CN113813107A

CN113813107A - Dressing and preparation method thereof

Info

Publication number: CN113813107A
Application number: CN202111087496.7A
Authority: CN
Inventors: 张俊丰; 莫晋文; 董杰
Original assignee: Huizhou Foryou Medical Devices Co Ltd
Current assignee: Huizhou Foryou Medical Devices Co Ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2021-12-21

Abstract

The application discloses a dressing and a preparation method thereof, wherein the dressing comprises: the wound contact layer comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed mode, and the percentage content of the thermoplastic fibers and the gel fibers in the wound contact layer is greater than or equal to 20%. The dressing has high wet strength, can completely fill uneven wound surfaces and can reduce fiber falling when being removed after use.

Description

Dressing and preparation method thereof

Technical Field

The application relates to the field of wound treatment, in particular to a dressing and a preparation method thereof.

Background

The dressing widely applied to acute and chronic wound care at present comprises a gel wound contact layer with high absorption performance, such as non-woven fabric dressings of alginate fiber dressings, carboxymethyl cellulose fiber dressings, carboxymethyl chitosan fiber dressings and the like. The dressing is soft and has good application property, and can completely contact with wound. Moreover, the dressing can absorb the exudate to form soft gel after contacting the exudate of the wound, so that the dressing can completely fill the uneven wound surface, and avoid the phenomenon that the local exudate can not be absorbed to form dead space to cause impregnation and infection.

However, due to the structural problem of the non-woven fabric, the dressing is fluffy, surface fibers are easy to fall off, when the dressing absorbs seepage liquid to form gel, the strength of the dressing is greatly reduced, the dressing is broken and the fibers fall off, so that part of the dressing can remain in a wound to cause risks, the wound must be cleaned, pain and discomfort of a patient are increased, and the healing time is delayed.

Disclosure of Invention

The purpose of this application is to solve among the prior art dressing easy breakage and the fibre easily drops, leads to the fibre probably to remain and causes the problem of risk in the wound.

In order to achieve the purpose, the scheme adopted by the application is as follows:

a dressing, comprising: the wound contact layer, wherein the wound contact layer comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed mode, and the percentage content of the thermoplastic fibers and the gel fibers in the wound contact layer is greater than or equal to 20%.

Optionally, the wound contact layer is made of gel fibers and thermoplastic fibers by a hot air process, a needle punching process or a needle punching followed by hot rolling process.

Optionally, the amount of thermoplastic or gelling fibres in the wound contact layer is between 20% and 80% of the wound contact layer.

Optionally, the dressing further comprises a liquid absorbent layer disposed on one side of the wound contact layer; the liquid absorption layer comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed mode, wherein the percentage content of the gel fibers in the liquid absorption layer is larger than the percentage content of the thermoplastic fibers in the liquid absorption layer; the percentage content of thermoplastic fibres in the wound contact layer is greater than the percentage content of thermoplastic fibres in the wicking layer.

Optionally, the thermoplastic fibers content in the liquid absorbent layer is 5% to 20% of the liquid absorbent layer, and/or the gelling fibers content in the liquid absorbent layer is 80% to 95% of the liquid absorbent layer.

Optionally, the dressing further comprises a surface layer, wherein the liquid absorbent layer is located between the wound contact layer and the surface layer, the surface layer and the wound contact layer being the same.

Optionally, the liquid absorbing layer is made of gel fibers and thermoplastic fibers through a needle punching process, a hot air process or a needle punching and hot rolling process.

Optionally, an antimicrobial agent is also included in any one or more of the wicking layer, the surface layer, and the wound contact layer.

Optionally, the gelling fibres in the wound contact layer and/or the wicking layer comprise any one or a mixture of at least two of alginate fibres, carboxymethyl cellulose fibres or carboxymethyl chitosan fibres in any ratio.

The application also provides a preparation method of the dressing, which comprises the following specific steps:

step S1: providing gel fibers and thermoplastic fibers according to a preset proportion, and uniformly mixing the gel fibers and the thermoplastic fibers to form mixed fibers, wherein the thermoplastic fibers and the gel fibers account for more than or equal to 20 percent of the mixed fibers;

step S2: processing the mixed fibers by a hot air process, a needling process or a needling-first and then hot rolling process to form a wound contact layer;

step S3: providing other functional layers;

step S4: the wound contact layer is compounded with other functional layers to form the dressing.

In step S1, the method further includes: the blended fibers are opened and carded to form a web of fibers.

Wherein, in the step S2, the hot air temperature of the hot air process is 130-150 ℃, and the hot air shaping time is 40-60 seconds; or the needling density of the needling process is 450-²Deep needle penetrationThe degree is 4-6 mm; or the hot rolling process in the technology of firstly needling and then hot rolling has the temperature of 180-200 ℃ and the pressure of 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds.

Wherein, in step S1, the thermoplastic fiber content or the gelling fiber content of the wound contact layer is 20% to 80% of the wound contact layer.

Wherein in step S3, the other functional layer comprises providing a liquid absorbent layer on the wound contact layer side; the liquid absorbing layer is formed by processing gel fibers and thermoplastic fibers which are mixed according to a preset proportion through a hot air process, a needling process or a needling-first and then hot rolling process;

wherein the percentage content of the gel fibers in the liquid absorbing layer is larger than the percentage content of the thermoplastic fibers in the liquid absorbing layer; percentage content of thermoplastic fibers in the wound contact layer.

Wherein the thermoplastic fiber content in the liquid absorbent layer accounts for 5-20% of the liquid absorbent layer, and/or the gel fiber content in the liquid absorbent layer accounts for 80-95% of the liquid absorbent layer.

