Medical wound seepage patch and preparation method thereof

Abstract

The invention provides a medical wound seepage patch and a preparation method thereof, and relates to the technical field of medical supplies. Comprising a one-way moisture absorption layer, a multi-layer water absorption structure layer and a backing layer, a metering color developing strip is arranged in the multi-layer water absorption structure layer, and a pH response color developing assembly is arranged on the side, away from the one-way moisture absorption layer, of the multi-layer water absorption structure layer; the multi-layer water absorption structure layer comprises a primary water absorption layer, a middle water absorption layer and a high water absorption layer which are stacked in sequence, and the primary water absorption layer is provided with flow guide column cotton which vertically penetrates through the middle water absorption layer; the pH response developing assembly comprises a pH sensing film and a transparent observation window, and the pH sensing film is loaded with a pH indicator; the one-way moisture absorption layer is formed by compounding a spunbond non-woven fabric surface layer, a fluffy cotton middle layer and a PE leakage-proof film bottom layer, and the spunbond non-woven fabric surface layer is provided with conical liquid guide holes. According to the seepage patch, one-way moisture absorption of the wound dressing can be achieved, the water absorption amount is large, the seepage absorption amount can be estimated, seepage properties can be judged, the replacement frequency of the wound dressing is reduced, resources are saved, and medical staff are assisted in evaluating the illness state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical supplies, more particularly to a medical wound exudate patch and a preparation method thereof. BACKGROUND

[0002] In clinical treatment, many patients need to be indwelled with various drainage tubes due to their illness conditions. For example, abdominal surgery patients often need to be indwelled with multiple drainage tubes, and exudation often occurs around the drainage tubes or even at the wound after the drainage tubes are removed. The ordinary gauze dressing and foam dressing have limited liquid absorption capacity. When the wound exudation is severe, the doctor needs to frequently change the dressing. If the dressing is not changed in time, the skin soaked by the liquid is prone to dermatitis, and the exudate liquid will also flow to the patient's clothes, bed sheet and quilt cover. The medical staff also needs to frequently change the bed sheet and quilt cover, which not only increases the workload of the medical staff, but also increases the medical cost and infection risk of the patient. Moreover, the ordinary dressing cannot measure or indicate the absorption capacity of the exudate, which is not conducive to the medical staff to master the exudate capacity of the patient, and thus affects the analysis and evaluation. In addition, the ordinary dressing also cannot indicate the pH of the exudate, which is not conducive to the medical staff to evaluate the nature of the exudate of the patient. SUMMARY

[0003] The present application aims to provide a medical wound exudate patch and a preparation method thereof to solve the problems in the background and realize one-way moisture absorption of the wound dressing with large water absorption capacity, estimate the absorption capacity of the exudate and judge the nature of the exudate, reduce the frequency of changing the wound dressing, save resources and assist the medical staff in evaluating the illness condition.

[0004] To achieve the above-mentioned purpose, in a first aspect, the present application provides a medical wound exudate patch, which comprises, from the skin contact side to the outside, a one-way moisture absorption layer, a multi-layer water absorption structure layer and a backing layer arranged in sequence. The multi-layer water absorption structure layer is provided with a metering color development strip. The side of the multi-layer water absorption structure layer away from the one-way moisture absorption layer is provided with a pH response color development component. The multi-layer water absorption structure layer comprises, from the skin contact side to the side away from the skin, a primary water absorption layer, an intermediate water absorption layer and a high-level water absorption layer stacked in sequence. The primary water absorption layer is provided with a drainage column cotton vertically penetrating into the intermediate water absorption layer. The pH response color development component comprises a pH sensing film loaded with a pH indicator. The one-way moisture absorption layer is composed of a spunbond nonwoven surface layer, a fluffy cotton intermediate layer and a PE leakage-proof film bottom layer. The spunbond nonwoven surface layer is provided with a conical liquid guiding hole.

[0005] Further, the spunbond nonwoven surface layer is polypropylene with a density of 20-30 g / m 2 . The conical liquid guiding hole has a diameter of 0.2-0.3 mm and a hole density of 50-80 pieces / cm². The fluffy cotton intermediate layer has a density of 40-60 g / m 2hydrophilic modified polyester fiber with a fiber diameter of 10-20 μm and a bulkiness of 8-12 cm 3 / g.

