A disposable degradable antibacterial sheet and a method for preparing the same

Abstract

The application provides a disposable degradable antibacterial drape and a preparation method thereof, and belongs to the technical field of medical composite materials. The drape is a three-layer composite structure, from top to bottom, the wear-resistant and anti-skid layer, the reinforced support layer and the flexible barrier layer, and the overall profile is a U-shaped, T-shaped or special-shaped structure compatible with the dental treatment table instrument tray. The wear-resistant and anti-skid layer is made of PBS or PBAT and starch blending, and the surface is embossed to provide anti-skid and wear-resistant properties; the reinforced support layer is made of PLA and natural fiber hot-pressing composite, which gives the drape anti-puncture and support performance; the flexible barrier layer is made of PBAT and nano calcium carbonate blending blow molding, which has excellent waterproof barrier and table surface anti-skid function. Through specific material combination and preparation, the drape can realize stable placement of instruments, wear-resistant and anti-puncture, waterproof and close fitting of the table surface, and all components are biodegradable, solving the technical problems of single function, easy displacement and environmental protection of the existing products.

Description

Technical Field

[0001] This invention relates to the field of medical composite materials technology, and in particular to a disposable biodegradable antibacterial dressing and its preparation method. Background Technology

[0002] During dental procedures, dentists frequently use a variety of sharp and delicate instruments, such as forceps, elevators, scalers, and burs. These instruments typically need to be temporarily placed on the instrument tray or tabletop of the treatment table. To ensure hygiene and ease of operation, a sheet is usually used to cover the tabletop.

[0003] Currently, there are two main types of drapes commonly used in clinical practice: one is traditional cotton drapes, which are reusable but have poor waterproofing, allowing blood, saliva, and other liquids to easily penetrate and cause contamination of the work surface and potential cross-infection, and the cost of cleaning and disinfection is high. The other is disposable plastic drapes (such as PE or PP film), which are waterproof but have significant drawbacks: firstly, the surface is too smooth, making instruments prone to slipping or even falling, affecting operational efficiency and posing safety hazards; secondly, the material is thin, not wear-resistant, and easily punctured by sharp instrument tips, causing the barrier function to fail; thirdly, the universal square design cannot fit well with dental treatment tables with complex curves, easily wrinkling and shifting, affecting the user experience.

[0004] With increasing environmental awareness, biodegradable materials are beginning to be used in the medical field. However, existing biodegradable drapes mostly focus on liquid absorption and barrier properties, and their mechanical properties, especially abrasion resistance and puncture resistance, often fail to meet the stringent requirements of frequent instrument placement and scratching. Therefore, developing a disposable instrument drape that combines excellent abrasion and puncture resistance, anti-slip function, close fit to the treatment table, and environmental friendliness has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a disposable biodegradable antibacterial dressing and its preparation method, in order to solve the above-mentioned technical problems.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: The present invention provides a disposable biodegradable antibacterial drape, which comprises, from top to bottom, a wear-resistant and anti-slip layer, a reinforcing support layer and a flexible barrier layer; the overall outline of the disposable biodegradable antibacterial drape is a U-shaped, T-shaped or irregular structure adapted to the instrument tray area of ​​the dental treatment table.

[0007] Furthermore, the wear-resistant and anti-slip layer is a microporous nonwoven fabric or film made by blending polybutylene succinate or polybutylene terephthalate with starch and hot pressing it with an embossing roller. The reinforcing support layer is obtained by hot pressing polylactic acid with natural jute or bamboo fiber; The flexible barrier layer is obtained by blow molding a mixture of polybutylene terephthalate and nano-calcium carbonate.

[0008] Furthermore, the basis weight of the wear-resistant and anti-slip layer is 20~50 g / m². 2 .

[0009] Furthermore, the mass content of natural jute or bamboo fiber in the reinforcing support layer is 20-40%, and the basis weight of the reinforcing support layer is 60-120 g / m². 2 .

[0010] Furthermore, the mass content of nano-calcium carbonate in the flexible barrier layer is 30-50%, and the thickness of the flexible barrier layer is 15-30 μm.