In step S3, the other functional layers further include providing a surface layer, wherein the liquid absorbent layer is located between the wound contact layer and the surface layer, and the surface layer is formed by processing the gel fibers and the thermoplastic fibers mixed according to a predetermined ratio through a hot air process, a needle punching process or a hot rolling process after needle punching.

Wherein in step S4, compounding the wound contact layer with other functional layers to form a dressing comprises: the wound contact layer and other functional layers are compounded to form the dressing through a hot rolling bonding process, an ultrasonic welding process or a needle punching and then hot rolling process.

Wherein, in step S4, the temperature of the hot rolling bonding process is 180-200 deg.C, and the pressure is 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds.

Wherein, in step S4, the ultrasonic frequency of the ultrasonic welding process is 10KHz-20KHz, the power is 2.5KW-3.5KW and the pressure is 4.5kg/cm²-5.5kg/cm²。

Wherein, before step S1, the method further includes: antibacterial agents are added to the gelling fibres.

The beneficial effect that this application possesses lies in: a dressing provided herein includes a wound contact layer. Wherein, the wound contact layer comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed way, and the percentage content of the thermoplastic fibers and the gel fibers in the wound contact layer is more than or equal to 20 percent. On the one hand, the gel fibers and the thermoplastic fibers are arranged in a mutually crossed mode, so that the structural strength between the gel fibers and the thermoplastic fibers in the dressing is increased, the acting force of adhesion between the gel fibers and the thermoplastic fibers is enhanced, the dressing can keep the integrity after being used and removed, and the fibers are reduced from falling off. On the other hand, the thermoplastic fibers and the gel fibers in the wound contact layer are arranged to account for more than or equal to 20 percent of the wound contact layer, wherein the thermoplastic fibers can enable the dressing to have higher wet strength and increase the liquid absorption capacity of the dressing, the gel fibers can enable absorbed seepage liquid to be generated into gel, and the generated gel is soft enough, so that the good application performance of the dressing is maintained.

Drawings

Fig. 1 is a schematic view of a dressing provided herein.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the specific embodiments described herein are merely illustrative of the application and are not limiting of the application. It should be further noted that, for the convenience of description, only some of the structures related to the present application are shown in the drawings, not all of the structures. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "comprising" and "having," as well as any variations thereof, in this application are intended to cover non-exclusive inclusions. For example, a process, method, article, or apparatus that comprises a list of steps is not limited to those listed, but may alternatively include other steps not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that the content, ingredient, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In order to explain technical contents, technical steps, and objects and effects achieved by the present invention in detail, the following detailed description is given with reference to the accompanying drawings in combination with the embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a dressing provided in the present application. In one aspect of the present application, a dressing 10 is provided that includes a wound contact layer 100. Wherein, the wound contact layer 100 comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed way, and the percentage content of the thermoplastic fibers and the gel fibers in the wound contact layer 100 is more than or equal to 20%.

Specifically, the cross arrangement of the gelling fibers and the thermoplastic fibers in the wound contact layer 100 increases the strength of the structural bond between the gelling fibers and the thermoplastic fibers in the dressing 10, which in turn enables the dressing 10 to maintain its integrity when removed after use, reducing fiber drop. Moreover, the percentage content of the thermoplastic fibers and the gelling fibers in the wound contact layer 100 is greater than or equal to 20%, wherein the thermoplastic fibers can provide high wet strength for the dressing 10, so that the dressing 10 can absorb a large amount of wound exudate, the gelling fibers can generate gel from the absorbed exudate, and the gel generated by the gelling fibers in the content ratio is soft enough to maintain good application performance of the dressing 10.

In some embodiments, the thermoplastic fibers and gelling fibers in the wound contact layer 100 are each present in an amount of 20% to 80% of the wound contact layer 100. Specifically, the thermoplastic fiber is present in an amount of 20% to 80% of the wound contact layer 100, and the gelling fiber is present in an amount of 80% to 20% of the wound contact layer 100. That is, the sum of the percentages of thermoplastic fibers and gelling fibers in the wound contact layer 100 equals 100%, except for some unavoidable impurities. For example, in some embodiments, the thermoplastic fibers are 20%, 35%, 50%, or 80%, etc. and the corresponding gelling fibers are 80%, 65%, 50%, or 20%, etc.

The thermoplastic fibers in the wound contact layer 100 have the characteristics of low density, high specific strength and high specific stiffness, so that high wet strength can be provided for the wound contact layer 100, the liquid absorption capacity of the wound contact layer 100 is improved, the melting point of the thermoplastic fibers is low, the thermoplastic fibers are easy to adhere to the gel fibers, and the overall strength of the dressing 10 is further improved. The gelling fibers in the wound contact layer 100 change the exudate into a single-phase elastic gel state when contacting the wound exudate, i.e., the exudate can be gelled, and the gelling fibers are more soft than the gel generated by the gelling fibers, so as to maintain the good application performance of the dressing 10.

In some embodiments, the wound contact layer 100 is made of gel fibers and thermoplastic fibers by a hot air process, a needle punching process, or a needle punching followed by hot rolling process.

Specifically, the wound contact layer 100 is a composite fiber in which gel fibers and thermoplastic fibers are formed into an interdigitated structure through a hot air process, a needle punching process, or a needle punching and then hot rolling process. The hot air process is a production and manufacturing mode that hot air penetrates through the fiber web of the gel fibers and the thermoplastic fibers to enable the fibers to be heated and melted to be bonded so as to form a cross structure, the structural strength of the manufactured wound contact layer 100 is large enough, the gel fibers and the thermoplastic fibers are combined more firmly, the purpose that the dressing 10 reduces fiber breakage and falling is achieved, and the wound contact layer 100 manufactured through the hot air process has the advantages of being fluffy, soft, good in elasticity, strong in heat retention and the like. And the needle-punching process is to form the wound contact layer 100 having a certain strength and bulkiness by entangling the fibers of the fibrous web of the gel fibers and the thermoplastic fibers with each other by means of needle-punching. The process of firstly needling and then hot rolling is the same as that of needling, firstly the wound contact layer 100 with certain strength and bulkiness is formed, then the wound contact layer 100 is plasticized and cooled through different hot rolling parameters, and finally the optimized wound contact layer 100 is manufactured, wherein the surface of the wound contact layer 100 can be smoother and not rough compared with the wound contact layer 100 formed only by the needling process, so that the purposes of flattening the surface of the dressing 10 and completely filling the surface of the wound are achieved.