[0006] Further, the primary water absorption layer has a thickness of 1-1.5 mm and is made of high water absorption cotton with a density of 80-100 g / m² and a water absorption ratio of ≥30 g / g; the flow guide column cotton is a cotton fiber bundle with a diameter of 1-1.5 mm and a number of 3-5.

[0007] Further, the intermediate water absorption layer has a thickness of 1.5-2 mm and is made of high water absorption resin composite non-woven fabric with a density of 100-120 g / m 2 Further, the high-level water absorption layer has a thickness of 2-2.5 mm and is made of super water absorption fiber felt with a density of 120-150 g / m 2 Further, the high-level water absorption layer has a thickness of 2-2.5 mm and is made of super water absorption fiber felt with a density of 120-150 g / m

[0008] Further, the metering color development strip is medical filter paper containing 0.5-1% bromocresol purple by mass fraction, has a width of 5-8 mm, and is provided along the longitudinal side of the flow guide column cotton and is provided with scale marks at 10 mm.

[0009] Further, the pH sensing film is a medical polyurethane film with a thickness of 0.1-0.2 mm and a surface load of 0.2-0.5% bromocresol green-methyl red mixed indicator by mass fraction, and the mass ratio of bromocresol green to methyl red in the mixed indicator is 1:1.

[0010] In a second aspect, the application provides a preparation method of the medical wound exudate patch, and has the following steps: (1) Preparation of the one-way moisture absorption layer: the spun-bond non-woven fabric surface layer, the fluffy cotton middle layer, and the PE leak-proof film bottom layer are sequentially compounded, wherein the spun-bond non-woven fabric surface layer is formed into a conical liquid guide hole by laser drilling; (2) Preparation of the multi-layer water absorption structure layer: the primary water absorption layer, the intermediate water absorption layer, and the high-level water absorption layer are prepared respectively, the flow guide column cotton is implanted between the primary water absorption layer and the intermediate water absorption layer, the water absorption layers are sequentially stacked and bonded, and the metering color development strip is fixed at the same time; (3) Preparation of the pH response color development assembly: the pH sensing film loaded with the pH indicator is pasted on the surface of the high-level water absorption layer; (4) Overall assembly: the one-way moisture absorption layer, the multi-layer water absorption structure layer, and the backing layer are sequentially compounded, the edge is coated with pressure-sensitive adhesive and covered with release paper, and the whole is packaged after sterilization.

[0011] Further, in step (1), the composite of the spunbond nonwoven fabric and the fluffy cotton adopts a hot rolling process, the temperature is 120-130℃, the pressure is 0.2-0.3MPa, and the speed is 5-8m / min; the PE leakage-proof film and the fluffy cotton are point-bonded by hot melt adhesive, the diameter of the adhesive point is 0.5-1mm, and the spacing is 3-5mm.

[0012] Further, in step (3), the preparation method of the pH-sensitive film is as follows: the medical polyurethane film is immersed in a 0.3% bromocresol green-methyl red mixed indicator solution for 1min, and then dried in a 40℃ vacuum drying oven for 30min.

[0013] Through the above technical solutions, the technical effects achieved by the present application are as follows: 1) The unidirectional moisture absorption layer adopts a three-layer composite structure, realizes efficient unidirectional liquid guiding through the conical liquid guiding hole and the 3D fluffy cotton, and effectively prevents the back seepage of the exudate together with the PE leakage-proof film, so as to keep the skin dry.

[0014] 2) The multi-layer water absorption structure layer adopts a gradient water absorption design, the water absorption rate gradually increases, and the total absorption amount can reach more than 50 times of the weight of the structure layer itself, so as to significantly reduce the frequency of dressing change.

[0015] 3) The metering color development strip directly displays the absorption amount of the exudate according to the climbing height of the exudate, and can realize semi-quantitative evaluation together with the scale marks, so as to facilitate the medical staff to grasp the dressing change time.

[0016] 4) The pH response color development assembly can real-time feedback the pH value of the exudate through color change (from red to green gradually in the range of pH 5.0-9.0), so as to assist in judging whether there is an infection risk of the wound (for example, the pH value of the exudate is usually increased when infected).

