COMPRESSION BANDAGE

Description

[0001] The invention relates to a compression bandage comprising at least two nonwoven layers.

[0002] Compression bandages are currently used, for example, for diabetic ulcers. The problem here is that, due to the clinical picture, various issues must be considered, namely, sufficient compression, but also a cushioning effect on the limb being treated.

[0003] For example, it may be necessary to apply padding and a compression bandage over it.

[0004] In compression therapy, a fundamental distinction must be made between so-called working pressure and so-called resting pressure. Resting pressure is the pressure exerted on the limb by the compression device (here, the compression bandage) when the limb is in a supine position. Working pressure is the pressure exerted on the limb when the muscles are moving. The working pressure should preferably be 20 to 40 mm Hg above the resting pressure.

[0005] It is also known to use different types of bandages. For example, so-called long-stretch bandages are known, which have very high elasticity and often have an extensibility of over 200%. In contrast, short-stretch bandages are known, which have only low extensibility and only low recovery force, but do not allow further stretching very early on and are thus able to build up a comparatively high working pressure. In contrast, short-stretch bandages build up only low resistance over a comparatively long range and then achieve a very high limitation of extensibility. Traditional short-stretch bandage compression therapy is a measure for the treatment of venous diseases. The materials for short-stretch bandages are usually made of non-elastic materials and elasticized through finishing processes. However, the elasticity decreases significantly during treatment.This can lead to a reduction in compression pressure in the application.

[0006] Known compression bandages are described, for example, in EP 2 275 062 A2, which describes an inner elastic bandage facing the skin with a stretched elastic substrate and a stretched foam layer arranged on the skin-facing side of the substrate, as well as a further stretched self-adhesive elastic bandage applied over this.

[0007] Furthermore, compression bandages made of several nonwoven layers sewn together are known, e.g. from WO 2017 / 109209, which can be combined with another bandage layer if necessary.

[0008] To achieve a high level of therapeutic safety, it is desirable that the therapeutically necessary compression pressure is achieved as accurately as possible. A variety of options are available in the state of the art for this. For example, markers are known that deform when the stretch is too great, allowing the therapist to detect excessive stretching and thus excessive application pressure. A disadvantage, however, is that this always requires trained personnel.

[0009] Furthermore, in the treatment of edema or chronic wounds, the goal is often not only to reduce existing edema and facilitate the accelerated removal of wound exudate, but also to counteract the healing process, particularly in chronic wounds where such compression therapies are used. For example, the wound exudate contains enzymes that prevent the formation of an extracellular matrix. Such enzymes include MMPs (matrix metalloproteinases). Therefore, additional wound dressings must be applied underneath the compression bandage. This poses the risk that the wound dressing will slip relative to the compression bandage and therefore not be effective as intended.

[0010] It is therefore desirable to provide a compression bandage, which can alternatively be referred to as a compression dressing or bandage, which has a high degree of application security while at the same time having good therapeutic properties.

[0011] Where the terms layer or position are used, they refer to the same object.

[0012] Based on this prior art, the invention solves the problem by a compression bandage having the features of claim 1.

[0013] The first nonwoven layer consists of a nonwoven material containing superabsorbent fibers (SAF). Such a bandage has the advantage that, in addition to being able to be worn for several days without a significant drop in compression pressure, the first nonwoven layer is also capable of absorbing and binding wound fluids. Superabsorbent fibers have been shown to inhibit proteases via diffusible mechanisms and, through direct binding, can compartmentalize them, thus removing them from the wound exudate or wound. In particular, superabsorbent fibers have been shown to be suitable for inhibiting proteases in chronic wounds. Furthermore, metalloproteases have been shown to be bound or compartmentalized by superabsorbent fibers, allowing these metalloproteases to be removed from wound fluids or a wound with the superabsorbent fibers.Thus, the superabsorbent fibers can absorb an excess of metalloproteases in chronic wounds in such a way that a natural healing process can take place.

[0014] The first nonwoven layer can consist of a nonwoven material into or onto which superabsorbent fibers are incorporated or applied. According to a special embodiment, the nonwoven material can also consist entirely of superabsorbent fibers.

[0015] The second nonwoven layer and the first nonwoven layer are stitch-bonded together using an elastic thread. The stitch length is 1.5 to 3 mm / rev with a maximum thread tension of 4 cN. The bonding occurs in the unstretched state.

[0016] By means of this design, it can be achieved that the at least two layers are connected by means of the stitch-bonding process and here preferably a Malimo or Maliwatt process, wherein the layers are preferably connected in the unstretched state by means of the elastic sewing thread.