In some embodiments, dressing 10 further comprises a liquid absorbent layer 200, and liquid absorbent layer 200 is disposed on one side of wound contact layer 100. Wherein the liquid absorbent layer 200 also comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed manner, and the content of the gel fibers in the liquid absorbent layer 200 in percentage in the liquid absorbent layer 200 is greater than the content of the thermoplastic fibers in the liquid absorbent layer 200 in percentage in the liquid absorbent layer 200; the percentage content of thermoplastic fibers in the wound contact layer 100 is greater than the percentage content of thermoplastic fibers in the wicking layer 200.

The reason why the percentage content of the gelling fibers in the liquid absorbent layer 200 to the liquid absorbent layer 200 is greater than the percentage content of the thermoplastic fibers in the liquid absorbent layer 200 to the liquid absorbent layer 200 is to enable the liquid absorbent layer 200 to contain more gelling fibers and thus to have higher gel generation capacity, and the gel generated by the gelling fibers at such a content is sufficiently soft and easily attached to the wound. The reason why the percentage content of the thermoplastic fibers in the wound contact layer 100 is greater than that of the thermoplastic fibers in the liquid absorbent layer 200 is to enable the wound contact layer 100 closer to the affected part of the wound to contain more thermoplastic fibers and to have higher wet strength, thereby being able to absorb more exudate. And the thermoplastic fibers have the characteristic of being easy to bond with the gel fibers, so that the bonding acting force between the thermoplastic fibers and the gel fibers is stronger, and the structure formed by the fibers in a crossed manner is stronger, thereby reducing the falling of the dressing 10.

In a specific embodiment, the thermoplastic fiber content in the liquid absorbent layer 200 is 5% to 20% of the liquid absorbent layer 200, and/or the gelling fiber content in the liquid absorbent layer 200 is 80% to 95% of the liquid absorbent layer 200. That is, the absorbent layer 200 only requires that the thermoplastic fiber content be 5% to 20% of the absorbent layer 200; or, the content of the gel fiber in the liquid absorbing layer 200 is only required to be 80% -95% of the liquid absorbing layer 200; alternatively, the content of thermoplastic fibers in the liquid absorbent layer 200 is 5% to 20% of the liquid absorbent layer 200, and the content of gelling fibers in the liquid absorbent layer 200 is 95% to 80% of the liquid absorbent layer 200.

More specifically, in some embodiments, the thermoplastic fiber content in the liquid absorbent layer 200 may comprise, for example, 5%, 10%, or 20% of the liquid absorbent layer 200. Alternatively, the gel fiber content in the liquid absorbent layer 200 may be 95%, 90%, 80%, or the like of the liquid absorbent layer 200. Alternatively, the thermoplastic fiber content in the liquid absorbent layer 200 may account for 5%, 10% or 20% of the liquid absorbent layer 200, and the gel-like fiber content in the liquid absorbent layer 200 corresponding thereto accounts for 95%, 90% or 80% of the liquid absorbent layer 200, and the like.

In some embodiments, wicking layer 200 is also made from gelling fibers and thermoplastic fibers by a needle punching process, a hot air process, or a needle punching followed by hot rolling process.

The purpose of using the needling process, the hot air process or the hot rolling process after needling in the liquid absorbent layer 200 is the same as the purpose of using the needling process, the hot air process or the hot rolling process after needling in the wound contact layer 100, so that the surface of the prepared liquid absorbent layer 200 is smoother and not rough, and the purposes of flattening the surface of the dressing 10 and completely filling the surface of the wound are achieved; or the fibers are mutually crossed and wound more tightly and orderly, so that the purposes that the surface structure strength of the dressing 10 is high and the fibers are not easy to drop are achieved.

In some embodiments, the dressing 10 further comprises a surface layer 300, and the surface layer 300 is disposed on the other side of the liquid absorbent layer 200. The liquid absorbent layer 200 is located between the wound contact layer 100 and the surface layer 300, and the surface layer 300 and the wound contact layer 100 may have the same or different compositions and structures.

Because of the similarity in structure and composition of the wound contact layer 100 and the wicking layer 200, the shape and color of the two layers are also quite similar. Therefore, in practical applications, the wound contact layer 100 and the liquid absorbent layer 200 are not easily distinguished. In some embodiments, the surface layer 300 is the same as the wound contact layer 100, so that the wound contact layer 100 is equivalently arranged on both sides of the liquid absorbent layer 200, and a foolproof effect is achieved, so that the wound contact layer 100 is not required to be distinguished from the bottom layer during use, the use is convenient, the convenience is improved, and the time is saved. While in some specific embodiments, when the surface layer 300 and the wound contact layer 100 are different, the surface layer 300 merely serves to protect the liquid absorbent layer 200, and also, the surface layer 300 and the wound contact layer 100 can be made to be clearly distinguishable. For example, some special pigments or patterns are added to the surface layer 300 to enable the surface layer 300 to be distinctly different from the wound contact layer 100.