[0017] 5) The materials of each layer are all medical-grade materials, have good biocompatibility, and the preparation process is mature, so the present application is suitable for large-scale production. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be described clearly and completely in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0019] In the following embodiments, the raw materials are all commercially available unless otherwise specified. EMBODIMENT

[0020] The medical wound exudate patch comprises, from the skin contact side to the outside, a one-way moisture absorption layer, a multi-layer water absorption structure layer and a backing layer arranged in sequence; wherein the multi-layer water absorption structure layer is provided with a metering color developing strip; the side of the multi-layer water absorption structure layer away from the one-way moisture absorption layer is provided with a pH response color developing component; and the multi-layer water absorption structure layer comprises, from the skin contact side to the skin side away, a primary water absorption layer, an intermediate water absorption layer and a high-level water absorption layer arranged in sequence, and the primary water absorption layer is provided with a flow guide column cotton vertically penetrating into the intermediate water absorption layer; the pH response color developing component comprises a pH sensing film, and the pH sensing film is loaded with a pH indicator; the one-way moisture absorption layer is composed of a spun-bonded non-woven fabric surface layer, a fluffy cotton intermediate layer and a PE leakage-proof film bottom layer; and the spun-bonded non-woven fabric surface layer is provided with a conical liquid guiding hole.

[0021] The spun-bonded non-woven fabric surface layer is made of polypropylene with a density of 20 g / m 2 The conical liquid guiding hole has a diameter of 0.2 mm and a hole density of 50 per cm 2 The fluffy cotton intermediate layer is made of hydrophilic modified polyester fiber with a density of 40 g / m 3 The fiber diameter is 10 μm, and the bulkiness is 8 cm The primary water absorption layer has a thickness of 1 mm and is made of high water absorption cotton with a density of 80 g / m 2 The flow guide column cotton is a bundle of cotton fibers with a diameter of 1 mm and a number of 3. The intermediate water absorption layer has a thickness of 1.5 mm and is made of high water absorption resin composite non-woven fabric with a density of 100 g / m 2 The high-level water absorption layer has a thickness of 2 mm and is made of super water absorption fiber felt with a density of 120 g / m The metering color developing strip is a medical filter paper containing 0.5% bromocresol purple, with a width of 5 mm and a length of 10 mm provided with scale marks, and is longitudinally arranged along the side of the flow guide column cotton. The pH sensing film is a 0.1 mm thick medical polyurethane film loaded with 0.2% bromocresol green-methyl red mixed indicator on the surface, and the mass ratio of bromocresol green to methyl red in the mixed indicator is 1:1.

[0022] The preparation method of the medical wound exudate patch comprises the following steps: (1) One-way moisture absorption layer preparation: the spun-bonded non-woven fabric surface layer and the fluffy cotton intermediate layer are compounded by hot rolling process at a temperature of 120℃, a pressure of 0.2 MPa and a speed of 5 m / min, and then the fluffy cotton intermediate layer and the PE leakage-proof film bottom layer are point-bonded by hot melt adhesive with an adhesive point diameter of 0.5 mm and a spacing of 3 mm, wherein the spun-bonded non-woven fabric surface layer is formed with a conical liquid guiding hole by laser drilling; (2) Multi-layer water absorption structure layer preparation: the primary water absorption layer, the intermediate water absorption layer and the high-level water absorption layer are prepared respectively, the flow guide column cotton is implanted between the primary water absorption layer and the intermediate water absorption layer, the water absorption layers are sequentially laminated and bonded, and the metering color developing strip is fixed. (3) Preparation of pH-responsive colorimetric component: Immerse the medical polyurethane membrane in a 0.3% bromocresol green-methyl red mixed indicator solution for 1 min, remove it and dry it in a vacuum drying oven at 40℃ for 30 min to obtain a pH sensing membrane. Then attach the pH sensing membrane loaded with pH indicator to the surface of the advanced absorbent layer. (4) Overall assembly: The unidirectional moisture-absorbing layer, the multi-layer water-absorbing structure layer and the backing layer are sequentially laminated, pressure-sensitive adhesive is applied to the edges and release paper is applied, and then packaged after sterilization. Example

