Wound cleansing products

Description

[0001] The invention relates to a wound cleansing article comprising a composite material having a foam layer and a fiber layer arranged on and in the foam layer, and to a method for its production.

[0002] In wound treatment, debridement—that is, the cleansing of necrotic (dead), infected, or damaged tissue, fibrin deposits, wound exudate, and other contaminants—plays an integral role. Necrotic tissue and / or a significant bacterial presence can severely impede wound healing. Therefore, it is medically advisable to perform debridement between each dressing change, especially in chronic wounds. There are various methods used for wound cleansing. With all methods, it is essential that the newly formed granulation and young epithelial tissue, which form during wound closure, are not damaged during the removal of dead tissue.

[0003] One method that is increasingly used is mechanical wound cleansing. This involves using various surface materials, such as textiles or sponges, to clean the wound. One advantage of mechanical wound cleansing is that it is easy to perform and can also be used by nursing staff in home care.

[0004] The requirements for surface structures for mechanical wound cleansing are diverse. Firstly, they must have an abrasive quality tailored to the application, allowing for the gentle, painless removal of necrotic tissue and slough. Secondly, they must exhibit good absorption capacity, allowing for the rapid absorption of loosened wound debris and thus preventing recontamination of the wound. In addition, the surface structure should also be suitable for cleansing the surrounding skin, for which a less abrasive surface is more suitable. Furthermore, the structure should be flexible, allowing for the cleaning of a wide variety of wound geometries, i.e., both large wounds and tunnels.

[0005] The use of various surface structures for mechanical wound cleansing is already known.

[0006] WO 2019 / 028057 A1 describes a hydrophilic foam with a moisture content between 20 wt.% and 60 wt.% and a structure that allows wound debridement. The disadvantage of this foam is that the abrasiveness is determined by the moisture content. In This is not practical in practice, as it is very time-consuming for nursing staff to dose the wound irrigation solution accurately. Another disadvantage is that no surfaces with different abrasivities are available for cleaning.

[0007] InWO 2019 / 057256 A1 describes two foam layers laminated together. One side of the foam has recesses and incisions. Various structures and surfaces are provided for cleaning. A disadvantage of this system is that the lamination of the two foams can lead to increased stiffness. Furthermore, different swelling behaviors of the foams pose the risk of delamination of the layers.

[0008] A commercially available foam for mechanical debridement is the Wound Cleaner ®< from Ligasano ®<. The reticulated hydrophobic foam demonstrates good cleaning performance due to its highly abrasive structure. However, this structure can also cause severe pain to the patient during application. The reticulated foam has a high porosity to remove solid and highly viscous wound components. However, this leads to reduced absorption capacity.

[0009] In addition to foams, the use of textile fabrics for wound cleansing is also described.

[0010] EP 2 365 794 B1 describes a wound cleansing device comprising a wipe, or being a wipe, having a carrier layer with projecting or arranged thereon threads made of synthetic fibers, which preferably have cut ends or end surfaces. A disadvantage is that the cleansing effect is achieved by the projecting fibers. This quickly leads to the fiber ends sticking together, particularly in wounds with viscous exudate, which results in a rapid depletion of the wipe's capacity. In addition, the cavities provided between the fibers, due to their elongated geometry, are not particularly well suited for absorbing and containing the wound components.

[0011] A commercially available product of the aforementioned design is the wound cleansing product Debrisoft®. In addition to the aforementioned disadvantages, the product has hard, polished edges that can cause severe pain upon contact with the wound bed.

[0012] However, the edges are necessary to hold the textile structure together, as cutting the product releases fibers that can lead to wound contamination. In addition, it is very stiff, making it suitable only for use on flat wounds. Furthermore, exudate is only bound to the surface and not absorbed into the structure of the cloth. Finally, it can only be used on one side.

[0013] EP 2777662 B1 describes a velour nonwoven fabric for use in wound cleansing, characterized by the fibers being arranged in loops. This has the advantage that the loop structure allows necrosis and wound secretions to be easily removed and absorbed into the structure. A disadvantage of the described invention is that abrasion and absorption are performed by the same layer and therefore cannot be varied independently of each other.

[0014] US 20030079324 A1 describes a process for producing a water-jet-bonded, structured, permeable nonwoven fabric with high absorption capacity and good abrasion resistance, particularly in a wet state. A disadvantage here is the low thickness of the material caused by the manufacturing process, which leaves little space for absorbing and containing wound components.

[0015] US 20170304485 A1 describes a particle-containing porous nonwoven matrix consisting of polyolefins and glass fibers, which contains a large number of microorganism-binding particles. A disadvantage of using glass fibers is their very high abrasiveness, which can be very unpleasant for the patient. Furthermore, different surfaces with different surface properties are not available.

[0016] A commercially available and widely used fiber-based mechanical wound cleansing product is cotton gauze. This is an open weave made of cotton yarns and is characterized by its low price and high versatility. A disadvantage of this product is that, due to the coarse yarn structure, it can be painful for the patient during application. Furthermore, there is a risk of wound contamination from fiber components detaching from the yarn, especially when cutting the gauze.