[0017] The advantage of a stitch-bonding process is that a bond can be created in several places at once, and the two layers cannot be separated once they have been joined. By selecting the stitch length in the longitudinal direction of the fabric from which the compression bandages are then made (stitch length being the distance between two stitches in the longitudinal stitch direction), and the sewing thread tension, the extensibility of the elastic composite can be adjusted. This creates a composite of the two layers that can no longer be separated by hand, yet is still controllably elastic. Depending on the selection of these parameters, the finished fabric contracts when relaxed, and wrinkles appear in the material.

[0018] The sewing technique and stitch length of the sewing thread are preferably adjusted so that the fibers on the first nonwoven layer on one side of the two-layer composite provide skin comfort and balancing functions, thus ultimately resulting in the compression bandage having two distinctly different sides that are highly functional for pressure equalization. Furthermore, the stitch length should be adjusted so that the desired absorbent and skin-friendly properties of the first nonwoven layer facing the skin are maintained.

[0019] However, other types of connections are also conceivable, such as needling, adhesive bonding, thermal bonding, welding, and / or pressure bonding. The connection can be made over a surface, even partially, or linearly or at specific points.

[0020] The first nonwoven layer is preferably the side of a compression bandage facing a limb, and the second nonwoven layer is the second side applied thereto. However, an arrangement in the opposite direction is also conceivable, provided that the second nonwoven layer or any additional layers provided allow the passage of exudate. In between, i.e. between the first and second nonwoven layers, or on the side of the second nonwoven layer facing away from the first nonwoven layer, additional layers with a cushioning effect or stabilizing or adhesive functions can be provided. In addition to additional nonwoven layers, film layers or layers made of elastic threads can also be provided. The layers can be continuous or discontinuous and, in particular, can cover the entire surface of the first and / or second nonwoven layer or only partially.

[0021] If a stitch-bonding process is intended, the Malimo or Maliwatt process is used to bond the layers, as is known in the art. For example, elasticity can be achieved by overstitching a rigid nonwoven or woven fabric with permanently elastic elastane threads in the longitudinal direction using the MALIWATT or Malimo stitch-bonding technique. The MALIWATT or Malimo stitch-bonding technique is described in Malimo Nähwirktechnologie (Maelmo Sewing Technology), Ploch, Böttcher, Scharch, VEB Fachbuchverlag Leipzig, 1978, 1st edition.

[0022] Preferably, one or both layers, i.e., the first nonwoven layer and the second nonwoven layer, can be inelastic and are then elasticized, for example, by a stitch-bonding process. This preferably also applies to other optional layers. Alternatively, elasticization can also be achieved by inserting or applying elastic threads or elastic films.

[0023] Further preferably, the first and second nonwoven layers are equal in their extent. In particular, they are formed with flush edges in the width direction. The two nonwoven layers lie flat against one another.

[0024] According to one embodiment, the first nonwoven layer can be a cotton nonwoven layer, in particular a thermofusion nonwoven layer, which may also be pre-needled if necessary. In both processes, namely thermobonding and thermofusion, the fibers of the nonwovens are laid in a specific direction using a combing process and prepared as nonwoven rolls using a textile functionalization process. They are stabilized by temperature or by temperature and pressure for further processing. During the thermofusion process, fibers with different melting points are fused together using hot-air dryers. The superabsorbent fibers are also processed in this process.

[0025] In the thermobonding process, the fibers are fused between heated calender rolls using heat and pressure.

[0026] In both cases, the result is soft, homogeneous nonwovens that are ideal and suitable for technical applications.

[0027] Due to the lack of pressure, the thermofusion process is more suitable for first fleece layers if these are to have a cushioning function.

[0028] The second nonwoven layer can preferably be a thermobonded nonwoven. The thermobonded nonwoven preferably exhibits only low stretchability while maintaining the desired rigidity. Polyester is preferably used as the base material for the nonwoven for the first and / or second nonwoven layer. Alternative materials include viscose, cellulose, alginate, acetate, polyamide, polyethylene, polypropylene, or combinations thereof. In principle, the second nonwoven layer can also contain superabsorbent fibers.

