Wound dressing, production and use thereof

Abstract

The invention relates to a multilayer wound dressing comprising an absorbent material containing layer as layer B, an odor-absorbing layer as layer D, a barrier layer as layer C located between layer B and layer D, wherein the size of layer D is larger than the size of layer B, and wherein the material of layer C comprises a polyether-based thermoplastic polyurethane characterized by a swelling behavior with water of at least 20 wt.% determined according to ASTM D-471 (2016). A further aspect of the invention relates to a process of producing a wound dressing and to a kit of parts comprising at least two wound dressings.

Description

[0001]WOUND DRESSING, PRODUCTION AND USE THEREOF Cross-Reference to Related Applications This application claims the benefit of priority to European Patent Application No. 24203070.8, filed on September 27, 2024, which is incorporated herein by reference in its entirety. Field of the Invention The invention relates to a wound dressing, in particular a multi-layer wound dressing. The wound dressing comprises at least the following layers: an absorbent material containing layer, an odor-absorbing layer, and a barrier layer located between the other two layers. Background Wound dressings of different sizes and functionality are commercially available. Various wound dressings are also described in the patent literature. WO 98 / 09589 A1 (Bristol Myers Squibb) describes a multilayered dressing comprising a fibrous absorbent layer for absorbing wound exudate, a barrier layer and an odor adsorbing layer where said barrier layer is located between the absorbent layer and the odor adsorbing layer. WO 2019 / 089856 A1 (Inmedbio) describes a multi-layer wound site dressing specifically designed to treat chronic wounds and simultaneously block external pathogens from infecting the wound site from the environment. The said wound dressing comprises five layers. The said layers of wound care dressing comprise (i) a permeable non-adherent woven or nonwoven membrane in contact with wound site, (ii) a nanofibrous composite layer made of superabsorbent, activated carbon and a polymer (iii) a hydrophobic insulating membrane which is permeable to air with an adhesive edge, (iv) a nanofibrous membrane made of polymer and activated carbon hosting functional germicidal ions, and (v) an air permeable nonwoven membrane with adhesive edge. WO 2018 / 119398 A1 (Calgon Carbon) describes a composite wound dressing including an activated carbon material, a barrier material layer, a liquid-absorbing material layer and an outer liquid- impermeable layer are disclosed herein. The composite wound dressings include a bond substantially bonding a portion of the liquid-impermeable outer layer and the barrier material layer to the activated carbon containing layer, the bond forming a sealed pouch of un-bonded layer of the composite and encapsulating the liquid-absorbing layer. US 2020 / 155355 A1 (Hill et al.) describes a wound dressing which includes a superabsorbent layer, a backing layer, and a charcoal layer. The superabsorbent layer is configured to absorb wound fluid. The backing layer is substantially impermeable to liquid and substantially permeable to vapor. The charcoal layer is positioned between the first side of the superabsorbent layer and the second, wound- facing side of the backing layer. EP 2000119 A1 (Royal College of Surgeons) describes a wound dressing comprising an absorbent core disposed on the dressing, and a wound healing substance around the absorbent core, the wound healing substance will be brought into contact with a periphery of the wound bed. US 5,973,221 (Seton Healthcare) describes a wound dressing formed from a body layer (1) with a wound-contacting layer (3) attached to an inner surface and a barrier backing layer (2) attached to an outer surface. The body layer (1) is a resiliently compressible moisture-absorbent polyurethane foam film. The wound-contacting layer (3) is preferably a hydrophilic moisture permeable foam film. The barrier backing layer (2) is a liquid and bacteria proof gas-permeable foam. US 10,426,670 B2 (Bluecher et al.) describes a wound dressing comprising at least one air permeable layer having a porous and / or foam-based structure, particularly in the form of a solid foam, and at least one sorbent in the form of activated carbon. However, there is still a desire for an improved wound dressing with odor-absorbing properties. Summary of Invention Generally, there is a need for a wound dressing which is able to absorb high amounts of wound exudate and also is able to absorb male odor. A problem with commercially available wound dressings is that moisture from wound exudate may migrate through a permeable superabsorbent material and may contaminate an odor-absorbing material, if present. This may negatively impact its odor-absorbing properties, which may further cause a bad smell of the wound dressing during use. Thus, there is a need for a barrier layer being able to protect the odor-absorbing material from wound exudate having been absorbed by the superabsorbent material. However, simply introducing a further layer may negatively affect the desired overall evaporation performance of the wound dressing. Permeability of a material or substance is defined by the ability to allow a liquid or gaseous substance to pass through. For a wound dressing a high moisture (from exudate) permeability is advantageous to allow the moisture to evaporate and keep a wound less wet or even dry. Hence permeability and evaporation performance are connected. Quantification of permeability can be done by measurement of vapor transmission rate (MVTR). Thus, the barrier layer needs to be highly permeable to vapor on the one hand, and highly impermeable to liquid on the other hand. It would also be advantageous if the barrier layer can easily be processed during production of the wound dressing. Further, the material of the barrier layer should be non-irritating and non-sensitizing. One or more of the above-mentioned problems are addressed by the invention described in the present text and claims. In one aspect the invention relates to a multilayer wound dressing comprising an absorbent material containing layer as layer B, an odor-absorbing layer as layer D, a barrier layer as layer C located between layer B and layer D, wherein the size of layer D is larger than the size of layer B, and wherein the material of layer C comprises a polyether-based thermoplastic polyurethane characterized by a swelling behavior with water of at least 20 wt.% determined according to ASTM D-471 (2016). A further aspect of the invention relates to a process of producing a wound dressing as described in the present text and claims. Yet another aspect of the invention relates to a kit of parts comprising at least two wound dressings as described in the present text and claims. Unless defined differently, for this description the following terms shall have the given meaning: The term “tissue site” in this context broadly refers to a wound, defect, or other treatment target located on or within tissue, including, but not limited to, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. The term “tissue site” may also refer to areas of any tissue that are not necessarily wounded or defective but are instead areas in which it may be desirable to add or promote the growth of additional tissue. A “wound” may include chronic, acute, traumatic, subacute, and dehisced wounds, partial-thickness burns, ulcers (such as diabetic, pressure, or venous insufficiency ulcers), flaps, and grafts, for example. As used herein the terms “wound-facing side” and “not wound-facing site” used with respect to the absorbent layer, the facing layer, the backing layer, and any other components in the medical articles, refer to the major surface of the indicated component that, in use, faces toward the wound surface or away from the wound surface, respectively. By “absorbent” it is meant that the material is preferably capable of absorbing fluids, particularly body fluids and preferably moderate to heavy amounts of body fluids, while retaining its structural integrity (i.e., remaining sufficiently intact such that it can perform the function of acting as an absorbent moist wound healing dressing, for example). Preferably, “absorbent” refers to a material that is able to absorb at least its own weight of an isotonic saline solution (0.9 wt.