[0023] A medical wound exudate dressing comprises, from the skin-contact side to the outer side, a unidirectional absorbent layer, a multi-layer absorbent structure layer, and a backing layer arranged sequentially. The multi-layer absorbent structure layer contains a metering color indicator strip, and a pH-responsive color indicator component is located on the side of the multi-layer absorbent structure layer away from the unidirectional absorbent layer. The multi-layer absorbent structure layer comprises, from the skin-contact side to the skin-away side, a primary absorbent layer, a secondary absorbent layer, and a senior absorbent layer stacked sequentially. The primary absorbent layer has a guide column cotton that vertically penetrates to the secondary absorbent layer. The pH-responsive color indicator component includes a pH-sensing membrane loaded with a pH indicator. The unidirectional absorbent layer is composed of a spunbond nonwoven fabric surface layer, a fluffy cotton intermediate layer, and a PE leak-proof membrane bottom layer. The spunbond nonwoven fabric surface layer has conical liquid-guiding holes.

[0024] Among them, the surface layer of spunbond nonwoven fabric has a density of 30 g / m³. 2 Polypropylene; conical liquid guiding holes with a diameter of 0.3 mm and a pore density of 80 pores / cm²; fluffy cotton intermediate layer with a density of 60 g / m². 2 The hydrophilic modified polyester fiber has a fiber diameter of 20μm and a bulkiness of 12cm. 3 / g. The primary absorbent layer is 1.5mm thick and is made of highly absorbent cotton with a density of 100g / m², and an absorbency ratio ≥50g / g; the guide column cotton consists of 5 cotton fiber bundles with a diameter of 1.5mm. The intermediate absorbent layer is 2mm thick and has a density of 120g / m². 2 The superabsorbent polymer composite nonwoven fabric contains 40% sodium polyacrylate superabsorbent polymer by mass, with a water absorption rate ≥60g / g; the advanced absorbent layer is 2.5mm thick and has a density of 150g / m³. 2 The superabsorbent fiber felt has an absorption rate ≥100g / g. The metering colorimetric strip is medical filter paper containing 1% bromocresol purple by mass, 8mm wide with graduations at 10mm, and longitudinally positioned along one side of the flow guide column cotton. The pH sensing membrane is a 0.2mm thick medical polyurethane membrane with a surface loaded with 0.5% bromocresol green-methyl red mixed indicator, where the mass ratio of bromocresol green to methyl red in the mixed indicator is 1:1.

[0025] The preparation method of the above-mentioned medical wound exudate dressing includes the following steps: (1) Preparation of unidirectional moisture-absorbing layer: The spunbond nonwoven fabric surface layer and the fluffy cotton intermediate layer are composited by hot rolling process at a temperature of 130℃, a pressure of 0.3MPa, and a speed of 8m / min. Then, the fluffy cotton intermediate layer and the PE leak-proof film bottom layer are bonded together by hot melt adhesive dots with a diameter of 1mm and a spacing of 5mm. The spunbond nonwoven fabric surface layer is formed into conical liquid guiding holes by laser perforation. (2) Preparation of multi-layer absorbent structure: Primary absorbent layer, intermediate absorbent layer and advanced absorbent layer are prepared respectively. Guide column cotton is inserted between the primary absorbent layer and the intermediate absorbent layer. Each absorbent layer is stacked and bonded in sequence, and the metering color developing strip is fixed at the same time. (3) Preparation of pH-responsive colorimetric component: Immerse the medical polyurethane membrane in a 0.3% bromocresol green-methyl red mixed indicator solution for 1 min, remove it and dry it in a vacuum drying oven at 40℃ for 30 min to obtain a pH-sensing membrane. Then attach the pH-sensing membrane loaded with pH indicator to the surface of the advanced absorbent layer. (4) Overall assembly: The unidirectional moisture-absorbing layer, the multi-layer water-absorbing structure layer and the backing layer are sequentially laminated, pressure-sensitive adhesive is applied to the edges and release paper is applied, and then packaged after sterilization. Example

