Multifunctional silk nonwoven fabric, tourniquet, preparation method and use thereof

Abstract

The application discloses a multifunctional silk non-woven fabric, a tourniquet and a preparation method and application thereof, and relates to the technical field of medical materials. The tourniquet is prepared from tearable non-woven fabric or fixing non-woven fabric or a combination of both. The tearable non-woven fabric comprises tearable needle punching non-woven fabric and tearable water jet non-woven fabric. The tearable non-woven fabric is prepared from silk through a needle punching method or a water jet method. The needle punching method comprises four steps of blanking, opening, carding and laying a web to obtain a needle punching web. The needle punching web is subjected to a needle punching step to obtain the tearable needle punching non-woven fabric. The water jet method comprises four steps of blanking, opening, carding and pre-wetting a web to obtain a water jet web. The water jet web is subjected to a water jet entangling step to obtain the tearable water jet non-woven fabric. The upper and lower surfaces of the needle punching web and the water jet web are both provided with a fiber drawing layer. The needle punching web and the water jet web are subjected to a needle punching step and a water jet entangling step respectively to obtain fixing needle punching non-woven fabric and fixing water jet non-woven fabric.

Description

Technical Field

[0001] This invention relates to a multifunctional medical nonwoven fabric, specifically to a multifunctional pure silk nonwoven fabric with hemostasis, antibacterial properties, wound healing promotion, and bandaging capabilities, and its preparation method. Background Technology

[0002] Blood is composed of blood cells, including red blood cells, white blood cells, and platelets, and plasma. Plasma contains a special protein called fibrinogen. When bleeding occurs, fibrinogen reacts to form fibrin, which is insoluble in blood and aggregates to form a clot. Generally, minor bleeding can be stopped by spontaneous clotting and simple hemostatic measures. However, if blood loss reaches 20% of the total blood volume, symptoms such as decreased blood pressure and rapid pulse will appear; if 30% or more of the total blood volume is lost in a short period of time, it may be life-threatening. Epidemiological studies of trauma show that the second peak of death occurs within hours after injury, mostly caused by massive hemorrhage, and often occurs during pre-hospital emergency care and patient transport. Since most of these deaths are preventable and can be saved, they are called preventable injuries or deaths. Massive limb bleeding and closed abdominal hemorrhage are the main causes of preventable injuries or deaths.

[0003] Nonwoven fabrics have a wide range of applications, including medical and hygiene, home decoration, clothing, and industrial nonwoven fabrics. However, medical nonwoven fabrics on the market have many drawbacks, including limited functionality, poor breathability, inability to absorb exudate, insufficient uniformity, poor portability, and a tendency to promote wound infection. Needle punching is a major method for producing nonwoven fabrics. Needle-punched nonwoven fabrics are produced using the needle-punching method, which utilizes the mechanical action of needles in a needle-punching machine to reinforce and bind the loose fiber web, thus achieving strength. The basic principle is as follows: A barbed needle with a triangular (or other cross-section) edge repeatedly punctures the fiber web. As the barbs penetrate the web, they force the surface and some inner layers of fibers into the web. Due to friction between the fibers, the originally loose web is compressed. When the needle withdraws from the web, the inserted fiber bundles detach from the barbs and remain in the web. Many fiber bundles become entangled, preventing the web from returning to its original loose state. After repeated punctures, a considerable number of fiber bundles are inserted into the web, causing the fibers to become intertwined, thus forming a needle-punched nonwoven material with a certain strength and thickness. Spunlace nonwovens are similar to needle-punched nonwovens, the difference being that they utilize high-pressure water jets to reinforce the fiber web.

[0004] Medical gauze and dressings are still widely used, but their limitations are obvious. For example, their performance is often limited in terms of breathability, anti-adhesion properties, antibacterial properties, and absorbency. Applying pressure bandages for hemostasis requires specialized training, and the absorption of blood during hemostasis can lead to hemorrhagic shock. Ideal biological dressings, on the other hand, require multiple functions: hemostasis, promoting wound healing, good breathability, high absorbency, good biocompatibility, wide availability of materials, ease of preparation and processing, high stability, and convenient transportation and storage, allowing for large-scale application across multiple fields.

[0005] The wettability of a solid refers to the ability of a liquid to spread on a solid surface, and is usually represented by the contact angle θ. It is generally accepted that when a water droplet is on a solid surface, if the contact angle θ is less than 90°, the surface is a hydrophilic surface; if θ is greater than 90°, the surface is a hydrophobic surface; and if θ is greater than 150°, the surface is a superhydrophobic surface.

[0006] The natural superhydrophobic properties of lotus leaves and other plant and animal surfaces inspired researchers Barthlott and Neinhuis. Fluorine compounds became an ideal choice for achieving superhydrophobic surfaces because fluorine atoms have extremely small atomic radii, are the most electronegative elements, and have a tightly packed outer electron cloud structure, resulting in very low inductive effects on other molecules. Furthermore, superhydrophobic surfaces are more closely related to surface roughness, which has been used to explain the strong repulsion of liquid droplets by solid surfaces. Surface roughness, for example, involves hierarchical structures containing two or more scales, including 3-10 micrometer-long papillary protrusions and low-surface-energy rod-like structures of approximately 50 nanometers. When fabrics are steam-ironed at 200°C, the high temperature causes hydrophobic grafted segments to migrate from the fiber interior to the fiber surface, enhancing the superhydrophobicity of cotton fabrics. Therefore, by treating silk nonwoven fabric raw materials with high temperatures to improve hydrophobicity, hydrophobic silk nonwoven fabrics can be prepared. Summary of the Invention

[0007] In view of the technical problems existing in the prior art, this application provides a tourniquet.

[0008] In a first aspect, the present invention provides a tourniquet, which is prepared from a tearable nonwoven fabric or a fixing nonwoven fabric or a combination of the two. The tearable nonwoven fabric includes tearable needle-punched nonwoven fabric and tearable spunlace nonwoven fabric. The tearable nonwoven fabric is prepared by needle punching or spunlace method. The needle punching method is to obtain a needle-punched fiber web by going through four steps of raw material-opening-carding-web laying, and then to obtain a tearable needle-punched nonwoven fabric by needle punching the fiber web. The spunlace method is to obtain a spunlace fiber web by going through four steps of raw material-opening-carding-pre-wetting fiber web, and then to obtain a tearable spunlace nonwoven fabric by spunlace interlocking and drying the spunlace fiber web. The nonwoven fabric for fixing includes a needle-punched nonwoven fabric for fixing and a spunlace nonwoven fabric for fixing. Both the upper and lower surfaces of the needle-punched fiber web and the spunlace fiber web are covered with a fiber drawing layer, and the needle-punched nonwoven fabric for fixing and the spunlace nonwoven fabric for fixing are obtained through a needle-punching step and a spunlace interlocking step, respectively.

[0009] As a further improvement to the first aspect, the tearable nonwoven fabric and the fixing nonwoven fabric are prepared in combination at a basis weight ratio of 1:1-20:1 (e.g., the tearable needle-punched nonwoven fabric and the fixing needle-punched nonwoven fabric are stacked at the basis weight ratio and then needle-punched; or a tourniquet is obtained by stacking a needle-punched fiber web for the tearable needle-punched nonwoven fabric and a needle-punched fiber web for the fixing needle-punched nonwoven fabric with a fiber filament layer at the basis weight ratio of 1:1-20:1 and then needle-punching; or a tourniquet is obtained by stacking a hydrospunched fiber web for the tearable hydrospunched nonwoven fabric and a hydrospunched fiber web for fixing the hydrospunched nonwoven fabric with a fiber filament layer at the basis weight ratio of 1:1-20:1 and then needle-punching; or the two nonwoven fabrics are stacked before the needle-punching / hydrospunching step and then needle-punched / hydrospunched); the thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 0.5-10 mm and 0.5-5 mm, respectively.