% sodium chloride in deionized water) after 24 hours at room temperature. That is, the material has an absorbency of at least 100 wt.%. More preferably, the absorbent material in the absorbent layer can absorb at least two times its weight (200 wt.% absorbency), even more preferably at least four times its weight (400 wt.% absorbency), and most preferably at least five times its weight (500 wt.% absorbency) of an isotonic saline solution after 24 hours at room temperature. By “gel” (or “polymer gel” or “polymeric gel material” or “hydrophilic gel”) it is meant a gel material capable of swelling on contact with (or water-based fluids such as body fluids including blood, plasma, and intracellular fluid or fluids similar to body fluids such as physiological saline), but does not dissolve in, water. The gels are substantially continuous, i.e., lacking a cellular or void structure (although minor defects such as entrapped air bubbles or fractures may be present) and thus generally in a solid or semi-solid form. The term “gel” is used regardless of the state of hydration. Preferably, the gel does not include water until it comes in contact with a surface from which it absorbs water (e.g., a wound). Significantly, even without water (or other plasticizing agents) preferred embodiments of the gel material of the present invention are flexible. “Hydrocolloid” means natural or synthetic polymer which forms gels or viscous solutions or suspensions in aqueous systems. “Polymer” includes or essentially consists of or consists of homopolymers, copolymers, such as block, graft, random and alternating copolymers, terpolymers, etc. “Ambient conditions” mean the conditions which the composition described in the present text is usually subjected to during storage and handling. Ambient conditions may, for example, be a pressure of 900 to 1,100 mbar, a temperature of 10 to 40 °C and a relative humidity of 10 to 100 %. In the laboratory ambient conditions are typically adjusted to 20 to 25 °C and 1,000 to 1,025 mbar (at maritime level). As used herein, “a”, “an”, “the”, “at least one” and “one or more” are used interchangeably. Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Adding an “(s)” to a term means that the term should include the singular and plural form. E.g. the term “additive(s)” means one additive and more additives (e.g.2, 3, 4, etc.). Unless otherwise indicated, all numbers expressing quantities of ingredients, measurement of physical properties such as described below and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. The terms “comprise” or “contain” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. “Consisting essentially of” means that specific further components can be present, namely those which do not materially affect the essential characteristic of the article or composition. “Consisting of” means that no further components should be present. The term “comprise” shall include also the terms “consist essentially of” and “consists of”. A composition or article is “essentially or substantially free of” a certain component, if the composition or article does not contain said component as an essential feature. Thus, said component is not wilfully added to the article or composition either as such or in combination with other components or ingredient of other components. An article or composition being essentially free of a certain component usually does not contain that component at all. However, sometimes the presence of a small amount of the said component is not avoidable e.g. due to impurities contained in the raw materials used. Brief Description of Figures Fig.1 shows the general working principle of the wound dressing of the present invention. Fig. 2a shows one option for the general layering concept of the wound dressing of the present invention. Fig. 2b shows another option for the general layering concept of the wound dressing of the present invention. Fig.3 provides data on the evaporation performance of wound dressings tested. Fig.4a and Fig.4b show pictures of wound dressings before and after a wetting test. Fig.5 shows pictures of wound dressings with differently sized odor-absorbing layers. Fig. 6 provides data showing how wound dressings with differently sized odor-absorbing layers perform in an odor-absorbing test. Detailed Description It has been found that the wound dressing and processes described in the present text are advantageous for a couple of reasons. The use or presence of a barrier layer between a layer containing a liquid absorbing material and a layer containing an odor-absorbing material may facilitate the fixation of either of the other layers to further layers, e.g. top or bottom layer, as appropriate. Using a barrier layer comprising a thermoplastic polyurethane material, in particular a film made of such a material, is advantageous for a couple of reasons. The material is sufficiently flexible and elastic, enabling an easy processing during the manufacturing process. The use of a sufficiently flexible and elastic material facilitates the laminating of the respective layer with other layers of the wound dressing, even if those other layers have a different size, shape and / or thickness. Moreover, already in dry state the material has a sufficient moisture vapor transmission rate. It was surprisingly found that upon contact with moisture, the material swells and by doing so the moisture vapor transmission rate even increases. This is in particular advantageous as with an increasing amount of absorbed fluid, the odor-absorbing properties of the odor-absorbing material are not negatively affected. Using an elastic intermediate layer does also not only facilitate the handling of the wound dressing during use (e.g., by wrapping it around a part of the body) but also reduces the risk of delamination of the layer during use. In particular an elastic barrier layer can more easily adapt to the changing volume of the absorbent material during use, i.e., when absorbing wound exudate. During use the absorbent material may expand by at least 500% in thickness. Using crushed activated charcoal as odor-absorbing material may further contribute to an advantageous bending behavior of the wound dressing during use. In particular the combined use of charcoal, in particular activated charcoal, as odor-absorbing material with a highly elastic intermediate barrier layer was found to be advantageous for reducing malodor during use. In addition, it was found that the use or presence of a layer containing an odor-absorbing material which has a larger size in x / y direction compared to the adjacent barrier layer is beneficial for the odor-absorbing performance of the wound dressing. Thus, the wound dressings described in the present text perform well with respect to odor-absorbing properties. The invention relates to a wound dressing, in particular to a multi-layer wound dressing. The wound dressing comprises at least 3 layers. In a preferred embodiment the wound dressing comprises at least 5 layers or essentially consists of or consists of 5, 6 or 7 layers. The wound dressing may further include a wound-facing layer (preferably, a liquid permeable facing layer) and a backing layer (preferably, a moisture vapor permeable backing layer) with the other layers located between the wound-facing layer and the backing layer. In the present text individual layers are referred to as layer A, B, C, D and E, wherein layer A is the wound-facing layer and layer E is the backing layer of the wound dressing. The wound dressing may further comprise a layer of pressure sensitive adhesive to secure the article to the skin, if desired. The wound dressing described in the present text comprises an absorbent material containing layer as layer B. Regarding orientation, layer B has a tissue-site or wound-facing surface and a not wound-facing surface. This layer preferably does not permit liquid water or exudate that enters the layer to exit the layer. Instead, the absorbent layer absorbs the exudate, and moisture in the exudate passes through an optional backing layer in a vapor form into the atmosphere. This layer permits wound exudate to be rapidly removed from the wound site and prevents liquids outside the dressing from contaminating the wound site. The absorbent layer includes