[0029] The superabsorbent fibers are preferably made of an organic material, which may include synthetic and / or natural materials, such as agar, pectin, and guar gum, or synthetic materials, such as synthetic hydrogel polymers. Synthetic hydrogel polymers include, for example, carboxymethylcellulose, alkali metal salts of polyacrylic acids, alkali metal salts of polymethacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene-maleic anhydride copolymers, polyvinyl ethers, hydroxypropylcellulose, polymers and copolymers of vinylsulfonic acid, polyacrylates, polymethacrylates, polyacrylate-polymethacrylate copolymers, polyacrylamides, and the like. Particularly preferred superabsorbent fibers are fibers made of alkali metal salts of polyacrylic acids, alkali metal salts of polymethacrylic acids, polyacrylates, polymethacrylates, or polyacrylate-polymethacrylate copolymers.The hydrogel polymers are preferably lightly cross-linked to make the materials essentially water-insoluble. Cross-linking can occur, for example, through irradiation or covalent, ionic, van der Waals, or hydrogen bonding. Suitable materials are available from various manufacturers, such as BASF and Stockhausen Inc.

[0030] In particular, it is provided that the second absorbent layer comprises a fiber fleece as absorbent material, which comprises a fiber mixture of superabsorbent fibers and supporting fibers. However, it can also be provided that the fiber fleece comprises superabsorbent fibers and supporting fibers, and the supporting fibers are selected from the group of thermoplastic fibers and / or cellulose fibers and / or viscose fibers. Most preferably, the fiber mixture comprises superabsorbent fibers, viscose fibers, and thermoplastic fibers, with polypropylene or polyethylene fibers also preferably being used as thermoplastic fibers. These thermoplastic fibers can also be present as so-called bicomponent fibers in the form of sheath-core fibers.

[0031] The second absorbent material preferably contains a fiber mixture comprising more than 20 wt.%, in particular more than 30 wt.%, preferably more than 40 wt.%, preferably more than 50 wt.%, and particularly preferably more than 60 wt.% superabsorbent fibers. This makes it possible to provide an absorbent pad with particularly high free absorption. A suitably treated wound dressing can remain on a wound for up to three or more days.

[0032] The term "superabsorbent" refers to a water-swellable, essentially water-insoluble material in the form of fibers that is capable of absorbing at least approximately 10 times, preferably approximately 20 times, and most preferably approximately 50 times or more, its weight in water. The superabsorbent material can be formed from an organic material, which can include synthetic and / or natural materials, such as agar, pectin, and guar gum, or synthetic materials, such as synthetic hydrogel polymers.Synthetic hydrogel polymers include, for example, carboxymethylcellulose, alkali metal salts of polyacrylic acids, alkali metal salts of polymethacrylic acids, polyacrylamides, polyvinyl alcohol, ethylene-maleic anhydride copolymers, polyvinyl ethers, hydroxypropylcellulose, polymers and copolymers of vinylsulfonic acid, polyacrylates, polymethacrylates, polyacrylate-polymethacrylate copolymers, polyacrylamides, and the like. Particularly preferred superabsorbent fibers are those made from alkali metal salts of polyacrylic acids, alkali metal salts of polymethacrylic acids, polyacrylates, polymethacrylates, or polyacrylate-polymethacrylate copolymers. The hydrogel polymers are preferably lightly crosslinked to render the materials essentially water-insoluble. Crosslinking can occur, for example, by irradiation or covalent, ionic, van der Waals, or hydrogen bonding.Suitable materials are available from various manufacturers such as BASF and Stockhausen Inc.

[0033] It is further preferred that the first nonwoven layer comprises, as absorbent material, a fiber nonwoven that comprises a fiber mixture of at least 20% by weight superabsorbent fibers, at least 10% by weight viscose or cellulose fibers, and at least 5% by weight thermoplastic fibers. It is particularly preferred that the second absorbent layer comprises, as absorbent material, a fiber nonwoven that comprises a fiber mixture of at least 40% by weight superabsorbent fibers, at least 20% by weight viscose or cellulose fibers, and at least 5% by weight thermoplastic fibers. Due to the proportion of supporting fibers in the fiber nonwoven, the amount of liquid to be absorbed is evenly distributed at the beginning of absorption.

[0034] The two layers, as well as other layers, if they are joined by overstitching, are fed together to a warp knitting machine and joined together by means of an elastic sewing thread, which can preferably be selected from a group consisting of cotton spun crepe threads, cotton twist crepe threads, textured polyamide yarns, textured polyester yarns, rubber threads or polyurethane elastane threads or a combination thereof.

[0035] The sewing thread can also be referred to as the warp thread. The thread runs in the machine direction of the warp knitting machine and not across it.