[0010] As a further improvement to the first aspect, the weight ratio of the tearable nonwoven fabric to the fixing nonwoven fabric is 5:1 or 10:1; the thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 1-5mm and 1-2mm, respectively.

[0011] Secondly, this application provides a method for preparing the tourniquet, which includes preparing a tearable nonwoven fabric and a fixation nonwoven fabric by needle punching and hydroentangling of silk respectively. The needle-punching method involves first processing silk through four steps: raw material preparation, opening, combing, and web laying to obtain a needle-punching fiber web. Then, the needle-punching fiber web is needle-punched to obtain a tearable needle-punched nonwoven fabric. Alternatively, a fiber drawing layer is laid on both the top and bottom surfaces of the needle-punched fiber web, and then needle-punched to obtain a fixing needle-punched nonwoven fabric. In the raw material preparation step, silk is first made into a silk quilt, and then baked at 200-230℃ for 0.5-2 hours to obtain a raw material for the needle-punched silk nonwoven fabric. The hydroentangling method involves first obtaining a hydroentangling web from silk through four steps: raw material preparation, opening, combing, and pre-wetting. Then, the hydroentangling web is hydroentangled and dried to obtain a tearable hydroentangling nonwoven fabric. Alternatively, a fiber drawing layer is laid on both sides of the hydroentangling web, and a fixed hydroentangling nonwoven fabric is obtained through a hydroentangling process. In the raw material preparation step, the silk is first made into a silk quilt, and then baked at 200-230℃ for 0.5-2 hours to obtain the raw material for hydroentangling silk nonwoven fabric.

[0012] As a further improvement to the second aspect, the needle-punching method for the tearable needle-punched nonwoven fabric includes the following steps: Step 1): Raw material preparation, which includes first making silkworm cocoons into silk quilts, and then baking them at 200-230℃ for 0.5-2 hours to obtain silk nonwoven fabric raw materials; Step 2) Opening: Place the silk nonwoven fabric blank into the opening machine for opening pretreatment; Step 3) Carding: The opened fibers are fed into a single cylinder double doffer carding machine to be carded into a fiber web, which then forms two layers of fiber web, and finally they are stacked together to form a multi-layer fiber web; the carding machine parameters are: cylinder 300 rad / min, doffer 7.26 rad / min, and cotton feed 0.77 rad / min. Step 4) Web laying: Cross-laying is used. The thin fiber web output from the carding machine passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers; the number of web laying layers is 2-5 layers. Step 5) Needling: The loose fiber web is repeatedly needled with a needle punching machine to reinforce it into a whole and form a tearable needle-punched nonwoven fabric; the needle punching machine parameters are: needle punching frequency 400-600 needles / minute, needle density 3000-3500 needles / meter, and needle punching depth 6-10 mm.

[0013] As a further improvement to the second aspect, the hydroentangling method for the tearable hydroentangled nonwoven fabric includes the following steps: Step 1) Raw material: First, the silkworm cocoons are made into silk quilts, and then baked at 200℃-230℃ for 0.5-2 hours to obtain silk non-woven fabric raw material; Step 2) Opening and impurity removal: The nonwoven fabric blank is put into the opening machine for opening pretreatment, and fiber impurities are removed at the same time as opening; Step 3): The silk nonwoven fabric blank processed in Step 2) is combed into a web, pre-wetted into a fiber web, hydroentangled, dried in an oven, and then wound up and stored to obtain a tearable hydroentangled silk nonwoven fabric. In the carding and web forming process, the carding machine parameters include parameters for multiple processes. In the carding process, the cylinder speed is controlled at 400-750 m / min, the work roll speed at 35-55 m / min, the stripping roll speed at 100-135 m / min, and the doffer speed at 10-30 m / min. In the pre-wetting web step, the process parameters are a pre-wetting hydroentangling pressure of 10-70 bar, and in the hydroneedling step, a hydroentangling pressure of 25-45 bar, a needle punching frequency of 300-600 Hz, and a feed speed of 1-2 m / min. The drying temperature is in the range of 50℃-120℃, and the air volume is controlled at 80,000-90,000 m³ / min. 3 / h.

[0014] As a further improvement to the second aspect, the following step is also included between step 1) and step 2): the silkworm nonwoven fabric blank of step 1) is opened after being subjected to hydrophilic modification treatment by plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali and / or silk edible salt.

[0015] Thirdly, this application provides a multifunctional silk nonwoven fabric, which can be configured as a tearable needle-punched nonwoven fabric, a fixing needle-punched nonwoven fabric, a tearable hydroentangled nonwoven fabric, and a fixing hydroentangled nonwoven fabric. The tearable needle-punched nonwoven fabric is prepared from silk through a needle-punching method. The fixed needle-punched nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower sides of the fiber web before needle punching. The tearable spunlace nonwoven fabric is prepared from silk through a hydroentangling process. The fixed hydroentangled nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower surfaces of the fiber web before hydroentanglement.

[0016] Fourthly, this application provides the use of the tourniquet for hemostasis, antibacterial purposes, and promoting wound healing.

[0017] The fiber drawing layer is obtained by drawing silk fibers during the preparation process using existing and well-known methods for drawing silk quilt fibers.

[0018] The following is a further detailed description of this application: Given the drawback of large blood loss when using medical gauze and dressings for hemostasis, which are still widely used, silk nonwoven fabrics are made hydrophobic to reduce bleeding during hemostasis.

[0019] Furthermore, due to its porous structure, silk fibers have a low density, are lightweight, and easy to carry, making them particularly suitable for pre-hospital emergency care. Silk has a high molecular aggregation energy and a suitable degree of crystallization, resulting in excellent mechanical properties, with a breaking strength similar to steel wire. Silk also possesses excellent hygienic properties, such as moisture absorption, breathability, antibacterial properties, portability, heat retention, safety (heat resistance, flame retardancy), UV protection through UV absorption, and antioxidant properties. These multiple advantages of silk make it possible to prepare ideal, multifunctional medical dressings with excellent overall performance.

[0020] This invention addresses the numerous disadvantages of existing conventional wound dressings and gauze by providing a medical multifunctional pure silk nonwoven fabric and its preparation method. The pure silk fabric of this invention is made by needle punching pure silk after high-temperature physical treatment, and is prepared in two forms: a tearable tourniquet and a fixation tourniquet, thus integrating hemostasis and bandaging functions.

[0021] This invention discloses a multifunctional silk nonwoven fabric with hemostatic properties. The silk nonwoven fabric is made of pure silk twisted together without adding other components. The physically treated hydrophobic silk is carded into a web and then needle-punched or hydroentangled to form the nonwoven fabric. To improve the strength and uniformity of the nonwoven fabric, a dense fiber drawing layer can be added to both sides of the silk twisted layer (needle-punched fiber web or hydroentangled fiber web) before needle-punching or hydroentanglement. This nonwoven fabric can be prepared in two forms: a loose, tearable fabric and a dense, fixative silk nonwoven fabric. It is cut, packaged, and sterilized according to a certain ratio, achieving integrated hemostasis and bandaging functions. After hemostasis, it is wrapped and fixed, making it convenient and quick to use, and can also assist in the fixation of fractures. The production process of this invention is simple, low-cost, and environmentally friendly. Due to the characteristics of pure silk, the finished nonwoven fabric has excellent portability, breathability, moisture absorption, antibacterial properties, promotes wound healing, has antioxidant properties, is heat-resistant, flame-retardant, and UV-resistant.

[0022] To achieve the above objectives, this invention can be implemented through the following method: pure silk without the addition of other components is physically treated at high temperature, then combed into a web, and then needle-punched or hydroentangled to form a nonwoven fabric. To improve the strength and uniformity of the nonwoven fabric, a dense fiber drawing layer can be set on both sides of the silk strand layer before needle punching or hydroentangling. This nonwoven fabric can be prepared into two forms: a loose and tearable fabric and a dense tourniquet for fixation. It can be cut, packaged, and sterilized according to a certain ratio.