an absorbent material that is capable of absorbing fluids, preferably moderate to heavy amounts of fluids such as body fluids, while retaining the structural integrity of the absorbent layer as a whole. In this respect layer B comprises an absorbent material, preferably a super-absorbent material. Examples of absorbent materials include creped cellulose wadding; melt blown polymers; chemically stiffened, modified or cross-linked cellulosic fibers; absorbent foams; absorbent sponges; superabsorbent polymers; absorbent gelling materials; or any other known absorbent material or combinations of materials. In some embodiments, the absorbent layer comprises a polymeric gel material. Optionally, the absorbent layer may be constructed primarily of gel materials, but may incorporate hydrocolloids, typically in the form of particles. Examples of hydrocolloids include, but are not limited to, natural gums, such as plant exudates (gum arabic, ghatti, karaya, and tragacanth), plant seed gums (guar, locust bean and acacia), seaweed extracts (agar, algin, alginate salts and carrageenin), cereal gums (starches and modified starches), fermentation or microbial gums (dextran and xanthan gum), modified celluloses (hydroxymethylcellulose, microcrystalline cellulose and carboxymethylcellulose) pectin, gelatin, casein and synthetic gums (polyvinylpyrrolidone, low methoxyl pectin, propyleneglycol alginates, carboxymethyl locust bean gum and carboxymethyl guar gum) and like water-swellable or hydratable hydrocolloids. The term “hydrocolloid” is used regardless of the state of hydration. The amount of hydrocolloid, if used in connection with the gel material, may preferably be less than about 5 wt.%, based on the total weight of the gel material. In some embodiments the absorbent material comprises an open-cell foam. The foam may include a synthetic polymer that is adapted to form a conformable open-cell foam that absorbs the wound exudate. Examples of suitable materials for the foams include synthetic organic polymers including, but not limited to polyurethanes, carboxylated butadiene-styrene rubbers, polyesters, and polyacrylates. The polymeric foams can be made of one or more types of monomers (e.g., copolymers) or mixtures (e.g., blends) of polymers. Examples of foam materials are described in the book entitled “Flexible Polyurethane Foams”, Dow Polyurethanes, editors R. Herrington and K. Hock, 1997. The foams can be of a wide range of thicknesses; from 0.5 mm or 1 mm to 10 mm or 30 mm thick. Further examples include superabsorbent fibrous webs (e.g., from National Nonwovens, Cincinnati, Ohio) or sachets containing superabsorbent material (e.g., Sorbion™ Sachet S available from Sorbion AG, Senden, Germany). Examples of a suitable absorbent core can further be found in a 3MTMTegaderm™ High Performance Foam Dressing (Solventum Corporation) or in 3MTMKerramax™ Care Superabsorbent Dressing (Solventum Corporation). Suitable constructions for the absorbent core are also described in e.g., US 6,838,589 (Liedtke et al.); US 7,030,288 (Liedtke et al.); and US 7,612,248 (Burton et al.). These documents are herewith incorporated by reference. The benefit of using these materials can be seen in that these materials are essentially biocompatible and are able to absorb huge amounts of liquid (e.g., at least 100 or 200 or 300 times its weight). Further, these materials are commercially available. Herein, “biocompatible” means that the material can be in contact with bodily tissues (including fluids) without adverse reactions. Typically, this occurs if, e.g., the residual monomers used to prepare a polymer used in the absorbent layer are present in less than about 1 percent by weight (wt.%) each, based on the total weight of the polymer. Preferably, the absorbent material is inherently bacteriostatic. Preferred absorbent layers are also flexible. Flexibility allows for the wound dressing containing the absorbent layer to be easily applied to a bend portion of a body, such as a joint, etc. Optionally, the absorbent layer may have a patterned surface on at least one major surface thereof. The patterned surface may provide a larger surface area for absorption of wound exudate when oriented toward the wound surface, while reducing the absorbent surface area in direct or indirect contact with the wound. More significantly, the patterned surface may reduce the propensity of the absorbent layer to swell and push against the wound, reduce mushrooming (i.e., expansion of the absorbent layer through a porous film), limit premature separation of an adhesive layer from the skin, and / or enhance integrity of the material upon hydration. The optional pattern imparted to the surface of the absorbent layer may be any suitable preselected three-dimensional pattern. The pattern can include an array of pattern elements that include, but are not limited to, ridges, channels, mounds, peaks, hemispheres, pyramids, cylinders, cones, blocks, and truncated variations and combinations thereof. The pattern may further include apertures having a predetermined shape and size extending through the thickness of the absorbent layer. The specific pattern element may be advantageously chosen to present reduced surface area in contact with a wound or the facing film if present. The reduced surface area may further retard the tendency of the absorbent layer to swell into the wound, mushroom, or adhere to the wound site. Especially useful elements include pyramids, cones and truncated versions thereof, and ridges that are triangular in cross section. The elements may be random or non-random in the x-orientation, the y-orientation, or both. For ease of manufacture, it may be preferable that the pattern comprises a non-random array of elements disposed on the surface of the absorbent layer. Layer B comprises the absorbent material and may comprise a further layer of e.g., a nonwoven material fixing the absorbent material, e.g., with an adhesive. The thickness of layer B in dry state is typically within a range of 200 to 4,000 µm, or 500 to 3,500 µm. The material of layer B may be characterized by an absorbent capacity of at least 100 wt.% or at least 200 wt.% or at least 300 wt.% determined according to EN13726:2023, Annex B. The material of layer B may even have an absorbance capacity of 15 to 30 g water per g absorbent material. Layer B may also have a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity. According to one embodiment, layer B is characterized as follows: having a thickness in the range of 200 to 4,000 mm (in dry state), an absorbance capacity of at least 100 wt.% determined according to EN13726:2023 (Annex B), and comprising a material selected from polyacrylate, polyacrylamide, polyvinyl alcohol, polymeric gel, hydrocolloid, or other superabsorbers. The wound dressing described in the present text further comprises a barrier layer as layer C. Regarding orientation, layer C has a wound-facing surface and a not wound-facing surface. Layer C comprises or essentially consists of or consists of a polyether-based thermoplastic polyurethane, preferably an aromatic polyether-based thermoplastic polyurethane. The material of layer C shows a swelling behavior with water of at least 20 wt.% or at least 25 wt.% or at least 30 wt.