[0017] WO 2013 / 113906 A1 describes a wound care article comprising at least one surface with abrasive properties, which is designed such that the wound care article is suitable for disrupting biofilms located in the wound and / or stimulating wound exudation upon movement of the article relative to the wound. The surface with abrasive properties can be a foam or fibers. Also described is a product containing both a polyurethane foam and a textile material laminated to it. A disadvantage of this composite material is its high rigidity and tendency to delaminate. Furthermore, the lamination impedes the transport of wound exudate through the structure.

[0018] A commercially available product with the aforementioned design is the wound cleansing product Cutimed® DebriClean. In addition to the aforementioned disadvantages, this product has the disadvantage of hard edges and high rigidity, making it suitable only for large wounds. Furthermore, it can only be used on one side.

[0019] The invention is based on the object of providing a wound cleansing article with which the aforementioned disadvantages can be at least partially eliminated. In particular, the wound cleansing article should enable effective and gentle wound cleansing. Necrotic tissue and deposits should be able to be removed without the application of strong force, thus minimizing the risk of damaging young granulation tissue. Furthermore, it should have at least two areas of different abrasiveness so that these can be independently optimized for cleaning the wound and the surrounding skin. This allows both the wound and the surrounding skin to be optimally cared for with a single article. Furthermore, the article should be usable for various wound geometries, for example, large-area or tunnel-shaped wounds.

[0020] Furthermore, the article should be able to be cut and used without significant loss of fibers.

[0021] DE202015103600U1 discloses another cleaning textile.

[0022] This object is achieved by a wound cleansing article according to claim 1, comprising a composite material which has a foam layer and a fiber layer arranged on and in the foam layer, wherein the fiber layer is at least partially thermally consolidated and wherein the foam layer and fiber layer are connected to one another by needling, wherein fibers of the fiber layer have penetrated into the foam layer and form capillary channels which extend from the fiber layer into the foam layer.

[0023] The wound cleansing article according to the invention is characterized by having a foam layer and a fiber layer that are bonded together by needling. Through this mechanical bond, fibers of the fiber layer penetrate the foam layer and form capillary channels. According to the invention, capillary channels are understood to be the elongated cavities created between the fibers aligned by needling. The capillary channels extend from the fiber layer into the foam layer and thus enable effective and rapid transport of exudate across the layers, as well as its containment throughout the wound cleansing article.

[0024] By needling the fiber layer and foam layer, a structure with high tensile strength is created. The composite material can thus have a maximum tensile strength / elongation measured according to EN 29073-03 (wet) of more than 40%, for example from 40% to 180%, preferably more than 50%, for example from 50% to 180%, even more preferably more than 60%, for example from 60% to 180%, even more preferably more than 70%, for example from 70% to 180%, even more preferably more than 80%, for example from 80% to 180%, even more preferably more than 90%, for example from 90% to 180%, and in particular more than 100%, for example from 100% to 180%. Furthermore, a two-sided material can be obtained in which there is no risk of delamination even upon swelling and the associated expansion of the layers.Furthermore, it was surprisingly discovered that the needling of the fiber layer and foam layer enables fluid transport between the layers, which allows for rapid removal of wound exudate and secure containment within the structure. According to the invention, the fibers of the fiber layer penetrate the foam layer and protrude at least partially from the side of the foam layer facing away from the fiber layer. This is advantageous because it allows for a particularly pleasant feel on the foam side. Furthermore, the protruding fiber ends, due to their high specific surface area, can further enhance the cleaning effect of the foam layer.

[0025] For some applications, using the fiber layer as the cleansing side is advantageous compared to the foam layer, as fibers are generally less abrasive than foams, allowing for gentle cleansing of the surrounding skin. Furthermore, the fibers offer a higher specific surface area than foam for cleansing and adsorbing small, dissolved wound debris and bacteria.

[0026] Furthermore, it was found that the wound cleansing article according to the invention enables gentle wound cleansing. In particular, viscous and encrusted components can be removed even with low pressure. Furthermore, the wound cleansing article according to the invention allows for various surface structures in a single material, so that different cleansing needs can be addressed with a single product.

[0027] According to the invention, the fiber layer is thermally bonded. This thermal bonding allows the fibers to be firmly fixed, thus reducing the risk of fiber loss and thus wound contamination. Furthermore, the degree of thermal bonding allows for a targeted adjustment of the abrasiveness.

[0028] Thermal bonding is preferably achieved by thermally bonding the fiber layer before applying it to the foam layer. This prevents damage to the foam layer due to heating.

[0029] Practical trials have shown that it is particularly useful for the fiber layer to be thermally bonded without compression. This has the advantage that a high proportion of the pore volume remains available to absorb wound components even after bonding. Furthermore, this allows for a fiber layer with a rough surface to be obtained, which facilitates the dissolution of difficult-to-dissolve deposits in the wound. Furthermore, this allows the flexibility of the fiber layer to be retained. Thermal bonding without compression can be achieved, for example, by treating the fiber layer with hot air, for example, in a through-air oven.