In some embodiments, when the composition and structure of the surface layer 300 and the wound contact layer 100 are the same, the gelling fibers in the wound contact layer 100, the liquid absorbent layer 200, or the surface layer 300 comprise any one of alginate fibers, carboxymethyl cellulose fibers, or carboxymethyl chitosan fibers, or a mixture of at least two thereof, in any ratio.

Among them, since alginate fibers, carboxymethyl cellulose fibers or carboxymethyl chitosan fibers have a strong exudate gelation ability when contacting wound exudate and have no specific chemical reaction when they are mixed with each other, any one or at least two of the alginate fibers, carboxymethyl cellulose fibers or carboxymethyl chitosan fibers may be mixed in any ratio in some embodiments.

More specifically, the thermoplastic fibers in the wound contact layer 100, the liquid absorbent layer 200, or the surface layer 300 are ES fibers.

The ES fibers are bicomponent fibers, the bicomponent fibers are of a sheath-core structure and comprise high-density polyethylene and polyethylene terephthalate or comprise high-density polyethylene and polypropylene (HDPE/PET or HDPE/PP), specifically, the skin layer of the sheath-core structure is made of high-density polyethylene (HDPE), the sheath-core structure has the characteristics of low melting point and easiness in bonding with other fibers, and the core layer is made of polyethylene terephthalate or polypropylene (PET or PP), so that the sheath-core structure can provide high wet strength for the dressing 10.

In some embodiments, the wound contact layer 100, the wicking layer 200, or the surface layer 300 are combined to form the dressing 10 by means of a hot rolling process, an ultrasonic welding process, or a hot rolling process after needling.

Different hot rolling parameters in the hot rolling process have different physical and mechanical property influences on the fiber layers, so that plasticization among fibers is facilitated, and the dressing 10 is in closer contact with the fiber layers, so that the falling of the fibers is reduced. Because the ultrasonic welding process is to melt the fiber layer and then cool the fiber layer to obtain the composite fiber with a multilayer structure, the structural strength of the dressing 10 is higher, and the falling of the fiber is reduced. Because the needling technology can make the fibre intercrossing winding in the fibrous layer inseparabler and orderly, be favorable to promoting dressing 10's surface strength to again through the process of hot rolling with dressing 10 after the acupuncture, can make dressing 10's surface more level and more smooth and not rough, thereby reach dressing 10 surfacing and can fill the purpose on wound surface completely.

In some embodiments, any one or more of the wound contact layer 100, wicking layer 200, or surface layer 300 further comprises an antimicrobial agent.

Wherein, the addition of the antibacterial agent in the dressing 10 can effectively treat the wound of a patient, thereby achieving the purposes of antibiosis and bacteriostasis. Furthermore, the silver ion antibacterial agent has broad-spectrum antibacterial and bacteriostatic activity, and a proper amount of the silver ion antibacterial agent is added in the dressing 10, so that gram-positive bacteria or gram-negative bacteria, certain molds and yeasts in the wound can be effectively killed and killed.

In some embodiments, the antimicrobial agent is any one of silver sulfate or silver chloride.

Wherein, the silver ion in the silver sulfate or the silver chloride is easy to adhere to the fiber in the dressing 10, and the dressing 10 containing a proper amount of the silver sulfate antibacterial agent or the silver chloride antibacterial agent has smoother touch, has no greasiness, and is suitable for clinical use.

In another aspect of the present application, there is provided a method of preparing a dressing as described above, the method comprising:

step S1: providing gel fibers and thermoplastic fibers according to a preset proportion, and uniformly mixing the gel fibers and the thermoplastic fibers to form mixed fibers, wherein the thermoplastic fibers and the gel fibers account for more than or equal to 20 percent of the mixed fibers.

Step S2: and processing the mixed fibers by a hot air process, a needling process or a needling-first and then hot rolling process to form the wound contact layer.

Step S3: other functional layers are provided.

Step S4: the wound contact layer is combined with other functional layers to form the dressing.

Wherein, through foretell step, thermoplastic fiber and the gel fibre homogeneous mixing of predetermineeing the proportion, thereby form the wound contact layer through hot-blast bonding, the acupuncture shaping or acupuncture earlier hot rolling again, can make the wound contact layer form the three-dimensional spatial structure of intercrossing setting between the fibre, and can firmly pin certain content thermoplastic fiber, for dressing provides higher wet state intensity and avoids the fibre to drop, and because the fibrous existence of certain content gel, can form soft gel with the sepage after the wound contact layer reaches the wound sepage, fill the wound surface of unevenness completely, avoid local sepage unabsorbable. The wound contact layer is compounded with other functional layers, so that higher gel generation capacity can be provided for the dressing, and the structure of the dressing is more fluffy and firm, and is easy to realize practical application.

In some other embodiments, before step S1, the method further includes: silver ion antibacterial agent is added into the gel fiber.

Specifically, firstly, adding gel fibers into an ethanol aqueous solution containing silver chloride or silver sulfate particles for soaking so as to adsorb a silver ion antibacterial agent on the surfaces of the gel fibers, then taking out the gel fibers, removing redundant solution in the gel fibers through pressing, then soaking the gel fibers in an ethanol solution containing alcohol-soluble resin so as to wrap and fix silver ion-containing antibacterial agent particles on the surfaces of the gel fibers, and finally, pressing and drying the gel fibers to prepare the gel fibers containing the silver ion antibacterial agent.

In a specific embodiment, the alcohol-soluble resin is polyvinyl butyral or polyvinyl acetate, and the content is 0.5% to 3.0% (w/w). For example, the content of polyvinyl butyral or polyvinyl acetate is 0.5%, 1.0%, 2.0%, or 3.0%.