[0023] This multifunctional pure silk nonwoven fabric is made from pure silk twisted together without any other components. The silk undergoes physical treatment, such as high-temperature treatment, before being opened, impurities removed, and combed into a web. It is then needle-punched or hydroentangled to form a loose, tearable nonwoven fabric. To improve the strength and uniformity of the nonwoven fabric, a dense fiber layer can be added to both sides of the silk twisted layer before needle punching or hydroentangling, creating a nonwoven fabric for fixation. Both the loose, tearable, and fixation nonwoven fabrics are cut, packaged, and sterilized in a specific ratio to create a tourniquet that integrates hemostasis and bandaging functions.

[0024] As a further improvement, a silk-making process that retains a certain proportion of sericin is adopted. Silkworm cocoons are made into silk quilts, which are then cut into short pieces of a certain length and width. After physical treatment, such as high-temperature treatment, the fabric is opened, impurities are removed, and it is combed into a web. It is then needle-punched or hydroentangled into a fluffy nonwoven fabric, which is a nonwoven fabric that can be torn and used for wound packing.

[0025] As a further improvement, to enhance the strength and uniformity of the nonwoven fabric, a dense fiber drawing layer can be set on both the upper and lower surfaces of the silk spunlace layer before needle punching or hydroentangling to prepare a nonwoven fabric for fixing.

[0026] As a further improvement, two types of non-woven fabric, loose and tearable, and fixed, are cut, packaged, and sterilized in a certain proportion to make a tourniquet that integrates hemostasis and bandaging functions.

[0027] As a further improvement, due to the excellent properties of silk, this nonwoven tourniquet possesses superior properties such as breathability, moisture absorption, antibacterial properties, antioxidant properties, heat and flame resistance, and UV resistance. The nonwoven fabric used for fixation can also serve as an auxiliary fixation for fractures. The nonwoven fabric of this invention has multiple functions.

[0028] As a further improvement, the needle-punching method for preparing tearable nonwoven fabric includes the following steps: (1) Raw material: The silkworm cocoons are boiled, reeled, refined and processed. During this process, glutaraldehyde can be used to cross-link and fix the sericin to reduce the loss of sericin during the refining process. After the silk quilt is made, it is cut into short cloths of a certain length and width. After physical treatment, such as baking at a high temperature of 200℃ to 230℃ (0.5 hours to 2 hours), the hydrophobicity of the material is improved, and the silk nonwoven fabric raw material is obtained. (2) Opening: The non-woven fabric blank is first manually torn open, and then put into the opening machine for opening pretreatment to remove fiber impurities at the same time. (3) Carding: The opened fibers are fed into a single cylinder double doffer carding machine to be carded into a fiber web. In order to reduce the unevenness of the fiber web and improve the quality, a double doffer configuration is adopted, which can form two layers of fiber web, which are finally superimposed to form a slightly thicker fiber web. (4) Web laying: Cross-laying is adopted. The thin fiber web output by the carding machine passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers. (5) Needle punching: The loose fiber web is repeatedly needled with a needle with a triangular (or other shape) cross section and hooked edges in a needle punching machine to reinforce it into a whole and form needle punched nonwoven fabric.

[0029] As a further improvement, the hydroentanglement preparation method for tearable nonwoven fabric includes the following steps: (1) Raw material: The silkworm cocoons are boiled, reeled, refined and processed. During this process, glutaraldehyde can be used to cross-link and fix the sericin to reduce the loss of sericin during the refining process. After the silk quilt is made, it is cut into short cloths of a certain length and width. After physical treatment, such as baking at a high temperature of 200℃ to 230℃ (0.5 hours to 2 hours), the hydrophobicity of the silk material is improved, and the silk nonwoven fabric raw material is obtained. (2) Modification (selection): Because the sericin in silk undergoes thermal denaturation after high-temperature physical treatment, its hydrophilicity is reduced. Silk nonwoven fabric blanks can be selected for hydrophilic modification treatment to improve adhesion to wounds. Hydrophilic treatment methods include plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali and edible salt, etc. (3) Opening: The non-woven fabric blank is first manually torn open, and then put into the opening machine for opening pretreatment to remove fiber impurities at the same time. (4) The nonwoven fabric is obtained by combing the raw silk fabric into a web, pre-wetting the web, hydroentangling and intertwining, drying in an oven and storing it.

[0030] As a further improvement, the preparation method of the nonwoven fabric for fixing is similar to the needle punching and hydroentangling steps mentioned above, except that there are fewer web layers and the thickness is thinner. In order to increase uniformity and strength, a dense fiber drawing layer is laid on both the upper and lower sides of the silk web weaving layer to prepare a nonwoven fabric for fixing with better uniformity and strength.

[0031] As a further improvement, the tourniquet, in the form of loose, tearable and fixed non-woven fabric, can be trimmed, rolled, packaged, sterilized, and stored according to the ratio of weight or volume.

[0032] As a further improvement, the ratio of the two types of nonwoven tourniquets, which can be torn and fixed, is 1:1 to 20:1 by weight, with a preferred ratio of 5:1 or 10:1.

[0033] As a further improvement, the tourniquet, which can be torn and fixed, has a thickness of 10 mm to 0.5 mm and 5 mm to 0.5 mm respectively, preferably 5 mm and 1 mm, or 2 mm and 1 mm respectively.

[0034] As a further improvement, the tourniquet packaging and sterilization are carried out with each package weighing 1 to 20 grams, preferably 5 grams or 10 grams; the packaging is sealed in a light-proof heat-sealed plastic bag; sterilization can be carried out by ethylene oxide or cobalt-60 irradiation.

[0035] As a further improvement, non-woven fabrics or tourniquets made of pure silk possess properties such as moisture absorption, wound healing promotion, antioxidant properties, antibacterial properties, portability, heat and flame resistance, UV resistance, breathability, and abundant raw material supply. Therefore, this material has many advantages such as good hemostatic effect, portability, high stability, easy storage, comfort, and low price, thus having a wide range of hemostatic applications, including clinical surgery, clinical trauma treatment, vehicle first aid kits for various models, home hemostasis, major emergencies, and pre-hospital care.

[0036] The specific implementation process of this invention is as follows: 1. Preparation of fluffy tearable nonwoven fabric: After silkworm cocoons are made into silk quilts, they are cut into short pieces of cloth, subjected to high-temperature physical treatment, then opened to remove impurities and combed into a web, and then needle-punched or hydroentangled to form fluffy tearable nonwoven fabric.

[0037] The needle-punching preparation method for nonwoven dressings includes the following steps: (1) Raw material: The silkworm cocoons are boiled, reeled, refined and processed. During this process, pretreatment methods (such as glutaraldehyde cross-linking) can be used to reduce the loss of sericin protein in the refining process. After the silk quilt is made, it is cut into short cloths of a certain length and width. Physical treatment, such as high temperature baking at 200°C to 230°C (0.5 hours to 2 hours), is performed to obtain the raw material of silk nonwoven fabric dressing. (2) Opening: First, manually tear the silk non-woven fabric blank, then put it into the opening machine to open and remove impurities; (3) Combing: The thick silk fibers that have undergone physical treatment are fed into a combing machine and combed into a fiber web, which can be stacked in multiple layers.

[0038] (4) Web laying: Cross-laying is adopted. The thin fiber web is output from the carding machine, passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers.

[0039] (5) Needle punching: The loose fiber web is repeatedly needle punched and reinforced to form needle punched nonwoven dressing.

[0040] The needle punching process can be summarized as follows: high-temperature treatment of block silk fibers, opening and impurity removal, carding into a web, pre-needling, reinforcement needle punching, and drying and winding.