[0011] This invention also provides a method for preparing a disposable biodegradable antibacterial dressing, comprising the following steps: 1) Mix polylactic acid with chopped jute fiber or bamboo fiber in a certain proportion, and then melt-blend and granulate the mixture through a twin-screw extruder to obtain composite granules; then hot-press the composite granules to obtain a reinforcing support layer. 2) Polybutylene succinate or polybutylene terephthalate adipate is blended with starch in a certain proportion and made into nonwoven fabric by meltblown spinning equipment or into film by casting method; then the nonwoven fabric or film is embossed by hot press roller with predetermined pattern to obtain wear-resistant and anti-slip layer. 3) Polybutylene terephthalate (PET) is blended with nano-calcium carbonate, then blown into a film using a blown film unit, and the film surface is corona treated to obtain a flexible barrier layer. 4) Using water-based polyurethane adhesive, the adhesive is applied to the upper and lower surfaces of the reinforcing support layer by a textured coating method. Then, the wear-resistant and anti-slip layer is laminated to the upper surface of the reinforcing support layer, and the flexible barrier layer is laminated to the lower surface of the reinforcing support layer to form a three-layer composite preform. 5) The three-layer composite blank is sent into the curing chamber and cured at 40~60℃ for 12~24 hours to allow the adhesive to fully cure; the cured composite blank is cut into U-shaped, T-shaped or irregular contours that are compatible with the instrument tray area of ​​the dental treatment table using an ultrasonic cutter or die-cutting machine; and the cut edges are heat-sealed to prevent interlayer separation. 6) After die-cutting and sealing, the product is sterilized by electron beam sterilization and then vacuum packaged.

[0012] Furthermore, the temperature of the melt blending granulation is 150~180℃, the temperature of the hot pressing is 160~175℃, and the pressure is 5~15MPa.

[0013] Furthermore, the blow molding temperature is 135~150℃, and the corona treatment power is 5~10kW.

[0014] The beneficial effects of this invention are: The three-layer composite structure of this invention works synergistically to achieve comprehensive functions including anti-slip instrument placement, wear resistance and puncture resistance, absolute waterproofing, and anti-slip table movement, perfectly meeting the needs of dental treatment scenarios. All core layer materials (PBS / PBAT / PLA / natural fibers) are compostable and biodegradable, completely decomposing under industrial composting conditions, significantly reducing medical plastic waste. The customized shape of this invention ensures a tight fit to the treatment table, preventing wrinkling and displacement; the reinforced support layer provides a stable operating surface, improving the efficiency and comfort of medical staff. The use of water-based adhesives and electron beam sterilization ensures the product's biosafety and aseptic performance. Detailed Implementation

[0015] The present invention provides a disposable biodegradable antibacterial drape, which comprises, from top to bottom, a wear-resistant and anti-slip layer, a reinforcing support layer and a flexible barrier layer; the overall outline of the disposable biodegradable antibacterial drape is a U-shaped, T-shaped or irregular structure adapted to the instrument tray area of ​​the dental treatment table.

[0016] In this invention, the wear-resistant and anti-slip layer is a microporous nonwoven fabric or film made by hot pressing a blend of polybutylene succinate or polybutylene terephthalate-adipate with starch and an embossing roller. The reinforcing support layer is obtained by hot pressing polylactic acid with natural jute or bamboo fiber; The flexible barrier layer is obtained by blow molding a mixture of polybutylene terephthalate and nano-calcium carbonate.

[0017] In this invention, zinc oxide, nano-silica, or nano-boron nitride are also added during the preparation of the wear-resistant and anti-slip layer.

[0018] In this invention, the basis weight of the wear-resistant and anti-slip layer is 20~50 g / m². 2 The preferred concentration is 25~45g / m³. 2 Further preferred is 30~40g / m 2 .

[0019] In this invention, the mass content of natural jute or bamboo fiber in the reinforcing support layer is 20-40%, preferably 25-35%, and more preferably 28-30%; the basis weight of the reinforcing support layer is 60-120 g / m³. 2 Preferably 70~110g / m 2 Further preferred is 80~100g / m 2 .

[0020] In this invention, the mass content of nano-calcium carbonate in the flexible barrier layer is 30-50%, preferably 35-45%, and more preferably 40%; the thickness of the flexible barrier layer is 15-30 μm, preferably 20-25 μm.