[0026] A medical wound exudate dressing comprises, from the skin-contact side to the outer side, a unidirectional absorbent layer, a multi-layer absorbent structure layer, and a backing layer arranged sequentially. The multi-layer absorbent structure layer contains a metering color indicator strip, and a pH-responsive color indicator component is located on the side of the multi-layer absorbent structure layer away from the unidirectional absorbent layer. The multi-layer absorbent structure layer comprises, from the skin-contact side to the skin-away side, a primary absorbent layer, a secondary absorbent layer, and a senior absorbent layer stacked sequentially. The primary absorbent layer has a guide column cotton that vertically penetrates to the secondary absorbent layer. The pH-responsive color indicator component includes a pH-sensing membrane loaded with a pH indicator. The unidirectional absorbent layer is composed of a spunbond nonwoven fabric surface layer, a fluffy cotton intermediate layer, and a PE leak-proof membrane bottom layer. The spunbond nonwoven fabric surface layer has conical liquid-guiding holes.

[0027] The surface layer of the spunbond nonwoven fabric has a density of 25 g / m³. 2 Polypropylene; conical liquid guiding holes with a diameter of 0.25 mm and a pore density of 70 pores / cm²; fluffy cotton intermediate layer with a density of 50 g / m². 2 Hydrophilic modified polyester fiber with a fiber diameter of 15μm and a bulkiness of 10cm. 3 / g. The primary absorbent layer is 1.2mm thick and consists of highly absorbent cotton with a density of 90g / m², and an absorption rate ≥40g / g; the guide column cotton consists of 4 cotton fiber bundles with a diameter of 1.2mm. The intermediate absorbent layer is 1.8mm thick and consists of cotton with a density of 102g / m². 2The superabsorbent polymer composite nonwoven fabric contains 35% sodium polyacrylate superabsorbent polymer by mass, with a water absorption rate ≥57g / g; the advanced absorbent layer is 2.2mm thick and has a density of 130g / m³. 2 The superabsorbent fiber felt has an absorption rate ≥100g / g. The metering colorimetric strip is medical filter paper containing 0.75% bromocresol purple by mass, 6mm wide, with graduation marks at 10mm, and longitudinally arranged along one side of the guide column cotton. The pH sensing membrane is a 0.15mm thick medical polyurethane membrane, with a surface loaded with 0.3% bromocresol green-methyl red mixed indicator, where the mass ratio of bromocresol green to methyl red in the mixed indicator is 1:1.

[0028] The preparation method of the above-mentioned medical wound exudate dressing includes the following steps: (1) Preparation of unidirectional moisture-absorbing layer: The spunbond nonwoven fabric surface layer and the fluffy cotton intermediate layer are composited by hot rolling process at a temperature of 125℃, a pressure of 0.25MPa, and a speed of 6m / min. Then, the fluffy cotton intermediate layer and the PE leak-proof film bottom layer are bonded together by hot melt adhesive dots with a diameter of 0.8mm and a spacing of 4mm. The spunbond nonwoven fabric surface layer is formed into conical liquid guiding holes by laser perforation. (2) Preparation of multi-layer absorbent structure: Primary absorbent layer, intermediate absorbent layer and advanced absorbent layer are prepared respectively. Guide column cotton is inserted between the primary absorbent layer and the intermediate absorbent layer. Each absorbent layer is stacked and bonded in sequence, and the metering color developing strip is fixed at the same time. (3) Preparation of pH-responsive colorimetric component: Immerse the medical polyurethane membrane in a 0.3% bromocresol green-methyl red mixed indicator solution for 1 min, remove it and dry it in a vacuum drying oven at 40℃ for 30 min to obtain a pH-sensitive membrane, and attach the pH-sensitive membrane loaded with pH indicator to the surface of the advanced absorbent layer. (4) Overall assembly: The unidirectional moisture-absorbing layer, the multi-layer water-absorbing structure layer and the backing layer are sequentially laminated, pressure-sensitive adhesive is applied to the edges and release paper is applied, and then packaged after sterilization.

[0029] Compared to Example 3, the spunbond nonwoven fabric surface of the unidirectional moisture-absorbing layer has no tapered liquid-guiding pores (using ordinary smooth polypropylene spunbond nonwoven fabric).

[0030] Compared to Example 3, there are no guide columns between the multi-layer absorbent structure.