[0041] The hydroentangling preparation method for nonwoven dressings includes the following steps: (1) Raw material: The silkworm cocoons are boiled, reeled, refined and processed. During this process, pretreatment methods such as glutaraldehyde cross-linking can be used to reduce the loss of sericin protein in the refining process. After the silk quilt is made, it is cut into pieces of a certain size and then subjected to physical treatment such as baking at a high temperature of 200℃ to 230℃ (0.5 hours to 2 hours) to obtain the raw material of silk nonwoven fabric. (2) Opening: Manually tear the non-woven fabric blank to open it, put it into the opening machine for opening pretreatment, and open it to remove impurities; (3) The silk nonwoven fabric blank is combed and laid into a web, and the fiber web is pre-wetted in preparation for hydroentangling; (4) Water needles intertwine, using multiple streams of water generated by high pressure to penetrate the fiber web, the fibers intertwine with each other, and the loose fiber web forms a non-woven dressing with a certain strength and complete structure. (5) The fabric is dried by dragging it through the oven at a certain speed and then rolled up to obtain the non-woven dressing.

[0042] 2. The nonwoven fabric for fixation is manufactured using the method described above, with a dense fiber filament layer added to both sides of the silk woven layer before needle punching or hydroentangling, and then needle punched. The added fiber filament layer improves the strength and uniformity of the nonwoven fabric, and the nonwoven fabric for fixation has fewer web layers and is thinner. These designs are to achieve the flexibility and breathability required for wrapping.

[0043] 3. The thickness of the two types of nonwoven tourniquets that can be torn and fixed can be 10 mm to 0.5 mm and 5 mm to 0.5 mm respectively, preferably 5 mm and 1 mm, or 2 mm and 1 mm respectively.

[0044] 4. Two types of non-woven fabric, loose and tearable, and fixed, are cut in a certain proportion. They can be trimmed and rolled according to weight or volume ratio. The ratio of non-woven fabric hemostatic bandages of the two types is from 1:1 to 20:1 by weight, with the preferred ratio being 5:1 or 10:1.

[0045] 5. Packaging, sterilization, and fabrication into a tourniquet integrating hemostasis and bandaging functions. Each package weighs 1 to 20 grams, preferably 5 grams or 10 grams; packaging uses a light-proof heat-sealed plastic bag; sterilization can be performed using ethylene oxide or cobalt-60 irradiation.

[0046] 6. The nonwoven fabric of this invention has multiple functions. Due to the many excellent properties of silk, this nonwoven tourniquet possesses excellent properties such as breathability, moisture absorption, antibacterial properties, antioxidant properties, heat and flame resistance, and UV resistance. The nonwoven fabric used for fixation can also play a supporting role in stabilizing fractures.

[0047] The present invention has the following advantages: 1. Significant Comprehensive Performance Advantages: This invention's pure silk nonwoven fabric is a novel hemostatic material with inherent biological activity. Since the nonwoven fabric is primarily made from silk, which possesses properties such as moisture absorption, wound healing promotion, antioxidant properties, antibacterial properties, portability, heat and flame resistance, UV resistance, breathability, and abundant raw material supply, this material offers numerous advantages, including excellent hemostatic effect, portability, high stability, easy storage, comfort, and low cost. In contrast, currently widely used medical gauze and dressings have significant limitations, particularly in terms of single function, breathability, anti-adhesion properties, antibacterial properties, and absorbency.

[0048] 2. Versatile and easy to use: The pure silk nonwoven fabric of this invention is prepared in two forms: fluffy and tearable, and dense tourniquet for fixation. It is cut and packaged in a certain proportion. The fluffy and tearable nonwoven fabric can be torn into dressings of different sizes according to the size and location of the wound. After the fluffy and tearable nonwoven fabric is used to fill and stop the bleeding, the tourniquet for fixation can be directly applied to the wound to complete the wrapping and fixation. It can also play an auxiliary role in fixing fractures. It has a multi-functional integrated function of hemostasis and bandaging.

[0049] 3. Wide range of hemostatic applications: It can be used in clinical surgery, clinical trauma management, vehicle first aid kits for various models, home hemostasis, major emergencies, and pre-hospital care. The soft and comfortable properties of the pure silk nonwoven fabric of this invention allow it to adhere closely to the wound, promote wound healing, absorb exudate, and prevent secondary infection, showing promising application prospects. Attached Figure Description

[0050] Figure 1 The fluffy, tearable silk nonwoven fabric prepared by needle punching in Example 1; Figure 2 The dense fixation silk nonwoven fabric prepared by needle punching method in Example 1 ( Figure 2 In the diagram, A represents the needle-punched nonwoven fabric used for fixing. Figure 2 (B in the diagram is a fixation diagram using a needle-punctured tourniquet). Figure 3 Example 3: YG(B)141D digital fabric thickness gauge for measuring the thickness of nonwoven fabric; Figure 4 Here is a scanning electron microscope image of the silk nonwoven fabric from Example 4; Figure 5 The hydrophobic contact angle of the silk nonwoven fabric in Example 5 (wherein) Figure 5 In this context, A represents the contact angle test of silk needle-punched nonwoven fabric. Figure 1 5. Figure 5 In this context, B represents the contact angle test for needle-punched nonwoven silk fabric. Figure 2 ); Figure 6 The hydrophobic amino acids in the silk nonwoven fabric of Example 6 ( Figure 6 In this context, A represents the hydrophobic amino acid test of silk nonwoven fabric. Figure 1 ,from Figure 6 As can be seen from A in the data, the content of high proportion amino acids (hydrophobic alanine) is significantly increased in the cloth-like charred silkworm cocoons. Figure 6 In the figure, B represents the hydrophobic amino acid test of silk nonwoven fabric. Figure 2 ,from Figure 6 As can be seen from B, the content of high proportions of amino acids (hydrophilic serine and tyrosine) in the cloth-like charred silkworm cocoons is significantly reduced. Figure 7 Example 7: In vitro cytotoxicity assay of silk nonwoven fabric extract; Figure 8 Schematic diagram of the coagulation mechanism of silk nonwoven fabric in Example 8 ( Figure 8 In this context, A represents the clotting mechanism of silk nonwoven fabric. Figure 1 , Figure 8 In this context, B refers to the clotting mechanism of silk nonwoven fabric. Figure 2 ); Figure 9 This is a representative image of the liver in the mouse liver oblique puncture bleeding model of Example 9; Figure 10 Example 10: Hemostatic effect of silk nonwoven fabric in a mouse liver oblique puncture bleeding model; Figure 11 Example 11: Hemostasis using silk nonwoven fabric in a rabbit femoral artery bleeding model; Figure 12 Example 12: Hemostatic effect of silk nonwoven fabric in a porcine femoral artery bleeding model; Figure 13 Antibacterial test of silk nonwoven fabric. Detailed Implementation

[0051] To further clarify the concept, technical solution, and advantages of the present invention, the present invention will be described in more detail below with reference to specific embodiments and accompanying drawings. Those skilled in the art should understand that these descriptions are merely exemplary and not intended to limit the scope of protection of the present invention. Furthermore, the omission of descriptions of certain structures and techniques in the following description does not imply that these structures and techniques are not protected.

[0052] In a first aspect, this application provides a tourniquet, which is prepared from a tearable nonwoven fabric or a fixing nonwoven fabric or a combination of the two; The tearable nonwoven fabric includes tearable needle-punched nonwoven fabric and tearable spunlace nonwoven fabric. The tearable nonwoven fabric is prepared by needle punching or spunlace method. The needle punching method is to obtain a needle-punched fiber web by going through four steps of raw material-opening-carding-web laying, and then to obtain a tearable needle-punched nonwoven fabric by going through a needle punching step. The spunlace method is to obtain a spunlace fiber web by going through four steps of raw material-opening-carding-pre-wetting fiber web, and then to obtain a tearable spunlace nonwoven fabric by going through spunlace interlocking and drying. The nonwoven fabric for fixing includes a needle-punched nonwoven fabric for fixing and a spunlace nonwoven fabric for fixing. Both the needle-punched and spunlace fiber webs have a fiber drawing layer laid on both their top and bottom surfaces, and are obtained through needle punching and spunlace interlocking steps, respectively. Specifically, silk is processed through four steps: raw material preparation, opening, carding, and web laying, to obtain a needle-punched fiber web. A fiber drawing layer is then laid on both the top and bottom surfaces of the needle-punched fiber web, followed by a needle punching step to obtain the needle-punched nonwoven fabric for fixing. Similarly, silk is processed through four steps: raw material preparation, opening, carding, and pre-wetting, to obtain a spunlace fiber web. A fiber drawing layer is then laid on both the top and bottom surfaces of the spunlace fiber web, followed by a spunlace interlocking step to obtain the spunlace nonwoven fabric for fixing.