[0021] This invention also provides a method for preparing a disposable biodegradable antibacterial dressing, comprising the following steps: 1) Mix polylactic acid with chopped jute fiber or bamboo fiber in a certain proportion, and then melt-blend and granulate the mixture through a twin-screw extruder to obtain composite granules; then hot-press the composite granules to obtain a reinforcing support layer. 2) Polybutylene succinate or polybutylene terephthalate adipate is blended with starch in a certain proportion and made into nonwoven fabric by meltblown spinning equipment or into film by casting method; then the nonwoven fabric or film is embossed by hot press roller with predetermined pattern to obtain wear-resistant and anti-slip layer. 3) Polybutylene terephthalate (PET) is blended with nano-calcium carbonate, then blown into a film using a blown film unit, and the film surface is corona treated to obtain a flexible barrier layer. 4) Using water-based polyurethane adhesive, the adhesive is applied to the upper and lower surfaces of the reinforcing support layer by a textured coating method. Then, the wear-resistant and anti-slip layer is laminated to the upper surface of the reinforcing support layer, and the flexible barrier layer is laminated to the lower surface of the reinforcing support layer to form a three-layer composite preform. 5) The three-layer composite blank is sent into the curing chamber and cured at 40~60℃ for 12~24 hours to allow the adhesive to fully cure; the cured composite blank is cut into U-shaped, T-shaped or irregular contours that are compatible with the instrument tray area of ​​the dental treatment table using an ultrasonic cutter or die-cutting machine; and the cut edges are heat-sealed to prevent interlayer separation. 6) After die-cutting and sealing, the product is sterilized by electron beam sterilization and then vacuum packaged.

[0022] In this invention, the temperature of the melt blending granulation is 150~180℃, preferably 160~170℃, and more preferably 165℃; the temperature of the hot pressing is 160~175℃, preferably 165~170℃; and the pressure is 5~15MPa, preferably 8~12MPa, and more preferably 10MPa.

[0023] In this invention, the temperature for blow molding is 135~150℃, preferably 140~150℃, and more preferably 140~145℃; the power for corona treatment is 5~10kW, preferably 5~8kW.

[0024] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0025] Example 1

[0026] Wear-resistant and anti-slip layer: Utilizing a blend of PBS and modified starch (mass ratio 80:20), produced by melt-blowing with a basis weight of 30 g / m². 2 The nonwoven fabric is then passed through a pair of hot press rollers, one of which has a fine granular pattern engraved on its surface. The fabric is then embossed at 120°C and 0.5MPa pressure to form a non-slip surface.

[0027] Reinforcing Support Layer: 70 parts of dried PLA resin and 30 parts of dried chopped jute fiber (5 mm in length) were mixed in a high-speed mixer for 5 minutes. The mixture was then melt-blended and granulated using a twin-screw extruder at 170°C. The granules were fed into a calender and calendered at 170°C and 10 MPa to a weight of 80 g / m³. 2 The board material.

[0028] Flexible barrier layer: 60 parts of PBAT and 40 parts of nano-calcium carbonate were mixed in an internal mixer at 150°C for 10 minutes to ensure uniform dispersion. The blend was then blown into a 20 μm thick film at 140°C using a blown film extruder. The film was subsequently subjected to corona treatment (5 kW power) to improve its surface energy and composite strength.

[0029] Lamination and processing: Using water-based polyurethane adhesive (40% solids content), it is applied through an anilox roller (100 mesh) at a rate of 5 g / m². 2 The coating (dry weight) is applied to the upper and lower surfaces of the reinforcing support layer. Then, the wear-resistant and anti-slip layer and the flexible barrier layer are immediately bonded to the upper and lower surfaces respectively, and compacted using a pair of pressure rollers (0.3 MPa pressure). The composite material is then placed in a 50°C curing chamber for 18 hours.

[0030] Die-cutting and post-processing: The cured material is placed on an ultrasonic cutter and cut using a pre-made U-shaped mold (referring to the dimensions of a certain brand of dental treatment table tray). During cutting, ultrasonic energy melts and bonds the three layers of material at the cut edge, forming a sealed cut edge. Finally, the finished product is sterilized with an electron beam (dose of 25kGy) and vacuum-packed in a medical dialysis paper-plastic bag.

[0031] The performance of the product obtained in Example 1 of this invention was tested, and the results are as follows: Puncture resistance (ASTM F1342): greater than 15N, much higher than ordinary plastic film (typically <5N).

[0032] Static friction coefficient (tabletop contact side, ASTM D1894): greater than 0.8, providing excellent anti-slip performance.

[0033] Hydrostatic pressure (AATCC 127): >10000Pa, fully meeting the requirements for medical liquid barrier.

[0034] Biodegradability (ISO 14855, under composting conditions): >90% biodegradability within 180 days.

[0035] Example 2

[0036] Wear-resistant and anti-slip layer: A non-woven fabric with a basis weight of 35 g / m² is produced by melt-blowing PBAT (85 parts) and corn starch (15 parts). The embossing depth is increased to provide a more significant anti-slip effect.