[0031] Compared to Example 3, there is no pH-responsive colorimetric component (the pH-sensing membrane is a blank medical polyurethane membrane, without bromocresol green-methyl red indicator).

[0032] Continuously drip 0.9% saline solution containing blue dye onto the "skin contact side" of the dressing and observe whether the exudate is unidirectionally transmitted. Press the "non-skin contact side" with filter paper and rate it according to the degree of blue turning of the filter paper: A (no blue, completely prevents backflow), B (small amount of blue, slight backflow), C (obvious blue, severe backflow).

[0033] Liquid absorption test: Weigh the dry dressing. m 0 After completely immersing in physiological saline, drain the surface liquid and weigh the product after absorption. m 1 Liquid absorption volume ( g / g) = ( m 1 -m 0 ) / m 0 .

[0034] pH indicator sensitivity test: At 37℃, buffer solutions with pH values ​​of 5.0, 6.0, 7.0, 8.0, and 9.0 were added to the pH sensing membrane. The degree of matching between the color and the theoretical color (pH 5.0 red, 6.0 orange-red, 7.0 yellow-green, 8.0 green, and 9.0 dark green) was observed. The rating was: A (perfect match), B (1-2 deviations), and C (≥3 deviations).

[0035] The results are shown in Table 1;

[0036] Analyze the results in Table 1: One-way liquid guidance and backflow prevention: Comparative Example 1 lacks a "conical liquid guiding hole", making it difficult for the seepage to be quickly and unidirectionally introduced into the absorbent layer, resulting in a sharp drop in the liquid absorption and severe backflow (rating C); while the "conical liquid guiding hole + PE leak-proof membrane" structure of Example 1- achieves efficient one-way liquid guidance and complete backflow prevention (rating A).

[0037] Liquid absorption: Comparative Example 2, due to the elimination of the guide column and baffle pad, had a liquid absorption volume that was only 1 / 2 of that of the Example.

[0038] pH indication sensitivity: Comparative Example 3 could not provide feedback on the acidity or alkalinity of the exudate due to the lack of a pH indicator (rating C); the "bromocresol green-methyl red composite indicator" in Examples 1-3 could accurately match the color changes at different pH levels (rating A).

[0039] In summary, this invention, through the synergistic design of "one-way moisture-absorbing layer + multi-layer gradient water-absorbing structure + pH response component + metering color indicator bar", is significantly superior to the comparative example in terms of liquid conduction and backflow prevention, liquid absorption volume, pH monitoring, etc., demonstrating the innovation and superiority of the technical solution.

[0040] Preventive wound inflammation test An in vitro 3D skin model was used. This model is composed of multi-layered differentiated keratinocytes and possesses normal skin barrier function, simulating the human skin's response to exudate. Simultaneously, simulated wound exudate (formulation: physiological saline + 5% fetal bovine serum + 0.1% albumin, pH=5.5±0.2, simulating normal wound exudate; infection simulated exudate: based on the above, add 10...) 6 CFU / mL Staphylococcus aureus, pH=7.2±0.2).

[0041] Each group of exudate patches was applied to the surface of a 3D skin model, with the application pressure controlled at 1.5 kPa (simulating the pressure of human skin adhesion). A continuous dripping mode was used: simulated normal exudate was continuously dripped into the center of each sample using a micro-pump at a drip rate of 0.1 mL / h (simulating the amount of moderate wound exudate), for 24 hours. Samples were removed, and the skin model culture medium was collected. The concentrations of IL-1α and TNF-α were detected using an ELISA kit. See Table 2.

[0042]

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A medical wound exudate dressing, characterized in that, The medical wound exudate patch comprises, from the skin-contact side to the outer side, a unidirectional absorbent layer, a multi-layer absorbent structure layer, and a backing layer arranged sequentially. The multi-layer absorbent structure is equipped with a metering color-developing strip, and a pH-responsive color-developing component is provided on the side of the multi-layer absorbent structure away from the unidirectional absorbent layer. The multi-layer absorbent structure includes a primary absorbent layer, a secondary absorbent layer, and a high-grade absorbent layer stacked sequentially from the side closest to the skin to the side furthest from the skin. The primary absorbent layer is provided with a guide column cotton that extends vertically to the secondary absorbent layer. The pH-responsive color-developing component includes a pH-sensing membrane loaded with a pH indicator. The unidirectional moisture-absorbing layer is composed of a spunbond nonwoven fabric surface layer, a fluffy cotton middle layer, and a PE leak-proof film bottom layer, and the spunbond nonwoven fabric surface layer is provided with conical liquid guiding holes.

