PVA-based biomedical dressing blow spinning forming device

Abstract

The invention discloses a PVA (polyvinyl alcohol)-based biomedical dressing blow spinning forming device, which belongs to the technical field of solution blow spinning and comprises a main air pipe, a mounting plate and a blow spinning nozzle movably mounted on the outer side of the mounting plate. The blowing and spinning nozzle is movably mounted on the outer side of the mounting plate and matched with the pressure compensation mechanism in the mounting plate for use, the position of the blowing and spinning nozzle can be automatically adjusted under the condition that the pressure in the air cavity fluctuates, and when the air pressure is higher than a working threshold value, the blowing and spinning nozzle is automatically driven to move upwards, the fiber flying path is prolonged, and the fiber flying efficiency is improved. When the air pressure is lower than a working threshold value, the blowing spinning nozzle is controlled to move downwards, the flying distance is shortened, the problem that fiber flying power is insufficient is solved, uneven deposition caused by fiber dispersion is prevented, and the technical problem that a traditional fixed nozzle cannot adapt to air pressure fluctuation is thoroughly solved. The spinning forming effect and the dressing finished product quality are obviously improved.

Description

Technical Field

[0001] This invention relates to a blown spinning apparatus, and more particularly to a blown spinning apparatus for PVA-based biomedical dressings, belonging to the field of solution blown spinning technology. Background Technology

[0002] Polyvinyl alcohol (PVA), as a polymer material with excellent biocompatibility, biodegradability and hydrophilicity, is widely used in the preparation of biomedical dressings. At present, solution blowing technology has become the core preparation technology for PVA-based biomedical dressing fiber membranes due to its advantages such as no need for high-voltage power supply, high production efficiency and strong process safety. It forms droplet jets by high-speed injection of PVA solution with compressed air. After being stretched by airflow and evaporated by solvent, the fibers are deposited on the collection device to form a shape, realizing the efficient preparation of dressing substrate.

[0003] However, in the actual blowing process of existing PVA-based biomedical dressings, the pressure of compressed air is easily affected by factors such as the stability of the gas source, airflow loss in the pipeline, and continuous working time, resulting in fluctuations. Traditional devices use a fixed nozzle assembly with a preset, fixed distance between it and the collection device, which cannot be dynamically adjusted according to real-time gas pressure differences. When the gas pressure is too high, the fiber jet's flight speed increases. If the distance between the nozzle and the collection device is too short, the solvent in the PVA solution cannot fully evaporate before fiber deposition, leading to excessive residual solvent on the fiber surface. Adjacent fibers are prone to adhesion, which damages the porous structure of the dressing and reduces its air permeability and mechanical stability. When the gas pressure is too low, the fiber jet's flight power is insufficient. If the distance between the nozzle and the collection device is too long, the fibers are easily dispersed by airflow disturbances during flight, resulting in uneven fiber deposition density on the collection device surface. The final dressing film exhibits problems such as thickness fluctuations and fiber agglomeration, severely affecting the spinning effect and the clinical performance of the dressing.

[0004] To address these issues, a PVA-based biomedical dressing blow spinning device was designed. Summary of the Invention

[0005] The main objective of this invention is to provide a PVA-based biomedical dressing blow spinning device. By movably mounting a blow spinning nozzle on the outside of a mounting plate, and cooperating with a pressure compensation mechanism inside the mounting plate, the device automatically adjusts the position of the blow spinning nozzle when the internal pressure of the air chamber fluctuates. When the air pressure is higher than the working threshold, the blow spinning nozzle is automatically driven to move upward, extending the fiber flight path and ensuring sufficient solvent evaporation, preventing fiber adhesion due to excessive residual solvent. When the air pressure is lower than the working threshold, the blow spinning nozzle is controlled to move downward, shortening the flight distance, solving the problem of insufficient fiber flight power, and preventing uneven deposition caused by fiber dispersion. This completely solves the technical problem that traditional fixed nozzles cannot adapt to air pressure fluctuations, significantly improving the spinning effect and the quality of the finished dressing. Through the mechanical transmission between the piston, spring, roller, and screw in the pressure compensation mechanism, the piston's extension and retraction movement with changes in air pressure is used to control the lifting and lowering of the limit rod via the elastic restoring force of the spring. The movement is then converted into a screw movement through the spiral guide groove on the outside of the roller. The rotational power ultimately achieves smooth lifting and lowering of the blown spinning nozzle. The mechanical transmission has a faster response speed and a lower structural failure rate. It can complete adaptive adjustment without additional programming control. In addition, the pressure compensation mechanism consists of an internal spiral tube, pressure plate, screw, worm gear, worm, adjustment knob, and protective cover. It can accurately calibrate the corresponding amplitude of air pressure fluctuation and nozzle lifting and lowering according to the initial pressure parameters of different production scenarios, further improving the accuracy of nozzle position adjustment and adapting to diverse dressing preparation needs. Two-component diversion pipes are set between the main air pipe and each air chamber. During operation, one-component diversion pipe is open. Each diversion pipe is equipped with a pipeline air filter and a solenoid valve. In conjunction with contact switches and indicator lights, it can automatically press the contact switch when the air pressure is too low, replace the open diversion pipe, and use the indicator lights to indicate that the pressure fluctuation is caused by filter blockage. In addition, the filter element inside the pipeline air filter can be replaced online to ensure the continuity of production.