[0037] Reinforcing support layer: A composite of dried PLA resin (60 parts) and dried chopped jute fiber (40 parts, 7 mm in length) is formed. This significantly enhances mechanical properties by increasing the content and length of the natural fibers. The weight after hot pressing is 100 g / m². 2 .

[0038] Flexible barrier layer: PBAT (55 parts) and nano-calcium carbonate (45 parts) are blended and blown into a film with a thickness of 25 μm. The higher filler content results in better anti-slip performance of the underlying layer.

[0039] Preparation process: Same as in Example 1, but the hot pressing pressure is increased to 12MPa to ensure density under high fiber content.

[0040] The product performance test results for Example 2 are as follows: Puncture resistance: 22.5N Abrasion resistance (Martindale method, mass loss after 5000 rpm): 18mg Static friction coefficient: 0.95 hydrostatic pressure: 12000Pa Biodegradability after 180 days: 88%.

[0041] Example 3

[0042] Wear-resistant and anti-slip layer: A film is made by casting PBS (95 parts) and modified starch (5 parts) with a basis weight of 25 g / m². 2 PBS has better softness than PBAT.

[0043] Reinforcing Support Layer: Dry PLA resin (85 parts) is compounded with bamboo fiber (15 parts, 3 mm in length). The fiber content is reduced, and softer bamboo fiber is selected to achieve better flexibility. Weight is 70 g / m². 2 .

[0044] Flexible barrier layer: PBAT (70 parts) and nano-calcium carbonate (30 parts) are blended and blown into a film with a thickness of 18 μm. Reducing the filler ratio makes the film itself more flexible.

[0045] Preparation process: Reduce the pressure of the pressure roller to 0.2MPa during the compounding process to prevent the material from over-hardening.

[0046] The product performance test results for Example 3 are as follows: Puncture resistance: 11.8N Abrasion resistance: 25mg (due to the thin film on the surface, the abrasion resistance is slightly lower than that of non-woven fabric). Static friction coefficient: 0.75 hydrostatic pressure: 9800Pa Bending stiffness (ASTM D4032): 2.1 cm Biodegradability after 180 days: 92%.

[0047] Example 4

[0048] Wear-resistant and anti-slip layer: Produced by melt-blowing with 83 parts PBAT, 15 parts corn starch, and 2 parts nano zinc oxide (ZnO) antibacterial agent, with a basis weight of 32 g / m². 2 The nonwoven fabric. Nano zinc oxide provides broad-spectrum, long-lasting antibacterial properties. Embossing treatment is the same as in Example 1.

[0049] Reinforcing support layer: 75 parts of dried PLA resin are compounded with 25 parts of dried chopped bamboo fiber (4 mm in length). Bamboo fiber itself has certain natural antibacterial properties, which are beneficial when compounded with PLA. The weight after hot pressing is 85 g / m². 2 .

[0050] Flexible barrier layer: Same as in Example 1, PBAT (60 parts) and nano calcium carbonate (40 parts) are blended and blow-molded into a film with a thickness of 20 μm, and then subjected to corona treatment.

[0051] Preparation process: basically the same as in Example 1, but pay attention to ensuring that the nano zinc oxide is evenly dispersed in the raw materials before melt-blowing.

[0052] The product performance test results for Example 4 are as follows: Puncture resistance: 17.2N Antibacterial properties: Antibacterial rate >99.5% (24-hour contact) Static friction coefficient: 0.83 hydrostatic pressure: 10800Pa 180-day biodegradability: 89% (adding trace amounts of nano zinc oxide did not have a significant impact on degradability).

[0053] Example 5

[0054] Wear-resistant and anti-slip layer: A blend of PBS (82 parts), modified starch (15 parts), and nano-silica (SiO2) (3 parts, for further improvement of wear resistance) is used, produced by melt-blowing with a basis weight of 35 g / m². 2 The non-woven fabric is embossed, and then biodegradable blue and green water-based inks are used to print the markings and text for the instrument placement area and the waste disposal area on its surface.

[0055] Reinforcing support layer: 70 parts of dried PLA resin are compounded with 30 parts of dried chopped jute fiber (5 mm in length). The weight after hot pressing is 90 g / m². 2 .

[0056] Flexible barrier layer: PBAT (65 parts) and nano-calcium carbonate (35 parts) are blended and blow-molded into a film with a thickness of 22 μm, and then subjected to corona treatment.

[0057] Preparation process: Before die-cutting, an additional flexographic printing process is added to print the designed pattern onto the wear-resistant and anti-slip layer. The remaining steps are the same as in Example 1.