% determined according to ASTM D-471 (2016). The swelling is often related to or correlated with the number of hydrogen bonds being available between the molecular chains of the material. Characterizing a polymer i.a. by its swelling behaviour is common in the art. As outlined above, such a swelling behavior is beneficial as it surprisingly seems to enhance the moisture vapor transmission properties of this layer. This allows sufficiently high permeability of moisture through layer C but keeps the material of the adjacent layer D dry. However, due to the water absorbency and swelling properties of layer C, the sealing strength of a sealing (e.g., by a sealing seam) between layer C and a backing layer E may be too weak and may lead to an undesired tearing of the wound dressing during use. One option for addressing this issue and which would not impact the sealing strength of envelope layers A and E is heat lamination of barrier layer C preferably to odor-absorbing layer D. Another option is using a non-heat lamination method. Such an option is often preferred from a manufacturing point of view. However, such a method typically requires the use of an adhesive layer coated to barrier layer C and using an adhesive coated layer C would negatively impact the moisture vapor transmission properties of layer C due to the presence of the adhesive. It has been found that these contradicting requirements can be addressed by using a pattern adhesive coating on barrier layer C. Adhesives which can be used include all types of pressure-sensitive adhesives (PSAs), in particular PSAs comprising (meth)acrylate (co)polymers, natural rubber or synthetic rubbers (e.g., silicone rubber) and others. Suitable patterns for grid or mesh elements of the coating include dots, lines, square, rectangular, rhombic, and hexagonal elements. The pattern coating can be regular or irregular. Any type of pattern design might be useful as long as the total coverage of the surface is significantly reduced (e.g., from 100% (continuously coated) down to preferably 10 to 60 % or 20 to 50% (grid or mesh or pattern) coated area. Such a ratio was found to provide a good balance between achieving a sufficient fixation of layer C to layer D and not affecting the moisture vapor transmission performance. The thickness of the adhesive pattern coating, if present, is typically in a range of 5 to 20 µm. It was found that a barrier layer C which is pattern coated with an adhesive can have the same or similar performance as regards moisture vapor transmission as a barrier layer C without such a pattern coating. The moisture vapor transmission performance is essentially not impacted by a pattern coating. Suitable polyether-based thermoplastic polyurethane materials and films are commercially available such as Estane™ 58237 (Lubrizol) or Estane™ 58245 TPU (Lubrizol) or Inspire 1184P-M40GD (grid adhesive coated TPU film (Transcontinental SA). These polyether-based thermoplastic polyurethane materials and resulting films produced therefrom typically have a basis weight in the range of 10 to 50 g / m2or 15 to 40 g / m2or 20 to 35 g / m2. If needed or desired, the polyether-based thermoplastic polyurethane material is processed to form a film. Suitable methods for producing a film from such materials are known to the person skilled in the art. The benefit of using such a material, in particular as film, can be seen in that this material has a good elongation behavior and / or a sufficient moisture vapor transmission rate. The size of layer C is larger than the size of layer B. This can be advantageous in that layer C is not only able to cover the immediate upper side of the absorbent material of layer B, but also the side areas of the absorbent material, in particular also during use when the absorbent material starts swelling. The thickness of layer C is typically within a range of 10 to 100 µm, or 20 to 50 µm. Layer C may be characterized by the following features alone or in combination: a) having a moisture vapor transmission rate (MVTR) of at least 1,000 g / m2, or at least 2,000 g / m2in 24h determined according to ASTM 96 / 96E-10 at 75% relative humidity and 40°C; b) having a tensile strength (at 100% elongation) in the range of 1 to 20 MPa, or 3 to 8 MPa determined according to EN ISO 527-3:2018. According to one embodiment, layer C is characterized as follows: comprising a material selected from an aromatic polyether-based thermoplastic polyurethane, having a thickness in the range of 10 to 100 µm (in dry state), a moisture vapor transmission rate of at least 1,000 g / m2in 24h determined according to ASTM 96 / 96E-10 at 75% relative humidity and 40°C, and a tensile strength (at 100% elongation) in the range of 1 to 20 MPa determined according to EN ISO 527-3:2018. The wound dressing described in the present text further comprises an odor-absorbing layer as layer D. Layer D comprises an odor-absorbing material. Regarding orientation, layer D has a wound-facing surface and a not wound-facing surface. The odor-absorbing material is often provided as a sheet. Examples of suitable odor-absorbing materials include charcoal, bentonite, zeolite and combination or mixtures thereof. Using charcoal as odor-absorbing material is often preferred, as this material can more easily be provided in sheet form. Charcoal is typically provided as so-called activated charcoal. The mass content of the odor-absorbing material in layer D is typically in the range of 90 to 100 wt.% with respect to the weight of layer D. The size of layer D is larger than the size of layer B. This can be advantageous in that an expanding layer B (due to exudate absorption) can be fully covered by layer D. Malodorous volatiles can therefore be trapped / adsorbed at the edges of the superabsorbent as well. It was found that already a small oversize of layer D, comparing to the size of layer B, increases the odor-absorbing properties. It was also found that the odor-absorbing properties improve with an increasing size of layer D compared to layer B. E.g., an oversize of layer D by at least 2 mm or 6 mm or 8 mm compared to the size of layer B was found to be advantageous. By oversize is meant that the protruding or overhanging parts of that layer extend in all directions (except for height) of this layer over the other layer by a certain width. The size of layer D can be of the same size as the size of layer C, in particular if layer D is laminated to layer C. Alternatively, the size of layer D can be larger than the size of layer C. Laminating layer C to layer D can be advantageous in that the production process can be simplified as the number of lamination and / or sealing steps to be performed at the end is reduced. The thickness of layer D is typically within a range of 300 to 1,000 µm, or 400 to 600 µm. According to one embodiment layer D is characterized as follows: comprising a material selected from charcoal, having a BET surface area (per gram of odor-absorbing material) in the range of 500 to 2,000 m2 / g, or 800 to 1,500 m2 / g, having a size SB< SD, and having a thickness in the range of 300 to 1,000 µm (in dry state). The wound dressing described in the present text may also comprise a wound-facing layer as layer A. Regarding orientation, layer A has a wound-facing surface and a not wound-facing surface. If present, layer A is intended to function as a support layer. Layer A may comprise a material selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide (such as nylon), polyethylene terephthalate or polypropylene textile fabric, wherein using a polyester material is sometimes preferred. Layer A is preferably soft, flexible, conformable, non-irritating and non-sensitizing for human skin. Further, layer A may be in the form of a moisture vapor permeable film, perforated film, woven, nonwoven or knit web or scrim. In some embodiments, layer A is conformable to anatomical surfaces and has a moisture vapor transmission rate (MVTR) of at least 600 g / m2per 24 hours at 75% relative humidity (RH) differential at 40°C. A preferred moisture vapor transmission rate of layer A is at least 600 g / m2in 24 hours at 75% relative humidity and 40°C. Layer A may also include openings through which wound exudate can pass. The barrier layer (layer C), in combination with layer A, if present, may be constructed to form a reservoir (e.g., a pouch or envelope) that surrounds the absorbent layer (layer B) and into which the exudate from the wound passes. The size of layer A is typically larger than the size of layer B and the size of layer D. This allows for a complete sealing of the other intermediate layers. According to one embodiment the size of layer A is essentially equal to the size of layer C and to the size of layer E. This can be advantageous in that it facilitates the co-laminating of the areas of the three layers which are not covered by the materials of layer B and layer D in one step. Layer A is not completely laminated to layer C, but only in those areas which are not covered by layer B. The thickness of layer A is typically within a range of 100 to 300 µm, or 150 to 250 µm. According to one embodiment, layer A is characterized as follows: comprising a material selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide (such as nylon), polyethylene terephthalate or polypropylene textile fabric; having a moisture vapor transmission rate (MVTR) of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C; and having a thickness in the range of 100 to 300 µm. The wound