[0006] The objective of this invention can be achieved by adopting the following technical solution: A PVA-based biomedical dressing blow spinning forming device includes a main air pipe, a mounting plate, and a blow spinning nozzle. The blow spinning nozzle is movably mounted on the outside of the mounting plate. The mounting plate has air chambers evenly distributed along its length. Each air chamber has an air supply pipe at its bottom end that communicates with the blow spinning nozzle. The mounting plate has a pressure compensation mechanism inside, which is connected to the blow spinning nozzle for adjusting the height of the blow spinning nozzle according to the air pressure fluctuations in the air chambers of the main air pipe. Two sets of parallel branch pipes are provided between the main air pipe and each air chamber. Each branch pipe is connected in series with a pipeline air filter and a solenoid valve. The mounting plate is equipped with a contact switch that is linked to the pressure compensation mechanism. Indicator lights are provided at the top of the mounting plate corresponding to the position of the blown spinneret. The contact switch, solenoid valve and indicator lights are electrically connected. The solenoid valve is controlled by the trigger signal of the contact switch to realize the automatic switching of the branch pipe.

[0007] Preferred: The pressure compensation mechanism includes a slide, a connecting rod, a screw, a piston, a spring, a sleeve, a strip groove, a limiting rod, a rotating assembly, and a pressure regulating assembly; The chutes are evenly and vertically opened on the side of the mounting plate along the length direction. Connecting rods are vertically and slidingly installed inside the chutes. The end of the connecting rod away from the inside of the chutes is fixedly connected to the blown spinning nozzle. A screw is vertically and rotatably installed inside the chutes, and the screw is threadedly connected to the connecting rod. The piston is vertically slidably disposed inside the air chamber. A spring is provided between the top of the piston and the top of the air chamber. A sleeve is fixed to the top of the piston and is sleeved outside the spring. A strip groove is vertically opened on the inner side of the air chamber. A limit rod is vertically slidably disposed inside the strip groove and is fixedly connected to the sleeve. The top of the screw is equipped with a rotating component, which drives the screw to rotate as the limit rod rises and falls; Each spring has a pressure regulating component at its top, which is used to adjust the initial pressure of the piston.

[0008] Preferably, the rotating assembly includes a transmission chamber, a rotating roller, and a spiral guide groove. The transmission chamber is located inside the mounting plate. The top end of the screw extends into the transmission chamber. The rotating roller is coaxially fixed to the top end of the screw. A spiral guide groove is provided on the outer side of the rotating roller. The end of the limiting rod away from the sleeve slides inside the spiral guide groove.

[0009] Preferably, the pressure regulating assembly includes an inner spiral tube, a pressure plate, a second screw, and an adjusting component. The inner spiral tube is vertically slidably disposed at the top of the air chamber. The pressure plate is fixed at the bottom end of the inner spiral tube, and the bottom end of the pressure plate is connected to the top of the spring. The second screw is installed on the internal thread of the inner spiral tube. The second screw is mounted on the mounting plate through a bearing and extends to the top of the mounting plate. An adjusting component is provided on the top of the mounting plate for simultaneously controlling the rotation adjustment of multiple sets of second screws.

