fibre 300. However, annealing may not be necessary if the temperature used during formation of the fibre 300 is sufficient to enable the hydrophobic material to diffuse towards an outer surface of the fibre 300 during formation. A suitable temperature may be between substantially 80° C. and substantially 230° C., depending on the polymer(s) chosen.
Alternatively, a different technique may be used to form a fibre 300 comprising a shape or configuration comprising one or more micro and/or nano-sized structures. For example, step 405 may comprise forming a fibre using a mixture of a hydrophobic material and a filler material. The filler material may be or comprise polymer particles and/or fibres (for example, micro and/or nano-sized particles and/or fibres), for example polyester (PES), polylactic acid (PLA), polyvinyl alcohol (PVA) etc. Additionally or alternatively, the filler material may be or comprise inorganic particles and/or fibres (for example, micro and/or nano-sized particles and/or fibres) such as calcium carbonate, clays, salt, silica, titanium dioxide (TiO2), Zinc Oxide (ZnO) etc. It will be appreciated that a number of conventional filler materials may be suitable, such as filler materials soluble in water or industry standard solvents. Forming the fibre may comprise using the method 400 substantially as described above. However, the fibre may be formed using a conventional nozzle having a substantially circular cross-section.
Step 410 may comprise at least partially removing the filler material from the formed fibre to form a fibre 300 comprising a shape or configuration comprising one or more micro and/or nano-sized structures, for example one or more projections and/or recesses in an outer surface of the fibre. Removing the filler material may comprise dissolving the filler material. That may require the fibre to be placed into a bath of a suitable reagent to allow the filler material to be dissolved, for example water, alcohols, esters, acids, dimethylformamide (DMF), or any other suitable organic or water based conventional solvent or mixture. One or more other methods such as ultrasonication and/or heating of the solvent may be used in conjunction with the dissolving, in order to aid with removal of the filler material.
From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of textiles, in particular waterproof fibres, yarns and/or fabrics or textiles, and which may be used instead of, or in addition to, features already described herein.
Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention.
Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. The applicant hereby gives notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.
For the sake of completeness, it is also stated that the term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality, and any reference signs in the claims shall not be construed as limiting the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2107272.3 | May 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2022/051277 | 5/20/2022 | WO |