In one embodiment, the concentration of the silver sulfate antimicrobial agent is 0.20% to 0.30%, for example, the concentration of the silver sulfate antimicrobial agent is 0.20%, 0.25%, or 0.30%. Alternatively, in another embodiment, the concentration of the silver chloride antimicrobial agent is 3.0% to 4.0%, for example, the concentration of the silver chloride antimicrobial agent is 3.0%, 3.5%, or 4.0%.

In one embodiment, the silver ion antibacterial agent is present in an amount of 0.1% to 2.0% by dry weight of the dressing. For example, the silver ion antimicrobial agent may be present at 0.1%, 1.0%, 1.5% or 2.0% of the dry weight of the dressing.

In some other embodiments, the above step S1, the gelling fibers and the thermoplastic fibrous tissue are mixed using a two-motion fly-cutter dispersive mixing technique to form mixed fibers. The technical core is as follows: the fibers in the form of bundles and lumps are broken up by a high-speed rotating fly cutter, and a mixed fiber is formed between the fibers outside the fly cutter by centrifugal force given to the fibers by the fly cutter while the fibers are broken up.

In some other embodiments, the step S1 further comprises, after the step of making the hybrid fiber: the blended fibers are opened and carded to form a web of fibers.

Specifically, the opening and carding process of the mixed fiber is also called as the free loosening and holding loosening process of the fiber, the free loosening of the fiber is to loosen the large (bundle) fiber in the mixed fiber into small (bundle) fiber by using needle punching, the holding loosening of the fiber is to make the small fiber which is entangled and curled mutually generate strain under the action of axial and radial stress, so that the fatigue phenomenon of partial fiber occurs, the self strength and the bending rigidity are reduced, the bending deformation is generated to separate into single fiber, and finally the fiber is straightened to be parallel, and the fibers with different physical properties are fully mixed, uniformly distributed and transferred to form the fiber cotton net with mutually crossed structures.

In some other embodiments, in step S1, the thermoplastic fibers or the gel fibers are both 20% to 80% of the blended fibers. It should be noted that, since the mixed fibers in step S1 are finally processed into the wound contact layer, that is, the content of the thermoplastic fibers or the gel fibers in each wound contact layer is 20% to 80% of the corresponding wound contact layer. Specifically, in some embodiments, the thermoplastic fibers are present in an amount of 20% to 80% of the blended fibers, and the gelling fibers are also present in an amount of 80% to 20% of the blended fibers. That is, the sum of the percentages of thermoplastic fibers and gelling fibers in the wound contact layer equals 100%, except for some unavoidable impurities. For example, the thermoplastic fibers are 20%, 35%, 50% or 80% by weight, while the corresponding gelling fibers are 80%, 65%, 50% or 20% by weight.

In some other embodiments, in step S2 above; the mixed fibers are formed into a wound contact layer by a hot air process. Wherein the hot air temperature of the hot air process is 130-150 ℃, and the hot air shaping time is 40-60 seconds. More specifically, the hot air temperature of the hot air process is 130 ℃, 140 ℃ or 150 ℃, and the hot air setting time is 60 seconds, 50 seconds or 40 seconds.

The thermoplastic fiber is made of high-density polyethylene, the melting point of the thermoplastic fiber is low, the high-density polyethylene is in a molten state when hot air passes through the thermoplastic fiber, the thermoplastic fiber can be bonded with the gel fiber, and finally the bonded fiber cotton net is cooled to form the wound contact layer which is high in fiber structure strength and is arranged in a mutually crossed mode.

In some other embodiments, the mixed fibers may also be formed into a wound contact layer by a needle punching process in step S2. Wherein the needling density of the needling process is 450-²The needling depth is 4-6 mm. More specifically, the needling density of the needling process is 450 punches/cm²500 thorn/cm²Or 550 thorn/cm²The depth of the corresponding prick is 6mm, 5mm or 4 mm.

Wherein, because 1 or 2 fibre can be colluded to the stroke every time of acupuncture, the degree of depth and the density of acupuncture are higher moreover, therefore almost every fibre can all obtain the winding in the fibre web, can form the wound contact layer that fibrous structure intensity is high and intercrossing set up with this cellucotton net through acupuncture many times.

In some other embodiments, the blended fibers may also be formed into a wound contact layer by a needle punching and hot rolling process in step S2. The operation steps of the needling process are the same as those of the wound contact layer formed by the needling process in the previous embodiment, and the wound contact layer obtained by the needling process is subjected to a hot rolling and bonding procedure to obtain the optimized wound contact layer. Wherein the temperature in the hot rolling bonding process is 180-200 ℃, and the pressure is 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds. For example, the temperature of the hot-rolling bonding process is 180 ℃, 190 ℃ or 200 ℃, and the pressure corresponding thereto is 2.5kg/cm²、2.0kg/cm²Or 1.5kg/cm²And the hot rolling time corresponding thereto is 70 seconds, 60 seconds or 50 seconds.

The hot rolling and bonding process is that the fiber web containing the low-melting-point thermoplastic fibers is placed in a bonding action area formed by a pair of hot roll systems, the low-melting-point thermoplastic fibers in the fiber web are softened and melted under the combined action of the temperature and the pressure of the hot rolls to generate bonding action, and after the fiber web leaves the bonding area, the fiber web is cooled and reinforced to form the wound contact layer which is high in fiber structure strength, mutually crossed and flat in surface.

In some other embodiments, in step S2, the grammage of each wound contact layer is set to 10-50 g/m according to the preset proportion and material of the gel fibers and the thermoplastic fibers². For example, the grammage of the wound contact layer is 10g/m²、30g/m²Or 50g/m²。

In some other embodiments, the other functional layer in step S3 above comprises a liquid absorbent layer, wherein the liquid absorbent layer is disposed on one side of the wound contact layer. The liquid absorbing layer is formed by uniformly mixing gel fibers and thermoplastic fibers according to a preset proportion to form mixed fibers, and then processing the mixed fibers through a needle punching process, a hot air process or a needle punching and hot rolling process. The percentage content of the gel fibers in the liquid absorbing layer is larger than the percentage content of the thermoplastic fibers in the liquid absorbing layer; the percentage content of thermoplastic fibres in the wound contact layer is greater than the percentage content of thermoplastic fibres in the wicking layer.