dressing described in the present text typically also comprises a backing layer as layer E. Regarding orientation, layer E has a wound-facing surface and a not wound-facing surface. Layer E may comprise a material being same or different from the material used for layer A. Layer E typically comprises a conformable organic polymeric material that preferably retains its structural integrity in moist environment. Herein, “conformable” films or sheets are those that conform to a surface, even upon movement of the surface, as with the surface of a body part. Suitable films or sheets have a composition and thickness that allow for the passage of moisture vapor through them. The film or sheet aids in the regulation of water vapor loss from the wound area beneath the dressing. The film or sheet also acts as a barrier to both bacteria and to liquid water or other liquids. Conformability is somewhat dependent on thickness, thus the thinner the film or sheet the more conformable the film or sheet. The moisture-vapor permeable polymeric films can be of a wide range of thicknesses. Preferably, they are from 10 µm or 12 µm to 75 µm or 250 µm thick, preferably 12 µm to 25 µm. Preferably the layer E, if present, is conformable to anatomical surfaces, and has a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C. The layer E can be made of one or more types of monomers (e.g., copolymers) or mixtures (e.g., blends) of polymers. Examples of suitable materials for layer E include synthetic organic polymers including but not limited to materials selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide (such as nylon), polyethylene terephthalate or polypropylene textile fabric. More particularly, the following materials were found to be suitable: polyester block copolymers (e.g., as commercially available from DuPont, Wilmington, Del., under the trade designation HYTREL™); polyvinyl chlorides (PVC); polyether-amide block copolymers (e.g. such as those commercially available under the trade designation PEBAX™ available from Elf-Atochem); polyethylene terephthalate (PET). Particularly preferred films comprise or consist of materials selected from polyesters and polyethylene, including polyethylene terephthalates. The films exhibit a resilient property that allows the films to have good conformability. The size of layer E is larger than the size of layer B and the size of layer D. The thickness of layer E is typically within a range of 100 to 300 µm, or 150 to 250 µm. According to one embodiment, layer E is characterized as follows: comprising a material selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric; having a moisture vapor transmission rate (MVTR) of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C; and having a thickness in the range of 100 to 300 µm. The wound dressing can typically be characterized by the following features alone or in combination: a) size: up to 100 cm or up to 80 cm or up to 50 cm in largest diameter; b) shape: rectangular, square, triangular, circular, elliptical; c) total thickness in dry state: up to 5 mm; d) total thickness in wet state: up to 50 mm; e) moisture vapor transmission rate (MVTR): at least 400 g / m2in 24hrs, or at least 600 g / m2in 24h, at least 800 g / m2in 24h at 75% relative humidity and 40°C. If the shape of the wound dressing is rectangular or square, the corners may be sharp or rounded. A combination of the following features is sometimes preferred: c) and e); c), d) and e). Further embodiments and aspects of the wound dressing of the present text are described below. Embodiment 1 A wound dressing comprising or essential consisting or consisting of the following layers: Layer A comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, Layer B comprising a material being selected from polyacrylates, polymeric gels materials, hydrocolloids, superabsorbers, having a thickness in the range of 200 to 4,000 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer C comprising a polyether-based thermoplastic polyurethane, preferably an aromatic polyether-based thermoplastic polyurethane, having a thickness in the range of 10 to 100 µm, having a swelling behavior with water of at least 20 wt.% determined according to ASTM D-471 (2016), having a moisture vapor transmission rate in the range of 1,000 to 10,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer D comprising charcoal, having a thickness in the range of 300 to 1,000 µm, having a BET surface in the range of 500 to 2,000 m2 / g, Layer E comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, the sizes of the layers being as follows: SA= SC= SE, or SA= SEand SC= SD. Embodiment 2 A wound dressing comprising or essential consisting or consisting of the following layers: Layer A comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, Layer B comprising a material being selected from polyacrylates, polymeric gels materials, hydrocolloids, superabsorbers, having a thickness in the range of 200 to 4,000 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer C comprising a polyether-based thermoplastic polyurethane, having a thickness in the range of 10 to 100 µm, having a swelling behavior with water of at least 20 wt.% determined according to ASTM D-471 (2016), having a moisture vapor transmission rate in the range of 1,000 to 10,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer D comprising charcoal, having a thickness in the range of 300 to 1,000 µm, having a BET surface in the range of 100 to 1,500 m2 / g, Layer E comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, the sizes of the layers being as follows: SA= SC= SE, or SA= SEand SC= SD. Embodiment 3 A wound dressing comprising or essential consisting of the following layers: Layer A comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, Layer B comprising a material being selected from polyacrylates, polymeric gels materials, hydrocolloids, superabsorbers, having a thickness in the range of 200 to 4,000 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer C comprising a polyether-based thermoplastic polyurethane, having a thickness in the range of 10 to 100 µm, having a swelling behavior with water of at least 30 wt.% determined according to ASTM D-471 (2016), having a tensile strength (at 100% elongation) of 1 to 20 MPa according to EN ISO 527- 3:2018, having a moisture vapor transmission rate in the range of 1,000 to 10,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer D comprising charcoal, having a thickness in the range of 300 to 1,000 µm, having a BET surface in the range of 100 to 1,500 m2 / g, Layer E comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, the sizes of the layers being as follows: SA= SC= SE, or SA= SEand SC= SD. Embodiment 4 A wound dressing comprising or essential consisting of the following layers: Layer A comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, Layer B comprising a material being selected from polyacrylates, polymeric gels materials, hydrocolloids, superabsorbers, having a thickness in the range of 200 to 4,000 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer C comprising a polyether-based thermoplastic polyurethane with a pattern adhesive coating on the side which faces Layer D, the pattern adhesive coating preferably covering 10 to 60% of the surface of Layer C, having a thickness in the range of 10 to 100 µm, having a swelling behavior with water of at least 30 wt.