[0058] The product performance test results for Example 5 are as follows: Puncture resistance: 18.5N Abrasion resistance: 16mg (The addition of nano-SiO2 significantly improves abrasion resistance) Static friction coefficient: 0.88 hydrostatic pressure: 11500Pa Print adhesion (ASTM D3359): 5B (Best grade, no peeling) Biodegradability after 180 days: 88%.

[0059] As can be seen from the above embodiments, the present invention provides a disposable biodegradable antibacterial drape and its preparation method. Through the above five embodiments, it can be seen that by adjusting the material formulation, ratio, and post-processing of the three-layer structure, the present invention can flexibly customize drape products focusing on different properties (such as high strength, high flexibility, antibacterial properties, and functional guidance) to meet the diverse clinical needs in oral treatment. All embodiments maintain puncture resistance and tabletop anti-slip properties far superior to traditional PE drapes, and while achieving excellent physical properties, ensure the core environmentally friendly characteristic of complete biodegradability. Embodiments 4 and 5 further introduce antibacterial and surface-functionalized fillers, demonstrating the strong scalability and market application potential of this technical solution.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A disposable biodegradable antibacterial sheet, characterized in that, From top to bottom, it includes a wear-resistant and anti-slip layer, a reinforcing support layer, and a flexible barrier layer; the overall outline of the disposable biodegradable antibacterial drape is a U-shaped, T-shaped, or irregular structure adapted to the instrument tray area of ​​the dental treatment table.

2. The disposable biodegradable antibacterial sheet according to claim 1, characterized in that, The wear-resistant and anti-slip layer is a microporous nonwoven fabric or film made by hot pressing a blend of polybutylene succinate or polybutylene terephthalate adipate and starch, and then formed by embossing rollers. The reinforcing support layer is obtained by hot pressing polylactic acid with natural jute or bamboo fiber; The flexible barrier layer is obtained by blow molding a mixture of polybutylene terephthalate and nano-calcium carbonate.

3. The disposable biodegradable antibacterial sheet according to claim 1 or 2, characterized in that, The weight of the wear-resistant and anti-slip layer is 20~50 g / m². 2 .

4. The disposable biodegradable antibacterial sheet according to claim 1 or 2, characterized in that, The reinforcing support layer contains 20-40% natural jute or bamboo fiber by mass, and the weight of the reinforcing support layer is 60-120 g / m². 2 .

5. The disposable biodegradable antibacterial sheet according to claim 1 or 2, characterized in that, The flexible barrier layer contains 30-50% by mass of nano-calcium carbonate, and the thickness of the flexible barrier layer is 15-30 μm.

6. The method for preparing the disposable biodegradable antibacterial dressing according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Mix polylactic acid with chopped jute fiber or bamboo fiber in a certain proportion, and then melt-blend and granulate the mixture through a twin-screw extruder to obtain composite granules; then hot-press the composite granules to obtain a reinforcing support layer. 2) Polybutylene succinate or polybutylene terephthalate adipate is blended with starch in a certain proportion and made into nonwoven fabric by meltblown spinning equipment or into film by casting method; then the nonwoven fabric or film is embossed by hot press roller with predetermined pattern to obtain wear-resistant and anti-slip layer. 3) Polybutylene terephthalate (PET) is blended with nano-calcium carbonate, then blown into a film using a blown film unit, and the film surface is corona treated to obtain a flexible barrier layer. 4) Using water-based polyurethane adhesive, the adhesive is applied to the upper and lower surfaces of the reinforcing support layer by a textured coating method. Then, the wear-resistant and anti-slip layer is laminated to the upper surface of the reinforcing support layer, and the flexible barrier layer is laminated to the lower surface of the reinforcing support layer to form a three-layer composite preform. 5) The three-layer composite blank is sent into the curing chamber and cured at 40~60℃ for 12~24 hours to allow the adhesive to fully cure; the cured composite blank is cut into U-shaped, T-shaped or irregular contours that are compatible with the instrument tray area of ​​the dental treatment table using an ultrasonic cutter or die-cutting machine; and the cut edges are heat-sealed to prevent interlayer separation. 6) After die-cutting and sealing, the product is sterilized by electron beam sterilization and then vacuum packaged.

7. The method for preparing the disposable biodegradable antibacterial dressing according to claim 6, characterized in that, The temperature for melt blending and granulation is 150~180℃, and the temperature for hot pressing is 160~175℃, with a pressure of 5~15MPa.

8. The method for preparing the disposable biodegradable antibacterial dressing according to claim 6 or 7, characterized in that, The blow molding temperature is 135~150℃, and the corona treatment power is 5~10kW.