[0030] It is further preferred if the fiber layer is a thermally bonded fiber layer. This is advantageous over fiber layers that are not thermally bonded across the entire surface, such as point-calendered fiber layers, as it prevents individual fibers from becoming detached from the fiber layer and contaminating the wound.

[0031] In a preferred embodiment of the invention, the fiber layer is a nonwoven fabric, in particular a nonwoven fabric according to DIN EN ISO 9092:2019-08, a woven fabric, a knitted fabric, and / or a knitted fabric, wherein the aforementioned fiber layers are each at least partially thermally bonded. Particularly preferably, the fiber layer is an at least partially thermally bonded nonwoven fabric, since its open structure allows particularly good penetration of the fibers into the foam layer.

[0032] The fiber layer can comprise a wide variety of fibers. Synthetic fibers are preferred because they are easy to sterilize. Further preference is given to hydrophobic fibers, i.e. fibers which are made at least on their surface from polymers whose surface energy is lower than 50 mJ / m2. Particularly suitable hydrophobic fibers are polyester and / or polyolefin fibers. The advantage of hydrophobic fibers is that they enable the binding and thus removal of bacteria. The binding of bacteria to hydrophobic fibers is described, for example, in N. Edwards et al. Role of surface energy and nanoroughness in the removal efficiency of bacterial contamination by nonwoven wipes from frequently touched surfaces, Science and Technology of advanced materials, 2017, Vol. 18, No. 1 197 -209. To form the framework structure, the fiber layer preferably comprises matrix fibers.According to the invention, matrix fibers are understood to be fibers that are not, or only to a small extent, thermally fused. Preference is given to thermoplastic matrix fibers which have a melting point of the lowest melting fiber component of above 170°C, for example from 170°C to 250°C, more preferably above 200°C. In one embodiment, the matrix fibers consist of one fiber component. In a further preferred embodiment, the matrix fibers consist of several fiber components. Particular preference is given to solid profile fibers, multilobal solid profile fibers, hollow fibers and / or solid profile bicomponent fibers (e.g. core / sheath, side-by-side). If the fiber layer comprises binding fibers, it is advantageous if the melting point of the fiber component contained in the matrix fiber with the lowest melting point is above the melting point of the fiber component contained in the binding fiber with the highest melting point.Preferably, the melting point of the fiber component with the lowest melting point in the matrix fiber is at least 10 °C, more preferably at least 30 °C, higher than the melting point of the fiber component with the highest melting point in the binder fiber. Suitable polymer classes for producing the matrix fibers can include, among others, polyesters, polyamides, polyolefins, polyacrylonitrile, cellulose, and / or polyvinyl alcohols.

[0033] Particularly suitable matrix fibers are hydrophobic matrix fibers.

[0034] The proportion of matrix fibers in the fiber layer is preferably at least 20 wt.%, for example from 20 wt.% to 90 wt.% and / or from 20 wt.% to 80 wt.%, and / or from 20 wt.% to 70 wt.%, more preferably at least 25 wt.%, for example from 25 wt.% to 80 wt.% and / or from 25 wt.% to 70 wt.%, more preferably at least 30 wt.%, for example from 30 wt.% to 70 wt.%, in each case based on the total weight of the fiber layer.

[0035] In a preferred embodiment, the fiber layer comprises a binder, for example, thermoplastic binders and / or binding fibers. Binding fibers are fibers that are at least partially fused, thereby creating bonding points between the fibers. This enables thermal bonding and targeted adjustment of the abrasiveness of the fiber layer. Preferably, at least one fusible fiber component of the binding fiber, in particular an externally arranged fusible fiber component, has a melting point that is lower than the melting point of other fiber components contained in the fiber layer, in particular lower than the melting point of the lowest-melting fiber component of the matrix fibers.

[0036] If the binding fiber comprises multiple meltable fiber components, the melting point of the highest-melting fiber component of the binding fiber is preferably more than 10°C, particularly preferably more than 30°C, below the melting point of the lowest-melting fiber component of the matrix fibers. Suitable binding fibers have a melting point of the highest-melting fiber component of below 250°C, for example, from 100°C to 200°C, even more preferably below 180°C, for example, from 100°C to 180°C, in particular below 175°C, for example, from 100°C to 175°C.

[0037] Preferred fusible components in binding fibers are polyolefin, polyester, polyamide, and / or mixtures thereof, as well as copolymers such as ethylene-vinyl acetate copolymers. Likewise preferred binding fibers are bicomponent fibers, in particular bicomponent fibers containing polyolefin, polyester, ethylene-vinyl acetate copolymers, polybutylene terephthalate, and / or mixtures thereof as the externally arranged fiber component. The binding fibers can have different cross-sectional geometries, such as solid-profile fibers, multilobal solid-profile fibers, hollow fibers, and solid-profile bicomponent fibers (e.g., core / sheath, side-by-side). Fusible binding fibers in the form of solid-profile fibers are preferred.

[0038] Particularly suitable binders are hydrophobic binding fibers, in particular polyester and / or polyolefin fibers.