[0010] Preferably, the adjusting component includes a worm gear, a worm, an adjusting knob, and a cover. The worm gear is coaxially mounted on the top of the screw, and the top of the worm gear is covered by the cover. A worm that meshes with the worm gear is rotatably mounted between the two ends of the cover. One end of the worm extends to the outer end of the cover, and an adjusting knob is fixed to the outer end of the worm.

[0011] Preferably, the contact switch is installed at the inner bottom of the slide and below the connecting rod. The connecting rod presses the contact switch and triggers the solenoid valve to switch the diversion pipe.

[0012] Preferably, the adjustment knob is circular in shape, and the outer side of the adjustment knob is evenly textured with anti-slip patterns.

[0013] Preferably, the interior of the spiral guide groove is coated with a wear-resistant polytetrafluoroethylene coating, and a bearing is provided at one end of the limiting rod located inside the spiral guide groove.

[0014] Preferably, the inner spiral tube is in the shape of a quadrangular prism, and a rectangular guide groove adapted to the inner spiral tube is vertically opened at the top of the air cavity.

[0015] Preferably, fixing rods are evenly provided along the length direction between the main air pipe and the side of the mounting plate, and the fixing rods are perpendicular to the surface of the main air pipe and the mounting plate.

[0016] The beneficial effects of this invention are as follows: This invention provides a PVA-based biomedical dressing blow spinning forming device. By movably mounting a blow spinning nozzle on the outside of a mounting plate and cooperating with a pressure compensation mechanism inside the mounting plate, the device can automatically adjust the position of the blow spinning nozzle when the internal pressure of the air chamber fluctuates. When the air pressure is higher than the working threshold, the blow spinning nozzle is automatically driven to move upward, extending the fiber flight path and ensuring sufficient solvent evaporation, thus preventing the fibers from sticking together due to excessive residual solvent. When the air pressure is lower than the working threshold, the blow spinning nozzle is controlled to move downward, shortening the flight distance, solving the problem of insufficient fiber flight power, and preventing uneven deposition caused by fiber dispersion. This completely solves the technical problem that traditional fixed nozzles cannot adapt to air pressure fluctuations, significantly improving the spinning forming effect and the quality of the finished dressing. Through the mechanical transmission between the piston, spring, rotating roller, and screw in the pressure compensation mechanism, the piston's expansion and contraction movement with changes in air pressure is used to control the lifting and lowering of the limit rod in conjunction with the elastic restoring force of the spring. This force is then converted into the rotational power of the screw through the spiral guide groove on the outside of the rotating roller, ultimately achieving smooth lifting and lowering of the blown yarn nozzle. The mechanical transmission has a faster response speed and a lower structural failure rate. It can achieve adaptive adjustment without additional programming control. In addition, the pressure adjustment component inside the pressure compensation mechanism, consisting of an inner spiral tube, pressure plate, screw two, worm gear, worm, adjustment knob, and protective cover, can accurately calibrate the corresponding amplitude of air pressure fluctuation and nozzle lifting and lowering according to the initial pressure parameters of different production scenarios, further improving the accuracy of nozzle position adjustment and adapting to diverse dressing preparation needs. By installing two sets of diversion pipes between the main air pipe and each air chamber, each set of diversion pipes is open during operation. Each diversion pipe is equipped with a pipeline air filter and a solenoid valve. In conjunction with a contact switch and an indicator light, the system can automatically press the contact switch when the air pressure is too low, replacing the open diversion pipe and providing an indication with the indicator light. This avoids air pressure fluctuations caused by filter blockage. In addition, the filter element inside the pipeline air filter can be replaced online, ensuring continuous production. Attached Figure Description

[0017] Figure 1 This is a top view of the structure of the present invention; Figure 2 This is an overall side sectional view of the present invention; Figure 3 This is a cross-sectional view of the mounting plate and main air pipe of the present invention. Figure 4 This is a cross-sectional view of the mounting plate of the present invention; Figure 5 This is a diagram of the transmission structure of the present invention; Figure 6 This is a view of the surface of the roller of the present invention; Figure 7 This is a top sectional view of the inner surface of the protective cover of the present invention; Figure 8 This is a side view of the mounting plate of the present invention; Figure 9 This is a side view of the main airway of the present invention.