Wherein, the percentage content that the gel nature fibre accounts for the imbibition layer in setting up the imbibition layer is greater than the percentage content that thermoplastic fiber accounts for the imbibition layer in the imbibition layer is in order to make the imbibition layer contain more gel nature fibre to make the dressing have higher production gel ability, and the gel that produces under this kind of content accounts for is enough soft, can laminate the wound better. Set up thermoplastic fiber's percentage content in the wound contact layer and be greater than thermoplastic fiber's percentage content in the imbibition layer in order to make the wound contact layer that is closer to the wound affected part contain more thermoplastic fiber to have higher wet strength, make the dressing have better imbibition ability and utilize thermoplastic fiber easily with the characteristics of gelatinous fibre bonding, make the adhesive effort stronger between thermoplastic fiber and the gelatinous fibre, the structure of intercrossing setting is stronger between the fibre, and then reduce dropping of dressing.

The forming process of the liquid absorption layer is the same as that of the wound contact layer, and the silver ion antibacterial agent is required to be added into the gel fibers, then the gel fibers and the thermoplastic fibers in a preset proportion are mixed through fiber tissues to form mixed fibers, then the mixed fibers are opened and carded to form a fiber cotton net, and finally the fiber cotton net is formed through a hot air process, a needling process or a needling and hot rolling process.

In some other embodiments, the thermoplastic fiber content in the liquid absorbent layer is between 5% and 20% of the liquid absorbent layer and/or the gelling fiber content in the liquid absorbent layer is between 80% and 95% of the liquid absorbent layer. That is, the liquid absorbent layer only requires that the thermoplastic fiber content is 5% to 20% of the liquid absorbent layer; or the content of the gel fiber in the liquid absorbing layer is only required to be 80-95 percent of the liquid absorbing layer; or the content of the thermoplastic fibers in the liquid absorbing layer is 5-20% of the liquid absorbing layer, and the content of the gel fibers in the liquid absorbing layer is 80-95% of the liquid absorbing layer.

Specifically, for example, the thermoplastic fiber content in the liquid absorbent layer is 5%, 10%, 15%, or 20% of the liquid absorbent layer; alternatively, the absorbent layer has a content of the gelling fibres of 95%, 90%, 85% or 80% of the absorbent layer. Alternatively, the thermoplastic fiber content in the liquid absorbent layer may be 5%, 10% or 20% of the liquid absorbent layer, and the gel fiber content in the liquid absorbent layer corresponding thereto may be 95%, 90% or 80% of the liquid absorbent layer 200, or the like.

In some other embodiments, the grammage of each liquid absorbent layer is set to 50-250 g/m according to a predetermined ratio and materials of the gel fibers and the thermoplastic fibers². For example, the absorbent layer has a grammage of 50g/m²、100g/m²、150g/m²Or 250g/m²。

In some other embodiments, in step S3, the other functional layers in step S3 further include a surface layer, and the surface layer is disposed on the other side of the liquid absorbent layer; the wicking layer is located between the wound contact layer and the surface layer. Further, the composition and structure of the surface layer and the wound contact layer may be the same or different.

In particular, because the wound contact layer and the wicking layer are similar in structure and composition, the shape and color of the two layers are also very similar. Therefore, in practical applications, the wound contact layer and the liquid absorbent layer are not easily distinguished. In some embodiments, the surface layer is the same as the wound contact layer, so that the wound contact layer is equivalently arranged on the two sides of the liquid absorption layer, a foolproof effect is achieved, the bottom layer is the wound contact layer without being distinguished specially during use, use is facilitated, convenience is improved, and time is saved. In some embodiments, when the surface layer and the wound contact layer are different, the surface layer merely serves to protect the liquid absorbent layer, and may also be made to be clearly distinguishable from the wound contact layer. For example, special pigments or patterns may be added to the surface layer to enable the surface layer to be distinctly different from the wound contact layer.

In some other embodiments, the wound contact layer is combined with other functional layers to form the dressing in step S4 by a hot rolling process, an ultrasonic welding process, or a needle punching and hot rolling process.

In some embodiments, the wound contact layer is laminated with other functional layers, such as the wicking layer and/or the surface layer described above, by a hot rolling process to form the dressing. Wherein the temperature of the hot rolling and bonding process is 180-200 ℃, and the pressure is 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds. For example, the temperature of the hot-rolling bonding process is 180 ℃, 190 ℃ or 200 ℃, and the pressure corresponding thereto is 2.5kg/cm²、2.0kg/cm²Or 1.5kg/cm²And the hot rolling time corresponding thereto is 70 seconds, 60 seconds or 50 seconds.

Wherein, the temperature of the hot rolling bonding process has the influence on the fibers in that the proper temperature is favorable for the melt flow extension of the fibers, the fibers are bonded with each other, and the fibers are condensed and connected together when the temperature is reduced to a certain temperature, so that the internal bonding strength of the fibers is increased and the expansion rate of the thickness after 24 hours of water absorption is reduced; the influence of the hot rolling time of the hot rolling bonding process on the fibers is that the proper hot rolling time is beneficial to the full melting of the fibers, so that more fibers are fused, and the layers in the dressing are combined more tightly.