[0039] The proportion of binding fibers in the fiber layer is preferably at least 10 wt.%, for example from 10 wt.% to 80 wt.% and / or from 10 wt.% to 70 wt.%, and / or from 10 wt.% to 60 wt.%, more preferably at least 25 wt.%, for example from 25 wt.% to 80 wt.% and / or from 25 wt.% to 70 wt.%, and / or from 25 wt.% to 60 wt.%, more preferably at least 30 wt.%, for example from 30 wt.% to 80 wt.% and / or from 30 wt.% to 70 wt.%, and / or from 30 wt.% to 60 wt.%, in each case based on the total weight of the fiber layer.

[0040] Thermoplastic binders can be copolyamide, copolyester, polyolefins, polyvinyl alcohol (PVA), ethylene-vinyl acetate (EVA), thermoplastic polyurethane (TPU), polycaprolactone, terpolymers, and / or mixtures thereof. The thermoplastic binder preferably contains the aforementioned polymers in an amount of more than 50 wt. %, particularly preferably more than 70 wt. %, in particular more than 90 wt. %, in each case based on the total weight of the binder. Preferred thermoplastic binders have a melting point of 90°C to 200°C. Particularly suitable thermoplastic binders are hydrophobic, i.e., made from polymers whose surface energy is less than 50 mJ / m2.

[0041] In a preferred embodiment, the fibers contained in the fiber layer, in particular the matrix fibers and / or the binding fibers, are staple fibers, preferably with a staple length between 20 mm and 150 mm, more preferably between 30 mm and 90 mm and in particular between 40 mm and 70 mm.

[0042] The fiber titer of the fibers contained in the fiber layer, in particular the matrix fibers and / or binding fibers, is preferably in the range of 0.9 dtex to 100 dtex (g / 10,000 m). More preferably, the fiber titer is between 1.5 dtex and 30 dtex, in particular between 3 dtex and 11 dtex.

[0043] Preferably, the fiber layer has an average thickness, determined microscopically, of at least 1.5 mm, for example from 1.5 mm to 10 mm, more preferably of at least 2 mm, for example from 2 mm to 10 mm, and / or from 4 mm to 10 mm and / or from 2 mm to 5 mm and / or from 5 mm to 8 mm.

[0044] The basis weight of the fiber layer is preferably 50 g / m 2< to 400 g / m 2< , more preferably 50 g / m 2< to 350 g / m 2< , even more preferably 50 g / m 2< to 300 g / m 2< , even more preferably 50 g / m 2< to 250 g / m 2< , in particular 50 g / m 2< to 200 g / m 2< .

[0045] According to the invention, a wide variety of foams, particularly polymer foams, can be used as the foam layer. The foam layer is preferably based on polyurethane foam, for example, polyether polyurethane or polyester polyurethane foam, polyetherester polyurethane foam, polyvinyl acetate foam, polyvinyl alcohol foam, or mixtures of these foams. The term "based on" means more than 50 wt.%, more preferably more than 70 wt.%, in particular more than 90 wt.%, based on the polymer content of the foam layer.

[0046] The foam layer particularly preferably contains a hydrophilic polymer foam, i.e. a foam with an absorption capacity of at least 4 g / g, for example from 4 g / g to 50 g / g, preferably from 4 g / g to 30 g / g, and even more preferably from 4 g / g to 25 g / g in a proportion of more than 50 wt.%, even more preferably more than 70 wt.%, in particular more than 90 wt.%, based on the polymer content of the foam layer. Also preferred is a polymer foam made from hydrophilic polymers, preferably hydrophilic polyurethanes, in particular hydrophilic polyurethanes as described in WO2018 / 007093. A hydrophilic polymer foam allows for the rapid absorption of viscous wound components. Furthermore, it enables the soaking of necrotic tissue if it is previously impregnated with wound irrigation solution and applied to the wound. A polyurethane foam is very particularly preferred, as it combines high hydrophilicity with good elasticity and retention.The advantage of good retention is the secure containment of removed wound components, so that recontamination of the wound or the wound environment can be prevented.

[0047] In a particularly preferred embodiment of the invention, the foam layer is open-celled. The term "open-celled" is understood according to the invention to mean that the majority of the pores are connected to one another by pore openings. This is advantageous in that absorbed wound components can be well absorbed into the structure and distributed evenly.

[0048] In a further preferred embodiment, the foam layer has at least one open-cell surface. The term "open-cell surface" is understood according to the invention to mean that the percentage of the area of ​​open pores to the total surface of the foam layer is at least 50%, for example, 50% to 98%, more preferably at least 60%, for example, 60% to 98%, in particular at least 70%, for example, 70% to 98%. The advantage of such an open-cell foam layer is that it has a slightly abrasive character, which allows for the gentle removal of deposits while simultaneously retaining dissolved wound components within the structure, thus preventing wound contamination.

[0049] In another embodiment, the foam layer comprises a reticulated foam. In reticulated foams, the open-cell structure is created by the rupture of the pore walls by means of a gas explosion in the foam pores.