[0053] As an improvement in the first aspect, the tearable nonwoven fabric and the fixing nonwoven fabric are prepared in a weight ratio of 1:1 to 20:1; the thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 0.5-10 mm and 0.5-5 mm, respectively.

[0054] As an improvement in the first aspect, the weight ratio of the tearable nonwoven fabric to the fixing nonwoven fabric is 5:1 or 10:1; the thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 1-5mm and 1-2mm, respectively.

[0055] Secondly, this application provides that the tourniquet is made of a tearable nonwoven fabric or a nonwoven fabric for fixing; Alternatively, the tourniquet may be prepared by combining a tearable nonwoven fabric and a fixation nonwoven fabric; Among them, tearable nonwoven fabric is prepared by needle punching and hydroentanglement of silk to obtain tearable needle-punched nonwoven fabric and tearable hydroentangled nonwoven fabric respectively. The needle-punching method involves obtaining a needle-punching fiber web from silk through four steps: raw material preparation, opening, carding, and web laying. This fiber web is then needle-punched to obtain a tearable needle-punched nonwoven fabric. In the raw material preparation step, the silk is first made into a silk quilt, and then baked at 200-230℃ for 0.5-2 hours to obtain the raw material for the needle-punched silk nonwoven fabric. The hydroentangling method involves four steps: raw material preparation, opening, carding, and pre-wetting to obtain a hydroentangling web. This web is then hydroentangled and dried to obtain a tearable hydroentangled nonwoven fabric. In the raw material preparation step, the silk is first made into a silk quilt, and then baked at 200-230℃ for 0.5-2 hours to obtain the raw material for the hydroentangled silk nonwoven fabric. The nonwoven fabric for fixing includes a needle-punched nonwoven fabric for fixing and a spunlace nonwoven fabric for fixing. A fiber drawing layer is laid on both the upper and lower surfaces of the needle-punched fiber web and the spunlace fiber web, and the needle-punched nonwoven fabric for fixing and the spunlace nonwoven fabric for fixing are obtained by needle punching and spunlace interlocking steps, respectively.

[0056] As a second improvement, the needle-punching method for the tearable needle-punched nonwoven fabric includes the following steps: Step 1): Raw material preparation: This includes making silkworm cocoons into silk quilts through reeling, refining and spinning, and then baking at 200-230℃ for 0.5-2 hours to obtain silk nonwoven fabric raw material; Step 2) Opening: Place the silk nonwoven fabric blank into the opening machine for opening pretreatment; Step 3) Carding: The opened fibers are fed into a single cylinder double doffer carding machine to be carded into a fiber web, which then forms two layers of fiber web, and finally they are stacked together to form a multi-layer fiber web; the carding machine parameters are: cylinder 300 rad / min, doffer 7.26 rad / min, and cotton feed 0.77 rad / min. Step 4) Web laying: Cross-laying is used. The thin fiber web output from the carding machine passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers; the number of web laying layers is 2-5 layers. Step 5) Needling: The loose fiber web is repeatedly needled with a needle punching machine to reinforce it into a whole and form a tearable needle-punched nonwoven fabric; the needle punching machine parameters are: needle punching frequency 400-600 needles / minute, needle density 3000-3500 needles / meter, and needle punching depth 6-10 mm.

[0057] As a second improvement, the hydroentangling method for tearable hydroentangled nonwoven fabric includes the following steps: Step 1) Raw material: After the silkworm cocoons are boiled, reeled, refined and processed into silk quilts, they are then baked at 200℃-230℃ for 0.5-2 hours to obtain the raw material of silk non-woven fabric. Step 2) Opening and impurity removal: The nonwoven fabric blank is put into the opening machine for opening pretreatment, and fiber impurities are removed at the same time as opening; Step 3): The silk nonwoven fabric blank processed in Step 2) is combed into a web, pre-wetted into a fiber web, hydroentangled, dried in an oven, and then wound up and stored to obtain a tearable hydroentangled silk nonwoven fabric. In the carding and web forming process, the carding machine parameters include parameters for multiple processes. In the carding process, the cylinder speed is controlled at 400-750 m / min, the work roll speed at 35-55 m / min, the stripping roll speed at 100-135 m / min, and the doffer speed at 10-30 m / min. In the pre-wetting web step, the process parameters are a pre-wetting hydroentangling pressure of 10-70 bar. In the hydroentangling and needle-entangling step, the process parameters are a hydroentangling pressure of 25-45 bar, a needle-punching frequency of 300-600 Hz, and a feed speed of 1-2 m / min. The drying temperature is in the range of 50℃-120℃, and the air volume is controlled at 80,000-90,000 m³ / min. 3 / h.

[0058] As an improvement in the second aspect, the following step is also included between step 1) and step 2): the silkworm nonwoven fabric blank from step 1 is opened after being hydrophilically modified by plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali and / or silk edible salt.

[0059] Thirdly, this application provides a multifunctional silk nonwoven fabric, which can be configured as a tearable needle-punched nonwoven fabric, a fixing needle-punched nonwoven fabric, a tearable hydroentangled nonwoven fabric, and a fixing hydroentangled nonwoven fabric. The tearable needle-punched nonwoven fabric is prepared from silk through a needle-punching method. The fixed needle-punched nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower sides of the fiber web before needle punching. The tearable spunlace nonwoven fabric is prepared from silk through a hydroentangling process. The fixed hydroentangled nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower surfaces of the fiber web before hydroentanglement.

[0060] Fourthly, this application provides the use of the tourniquet for hemostasis, antibacterial purposes, and promoting wound healing.

[0061] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; and the materials and reagents used are commercially available unless otherwise specified.

[0062] Example 1 A: Needle punching method for preparing silk nonwoven fabric Needle-punched nonwoven fabric is produced using a needle-punching method. This process relies entirely on mechanical action—the piercing action of needles in a needle-punching machine—to strengthen and bind the loose fiber web, thus achieving strength. Silk fiber bundles entangle the web, preventing it from returning to its original loose state. Through repeated needle punching, a significant number of fiber bundles are penetrated into the web, causing the fibers to become intertwined, thereby forming a needle-punched nonwoven material with a certain strength and thickness.

[0063] The preparation process involves sequentially opening, carding, and needle-punching short fibers to form nonwoven fabrics of varying thicknesses.

[0064] In needle punching, the number of punches, the depth of punching, the density of punching, the type of needle, and the arrangement of the needles are the main factors affecting the fluffiness, density, and quality of the finished product. Example parameters for a needle punching machine: punching frequency 500 punches / minute, needle density 3200 needles / meter, and punching depth 8 mm. This invention is not limited to these parameters.

[0065] The specific preparation method of the fluffy, tearable needle-punched silk nonwoven fabric is as follows: Step 1): Raw material preparation, which includes making silkworm cocoons into silk quilts through silk reeling, refining and silk making, and then baking at 200℃ for 2 hours to obtain silk nonwoven fabric raw material. Step 2) Opening: Cut the silk nonwoven fabric blank into short pieces of a certain length and width, for example, about 5cm-10cm in length and width, and put them into the opening machine for opening pretreatment; Step 3) Carding: The opened fibers are fed into a single cylinder double doffer carding machine to be carded into a fiber web, which then forms two layers of fiber web, and finally they are stacked together to form a multi-layer fiber web; Carding machine parameters: cylinder 300 rad / min, doffer 7.26 rad / min, cotton feed 0.77 rad / min.