In some other embodiments, the wound contact layer is composited with other functional layers, such as the wicking layer and/or the surface layer described above, by an ultrasonic welding process to form the dressing. Wherein the ultrasonic frequency of the ultrasonic welding process is 10KHz-20KHz, the power is 2.5KW-3.5KW and the pressure is 4.5kg/cm²-5.5kg/cm². For example, the ultrasonic frequency of the ultrasonic welding process is 10KHz, 15KHz or 20KHz, the corresponding power is 3.5KW, 3.0KW or 2.5KW and the corresponding pressure is 5.5kg/cm²、5.0kg/cm²Or 4.5kg/cm²。

Wherein, when the ultrasonic wave acted on the fibre contact surface, can produce the high-frequency vibration of several tens of thousands of times per second, this kind of high-frequency vibration who reaches certain amplitude, through last weldment ultrasonic energy transfer to the soldering zone, because the soldering zone is two welded interface department acoustic resistance big promptly, consequently can produce local high temperature, again because the inside thermal conductivity of fibre is poor, can not in time give off the heat in time for a while, the heat gathering is in the soldering zone, causes two fibre contact surfaces to melt rapidly, in addition after certain pressure, makes it fuse into an organic whole. After the ultrasonic wave stops acting, the pressure is kept for several seconds to solidify and form the fiber layer, so that a firm molecular chain is formed, the purpose of welding different fiber layers is achieved, and the welding strength can be close to the strength of raw materials.

In some other embodiments, the wound contact layer may be combined with other functional layers, such as the wicking layer and/or the surface layer described above, to form the dressing by a needle punching followed by a hot roll bonding process. Wherein the hot rolling bonding process is the same as the hot rolling bonding process in the above embodiment, and the needling density of the needling process is 450-²The needling depth is 4-6 mm. For example, the needling density of the needling process is 450 punches/cm²500 thorn/cm²Or 550 thorn/cm²The depth of the corresponding prick is 6mm, 5mm or 4 mm.

Wherein, because 1 or 2 fibers can be caught to the stroke of acupuncture every time, and the degree of depth and the density of acupuncture are higher moreover, therefore almost every fiber can all obtain the winding in the fibre web, can process each fibre cotton layer through many times of acupuncture and form this dressing.

In some other embodiments, when the composition and structure of the surface layer and the wound contact layer are the same, the gelling fibers in the wound contact layer, the wicking layer, or the surface layer comprise any one of alginate fibers, carboxymethyl cellulose fibers, or carboxymethyl chitosan fibers, or a mixture of at least two thereof, in any ratio.

Wherein, the alginate fiber, the carboxymethyl cellulose fiber or the carboxymethyl chitosan fiber have strong exudate gelation ability when contacting wound exudate and have no special chemical reaction when being mixed with each other. Further, under the same environmental conditions, the alginate fibers, carboxymethyl cellulose fibers or carboxymethyl chitosan fibers have an aspect in their ability to produce gels: carboxymethylcellulose fibers and carboxymethyl chitosan fibers have comparable and high gelling abilities, while alginate fibers have a weaker gelling ability than carboxymethylcellulose fibers and carboxymethyl chitosan fibers. Therefore, in some embodiments, any one or at least two of alginate fibers, carboxymethyl cellulose fibers, or carboxymethyl chitosan fibers may be mixed in any ratio, and the difference in the gelling ability among the three should be noted at the time of addition, and thus an appropriate mixing ratio is selected.

In some other embodiments, when the composition and structure of the surface layer and wound contact layer are the same, the thermoplastic fibers in the wound contact layer, surface layer, or wicking layer are ES fibers (HDPE/PET or HDPE/PP).

Because the ES fiber is a bicomponent fiber which is in a sheath-core structure, the skin layer is made of high-density polyethylene (HDPE) and has the characteristics of low melting point and easy bonding with other fibers, and the core layer is made of polyethylene terephthalate or polypropylene (PET or PP), the ES fiber can provide higher wet strength for the dressing.

For example, in one embodiment, the gelling fibers in the wound contact layer are alginate fibers, the thermoplastic fibers are ES fibers, the gelling fibers in the liquid absorbent layer are carboxymethyl cellulose fibers, the thermoplastic fibers are ES fibers, the gelling fibers in the surface layer are alginate fibers, and the thermoplastic fibers are ES fibers.

For example, in another embodiment, the gelling fibers in the wound contact layer are carboxymethyl chitosan fibers, the thermoplastic fibers are ES fibers, the gelling fibers in the liquid absorbent layer are carboxymethyl cellulose fibers, the thermoplastic fibers are ES fibers, the gelling fibers in the surface layer are carboxymethyl chitosan fibers, and the thermoplastic fibers are ES fibers.

The application provides a wound contact layer of dressing contains thermoplastic fiber and gel nature fibre, and thermoplastic fiber through mixing with gel nature fibre, through hot-blast bonding, acupuncture shaping or acupuncture earlier at the process of hot rolling, forms the 3 dimension spatial structure that intercrossing set up between the fibre, firmly pins thermoplastic fiber, can provide high wet attitude intensity and avoid the fibre to drop for the dressing, has improved the defect of current fibre non-woven fabric dressing. And due to the existence of the gel fiber, the dressing can absorb the exudate and form soft gel after contacting the wound exudate, so that the dressing can completely fill the uneven wound surface, and the phenomenon that the local exudate cannot be absorbed to form a dead space to cause impregnation and infection is avoided. Further, the liquid absorbent layer of the dressing also contains thermoplastic fibers and gel fibers, and the layer mainly contains gel fibers so as to be capable of gelling the liquid seepage as much as possible, and the contained thermoplastic fibers provide high wet strength and liquid absorption capacity; the surface layer of the dressing achieves the purposes of easy distinguishing and easy practical use, and finally, the three fiber layers are bonded and fixed through hot rolling, ultrasonic welding or a process of needling firstly and then hot rolling, so that an integral structure is formed.