[0050] The basis weight of the foam layer is preferably 50 g / m 2< to 600 g / m 2< , more preferably 80 g / m 2< to 500 g / m 2< , more preferably 100 g / m 2< to 400 g / m 2< , even more preferably 120 g / m 2< to 350 g / m 2< , in particular 120 g / m 2< to 250 g / m 2< .

[0051] The average thickness of the foam layer is preferably 1 mm to 15 mm, particularly preferably 2 mm to 10 mm and particularly preferably 3 mm to 8 mm.

[0052] The average pore size of the foam layer is at least 0.2 mm, for example 0.2 mm to 3 mm, more preferably at least 0.25 mm, for example 0.25 mm to 2.5 mm, in particular at least 0.3 mm, for example 0.3 mm to 2.2 mm.

[0053] In a further preferred embodiment of the invention, the average density of the foam layer is at least 50 kg / m 3< , preferably from 70 kg / m 3< to 150 kg / m 3< and in particular from 90 kg / m 3< to 150 kg / m 3< .

[0054] In a preferred embodiment, the composite material has an absorption capacity of at least 4 g / g, for example from 4 g / g to 50 g / g, preferably from 4 g / g to 30 g / g and more preferably from 6 g / g to 25 g / g.

[0055] The basis weight of the composite material is preferably 100 g / m 2< to 1000 g / m 2< , more preferably 200 g / m 2< to 900 g / m 2< , more preferably 200 g / m 2< to 600 g / m 2< , even more preferably 200 g / m 2< to 500 g / m 2< , in particular 250 g / m 2< to 450 g / m 2< .

[0056] In a preferred embodiment of the invention, the composite material comprises a hydrophilic foam layer in combination with a hydrophobic fiber layer. A hydrophilic foam layer is understood to mean a foam layer with an absorption capacity of at least 4 g / g, for example from 4 g / g to 50 g / g, preferably from 4 g / g to 30 g / g, and even more preferably from 4 g / g to 25 g / g. Also preferred is a foam layer consisting of a polymer foam containing hydrophilic polymers, preferably hydrophilic polyurethanes, in particular hydrophilic polyurethanes as described in WO2018 / 007093, preferably in a proportion of at least 50 wt.%, even more preferably at least 70 wt.%, in particular at least 90 wt.%, based on the total weight of the foam layer.

[0057] In a particularly preferred embodiment, the composite material comprises a hydrophilic foam layer in combination with a hydrophobic fiber layer, wherein hydrophobic fibers of the fiber layer penetrate the hydrophilic foam layer and protrude at least partially from the side of the foam layer facing away from the fiber layer. This embodiment is advantageous in that a bifunctional surface is provided on the foam layer, which, due to the hydrophilic nature of the foam layer, enables rapid absorption of viscous wound components and, at the same time, enables the adsorption of bacteria and other hydrophobic components due to the comparatively high specific surface area of ​​the protruding fibers.

[0058] A hydrophobic fiber layer is understood to mean a fiber layer that contains hydrophobic fibers, i.e., fibers made of polymers whose surface energy is less than 50 mJ / m 2 , preferably in a proportion of at least 50 wt.%, more preferably at least 70 wt.%, in particular at least 90 wt.%, based on the total weight of the fiber layer. Particularly suitable hydrophobic fibers are polyester and / or polyolefin fibers.

[0059] For use in wound cleansing, the wound cleansing article is preferably sterile.

[0060] A further object of the present invention relates to the production of a wound cleansing article according to the invention comprising the following steps: A Arranging an at least partially thermally consolidated fiber layer on a foam layer; B Needling the foam layer and fiber layer such that a composite material is formed in which fibers of the fiber layer have penetrated into the foam layer and form capillary channels extending from the fiber layer into the foam layer.

[0061] A further subject of the present invention relates to an alternative production of a wound cleansing article according to the invention comprising the following steps: A Arranging a fiber layer on a foam layer; B Needling the foam layer and fiber layer to form a composite material in which fibers from the fiber layer have penetrated the foam layer and form capillary channels extending from the fiber layer into the foam layer. C Thermally bonding the composite material. Measurement methods:

[0062] Determination of open-cell surface: The open-cell surface is determined by taking a light microscopic image (interference microscope, green light source) of the foam layer's surface, measuring 1 cm x 1 cm, and then by optical evaluation. The percentage of the area of ​​open pores relative to the total surface of the foam layer is determined.

[0063] Pore ​​diameter of the pores in the foam layer: The pore diameter is determined by optical evaluation of light microscopy images by creating an outer circle. The pore diameter corresponds to the diameter of the outer circle. The average is calculated from the evaluation of at least 10 pores.

[0064] Absorption capacity: For absorption measurements, a test solution as described in BS EN 13726-1:2002 is used. A 100 cm² sample is first weighed (W1), then placed in the test solution and left there for at least ten minutes. The sample is then carefully grasped at one corner without squeezing the sample and allowed to drain for two minutes. The weight is then determined again (W2). The absorption capacity is then calculated by dividing the difference between W2 and W1 by the initial weight W1 as absorption [g] per [g]. Density of the foam layer: The density is determined by cutting out a sample, weighing it, and determining the thickness. The volume is then calculated by multiplying the thickness by the area of ​​the sample and finally dividing the weight by the volume.