[0066] Step 4) Web laying: Cross-laying is used. The thin fiber web output from the carding machine passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers. In this web laying step, the process parameter is that the number of web laying layers can be 4. Step 5) Needling: Repeatedly needle the loose fiber web using a needle punching machine to reinforce it into a whole, forming a tearable needle-punched nonwoven fabric. Example needle punching machine parameters: needle punching frequency 500 needles / minute, needle density 3200 needles / meter, needle punching depth 8mm. The tearable needle-punched nonwoven fabric can be used alone as a tourniquet. Considering the strength required for tourniquet bandaging and fixing wounds, the tearable needle-punched nonwoven fabric can be used in combination with fixation needle-punched nonwoven fabric / fixation hydroentangled nonwoven fabric. A weight ratio of 1:1-20:1 yields better results, with 5:1 or 10:1 being optimal.

[0067] The preparation method of the fixation needle-punched silk nonwoven fabric is similar to the preparation method of the above-mentioned fluffy tearable needle-punched nonwoven fabric. The difference is that: a layer of fiber filament is laid on both the top and bottom surfaces of the fluffy fiber web obtained after the web laying treatment in step 4), and then the fixation needle-punched nonwoven fabric is obtained by needle-punching reinforcement in step 5). The prepared fixation needle-punched nonwoven fabric can also be used alone as a tourniquet.

[0068] The result was a successful preparation of a fluffy, tearable, and densely fixed needle-punched silk nonwoven fabric, such as... Figure 1 and Figure 2 As shown in A in the diagram.

[0069] B: Preparation of spunlace silk nonwoven fabric by hydroentanglement The preparation method of the fluffy tearable spunlace nonwoven fabric includes: Step 1) Raw material: After the silkworm cocoons are boiled, reeled, refined and processed into silk quilts, they are baked at 200℃ for 2 hours to obtain the raw material of silk nonwoven fabric. Step 2) Opening: The nonwoven fabric blank is put into the opening machine for opening pretreatment, and fiber impurities are removed at the same time. Step 3): The silk nonwoven fabric blank processed in Step 2) is carded into a web, pre-wetted into a fiber web, hydroentangled, dried in an oven, and then wound and stored to obtain a tearable hydroentangled silk nonwoven fabric. In the carding process, the carding machine parameters include multiple process parameters. During the carding process, the cylinder speed is controlled at 600 m / min, the work roll speed at 40 m / min, the stripping roll speed at 120 m / min, and the doffer speed at 20 m / min. In the pre-wetted web step, the process parameters are a pre-wetting hydroentanglement pressure of 40 bar, and in the hydroentanglement step, a hydroentanglement pressure of 35 bar, a needle punching frequency of 450 Hz, and a feed speed of 1.5 m / min. The drying temperature is within the range of 80℃, and the air volume is controlled at 80,000 m³ / min. 3 / h.

[0070] The tearable spunlace nonwoven fabric can be used alone as a tourniquet. Considering the strength required for tourniquets to bandage and fix wounds, the tearable spunlace nonwoven fabric can be used in combination with fixation needle-punched nonwoven fabric / fixation spunlace nonwoven fabric. The effect is better when the weight ratio is 1:1-20:1, and the effect is best when it is 5:1 or 10:1.

[0071] Furthermore, if the following hydrophilic modification step is added between steps 1) and 2): the silk nonwoven fabric preform from step 1 is opened after undergoing hydrophilic modification treatment by plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali, and / or edible salt. This is because the sericin in the silk undergoes thermal denaturation during the preform preparation process due to high-temperature physical treatment, resulting in reduced hydrophilicity. Therefore, hydrophilic modification treatment can be selected for the silk nonwoven fabric preform to improve its adhesion to wounds.

[0072] The preparation method of fixed spunlace nonwoven fabric is similar to that of tearable spunlace nonwoven fabric. The difference is that after the fiber web is pre-wetted in step 3), a fiber drawing layer is laid on both the upper and lower surfaces of the fiber web. Then, the fixed spunlace nonwoven fabric is prepared by hydroentanglement, drying, and winding.

[0073] C: Preparation of tourniquet The tourniquet can be prepared by cutting a certain shape from a tearable needle-punched nonwoven fabric; or it can be prepared by cutting a certain length and width from a fixing needle-punched nonwoven fabric; or a tearable spunlace nonwoven fabric and a fixing spunlace nonwoven fabric can be cut into certain shapes to prepare a tearable spunlace tourniquet and a fixing spunlace tourniquet respectively. Considering that the tourniquet needs a certain strength when used for bandaging and fixation, a fixing needle-punched tourniquet and a fixing spunlace tourniquet are preferred.

[0074] Alternatively, the tourniquet can be prepared by combining a tearable needle-punched / spunlace nonwoven fabric and a fixation needle-punched / spunlace nonwoven fabric at a basis weight ratio of 1:1 to 20:1, and cutting them into a certain shape. Preferably, the basis weight ratio of the tearable nonwoven fabric to the fixation nonwoven fabric is 5:1 or 10:1; the thicknesses of the tearable nonwoven fabric and the fixation nonwoven fabric are 0.5-10 mm and 0.5-5 mm, respectively. Figure 2 As shown in B, a fixation needle-punched tourniquet is prepared by cutting a certain shape from needle-punched nonwoven fabric.

[0075] Example 2 Production capacity estimation of silk nonwoven fabric prepared by needle punching method It is estimated that 1 jin (approximately 500 grams) of raw silk can be needle-punched into non-woven silk fabric with dimensions of 40cm wide x 1m long. Based on an 8-hour workday, the estimated production capacity of one set of equipment is 25 kg. Furthermore, with 2 people operating 4-5 machines simultaneously, and the machines capable of continuous production, the estimated production capacity can reach even greater levels.

[0076] Example 3 Thickness Measurement of Tearable Needle-Punched Silk Nonwoven Fabric like Figure 3 As shown, the thickness of the tearable needle-punched silk nonwoven fabric was measured using a YG(B)141D digital fabric thickness gauge from Wenzhou Darong Textile Standard Instrument Factory. The pressure was 200cN. During the gradual increase of pressure, the thickness reading decreased until it stabilized at a certain value.

[0077] Example 4 Scanning electron microscopy observation of tearable needle-punched silk nonwoven fabric Scanning electron microscopy (SEM) experiments were conducted to observe the microstructure of nonwoven fabrics. An SEM image of the tearable needle-punched silk nonwoven fabric is shown below. Figure 4 It can be seen that the silk fibers cross-link to form a rough structure with certain pores, which is one of the important reasons for the hydrophobic structure of silk nonwoven fabric. The fiber diameter of the scanning electron microscope image was measured by Image J, which is about 10 μm, and the coefficient of variation CV < 13.

[0078] Example 5 Measurement of hydrophobic contact angle of tearable needle-punched silk nonwoven fabric Contact angle was measured using an optical contact angle meter (OCA 50AF, DataPhysics Instruments GmbH, Germany). A contact angle greater than 90° is known to indicate hydrophobicity. Figure 5 The diagram shows a water droplet (A) added to a needle-punched nonwoven fabric. Figure 5 In Figure B (left), the contact angle is 161°; the contact angle measured by the built-in software is shown below. Figure 5Figure B (right) shows a contact angle of nearly 150°. Both measurement methods indicate that the hydrophobicity of the needle-punched nonwoven fabric reaches the level of superhydrophobicity.