[0036] The finished, in particular sewn, sheet-like structure of the compression bandage preferably has optimized stretch, wherein it can be provided with particular preference that the maximum extensibility of the compression bandage corresponds to a predetermined optimal stretchability, and any stretching of the compression bandage beyond this is limited by a stretch threshold. In this way, the security of application can be significantly increased because even inexperienced users can stretch the compression bandage up to the stretch threshold, whereby not only the maximum extensibility but also the optimal stretch and thus the optimal compression pressure is achieved and the compression bandage can be applied in this maximally stretched state. The stretch threshold can be set in various ways. For example, the elasticity can be adjusted using thermal treatment (including thermosetting).

[0037] If the bandage serves as a cushioning bandage, in order to achieve an optimal cushioning effect, it can preferably be provided that the thickness of the nonwoven layer serving as a cushioning layer is 0.3-12 mm, preferably 0.4-6 mm and more preferably 0.5-3 mm, particularly preferably 0.6-1.2 mm.

[0038] In the preferred case of a stitch-bonding process, the two layers are laid in a relaxed state after the sewn fabric has been further processed into a compression bandage using longitudinal fabrication. These two layers are then laid in waves to create an irregular surface. This irregular surface, in addition to its primary function as a compensating layer for the compression bandage and its secondary function of adjustable stretchability and thus increased application security, also results in the waves creating a pattern on the surface made up of raised and lowered material. This pattern is not completely eliminated even when fully stretched, thus creating an additional massage or drainage effect during therapy.

[0039] In order to further improve the application security, it may be provided to provide a cohesive coating on the side of the compression bandage facing away from the wearer, in particular the side of the compression bandage facing away from the first nonwoven layer, in particular on the second nonwoven layer.

[0040] One possible design for the compression bandage is a bandage made of two nonwoven layers of polyester material with superabsorbent fibers in at least one of the two layers. The two-layer base fabric is obtained by longitudinally sewing a rigid polyester nonwoven fabric with permanently elastic elastane threads using the MALIWATT stitch-bonding technique. The MALIWATT stitch-bonding technique is described in Malimo Nähwirktechnologie (Maelimo Sewing Technology), Ploch, Böttcher, Scharch, VEB Fachbuchverlag Leipzig, 1978, 1st edition. This compression bandage is coated on one surface with a cohesive adhesive to achieve the desired cohesive adhesive effect.

[0041] The bandage comprises the following composition across both layers: 65% polyester, 8% elastane, 7% synthetic rubber, area weight stretched 105 + / - 20 g / m² according to DIN 61632, extensibility / retraction according to DIN 61632 65 + / -20%

[0042] In order to apply a resting pressure, it can also be provided to combine the compression bandage according to the invention with another compression bandage, in particular to wrap it over, which can be designed, for example, as a long-stretch bandage, ie to provide a compression pressure from the beginning of the stretching, which, however, does not increase abruptly.

[0043] An additional bandage for resting pressure is preferably an elastic, cohesive nonwoven bandage of type 752, trade name NOWOPRESS 752, manufacturer: Karl Otto Braun GmbH & Co. KG, Wolfstein, Germany, as a compression bandage with long-stretch properties. The base fabric is obtained by longitudinally sewing a rigid polypropylene nonwoven with permanently elastic elastane threads using the MALIWATT stitch-bonding technique. The MALIWATT stitch-bonding technique is described in Malimo Nähwirktechnologie (Maelmo Sewing Technology), Ploch, Böttcher, Scharch, VEB Fachbuchverlag Leipzig, 1978, 1st edition. This bandage layer is coated on both surfaces with a cohesive adhesive based on polyisoprene rubber to achieve the desired cohesive adhesive effect.The bandage is constructed as follows: 60% polypropylene, 12% elastane, 28% IR rubber Base fleece: PP spunbond fleece, 35 g / m², thermally embossed Sewing thread 133 dtex elastane (DORLASTAN, BAYER) Sewing thread density 45 threads per 10 cm width Sewing thread stitch length, weave 3 mm, open fringe Surface weight stretched 59 g / m² Elasticity in the longitudinal direction (warp direction) Extensibility / retraction according to DIN 61632 160% / 99% Adhesive strength side A / B 60 cN / cm.

[0044] The invention therefore also relates to a combination bandage comprising the described compression bandage with a first and second nonwoven layer, which in particular provides a working pressure for compression therapy, and a further bandage, which is in particular designed as a long-stretch bandage for the resting pressure.

[0045] The classification into the categories of short-stretch, medium-stretch, or long-stretch bandages is based on their extensibility and can be found, for example, in P. Asmussen, B. Söllner, Compression Therapy Principles and Practice, Urban & Fischer Publishing in Elsevier, 2004, page 121. The extensibility is determined according to DIN 61632.