[0065] Thickness of the foam layer: The thickness of the foam layer is determined microscopically before needling with the fiber layer. Character description Short description of the drawing

[0066] The drawings show: Fig. 1 the average of a CT image of a composite material according to the invention, Fig. 2 the cross-section of a light microscopy image of a composite material according to the invention after wound cleansing, Fig. 3 the cross-section of a scanning electron microscopy image of a cotton gauze after wound cleaning, Fig. 4 the cross-section of a scanning electron microscopy image of a wound cleansing material according to the invention after wound cleansing, Fig. 5 the defined movement of a wiping cycle for cleaning a test wound on pig skin, Fig. 6 the cross-section of a scanning electron microscopy image of the product Debrisoft ®< after wound cleansing.

[0067] Fig. 1shows the cross-section of a CT image of a composite material 1 according to the invention, which comprises a foam layer 2 and a fiber layer 3 arranged thereon. Foam layer 2 and fiber layer 3 are bonded together by needling, so that fibers of fiber layer 3 have penetrated into foam layer 2 and form capillary channels 4 therein. It can be seen that the capillary channels 4 extend from fiber layer 3 into foam layer 2.

[0068] Fig. 2 shows a cross-sectional light microscopy image of a composite material 1 according to the invention after wound cleansing with the foam side. The figure illustrates the interface between foam layer 2 and fiber layer 3 as boundary line 5. It is clearly visible how wound components are absorbed deep into foam layer 2 and cross boundary line 5, i.e., have penetrated into fiber layer 3.

[0069] Fig. 3This shows a cross-section of a scanning electron microscopy image of a cotton gauze after wound cleansing. It clearly shows how the wound components are only trapped on the surface of the cotton gauze (area within the dotted-dash line).

[0070] Fig. 4 This image shows a cross-section of a scanning electron micrograph of a wound cleansing material according to the invention after wound cleansing. It clearly shows how wound exudate is transported from the foam layer into the fiber layer along the capillary channels formed by the fibers (marked within the dotted line).

[0071] Fig. 5 shows the defined movement of a wiping cycle for cleaning a test wound on porcine skin. The wound surface 6 is cleaned with low pressure (to simulate gentle cleaning) and in a defined horizontal 7 and vertical 8 movement, resulting in a wiping cycle 9.

[0072] Fig. 6This shows a cross-section of a scanning electron microscopy image of Debrisoft® after wound cleansing. It clearly shows how the wound components are only trapped on the surface (area within the oval). Examples Example 1: Making a foam layer

[0073] A water phase is prepared for foam production by dissolving / dispersing the surfactant Pluronic F87 at a concentration of 0.5 wt.%. At the same time, a Teflon mold with sufficient depth to produce a 7 mm thick foam is lined with casting paper. The prepolymer Hypol 2001 is added to the water phase at a concentration of 40 wt.% and mixed at room temperature using a dispersing disc (1600 rpm). The resulting mixture is immediately poured into the mold. It is foamed against air and cured for 10 minutes. The casting paper is then removed and dried at 150 °C for 3 hours. Example 2: Manufacturing a thermally bonded fiber layer

[0074] Staple fibers are used to produce the thermally bonded fiber layer: 70 wt.% polyester fibers (Grisuten® from Märkische Faser GmbH) with a fiber titer of 1.7 dtex and a fiber length of 60 mm, and 30 wt.% of a polyethylene terephthalate / polyethylene core-sheath binding fiber (Trevira® 256 from Trevira GmbH) with a fiber titer of 3 dtex and a fiber length of 50 mm. These staple fibers are laid into a fiber layer using a carding machine according to processes known to those skilled in the art. The basis weight of the fiber layer is 150 g / m². The fiber layer is then thermally bonded in a hot-air oven at 150°C and a speed of 2 m / min. Example 3: Manufacturing a wound cleansing article by mechanically needling a fiber layer and a foam layer

[0075] To produce the wound cleansing article according to the invention, an open-pore foam layer from Example 1 and a thermally bonded fiber layer from Example 2 are provided. In a needling process, the nonwoven layer is needled to the foam layer with a penetration density of 100 / cm² and a penetration depth of 10 mm. The surface of the nonwoven layer that was facing away from the belt side in the oven is on the side facing away from the foam layer surface. The needling process bonds the foam layer and fiber layer to one another. This creates both a mechanically stable composite and a slightly fibrous surface on the foam. Furthermore, the fibers of the fiber layer penetrate the foam layer, form capillary channels in the foam layer, and protrude at least partially from the side of the foam layer facing away from the fiber layer. The resulting composite material exhibits higher abrasiveness on the foam layer than on the fiber layer.Due to the fibers protruding from the foam layer, the foam layer has a more pleasant feel than the pure foam layer. The composite material is then assembled to produce a wound cleansing product. No significant fiber loss occurs during this process. Example 4: Determination of the mechanical stability of the composite material from Example 3

[0076] The mechanical stability of the composite material according to the invention is determined by measuring the tensile strength of the longitudinally oriented tensile test according to EN 29073-03 (deviations: no conditioning and a pull-off speed of 200 mm / min) using a specimen measuring 300 x 50 mm. Dry and wet tensile strength were determined, as wound cleansing materials are typically applied moist. To assess wet tensile strength, the specimens were placed in tap water for approximately 30 minutes, then gently squeezed and hung for 5-10 minutes to drain.