[0079] Example 6 Determination of hydrophobic amino acids in silk nonwoven fabric The amino acid content changes of silkworm cocoons and high-temperature hydrophobic treated silk were analyzed using an amino acid analyzer. Compared to silkworm cocoons, the proportion of hydrophilic amino acids in the silk nonwoven fabric decreased in threonine, serine, and lysine; while the proportion of hydrophobic amino acids increased in alanine, valine, isoleucine, and phenylalanine. Compared to the silkworm cocoon sample, Figure 6 The A in the figure indicates that the hydrophobic amino acid with a significantly increased proportion of amino acids in the cloth-like charred silkworm cocoon sample (tested with tearable needle-punched silk nonwoven fabric) is alanine. Figure 6 B indicates that the hydrophilic amino acids with a significantly reduced proportion of amino acids in the cloth-like charred silkworm cocoon sample include serine and tyrosine.

[0080] Example 7 Cytotoxicity test of extract from tearable needle-punched silk nonwoven fabric In vitro cytotoxicity was tested using L929 cells according to GB / T 16886.5. Figure 7 The results showed that the 100% extract of 2mm thick No. 3 needle-punched nonwoven fabric (X3) exhibited Grade I in vitro toxicity to L929 cells after 24 hours of intervention, as did its raw material (X0), both meeting the acceptable standards. The positive control (0.3% phenol) showed a Grade II relative growth rate (RGR), indicating moderate to severe cytotoxicity. The 100% extract of Johnson & Johnson Q (Q) positive hemostatic material immediately turned yellow and turbid upon addition to the culture medium, and adherent cells were not visible under a microscope. Its RGR after 24 hours of intervention with L929 cells was Grade III, indicating moderate to severe cytotoxicity. In summary, the in vitro cytotoxicity test results of silk nonwoven fabric indicate that it is safer than commercially available Johnson & Johnson Q.

[0081] Example 8 Experiment on the coagulation mechanism of tearable needle-punched silk nonwoven fabric The coagulation mechanism test involved reacting platelet-free plasma anticoagulated with human sodium citrate with 20 mg of tearable needle-punched silk nonwoven fabric to detect prothrombin time (PT), activated partial thromboplastin time (APTT), and coagulation factors II, V, VII, VIII, X, and XII.

[0082] 1) Specimen preparation Thirty plasma samples with normal routine coagulation parameters and D-dimer test results were selected and mixed to prepare test plasma. Samples from individuals with infections, tumors, trauma, post-operative conditions, pregnancy, newborns, hepatitis, or autoimmune diseases were avoided. Individual samples should be free of hemolysis, clots, jaundice, and lipemia. 1 ml of plasma was collected from each donor sample. Each donor sample was treated with a solution containing 10... 9 Vacuum anticoagulation blood collection tubes containing 3 ml of 1000 rpm sodium citrate solution were used to collect the sample. The capped tubes containing the sample were centrifuged at the specified speed and time (room temperature, 3000 rpm / min, 15 min) to obtain platelet-deficient plasma (platelet count <10×109 / L) for testing.

[0083] 2) Detection methods (1) Take 3 ml of mixed plasma and test it using the STARMax fully automated coagulation analyzer manufactured by STARMax Corporation. Use original matching reagents. The test indicators include: prothrombin time (PT), activated partial thromboplastin time (APTT), and coagulation factors II, V, VII, VIII, X, and XII. Each test item is repeated 3 times for each sample, and the test results are recorded.

[0084] (3) Add 500 μL of mixed plasma to each test tube containing 20 mg of silk nonwoven fabric, for a total of 6 tubes. Incubate at 37 °C for 3 min. Then collect approximately 3 ml of plasma from each of the 6 test tubes that came into contact with the silk nonwoven fabric for testing. The tests were performed using a STARMax fully automated coagulation analyzer manufactured by STAR Max, using original and compatible reagents. The test indicators included: prothrombin time (PT), activated partial thromboplastin time (APTT), and coagulation factors II, V, VII, VIII, IX, X, XI, and XII. Each test was repeated 3 times for each sample, and the results were recorded.

[0085] 3) Results Figure 8 The result in A indicates that, compared to the control group, the platelet-free plasma samples treated with 20mg of silk nonwoven fabric did not show significant changes in PT, activated partial thromboplastin time (APTT), and coagulation factors II, V, VII, VIII, IX, X, XI, and XII, suggesting that the coagulation mechanism of silk nonwoven fabric did not function through these indicators.

[0086] Further investigation was conducted using scanning electron microscopy to observe the microscopic effects of human citrate anticoagulation on silk nonwoven fabric, in order to study the hemostatic mechanism. Figure 8B in the figure indicates that after the silk nonwoven fabric (WFB) interacts with whole blood cells, a large number of red blood cells aggregate to form a significant fibrin network; when it interacts with red blood cells, dense aggregates of red blood cells are formed; when it interacts with platelets, platelet aggregation also occurs, but the morphology of red blood cells and platelets does not change. This indicates that the hemostatic mechanism of the silk nonwoven fabric is through a physical mechanism, namely, by aggregating blood cells and forming a fibrin network.

[0087] Example 9 Preparation of a mouse liver oblique puncture bleeding model A mouse model of liver hemorrhage was established by puncturing the left lobe of the liver with a 16G needle at 30°C. Figure 9 This study aimed to evaluate the hemostatic effect of silk nonwoven fabric on liver bleeding in mice.

[0088] Example 10 Hemostasis test of tearable needle-punched silk nonwoven fabric in a mouse liver oblique puncture bleeding model After establishing the liver hemorrhage model, approximately 2 mg of a 5mm x 5mm tearable needle-punched nonwoven fabric was placed at the hemorrhage point in the liver. The results showed that the time required for hemostasis using the tearable needle-punched nonwoven fabric (approximately 40 seconds) was significantly shorter than that of the untreated control group (approximately 70 seconds). Figure 10 The results showed that the wound was easy to clean after hemostasis, while the untreated group had a full abdomen filled with blood.

[0089] Example 11 Hemostasis and stable hemostasis for more than 4 hours in a rabbit femoral artery bleeding model using silk nonwoven fabric The rabbit femoral artery was dissected and exposed from the surrounding tissue, partially cut, and allowed to bleed freely for 30 seconds. 6.52g of blood was absorbed by gauze, and 2g of [unclear - possibly a specific type of gauze] was placed on it. Figure 2 The fixation tourniquet shown in B (obtained from fixation needle-punched nonwoven fabric) is shown in the results. Figure 11 After covering the wound with silk nonwoven fabric, it was found that the hydrophobic material effectively blocked the blood flow, resulting in almost instantaneous cessation of active bleeding. Bleeding completely stopped within 2 minutes. Upon removing the silk nonwoven fabric, it was observed that only a small amount of blood had seeped into the material, with a blood loss of approximately 4g. No hemostatic material residue remained on the bleeding wound. The material exhibited moderate adhesion to the wound, facilitating wound cleaning without leaving any residue. Stable hemostasis was maintained for over 4 hours, and even significant movement of the wound did not cause bleeding.

[0090] Example 12 Hemostasis test of silk nonwoven fabric in a porcine femoral artery bleeding model After anesthetizing the pig, the femoral artery on one side was isolated, and the descending branch of the femoral artery was located. About 0.5 cm above the branch point proximal to the heart, half the circumference of the vessel wall was cut vertically along the cross-section of the vessel (pre-treated with 2% lidocaine to relieve vasospasm). The femoral artery was observed to be spurting blood. The blood was allowed to spurt freely for 30 seconds, and the amount of bleeding during this period was collected and recorded with blank gauze. After the free spurting of blood ended, a tearable needle-punched non-woven silk fabric was applied to the bleeding site of the femoral artery injury with a certain pressure. The pressure was applied for 3 minutes at a time, and the pressure was removed after 3 minutes. The wound was observed to see if there was still active bleeding. Figure 12 The results showed that the application of the tearable needle-punched silk nonwoven fabric quickly stopped active bleeding, with minimal blood seepage into the material and a blood loss of approximately 5.35g. There were no significant differences in blood routine tests, coagulation parameters, and thromboelastography results before and after hemostasis.