% determined according to ASTM D-471 (2016), having a tensile strength (at 100% elongation) of 1 to 20 MPa according to EN ISO 527- 3:2018, having a moisture vapor transmission rate in the range of 1,000 to 10,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer D comprising charcoal, having a thickness in the range of 300 to 1,000 µm, having a BET surface in the range of 100 to 1,500 m2 / g, Layer E comprising a material being selected from polyester, polyethylene, polypropylene, polyamide, preferably polyethylene terephthalate, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, the sizes of the layers being as follows: SA= SE, SC= SDand SD> SB. The wound dressing described in the present text does not comprise a vapor impermeable layer. The invention also relates to a process for producing the wound dressing described in the present text. A suitable process typically comprises or essentially consists of or consists of the following steps: a) providing a lower (support) layer A, b) placing layer B (containing absorbent material) on top of layer A, c) placing, or if desired laminating layer C (barrier layer) to layer A and optionally also to layer B, d) placing layer D (odor-absorbing layer) on top of layer C, e) placing layer E (backing layer) on top of layer D, f) sealing together these sections of layer A, layer C and layer E which are not overlapping with layer B and layer D. Another process may comprise or essentially consist of or consist of the following steps: a) providing a lower (support) layer A, b) placing layer B (containing absorbent material) on top of layer A, c) placing layer C (barrier layer) and layer D (odor-absorbing layer) on top of layer B, wherein layer C is laminated to layer D, d) placing layer E (backing layer) on top of layer D, e) sealing together these sections of layer A and layer E which are not overlapping with layer B and layer D. The wound dressing described in the present text is typically stored under hygienic conditions before use. Means for storing the wound dressing include the packaging in a sealed pouch, a container, or a combination thereof. The wound dressing is for use in a process of treating a tissue site, in particular a wound of a human being or animal. Such a process typically comprises the following steps: providing the wound dressing described in the present text, applying the wound dressing with its wound-facing site to a wound, optionally having the wound dressing absorb wound exudate. The wound dressing of the present text is useful for treating any kind of tissue defects and wounds, in particular for treating the following wounds: wounds caused e.g. by an external trauma (“mechanical wounds”), thermal wounds caused e.g. by the action of extreme heat or cold, chemical wounds caused e.g. by action of chemicals, tissue breaks or damage caused by e.g. actinic radiation, wounds caused by ulcers, wounds caused by circulatory disorder. Exudates which can be absorbed include blood, plasma, pus, and mixtures thereof. The invention is also related to a kit of parts comprising at least two wound dressings described in the present text and optionally an instruction of use. The wound dressings may be identical or differ from each other with respect to size, shape or use of application. The wound dressing may have the shape of a circle, ellipse, triangle, square, rectangle, or combination thereof. The wound dressing described in the present text is further illustrated by the attached figures. Fig.1 shows the general principle of the wound dressing of the present invention. The wound dressing comprises a wound-facing contact layer (A), a layer with an absorbent, in particular superabsorbent material (B), a barrier layer (C), an odor-absorbing layer (D) and an upper dressing layer (E). Shown are also the relative properties of the respective layers with respect to permeability to exudate and volatiles. The amount of exudate is reduced from bottom (wound) to the upper side of the wound dressing, whereas the major portion of exudate is absorbed in Layer B. As regards volatiles, these are absorbed on the one hand mainly by layer B. Volatiles which are not absorbed by layer B will be absorbed by layer D, so that only a minor portion of the volatiles may migrate from the upper layer of the wound dressing. Fig. 2a shows one embodiment for a general layering concept of the wound dressing described in the present text. In this embodiment, the sizes of layer A, layer C and layer E are essentially the same, whereas the size of layer D is larger than the size of layer B. Further, the size of layer C is larger than the size of layer B. This has the benefit that the material of layer B and the material of layer D are each contained in a kind of envelope. Wound exudate cannot migrate from layer B to layer D. Fig.2b shows another embodiment for a general layering concept of the wound dressing described in the present text. In this embodiment, the sizes of layer A and layer E are essentially the same, whereas the size of layer D is larger than the size of layer B. Further, the size of layer C is essentially the same as the size of layer D. This embodiment has the benefit that layer C can more easily be laminated to layer D, which may simplify the manufacturing process. The complete disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. The invention is not limited to the embodiments disclosed herein. One skilled in the art will appreciate that many alternative embodi- ments of the invention can be made without departing from the spirit and scope of thereof. The above specification, examples and data provide a description of the manufacture and use of the articles and methods of the invention. The following examples are given to illustrate the invention. Examples Unless otherwise indicated, all parts and percentages are on a weight basis, all water is de-ionized water, and all molecular weights are weight average molecular weight. Moreover, unless otherwise indicated all experiments were conducted at ambient conditions (23°C; 1013 mbar). Methods Evaporation Test If desired, the following test can be used for determining the evaporation performance of the wound dressing described in the present text. The wound dressings in dry state are placed on glass plates and fixed at one edge with tape. The dry wound dressings with glass plates are weighted. As a next step the wound dressings with glass plate are inserted for 7 min into Solution A (37+ / -2°C), removed and kept for 45s with an angle of 70° to allow the residual water to drop down. Solution A: 8.298g sodium chloride and 0.368g calcium chloride diluted in 1,000 ml demineralized water. Remaining excess water is carefully removed from the glass plate using a paper wipe. The wet wound dressings with the glass plates are weighted again. The weight is referred to as initial wet weight at time point T(0). The wet wound dressings with the glass plates are placed for 24hrs on a heating plate (37+ / -2°C). The weight loss is determined by measuring the weight within regular intervals T(1), … T(n). The determined values are recorded and compared to the reference sample containing an odor- absorbing layer D, but no barrier layer C. Wetting Test If desired, the following test can be used for determining the barrier performance under pressure. Prototypes of the wound dressing are opened and the upper (dressing) layer E and (charcoal) layer D are removed. The remaining wound dressing is placed on a working bench with the (barrier) layer C up. A paper towel (5 x 5 cm) is placed on top of layer C followed by a weight of 252.2g and a base area of 2.9 cm * 2.9 cm. Immediately after application of the weight a photo is taken; see also Fig.4a. After 90 s the weight is removed and another photo is taken; see also Fig.4b. The wet barrier properties under pressure of the tested barrier films can be determined by visual inspection of the paper towel, whether it is wet or not and if yes, to which extent. Alternatively, the difference in weight of the paper towel before and after the application of the weight can be determined. Moisture Vapor Transmission Rate (MVTR) The MVTR can be determined according to ASTM E96 / E96M-10 at 40 ± 0.5°C and relative humidity (RH) of 75 ± 2%. 100mL glass bottle having a lid with an 27mm screw cap opening hole are filled with 50 ml of distilled water. The sample is fixed between the bottle opening and a cap. Rubber sealings are placed on both sides of the samples to ensure a tight seal. The test bottle containing water and sample is weighted before and after exposure to climatic conditions for 24 hours to determine MVTR. Swelling Behavior If desired, the swelling behavior can be determined according to ASTM D-471 (2016). Tensile Strength If desired, tensile strength can be determined according to EN ISO 527-3:2018. BET Surface If desired, the BET surface can be determined according to ISO 9277:2010. Basis Weight The basis weight is typically provided by the manufacturer of the material but can also be determined according to ASTM D8136. Odor-Absorption Test If desired, performance of odor-absorbing properties can be determined as follows: A sample is placed over a stainless-steel plate with recess and covered with a perspex dome. A 50ml syringe attached to a syringe driver is filled with a 2 wt.