[0046] The invention is described in more detail below with reference to a drawing. Further advantages and features of the invention will become apparent from the remaining application documents.

[0047] The drawing shows Figure 1 a manufacturing process for such a compression bandage.

[0048] In Figure 1It is shown that a first nonwoven layer 2, which is provided with superabsorbent fibers, and a second nonwoven layer 1 are each fed as roll material. The first nonwoven layer 2 can consist of a nonwoven prefabricated with superabsorbent fibers or entirely of superabsorbent fibers, or a nonwoven material can be coated with superabsorbent fibers in the device 3. The two nonwoven materials 1 and 2 are preferably joined together in a stitch-bonding process by means of a warp-knitting machine, which is provided with the reference number 5, wherein the elasticizing means 4, which here are designed as elastane threads and serve as warp threads, are fed to the warp-knitting machine 5. The stitch-bonding process works with a hook, by means of which the layers are sewn over with the elastic sewing threads.The sewing thread is an elastically pre-stretched thread which is inserted with a predetermined stitch length and a predetermined sewing thread tension, and thus leads to a contraction of the layer composite (fabric) after the elastic material has been relaxed.

[0049] Alternatively, other elasticizing agents can also be used and added.

[0050] If no stitch-bonding process is used, another device 5 can be used in which the layers are joined together and elasticized.

[0051] The material, which is connected to one another in particular via the elastic sewing thread, is then wound onto a roll 6, whereby, if necessary, it can be made up into bandages in the longitudinal direction beforehand.

[0052] The compression bandages designed in this way correspond in their characteristics to a short-stretch bandage, which initially shows almost no increase in force when stretched, in order to then realize a sudden increase and thus a stretch threshold, whereby the stretch threshold here lies in the range of the optimal therapy pressure, so that at maximum stretch of the compression bandage, the optimal therapy pressure for the compression therapy can be set at the same time when applied under this pre-tension.

[0053] The superabsorbent fibers contained in the first nonwoven layer bind wound exudates and draw them away from the wound. This can positively influence wound healing by removing enzymes that can negatively impact healing.

Claims

1. Compression bandage comprising a first nonwoven layer (1) and at least a second nonwoven layer (2) which is connected to the first nonwoven layer in a planar manner, the two nonwoven layers (1,2) being interconnected by means of a stitch-bonding process via an elastic sewing thread (4), characterized in that superabsorbent fibers are provided in the first nonwoven layer.

2. Compression bandage according to claim 1, characterized in that the first nonwoven layer (1) is directed towards a wearer of the compression bandage in the applied state and is designed in particular as a padding layer.

3. Compression bandage according to any one of the preceding claims, characterized in that the first nonwoven layer (1) is a thermofusion nonwoven.

4. Compression bandage according to any one of the preceding claims, characterized in that the second nonwoven layer (2) is a thermobond nonwoven.

5. Compression bandage according to any one of the preceding claims, characterized in that the material of one or both of the layers (1, 2) is inelastic.

6. Compression bandage according to any one of the preceding claims, characterized in that the thickness of the first nonwoven layer (1) is 0.6-1.2 mm.

7. Compression bandage according to any one of the preceding claims, characterized in that the nonwoven material of the first and / or second nonwoven layer (2) comprises polyester, in particular consists thereof.

8. Compression bandage according to any one of the preceding claims, characterized in that the superabsorbent fibers consist of polyacrylate.

9. Compression bandage according to any one of the preceding claims 5-8, characterized in that the elastic sewing threads (4) are selected from a group of cotton spun crepe threads, cotton twisted crepe threads, textured polyamide yarns, textured polyester yarns, rubber threads or polyurethane elastane threads or a combination thereof.

10. Compression bandage according to any one of the preceding claims, characterized in that the compression bandage has a stretch threshold that indicates the maximum stretchability.

11. Compression bandage according to any one of the preceding claims, characterized in that the maximum stretchability corresponds to a therapeutically predetermined application pressure of the compression bandage on a limb of a wearer.

12. Compression bandage according to any one of the preceding claims, characterized in that a side of the compression bandage facing away from the wearer has a cohesive coating.

13. Compression bandage assembly comprising a first compression bandage according to any one of the preceding claims and a second compression bandage which can be applied in particular over the first compression bandage.

14. Compression bandage assembly according to claim 13, characterized in that the first compression bandage applies a working pressure and the second compression bandage applies a resting pressure to a limb in the applied state.