[0091] Example 13 Antibacterial test of silk nonwoven fabric Samples and groups: 1cm x 1.5cm tearable needle-punched nonwoven fabric (WFB) was disinfected by immersion in 75% ethanol, with 3 samples per group, suitable for 24-well size; samples were then air-dried overnight in a biosafety cabinet. The control groups were PBS-treated and penicillin-treated groups.

[0092] OD 600 Conversion to bacterial concentration: OD of Escherichia coli (ATCC25922) 600 =0.1, 10(7) times CFU / ml; OD of Staphylococcus aureus (ATCC29213) 600 = Approximately 0.25, CFU is approximately 2-10^8 (physiological saline).

[0093] OD 600 Measurement and sampling: 0h, diluted to 10 6 CFU / mL, 24-well plates were incubated in thiol medium at 37℃, and the OD of each sample was measured at 2h, 4h, 6h, 8h and 24h. 600 Values ​​and sampling. After 24 hours, the bacterial suspension was diluted 1000-fold, and 100 μL of the diluted solution was spread onto an agar plate. Bacterial clones were observed to study antibacterial activity.

[0094] See results Figure 13 After 24 hours of bacterial suspension culture, compared with the PBS control group, WFB significantly reduced the OD of ATCC25922 and ATCC29213. 600 It significantly inhibits bacterial growth.

[0095] The embodiments described in the above specification are only some embodiments of the present invention. Various changes and improvements based on the present invention without departing from the concept and scope of the present invention fall within the scope of the present invention as claimed.

Claims

1. A method for preparing a tourniquet, characterized in that: The tourniquet is made of tearable nonwoven fabric or fixation nonwoven fabric or a combination of the two. Tearable nonwoven fabric and fixing nonwoven fabric are prepared from silk by needle punching and hydroentangling methods, respectively; the tearable nonwoven fabric includes tearable needle-punched nonwoven fabric and tearable hydroentangled nonwoven fabric; the fixing nonwoven fabric includes fixing needle-punched nonwoven fabric and fixing hydroentangled nonwoven fabric. The needle-punching method involves first processing silk through four steps: raw material preparation, opening, combing, and web laying to obtain a needle-punching fiber web. Then, the needle-punching fiber web is needle-punched to obtain a tearable needle-punched nonwoven fabric. Alternatively, a fiber drawing layer is laid on both the top and bottom surfaces of the needle-punched fiber web, and then needle-punched to obtain a fixing needle-punched nonwoven fabric. In the raw material preparation step, silk is first made into a silk quilt, and then baked at 200-230℃ for 0.5-2 hours to obtain a raw material for the needle-punched silk nonwoven fabric. The hydroentangling method involves first processing silk through four steps: raw material preparation, opening, carding, and pre-wetting, to obtain a hydroentangling web. Then, the hydroentangling web is hydroentangled and dried to obtain a tearable hydroentangled nonwoven fabric. Alternatively, a fiber drawing layer is laid on both sides of the hydroentangling web, and a fixed hydroentangled nonwoven fabric is obtained through a hydroentangling process. In the raw material preparation step, silk is first processed into silk quilts, and then baked at 200-230℃ for 0.5-2 hours to obtain the raw material for the hydroentangling silk nonwoven fabric. When a tourniquet is made of a combination of a tearable nonwoven fabric and a fixation nonwoven fabric, the tearable nonwoven fabric and the fixation nonwoven fabric are prepared in a weight ratio of 1:1 to 20:

1.

2. The preparation method according to claim 1, characterized in that: The thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 0.5-10mm and 0.5-5mm, respectively.

3. The preparation method according to claim 2, characterized in that: The weight ratio of the tearable nonwoven fabric to the fixing nonwoven fabric is 5:1 or 10:1; the thicknesses of the tearable nonwoven fabric and the fixing nonwoven fabric are 1-5mm and 1-2mm, respectively.

4. The preparation method according to claim 1, characterized in that: The needle-punching method for the tearable needle-punched nonwoven fabric includes the following steps: Step 1): Raw material preparation, which includes first making silkworm cocoons into silk quilts, and then baking them at 200-230℃ for 0.5-2 hours to obtain silk nonwoven fabric raw materials; Step 2) Opening: Place the silk nonwoven fabric blank into the opening machine for opening pretreatment; Step 3) Carding: The opened fibers are fed into a single cylinder double doffer carding machine to be carded into a fiber web, which then forms two layers of fiber web, and finally they are stacked together to form a multi-layer fiber web; the carding machine parameters are: cylinder 300 rad / min, doffer 7.26 rad / min, and cotton feed 0.77 rad / min. Step 4) Web laying: Cross-laying is used. The thin fiber web output from the carding machine passes through the inclined curtain to the top horizontal curtain, and then enters the clamping curtain. It swings back and forth to form a fiber web of a certain thickness. The thickness of the fabric can be precisely controlled by controlling the number of web laying layers; the number of web laying layers is 2-5 layers. Step 5) Needling: The loose fiber web is repeatedly needled with a needle punching machine to reinforce it into a whole and form a tearable needle-punched nonwoven fabric; the needle punching machine parameters are: needle punching frequency 400-600 needles / minute, needle density 3000-3500 needles / meter, and needle punching depth 6-10mm.

5. The preparation method according to claim 1, characterized in that: The hydroentangling method for the tearable hydroentangled nonwoven fabric includes the following steps: Step 1) Raw material: First, the silkworm cocoons are made into silk quilts, and then baked at 200℃-230℃ for 0.5-2 hours to obtain silk non-woven fabric raw material; Step 2) Opening and impurity removal: The nonwoven fabric blank is put into the opening machine for opening pretreatment, and fiber impurities are removed at the same time as opening; Step 3): The silk nonwoven fabric blank processed in Step 2) is combed into a web, pre-wetted into a fiber web, hydroentangled, dried in an oven, and then wound and stored to obtain a tearable hydroentangled silk nonwoven fabric. In the carding and web forming process, the carding machine parameters include parameters for multiple processes. In the carding process, the cylinder speed is controlled at 400-750 m / min, the work roll speed at 35-55 m / min, the stripping roll speed at 100-135 m / min, and the doffer speed at 10-30 m / min. In the pre-wetting web step, the process parameters are: pre-wetting hydroentangling pressure 10-70 bar; and in the hydroentangling interlocking step, the process parameters are... The hydroentangling pressure is 25-45 bar, the needle punching frequency is 300-600 Hz, and the feeding speed is 1-2 m / min; the drying temperature is in the range of 50℃-120℃, and the air volume is controlled at 80000-90000 m3 / h.

6. The preparation method according to claim 4 or 5, characterized in that: Between step 1) and step 2), the following step is also included: the silkworm nonwoven fabric blank of step 1) is opened after being subjected to hydrophilic modification treatment by plasma, ultrasound, microwave, lauryl alcohol, hydrogen peroxide, baking soda, edible alkali and / or silk edible salt.

7. A multifunctional silk nonwoven fabric, characterized in that: The multifunctional silk nonwoven fabric is prepared by any of the preparation methods described in claims 1-6. The silk nonwoven fabric can be configured as a tearable needle-punched nonwoven fabric, a fixing needle-punched nonwoven fabric, a tearable hydroentangled nonwoven fabric, and a fixing hydroentangled nonwoven fabric. The tearable needle-punched nonwoven fabric is prepared from silk through a needle-punching method. The fixed needle-punched nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower sides of the fiber web before needle punching. The tearable spunlace nonwoven fabric is prepared from silk through a hydroentangling process. The fixed hydroentangled nonwoven fabric is obtained by laying fiber filament layers on both the upper and lower surfaces of the fiber web before hydroentanglement.

8. Use of the tourniquet prepared by any one of claims 1-6 for hemostasis, antibacterial purposes, and wound healing promotion.

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