[0018] In the diagram: 1. Main air pipe; 2. Mounting plate; 3. Fixing rod; 4. Air chamber; 5. Diverter pipe; 6. Spinning nozzle; 7. Air supply pipe; 8. Pressure compensation mechanism; 801. Slide groove; 802. Connecting rod; 803. Screw one; 804. Piston; 805. Spring; 806. Sleeve; 807. Strip groove; 808. Limiting rod; 809. Transmission chamber; 810. Rotary roller; 811. Spiral guide groove; 812. Inner spiral tube; 813. Pressure plate; 814. Screw two; 815. Worm gear; 816. Worm; 817. Adjusting knob; 818. Protective cover; 9. Pipeline air filter; 10. Solenoid valve; 11. Contact switch; 12. Indicator light. Detailed Implementation

[0019] To enable those skilled in the art to more clearly understand the technical solution of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Example

[0020] like Figures 1-9As shown, this embodiment provides a PVA-based biomedical dressing blow spinning forming device, including a main air pipe 1, a mounting plate 2, and a blow spinning nozzle 6. The blow spinning nozzle 6 is movably installed on the outside of the mounting plate 2. The interior of the mounting plate 2 is evenly provided with air chambers 4 along the length direction. The bottom end of each set of air chambers 4 is provided with an air supply pipe 7 that communicates with the blow spinning nozzle 6. The mounting plate 2 is provided with a pressure compensation mechanism 8, which is connected to the blow spinning nozzle 6 for adjusting the height of the blow spinning nozzle 6 according to the air pressure fluctuation in the air chambers 4 of the main air pipe 1. Two sets of parallel diversion pipes 5 are provided between the main air pipe 1 and each air chamber 4. Each diversion pipe 5 is connected in series with a pipeline air filter 9 and a solenoid valve 10. The mounting plate 2 is equipped with a contact switch 11 that is linked to the pressure compensation mechanism 8. The top of the mounting plate 2 is equipped with an indicator light 12 at the position corresponding to the blow-blowing nozzle 6. The contact switch 11, the solenoid valve 10 and the indicator light 12 are electrically connected. The solenoid valve 10 is controlled by the trigger signal of the contact switch 11 to realize the automatic switching of the diversion pipes 5.

[0021] When the device is working, the main air pipe 1 supplies compressed air to the air chamber 4 inside the mounting plate 2. The compressed air is then introduced into the blown head 6 via the air supply pipe 7, providing airflow power for the blown spinning of PVA solution. When the air pressure in the air chamber 4 fluctuates due to factors such as the stability of the air source and pipeline losses, the pressure compensation mechanism 8 inside the mounting plate 2 works in conjunction with the blown head 6 to automatically adjust the height of the blown head 6: when the air pressure is higher than the working threshold, the blown head 6 moves upward to extend the fiber flight path, ensuring that the solvent in the PVA solution evaporates fully and avoiding fiber adhesion; when the air pressure is lower than the working threshold, the blown head 6 moves downward to shorten the flight distance, solving the problem of insufficient fiber flight power and preventing uneven deposition.

[0022] In the two sets of parallel branch pipes 5 between the main air pipe 1 and the air chamber 4, initially, one branch pipe 5 is open, and the pipeline air filter 9 filters the compressed air. When the filter element of the pipeline air filter 9 becomes clogged, causing the air pressure to remain too low, the pressure compensation mechanism 8 is triggered by the contact switch 11. The contact switch 11 controls the solenoid valve 10 to switch to the other branch pipe 5. At the same time, the indicator light 12 at the corresponding position of the spinning nozzle 6 lights up to indicate that the branch pipe 5 is automatically switched. The filter element can be replaced online to ensure continuous production. Example

[0023] The solution in Example 1 will be further described below with reference to its specific working method. In this embodiment, the pressure compensation mechanism 8 includes a slide 801, a connecting rod 802, a screw 803, a piston 804, a spring 805, a sleeve 806, a strip groove 807, a limiting rod 808, a rotating assembly, and a pressure regulating assembly. The slide groove 801 is evenly and vertically opened on the side of the mounting plate 2 along the length direction. The interior of the slide groove 801 is vertically and slidably equipped with a connecting rod 802. The end of the connecting rod 802 away from the interior of the slide groove 801 is fixedly connected to the blown spinneret 6. The interior of the slide groove 801 is vertically and rotatably equipped with a screw 803, and the screw 803 is threadedly connected to the connecting rod 802. The piston 804 is vertically slidably disposed inside the air chamber 4. A spring 805 is provided between the top of the piston 804 and the inner top of the air chamber 4. A sleeve 806 is fixed to the top of the piston 804 and is sleeved on the outside of the spring 805. A strip groove 807 is vertically opened on the inner side of the air chamber 4. A limit rod 808 is vertically slidably disposed inside the strip groove 807 and is fixedly connected to the sleeve 806. The top of the screw 803 is equipped with a rotating component, which drives the screw 803 to rotate as the limit rod 808 rises and falls. Each spring 805 is equipped with a pressure regulating component at its top, which is used to regulate the initial pressure of the piston 804.