The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made according to the content of the present specification and the accompanying drawings, or which are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims

1. A dressing, characterized by: the dressing comprises:

a wound contact layer comprising cross-disposed gelling fibers and thermoplastic fibers, both the thermoplastic fibers and the gelling fibers comprising greater than or equal to 20% of the wound contact layer.

2. The dressing of claim 1, wherein the wound contact layer is formed by hot air process, needle punching process, or needle punching followed by hot rolling process for the gelling fibers and the thermoplastic fibers.

3. The dressing of claim 1, wherein the thermoplastic fibers or the gelling fibers are each present in the wound contact layer in an amount of 20% to 80% of the wound contact layer.

4. The dressing of any one of claims 1-3, further comprising a wicking layer disposed on one side of the wound contact layer;

the liquid absorbing layer comprises gel fibers and thermoplastic fibers which are arranged in a mutually crossed mode, and the percentage content of the gel fibers in the liquid absorbing layer is larger than the percentage content of the thermoplastic fibers in the liquid absorbing layer;

the percentage content of the thermoplastic fibers in the wound contact layer is greater than the percentage content of the thermoplastic fibers in the liquid absorbent layer.

5. A dressing according to claim 4, wherein the thermoplastic fibres content in the liquid absorbent layer is between 5% and 20% of the liquid absorbent layer and/or the gelling fibres content in the liquid absorbent layer is between 80% and 95% of the liquid absorbent layer.

6. The dressing of claim 4, further comprising a surface layer, the wicking layer being located between the wound contact layer and the surface layer, the surface layer and the wound contact layer being the same.

7. The dressing of claim 6, wherein the wicking layer is formed from the gelling fibers and the thermoplastic fibers by a needle punching process, a hot air process, or a needle punching followed by hot rolling process.

8. The dressing of claim 6 wherein any one or more of the wicking layer, the surface layer, and the wound contact layer further comprises an antimicrobial agent.

9. The dressing of claim 6, wherein the gelling fibers in the wound contact layer and/or the wicking layer comprise any one or a mixture of at least two of alginate fibers, carboxymethyl cellulose fibers, or carboxymethyl chitosan fibers in any ratio.

10. A preparation method of the dressing is characterized in that;

step S1: providing gel fibers and thermoplastic fibers according to a preset proportion, and uniformly mixing the gel fibers and the thermoplastic fibers to form mixed fibers, wherein the percentage content of the thermoplastic fibers and the percentage content of the gel fibers in the mixed fibers are both more than or equal to 20%;

step S3: providing other functional layers;

step S4: compounding the wound contact layer with the other functional layer to form the dressing.

11. The method for preparing a porous material according to claim 10, wherein in the step S1, the method further comprises: the mixed fibers are opened and carded to form a fibrous web.

12. The preparation method according to claim 10, wherein in the step S2, the hot air temperature of the hot air process is 130 ℃ to 150 ℃, and the hot air setting time is 40 seconds to 60 seconds; or the needling density of the needling process is 450-550 needling/cm²The needling depth is 4-6 mm; or the temperature of the hot rolling process in the first needling and then hot rolling process is 180-200 ℃, and the pressure is 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds.

13. The method of claim 10, wherein in the step S1, the thermoplastic fiber content or the gelling fiber content is 20% to 80% of the mixed fiber.

14. The method of claim 10, wherein in the step S3, the other functional layers include providing a liquid absorbent layer on the wound contact layer side; the liquid absorbing layer is formed by processing gel fibers and thermoplastic fibers which are mixed according to a preset proportion through a hot air process, a needling process or a needling-first and then hot rolling process;

wherein the percentage content of the gel fibers in the liquid absorbent layer to the liquid absorbent layer is greater than the percentage content of the thermoplastic fibers in the liquid absorbent layer to the liquid absorbent layer; the percentage content of the thermoplastic fibers in the wound contact layer is greater than the percentage content of the thermoplastic fibers in the liquid absorbent layer.

15. The production method according to claim 14, wherein the thermoplastic fiber content in the liquid absorbent layer is 5% to 20% of the liquid absorbent layer, and/or the gel fiber content in the liquid absorbent layer is 80% to 95% of the liquid absorbent layer.

16. The method as claimed in claim 14, wherein in the step S3, the other functional layers further comprise providing a surface layer, the liquid absorbent layer is located between the wound contact layer and the surface layer, and the surface layer is formed by processing the gel fiber and the thermoplastic fiber mixed in a predetermined ratio through a hot air process, a needle punching process or a hot rolling process after needle punching.

17. The method for preparing a wound dressing according to claim 10, wherein in the step S4, the compounding the wound contact layer and the other functional layer to form the dressing comprises: and compounding the wound contact layer and the other functional layers to form the dressing through a hot rolling bonding process, an ultrasonic welding process or a first needling and then hot rolling process.

18. The production method according to any one of claims 10 to 17,

the step S4 includes integrating the wound contact layer and the other functional layer by hot rolling; wherein

The temperature of the hot rolling bonding process is 180-200 ℃, and the pressure is 1.5kg/cm²-2.5kg/cm²And the hot rolling time is 50 seconds to 70 seconds.

19. The production method according to any one of claims 10 to 17,

the step S4 includes compounding the wound contact layer and the other functional layer into a whole by ultrasonic welding; wherein

The ultrasonic frequency of the ultrasonic welding process is 10KHz-20KHz, the power is 2.5KW-3.5KW and the pressure is 4.5kg/cm²-5.5kg/cm²。

20. The method according to any one of claims 10 to 17, further comprising, before step S1: an antimicrobial agent is added to the gelling fibers.