% aqueous diethylamine solution. The solution is then infused onto the sample through the recess via the syringe driver which is set at an infusion rate of 30ml / h. The time taken for a gas analyzer to detect diethylamine concentration of up to 20 ppm is recorded. The volume of test solution that has been applied to the dressing is then calculated. As odor measurement device a zNose Model 4300 (Tech Mondial Ltd.) is used. Measurements are done with an artificial fluid insertion flow rate of 0.5 ml / min. The more diethyl amine solution which can be absorbed before reaching the 500 cts threshold, the higher the anti-odor performance of the sample is. A higher volume of the test solution indicates better odor-absorbing properties. This test method is further described in Journal of Wound Care May Vol. 7, No. 5, 1998; Odour-absorbing dressings (S. Thomas et.al.). Materials The following materials were used: Material Source Layer E nonwoven polyethylen / polyester material (Sawabond™ Sandler AG with 12g / m²) Layer D activated carbon material (Flexsorb™ FM30K) Chemviron Layer C1 Film made of thermoplastic aromatic polyether-based Solventum thermoplastic polyurethane material (E58237 from Lubrizol), 25 g / m² to 28 g / m² basis weight, processed according to example 1 of US 2001 / 0027285 A1 (Heinecke et al.); coated with a pressure sensitive adhesive Layer C2 Film made of thermoplastic aromatic polyether-based Solventum thermoplastic polyurethane material (E58237 from Lubrizol); 25 g / m2to 28 g / m2basis weight processed according to example 1 of US 2001 / 0027285 A1 (Heinecke et al.) Layer C3 Film made of thermoplastic polyether-based polyurethane Covestro material (LPT9153 TL1); 25 g / m2to 28 g / m2basis weight Layer C4 Inspire 1184P-M40GD, grid adhesive coated TPU film Transcontinental (TPU: 16 µm, Adhesive: 10 g / m2; TPU 40% adhesive SA coated, 60% non-coated); 18 to 20 g / m2basis weight for TPU film Layer B Superabsorbent material (core layer of 3MTMKerramax™ Eumar Technology Care Superabsorbent Dressing) Layer A nonwoven Polyethylen / polyester material (Sawabond™) Sandler AG Table 1 Samples The following wound dressing samples (WD) were produced: WD1 WD2 WD3 WD4 WD5 WD6 Layer E + + + + + + Layer D n.p. + + + + + (odor absorber) Layer C n.p. n.p. C1 C2 C3 C4 (barrier) (with PSA) Layer B + + + + + + (superabsorber) Layer A + + + + + + Table 2; n.p. = not present Production Method for Wound Dressings The wound dressings were be prepared as follows: Wound Dressing (WD3) The absorbent layer B was cut to a size of 7.5 x 7.5 cm. The odor-absorbing layer D was cut to a size 9 x 9 cm. The inside area (inside the sealings) is 10 x 10 cm. Absorbent layer B was placed on wound contact layer A and the barrier layer C was laminated on top over the full area. In a further step the odor-absorbing layer D and the upper dressing layer E were placed and the composite sealed using a standard sealing bar. Sealing was done in a manner that three layers, lower wound contact layer A, barrier layer C and upper dressing layer E were sealed together. Wound Dressing (WD4) Absorbent layer B was placed on wound contact layer A and the pressure-sensitive-adhesive (PSA)- free barrier layer C was placed on top over the full area. Next steps were conducted as described above for WD3. Wound Dressing (WD5) Absorbent layer B was placed on wound contact layer A and the PSA-free barrier layer C was placed on top over the full area. Next steps were conducted as described above for WD3. Wound Dressing (WD1) Absorbent layer B was placed on wound contact layer A. The upper dressing layer E was placed and the whole sealed using a standard sealing bar. Wound Dressing (WD2) Absorbent layer B was placed on wound contact layer A followed by the carbon layer D and the upper dressing layer E. The whole was sealed using a standard sealing bar. Wound Dressing (WD6) Absorbent layer B was placed on wound contact layer A and the grid adhesive coated barrier layer C4 was placed on top over the full area. Next steps were conducted as described above for WD3. Wound Dressing (WD7 – “P-26”) Wound Dressing WD7 was produced according to the process described for Wound Dressing WD6, with the following dimensions: Size of layer A: 10.5x10.5 cm; Size of layer B: 7.5 x7.5 cm; Size of layer C: 8.1x8.1 cm; Size of layer D: 8.1x8.1 cm; Size of layer E: 10.5x10.5 cm; 7.5 mm overlap / oversize per edge. Wound Dressing (WD8 – “P-12”) Wound Dressing WD8 was produced according to the process described for Wound Dressing WD3, with the following exceptions: Layer C2 was laminated to layer D first. The laminate of layer C2 and layer D was put on layer A. Finally, layer A was sealed to layer E. The dimensions used were as follows: Size of layer A: 11x11 cm; Size of layer B: 7.5x7.5 cm; Size of layer C: 9x9 cm; Size of layer D: 9x9 cm; Size of layer E: 11x11 cm; 3 mm overlap / oversize per edge. Wound Dressing (WD9 – “P-27”) Wound Dressing WD9 was produced according to the process described for Wound Dressing WD6, with the following dimensions: Size of layer A: 3x13 cm; Size of layer B: 7.5 x7.5 cm; Size of layer C: 10.5x10.5 cm; Size of layer D: 10.5x10.5 cm; Size of layer E: 13x13 cm; 15 mm overlap / oversize per edge. Wound Dressing (WD0 – “P-23”) Wound Dressing WD0 was produced like WD7 with the following dimensions: Size of layer A: 10x10 cm; Size of layer B: 7.5x7.5 cm; Size of layer C: 7.5x7.5 cm; Size of layer D: 7.5x7.5 cm; Size of layer E: 10x10 cm; 3 mm overlap / oversize per edge. Pictures of Wound Dressings WD7, WD8 and WD9 are shown in Fig.5, from left to right. Testing – Evaporation Properties and Wetting Behaviour Wound Dressings WD1 to WD5 were evaluated with respect to their evaporation properties, wetting behavior and swelling behaviour. Evaluation / Results WD1 WD2 WD3 WD4 WD5 WD6 Evaporation* (%) 105 100 49 95 57 95 Wetting n.t. --- +++ +++ n.t. +++ Swelling n.a. n.a. about about 40% about about (Layer C) 40% <2% 37%** Table 3; n.t. = not tested; n.a. = not applicable; *: evaporation relative to WD2; **: for pure TPU film WD4 and WD6 are inventive examples. The results of the evaporation test are further visualized in Fig.3. Fig. 3 provides data on the evaporation performance of the wound dressings which were tested (cf. example section). The reference sample WD1 (not containing an odor-absorbing material) is shown on the left side, followed to the right by the reference sample WD2 containing an odor-absorbing material, the comparative sample WD3 containing a barrier layer with an adhesive, the inventive example WD4 and a further comparative example WD5 where a barrier layer with a different polyurethane material was used. As regards the evaporation performance it was found that the inventive example (WD4) essentially performed as good as the two reference samples on the left side (WD1 and WD2). At the start of the test, T(0), the Solution A content was approximately 70-80 g for all samples. Depending on the barrier material, more or less water from Solution A was evaporated. As expected, both reference samples (WD1 and WD2) performed similarly. After 24 hrs both references samples have lost about two thirds or more of their original water content. Samples WD4 and WD6 were found to be the best performing samples and are comparable to the reference samples WD1 and WD2. Samples WD3 and WD5 were less effective. The relative performance of Samples WD4 and WD6 was 95% whereas the other Samples WD3 and WD5 performed with ca.50%. The barrier layer C2 used in Sample WD4 had almost no impact on the evaporation performance compared to a conventional superabsorbent / odor-absorbing layer composite dressing. Similarly, the presence of the grid adhesive coating with layer C4 has almost no impact on the evaporation performance, either. Further, at the end of the test it was also visually observed that only the samples with a barrier layer (WD3 and WD4) looked and felt dry, whereas the sample without a barrier layer (WD2) was wet (Fig.4a and Fig.4b). Testing – Odor Control Performance Wound Dressings WD7, WD8 and WD9 were analyzed with respect to their odor control performance using the above-described test method. The test results are shown in Fig. 6. The results show a significant relationship between odor control performance and size ratio. It was also found that even a rather small increase of the size ratio (of some mm as regarding the oversize) can impact and improve the performance.