[0024] When the air pressure inside the air chamber 4 changes, the piston 804 slides vertically along the air chamber 4: when the air pressure increases, it pushes the piston 804 upward, compressing the spring 805; when the air pressure decreases, the spring 805 elastically resets, pushing the piston 804 downward. The sleeve 806 is fitted outside the spring 805 to prevent the spring 805 from deforming and shifting, and simultaneously drives the limiting rod 808 in the strip groove 807 to rise and fall synchronously. When the limiting rod 808 rises and falls, it drives the rotating component to operate, which in turn drives the screw 803 to rotate. The screw 803 is threadedly engaged with the connecting rod 802, converting the rotational motion into the vertical movement of the connecting rod 802, ultimately realizing the height adjustment of the blown spinning nozzle 6. The pressure adjustment component at the top of the spring 805 can preset the initial pressure of the piston 804 to adapt to different blown spinning process requirements.

[0025] In this embodiment, the rotating assembly includes a transmission chamber 809, a rotating roller 810, and a spiral guide groove 811. The transmission chamber 809 is located inside the mounting plate 2. The top end of the screw 803 extends into the transmission chamber 809. The rotating roller 810 is coaxially fixed to the top end of the screw 803. The spiral guide groove 811 is provided on the outer side of the rotating roller 810. The end of the limiting rod 808 away from the sleeve 806 slides inside the spiral guide groove 811.

[0026] Under normal operating conditions, the limit rod 808 is initially positioned in the middle of the spiral guide groove 811, and the connecting rod 802 connected to the spinning nozzle 6 is simultaneously positioned in the middle of the slide groove 801, ensuring that the spinning nozzle 6 has bidirectional adjustable stroke. When the limit rod 808 rises and falls with the piston 804 and the sleeve 806, its end slides within the spiral guide groove 811. Utilizing the guiding effect of the spiral guide groove 811, the roller 810 is driven to rotate, and the roller 810 drives the screw 803 to rotate synchronously, completing the power transmission. The wear-resistant polytetrafluoroethylene coating inside the spiral guide groove 811, in conjunction with the bearing at the end of the limit rod 808, reduces sliding friction and improves transmission stability.

[0027] In this embodiment, the pressure regulating assembly includes an inner spiral tube 812, a pressure plate 813, a second screw 814, and an adjusting component. The inner spiral tube 812 is vertically slidably disposed at the top of the air chamber 4. The bottom end of the inner spiral tube 812 is fixed with the pressure plate 813, and the bottom end of the pressure plate 813 is connected to the top of the spring 805. The second screw 814 is installed on the internal thread of the inner spiral tube 812. The second screw 814 is mounted on the mounting plate 2 through a bearing, and the second screw 814 extends to the top of the mounting plate 2. The top of the mounting plate 2 is provided with an adjusting component for simultaneously controlling the rotation adjustment of multiple sets of second screws 814.

[0028] Rotating the adjusting piece on the top of the mounting plate 2 can drive the screw 814 to rotate. The screw 814 is threadedly engaged with the inner spiral tube 812, causing the inner spiral tube 812 to move vertically along the rectangular guide groove. This, in turn, compresses or releases the spring 805 through the pressure plate 813, adjusting the preload of the spring 805. Finally, the initial pressure of the piston 804 is calibrated, achieving precise matching between air pressure fluctuations and the lifting amplitude of the blowing nozzle 6.

[0029] In this embodiment, the adjusting component includes a worm gear 815, a worm 816, an adjusting knob 817, and a cover 818. The worm gear 815 is coaxially mounted on the top of the screw 814. The top of the worm gear 815 is covered by the cover 818. The worm 816, which meshes with the worm gear 815, is rotatably mounted between the two ends of the cover 818. One end of the worm 816 extends to the outer end of the cover 818, and the adjusting knob 817 is fixed to the outer end of the worm 816.