[0077] Table 1 shows a comparison of the maximum tensile strength and maximum tensile elongation for an open-cell foam, the composite material according to the invention, and the standard cotton gauze. The composite material according to the invention has a significantly higher maximum tensile strength in the wet and dry state compared to a pure open-cell foam. By penetrating the foam layer through the fiber layer, the foam layer is mechanically reinforced and the tensile strength increased. In the dry state, this achieves the strength of a standard cotton compress. In the wet state, the composite material according to the invention has a lower but sufficient maximum tensile strength than the standard cotton gauze. The maximum tensile elongation, on the other hand, is significantly higher than that of the cotton gauze. This makes the composite material according to the invention ideally suited for moist wound cleansing, as the high extensibility can prevent tearing during cleansing.Furthermore, the increased stretch offers the advantage that the composite material can adapt better to the wound bed. Table 1: Comparison of mean ultimate tensile force and ultimate tensile force elongation for open-cell foam, a composite material according to the invention and standard cotton gauze Dry Wet Maximum tensile force [N] Maximum tensile force elongation [%] Maximum tensile force [N] Maximum tensile force elongation [%] Open-cell foam layer [2.5 mm] 22,1 165,8 10,2 58,9 Composite material according to the invention [~4 mm] 87,4 135,3 76,0 130,3 Standard cotton gauze [< 1 mm] 83,3 5,0 143,7 8,2 Example 5: Determination of the cleaning performance of the wound cleansing article in an ex-vivo wound model

[0078] The composite material produced in Example 3 was punched to a size of 10 cm x 10 cm to produce a wound cleansing article according to the invention. The cleansing performance of the wound cleansing article according to the invention was evaluated using an ex vivo wound model on porcine skin. The wound to be cleansed was prepared as follows: First, the porcine skin was fixed in a frame (wound area 10 cm x 10 cm) with the inner skin side facing up and scored with a scalpel in the form of a grid pattern. The skin was then lightly burned with a flame beer torch (20 seconds, medium flame, distance approx. 20 cm) so that an uneven wound base was created by gaping the incisions. Any escaping fat was carefully removed by dabbing with a paper towel. Subsequently, 4 mL of egg white solution (100 g / L egg white powder (e.g.Body&Fit Egg White Powder is applied in phosphate-buffered saline solution (8.0 g / L sodium chloride (NaCl), 0.2 g / L potassium chloride (KCl), 1.42 g / L disodium hydrogen phosphate (Na2HPO4) or 1.78 g / L disodium hydrogen phosphate dihydrate (Na2HPO4• 2 H2O), 0.27 g / L potassium dihydrogen phosphate (KH2PO4)) and burned again using a flame burner (30 seconds, medium flame, distance approx. 20 cm). The egg white solution is suitable for simulating fibrin deposits in the wound. In a final step, 2 g of artificial exudate solution (5% Blanose, 40 g / L protein powder, 1 g / L sugar, artificial blood (150 drops to 300 mL, 2 g / L sunflower oil, 3.7 g / L sodium carbonate, 3 g / L quartz sand, all dissolved in PBS) are applied to the wound using a wooden spatula and burned again until a (partial) black crust forms (30 seconds, medium flame, distance approx. 20 cm).The simulated wound is left to rest for 2 hours at room temperature so that previously applied exudate cannot be easily removed.

[0079] For cleaning, the wound cleansing device was moistened with water on the foam side (10 cm x 10 cm) with 5 sprays and placed on the wound with the foam side facing the wound surface for one minute. The wound surface was then cleaned with low pressure (to simulate gentle cleaning) and in a defined horizontal and vertical movement, resulting in a wiping cycle (see Figure 5 ). Cleaning takes place for 3 minutes with 11 wiping cycles.

[0080] The cleaning performance was evaluated by analyzing the burned (black) areas before and after wound cleaning. The prepared pig hides were photographed using a Canon D70 SLR camera with a 60 mm fixed focal length lens and a copy stand. Care was taken to ensure that the illumination and distance (resulting magnification) between the object and the lens remained consistent across all images. During the examination, a metal frame was applied to smooth the pig hides. Using thresholding and a 15 x 15 pixel median filter, the black areas in the image were identified and marked in green. A histogram upper limit of 80 was selected for all images. This, along with the consistent imaging setup, ensures that the results for all samples are comparable. As a final step, the region of interest (ROI) for meaningful evaluation was defined.Due to the calibration of the images during capture, it was subsequently possible to specify the marked areas as area fractions in µm. Table 2: Comparison of the cleaning performance of cotton gauze, Debrisoft ®< and a wound cleansing article according to the invention Area before cleaning [mm 2< ] Area after cleaning [mm 2< ] Cleaning performance in [%] cotton gauze 629,0 286,0 54,5 cotton gauze 1491,0 1010,0 32,3 Debrisoft ®< 3162,0 1276,0 59,6 Debrisoft ®< Inventive 3374,0 1289,0 61,7 Wound cleaning article according to the invention 2924,0 922,0 68,5 Wound cleaning products 59,0 14,0 76,3 Example 6 Determination of the absorption of wound components by the wound cleansing article according to the invention from Example 5