Claims

Claims 1. A wound dressing comprising an absorbent material containing layer as layer B, an odor-absorbing layer as layer D, a barrier layer as layer C located between layer B and layer D, wherein the size of layer D is larger than the size of layer B, and wherein the material of layer C comprises a polyether-based thermoplastic polyurethane characterized by a swelling behavior with water of at least 20 wt.% determined according to ASTM D-471 (2016).

2. The wound dressing according to the preceding claim comprising at least the following layers a wound-facing layer as layer A with a size SA, layer A comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric, an absorbent material containing layer as layer B with a size SB, a barrier layer as layer C with a size SC, layer C comprising a polyether-based thermoplastic polyurethane material, in particular an aromatic polyether-based thermoplastic polyurethane material, an odor-absorbing layer as layer D with a size SD, layer D comprising an odor-absorbing material, a backing layer as layer E with a size SE, layer E comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric, wherein SB< SC.

3. The wound dressing according to the preceding claim, wherein the sizes of the layers meet either of the following conditions: sizes SA, SCand SEnot deviating from each other by more than 5%, preferably wherein essentially SA= SC= SE; or SA= SEand SC= SD.

4. The wound dressing according to any of the preceding claims, layer B being characterized by the following features alone or in combination: thickness TB: 200 to 4,000 µm; water-absorbing capacity: at least 100 wt.% determined according to EN13726:2023; comprising a material selected from polyacrylate, polyacrylamide, polyvinyl alcohol, polymeric gel, or other superabsorbers.

5. The wound dressing according to any of the preceding claims, layer C being characterized by the following features alone or in combination:thickness TC: 10 to 100 µm; tensile strength (at 100% elongation) 1 to 20 MPa according to EN ISO 527-3:2018; basis weight in the range of 10 g / m2to 50 g / m2; moisture vapor transmission rate of at least 1,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C.

6. The wound dressing according to any of the preceding claims, layer D being characterized by the following features alone or in combination: thickness TD: 300 to 1,000 µm; BET surface area of odor-absorbing material: 500 to 2,000 m2 / g; comprising an odor-absorbing material being selected from charcoal, bentonite, zeolite and mixtures thereof; size of layer D being larger than size of layer C by at least 2 mm in each direction except for height.

7. The wound dressing according to any of the preceding claims, either layer B and layer C being jointly laminated, or layer D and layer C being jointly laminated.

8. The wound dressing according to any of the claims 2 to 7, layer A being characterized by the following features alone or in combination: thickness TA: 100 to 300 µm; being water-permeable; moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C; comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric.

9. The wound dressing according to any of claims 2 to 8, layer E being characterized by the following features alone or in combination: thickness TE: 100 to 300 µm; being water-permeable; moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C; comprising a material being selected from nonwoven or woven cotton, viscose, polyester, polyethylene, polypropylene, polyamide, polyethylene terephthalate or polypropylene textile fabric.

10. The wound dressing according to any of the preceding claims, the wound dressing comprising a pattern adhesive coating between layer C and layer D, the pattern adhesive coating preferably covering 10 to 60% of the surface of layer C.

11. The wound dressing according to any of the preceding claims being characterized by the following features alone or in combination largest diameter: up to 100 cm; shape: rectangular, square, triangular, circular, elliptical; total thickness in dry state: up to 5 mm; total thickness in wet state: up to 50 mm.

12. The wound dressing according to any of claims 2 to 11, layer A and layer E differing from each other with respect to the following features alone or in combination: material composition; color; density; thickness; labelling.

13. The wound dressing according to any of claims 2 to 12 comprising or essential consisting of the following layers: Layer A comprising a nonwoven polyester material, polyethylene material, or polyester / polyethylene material, having a thickness in the range of 100 to 300 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, Layer B comprising a material being selected from polyacrylates, polymeric gels materials, hydrocolloids, superabsorbers, having a thickness in the range of 200 to 4,000 µm, having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer C comprising a polyether-based thermoplastic polyurethane, having a thickness in the range of 10 to 100 µm, having a moisture vapor transmission rate in the range of 1,000 to 10,000 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity, Layer D comprising charcoal, having a thickness in the range of 300 to 1,000 µm, having a BET surface in the range of 500 to 2,000 m2 / g, Layer E comprising a nonwoven polyester material, polyethylene material, or polyester / polyethylene material, having a thickness in the range of 100 to 300 µm,having a moisture vapor transmission rate of at least 600 g / m2in 24h determined according to ASTM E96 / E96M-10 at 75% relative humidity and 40°C, the sizes of the layers being as follows: SA= SC= SE, or SA= SEand SC= SD.

14. A process of producing the wound dressing described in any of claims 2 to 13, the process comprising either the steps of a) providing layer A, b) placing layer B on top of layer A, c) placing layer C on top of layer B, d) placing layer D on top of layer C, e) placing layer E on top of layer D, f) sealing together those sections of layer A, layer C and layer E which are not overlapping with layer B and layer D. or the steps of a) providing layer A, b) placing layer B on top of layer A, c) placing layer C and layer D on top of layer B, wherein layer C is laminated to layer D d) placing layer E on top of layer D, e) sealing together these sections of layer A and layer E which are not overlapping with layer B and layer D wherein layers A to E are as described in any of the preceding claims.

15. Kit of parts comprising at least two wound dressings according to any of claims 1 to 13, the wound dressing be same or different with respect to size, shape or intended use, optionally an instruction for use, and optionally fixation means.

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