[0030] Rotating the adjustment knob 817 drives the worm gear 816 to rotate between the two ends of the cover 818. The worm gear 816 meshes with the worm wheel 815 at the top of each set of screws 814. Through the transmission characteristics of the worm wheel 815 and the worm gear 816, multiple sets of screws 814 are driven to rotate synchronously, realizing the unified adjustment of multiple pressure adjustment components, improving operating efficiency, and adapting to the synchronous parameter calibration of multiple blow-blowing nozzles 6 in mass production.

[0031] In this embodiment, the contact switch 11 is installed at the inner bottom end of the slide 801 and located below the connecting rod 802. The connecting rod 802 presses the contact switch 11 and triggers the solenoid valve 10 to switch the diversion pipe 5.

[0032] When the air pressure in the air chamber 4 is too low, the pressure compensation mechanism 8 drives the connecting rod 802 to move down to the contact switch 11 and presses it to trigger. The contact switch 11 sends an electrical signal to the solenoid valve 10 to control the currently connected diversion pipe 5 to close, while opening another set of parallel diversion pipes 5 to complete the switching of the filter pipeline. The indicator light 12 at the corresponding position of the blow-blowing nozzle 6 lights up simultaneously, reminding the staff to replace the filter element of the original diversion pipe 5 pipeline air filter 9 in time to ensure the airflow filtration effect.

[0033] In this embodiment, the adjustment knob 817 is circular in shape, and anti-slip textures are evenly distributed on the outer side of the adjustment knob 817.

[0034] The anti-slip texture on the outside of the adjustment knob 817 increases grip friction and makes rotational adjustment easier.

[0035] In this embodiment, the interior of the spiral guide groove 811 is coated with a polytetrafluoroethylene wear-resistant coating, and the end of the limiting rod 808 located inside the spiral guide groove 811 is provided with a bearing.

[0036] The wear-resistant polytetrafluoroethylene coating inside the spiral guide groove 811, together with the bearing at the end of the limit rod 808, reduces sliding friction and improves transmission stability.

[0037] In this embodiment, the internal helical tube 812 is in the shape of a quadrangular prism, and a rectangular guide groove adapted to the internal helical tube 812 is vertically opened at the top of the air cavity 4.

[0038] The inner screw tube 812 is designed as a quadrangular prism to prevent it from rotating synchronously with the screw 814, thus ensuring adjustment accuracy.

[0039] In this embodiment, a fixing rod 3 is uniformly provided along the length direction between the main air pipe 1 and the side of the mounting plate 2, and the fixing rod 3 is perpendicular to the surface of the main air pipe 1 and the mounting plate 2.

[0040] The fixing rods 3 are evenly distributed along the length of the main air pipe 1 and the side of the mounting plate 2, and are perpendicular to the surfaces of the main air pipe 1 and the mounting plate 2. Their function is to strengthen the connection stability between the main air pipe 1 and the mounting plate 2, prevent the mounting plate 2 from shifting due to pipeline vibration during airflow, and ensure the accuracy of the position adjustment of the blown nozzle 6 and the stability of the spinning process. Example

[0041] The solutions in Embodiment 1 and Embodiment 2 will be further described below with reference to their specific working methods. Initial parameter adjustment stage: According to the blown spinning process requirements of PVA-based biomedical dressings, rotate the adjustment knob 817. Through the meshing transmission of the worm gear 816 and worm wheel 815, multiple sets of screws 814 are driven to rotate synchronously. The screws 814 are threadedly engaged with the inner spiral tube 812, causing the inner spiral tube 812 to move vertically along the rectangular guide groove at the top of the air chamber 4. The pressure plate 813 compresses or releases the spring 805, calibrating the initial pressure of the piston 804, determining the correspondence between air pressure fluctuations and the lifting amplitude of the blown spinning nozzle 6, and completing the initial parameter calibration of the device.

[0042] Normal blowing and air pressure compensation stage: The main air pipe 1 delivers compressed air to the air chamber 4. After being filtered by the pipeline air filter 9, it is introduced into the blowing nozzle 6 by the air supply pipe 7. The blowing nozzle 6 atomizes the PVA solution to form droplet jets. After being stretched by the airflow and evaporated by the solvent, the fibers are deposited and formed on the collection device.