2. The medical wound exudate dressing according to claim 1, characterized in that, The spunbond nonwoven fabric surface layer has a density of 20-30 g / m³. 2 The polypropylene; the diameter of the conical liquid guiding holes is 0.2-0.3 mm, and the pore density is 50-80 pores / cm²; the fluffy cotton intermediate layer has a content of 40-60 g / m². 2 Hydrophilic modified polyester fibers with a fiber diameter of 10-20μm and a bulk of 8-12cm. 3 / g.

3. The medical wound exudate dressing according to claim 1, characterized in that, The primary absorbent layer is 1-1.5mm thick and is made of highly absorbent cotton with a density of 80-100g / m² and an absorbency ratio of ≥30g / g; the guide column cotton is a bundle of cotton fibers with a diameter of 1-1.5mm, consisting of 3-5 strands.

4. The medical wound exudate dressing according to claim 1, characterized in that, The intermediate absorbent layer has a thickness of 1.5-2mm and a density of 100-120g / m³. 2 The superabsorbent polymer composite nonwoven fabric contains 30-40% sodium polyacrylate superabsorbent polymer by mass, with a water absorption rate ≥50g / g; the advanced absorbent layer has a thickness of 2-2.5mm and a density of 120-150g / m³. 2 The super absorbent fiber felt has a water absorption rate of ≥100g / g.

5. The medical wound exudate dressing according to claim 1, characterized in that, The metering colorimetric strip is a medical filter paper containing 0.5-1% bromocresol purple by mass, with a width of 5-8 mm and a 10 mm graduation mark, and is set longitudinally along one side of the guide column cotton.

6. The medical wound exudate dressing according to claim 1, characterized in that, The pH sensing membrane is a 0.1-0.2 mm thick medical polyurethane membrane, with a surface loading of 0.2-0.5% by mass of a bromocresol green-methyl red mixed indicator, wherein the mass ratio of bromocresol green to methyl red in the mixed indicator is 1:

1.

7. A method for preparing a medical wound exudate dressing as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Preparation of unidirectional moisture-absorbing layer: The spunbond nonwoven fabric surface layer, the fluffy cotton middle layer and the PE leak-proof film bottom layer are sequentially laminated, wherein the spunbond nonwoven fabric surface layer is laser-drilled to form conical liquid guiding holes; (2) Preparation of multi-layer absorbent structure: Primary absorbent layer, intermediate absorbent layer and advanced absorbent layer are prepared respectively. Guide column cotton is inserted between the primary absorbent layer and the intermediate absorbent layer. Each absorbent layer is stacked and bonded in sequence, and the metering color developing strip is fixed at the same time. (3) Preparation of pH-responsive colorimetric component: A pH-sensing membrane loaded with pH indicator is attached to the surface of an advanced absorbent layer; (4) Overall assembly: The unidirectional moisture-absorbing layer, the multi-layer water-absorbing structure layer and the backing layer are sequentially laminated, pressure-sensitive adhesive is applied to the edges and release paper is applied, and then packaged after sterilization.

8. The preparation method according to claim 7, characterized in that, In step (1), the composite of the spunbond nonwoven fabric and the fluffy cotton is carried out by hot rolling process, with a temperature of 120-130℃, a pressure of 0.2-0.3MPa, and a speed of 5-8m / min; the PE leak-proof film and the fluffy cotton are bonded together by hot melt adhesive dots, with an adhesive dot diameter of 0.5-1mm and a spacing of 3-5mm.

9. The preparation method according to claim 8, characterized in that, In step (3), the pH sensing membrane is prepared by immersing the medical polyurethane membrane in a 0.3% bromocresol green-methyl red mixed indicator solution for 1 minute, and then drying it in a vacuum drying oven at 40°C for 30 minutes.

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