[0081] To determine the absorption of wound components in the wound cleansing product, light and scanning electron microscopy images were taken. One can clearly see ( Figure 2 ) that a transport of wound components beyond the foam layer into the fiber layer occurs. In contrast, absorption occurs with cotton gauze ( Figure 3 Area within dash-dot oval) and Debrisoft ( Figure 6 Area within oval) only on the surface, or in the upper part of the structure. Furthermore, it is evident ( Figure 3dashed area) that the capillary channels enable cross-layer transport and containment of exudate throughout the entire wound cleansing device.

[0082] The wound cleansing article according to the invention is tested for its absorbency compared to cotton gauze and the product Debrisoft® according to BS EN 13726-1:2002. It was found to exhibit increased absorption of the aqueous test solution compared to standard cotton gauze and the product Debrisoft® (see Table 3). This has the advantage of allowing more wound components and fluids, such as irrigation solutions used to support wound cleansing and / or wound exudate, to be absorbed within one wound cleansing application. Table 3: Comparison of the absorption of cotton gauze, Debrisoft ®< and a wound cleansing article according to the invention Absorption [g / g] cotton gauze 5,2 Debrisoft ®< 5,9 Wound cleansing article according to the invention 6,5

Claims

1. Wound cleaning article comprising a composite material (1) which has a foam layer (2) and a fibre layer (3) arranged on and in the foam layer (2), wherein the fibre layer (3) is at least partially thermally consolidated and the foam layer (2) and fibre layer (3) are connected to one another by needling, where fibres of the fibre layer (3) have penetrated into the foam layer (2) and form capillary channels (4) which extend from the fibre layer (3) into the foam layer (2), characterized in that the fibres of the fibre layer (3) penetrate the foam layer (2) and protrude at least partially from that side of the foam layer (2) that faces away from the fibre layer (3).

2. Wound cleaning article according to Claim 1, characterized in that the fibre layer (3) comprises synthetic fibres.

3. Wound cleaning article according to Claim 1 or 2, characterized in that the fibre layer (3) comprises matrix fibres and a binder, more particularly binding fibres.

4. Wound cleaning article according to one or more of the preceding claims, characterized in that the fibre layer (3) comprises hydrophobic fibres, more particularly polyesters and / or polyolefin fibres.

5. Wound cleaning article according to one or more of the preceding claims, characterized in that the fibres contained in the fibre layer (3), more particularly the matrix fibres and / or the binding fibres, are staple fibres, preferably having a staple length of between 20 mm and 150 mm.

6. Wound cleaning article according to one or more of the preceding claims, characterized in that the foam layer (2) comprises a hydrophilic polymer foam in a fraction of more than 50% by weight, more preferably more than 70% by weight, more particularly more than 90% by weight, based on the polymer fraction of the foam layer (2).

7. Wound cleaning article according to one or more of the preceding claims, characterized in that the foam layer (2) is open-celled.

8. Wound cleaning article according to one or more of the preceding claims, characterized in that the foam layer (2) has at least one open-celled surface.

9. Wound cleaning article according to one or more of the preceding claims, characterized by a tensile strength / elongation, measured according to EN 29073-03 (wet), of more than 40%.

10. Wound cleaning article according to one or more of the preceding claims, characterized in that the composite material (1) comprises a hydrophilic foam layer (2) in combination with a hydrophobic fibre layer (3).

11. Wound cleaning article according to Claim 10, characterized in that hydrophobic fibres of the fibre layer (3) penetrate the hydrophilic foam layer (2) and protrude at least partially from that side of the foam layer (2) that faces away from the fibre layer (3).

12. Wound cleaning article according to one or more of the preceding claims, characterized in that it is sterile.

13. Method for producing a wound cleaning article of the invention, comprising steps as follows: A arranging an at least partially thermally consolidated fibre layer (3) on a foam layer (2); B needling foam layer (2) and fibre layer (3) in such a way as to form a composite material (1) in which fibres of the fibre layer (3) have penetrated into the foam layer (2) and form capillary channels (4) which extend from the fibre layer (3) into the foam layer (2).

14. Method for producing a wound cleaning article of the invention, comprising steps as follows: A arranging a fibre layer (3) on a foam layer (2); B needling foam layer (2) and fibre layer (3) in such a way as to form a composite material (1) in which fibres of the fibre layer (3) have penetrated into the foam layer (2) and form capillary channels (4) which extend from the fibre layer (3) into the foam layer (2); C thermally consolidating the composite material (1) .