[0043] When the air pressure in air chamber 4 rises above the working threshold, the air pressure pushes piston 804 upward, compressing spring 805. Sleeve 806 moves upward synchronously with piston 804, causing limiting rod 808 in strip groove 807 to move upward. The end of limiting rod 808 slides within spiral guide groove 811 of roller 810, driving roller 810 to rotate. Roller 810 drives screw 803 to rotate synchronously. Screw 803 is threadedly engaged with connecting rod 802, converting the rotational motion into upward movement of connecting rod 802. The spinning nozzle 6 moves upward with connecting rod 802, extending the fiber flight path, ensuring sufficient solvent evaporation, preventing adjacent fibers from sticking together, and guaranteeing the porous structure and breathability of the dressing.

[0044] When the air pressure in the air chamber 4 drops below the working threshold, the spring 805 elastically resets, pushing the piston 804 downward. The sleeve 806 drives the limiting rod 808 downward. The limiting rod 808 drives the rotating roller 810 to rotate in the opposite direction through the spiral guide groove 811. The screw 803 rotates in the opposite direction, driving the connecting rod 802 downward. The blowing nozzle 6 moves downward synchronously, shortening the fiber flight distance, compensating for insufficient flight power, preventing the fiber from being dispersed by airflow disturbance, ensuring uniform fiber deposition density, and improving the consistency of dressing film thickness.

[0045] During the switching of the diversion pipe 5 and the replacement of the filter element: When the filter element inside the pipeline air filter 9 becomes clogged, causing a continuous decrease in air pressure in the air chamber 4, the pressure compensation mechanism 8 drives the connecting rod 802 to move down to the bottom of the slide groove 801, pressing the contact switch 11. After the contact switch 11 is triggered, it sends an electrical signal to the solenoid valve 10, controlling the solenoid valve 10 on the currently connected diversion pipe 5 to close, while simultaneously opening the solenoid valve 10 on another set of parallel diversion pipes 5, realizing rapid switching of the filter pipeline and avoiding air pressure fluctuations from affecting the spinning effect.

[0046] At the same time, indicator light 12 on the top of mounting plate 2, corresponding to the position of the spinning nozzle 6, illuminates, prompting the operator to check for filter blockage. Operators can replace the filter element of the pipeline air filter 9 on the closed diversion pipe 5 while the device is continuously operating, achieving online maintenance and ensuring production continuity. After filter element replacement, the original operating state of the diversion pipe 5 can be restored by manually operating the solenoid valve 10 or by waiting for the next switching signal.

[0047] The above description is merely a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A PVA-based biomedical dressing blow spinning device, comprising a main air pipe (1), a mounting plate (2), and a blow spinning nozzle (6), characterized in that: The blowing nozzle (6) is movably installed on the outside of the mounting plate (2). The interior of the mounting plate (2) is evenly provided with air chambers (4) along the length direction. Each set of air chambers (4) is provided with an air supply pipe (7) connected to the blowing nozzle (6) at the bottom end. The mounting plate (2) is provided with a pressure compensation mechanism (8). The pressure compensation mechanism (8) is connected to the blowing nozzle (6) and is used to adjust the height of the blowing nozzle (6) according to the air pressure fluctuation in the air chamber (4) of the main air pipe (1). Two sets of parallel diversion pipes (5) are provided between the main air pipe (1) and each air chamber (4). Each diversion pipe (5) is connected in series with a pipeline air filter (9) and a solenoid valve (10). The mounting plate (2) is provided with a contact switch (11) that is linked with the pressure compensation mechanism (8). The top of the mounting plate (2) is provided with an indicator light (12) corresponding to the position of the blow-blowing nozzle (6). The contact switch (11), the solenoid valve (10) and the indicator light (12) are electrically connected. The solenoid valve (10) is controlled by the trigger signal of the contact switch (11) to achieve automatic switching of the diversion pipe (5).

2. The PVA-based biomedical dressing blow spinning apparatus according to claim 1, characterized in that: The pressure compensation mechanism (8) includes a slide (801), a connecting rod (802), a screw (803), a piston (804), a spring (805), a sleeve (806), a strip groove (807), a limit rod (808), a rotating assembly, and a pressure regulating assembly; The slide groove (801) is evenly and vertically opened on the side of the mounting plate (2) along the length direction. The interior of the slide groove (801) is vertically and slidably equipped with connecting rods (802). The end of the connecting rod (802) away from the interior of the slide groove (801) is fixedly connected to the blow spinning nozzle (6). The interior of the slide groove (801) is vertically and rotatably equipped with a screw (803), and the screw (803) is threadedly connected to the connecting rod (802). The piston (804) is vertically slidably disposed inside the air chamber (4). A spring (805) is provided between the top of the piston (804) and the inner top of the air chamber (4). A sleeve (806) is fixed to the top of the piston (804), and the sleeve (806) is sleeved outside the spring (805). A strip groove (807) is vertically opened on the inner side of the air chamber (4). A limit rod (808) is vertically slidably disposed inside the strip groove (807). The limit rod (808) is fixedly connected to the sleeve (806). The top of the screw (803) is provided with a rotating component, which drives the screw (803) to rotate as the limit rod (808) rises and falls; Each spring (805) has a pressure regulating component at its top, which is used to regulate the initial pressure of the piston (804).

3. The PVA-based biomedical dressing blow spinning apparatus according to claim 2, characterized in that: The rotating assembly includes a transmission chamber (809), a rotating roller (810), and a spiral guide groove (811). The transmission chamber (809) is located inside the mounting plate (2). The top end of the screw (803) extends into the transmission chamber (809). The rotating roller (810) is coaxially fixed to the top end of the screw (803). The spiral guide groove (811) is provided on the outer side of the rotating roller (810). The end of the limiting rod (808) away from the sleeve (806) slides inside the spiral guide groove (811).

4. The PVA-based biomedical dressing blow spinning apparatus according to claim 2, characterized in that: The pressure regulating assembly includes an inner spiral tube (812), a pressure plate (813), a second screw (814), and an adjusting component. The inner spiral tube (812) is vertically slidably disposed at the top of the air chamber (4). The bottom end of the inner spiral tube (812) is fixed with a pressure plate (813). The bottom end of the pressure plate (813) is connected to the top of the spring (805). The inner spiral tube (812) is threaded with a second screw (814). The second screw (814) is mounted on the mounting plate (2) through a bearing and extends to the top of the mounting plate (2). The top of the mounting plate (2) is provided with an adjusting component for simultaneously controlling the rotation adjustment of multiple sets of second screws (814).

5. The PVA-based biomedical dressing blow spinning apparatus according to claim 4, characterized in that: The adjusting components include a worm gear (815), a worm (816), an adjusting knob (817), and a cover (818). The worm gear (815) is coaxially mounted on the top of the screw (814). The top of the worm gear (815) is covered by the cover (818). The worm (816) that meshes with the worm gear (815) is rotatably mounted between the two ends of the cover (818). One end of the worm (816) extends to the outer end of the cover (818). The adjusting knob (817) is fixed to the outer end of the worm (816).

6. The PVA-based biomedical dressing blow spinning apparatus according to claim 2, characterized in that: The contact switch (11) is installed at the inner bottom of the slide (801) and below the connecting rod (802). The connecting rod (802) presses the contact switch (11) and triggers the solenoid valve (10) to switch the shunt pipe (5).

7. The PVA-based biomedical dressing blow spinning apparatus according to claim 5, characterized in that: The adjustment knob (817) is circular in shape, and anti-slip textures are evenly distributed on the outer side of the adjustment knob (817).

8. The PVA-based biomedical dressing blow spinning apparatus according to claim 3, characterized in that: The interior of the spiral guide groove (811) is coated with a wear-resistant polytetrafluoroethylene coating, and the end of the limiting rod (808) located inside the spiral guide groove (811) is provided with a bearing.

9. The PVA-based biomedical dressing blow spinning apparatus according to claim 4, characterized in that: The inner spiral tube (812) is shaped like a quadrangular prism, and the top of the air cavity (4) is vertically provided with a rectangular guide groove that is compatible with the inner spiral tube (812).

10. The PVA-based biomedical dressing blow spinning apparatus according to claim 1, characterized in that: A fixing rod (3) is evenly provided along the length direction between the side of the main air pipe (1) and the mounting plate (2), and the fixing rod (3) is perpendicular to the surface of the main air pipe (1) and the mounting plate (2).

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