High-density tubular polyester fabric ultrasonic atomization coating spraying device and method

Abstract

The application discloses a high-density tubular polyester fabric ultrasonic atomization coating spraying device and method, and relates to the technical field of medical textile material surface coating treatment. The spraying device comprises a supporting unit, a feeding unit and an atomization spraying unit. The supporting unit is used for tensioning and fixing the tubular polyester fabric and making axial and circumferential movements. The feeding unit is used for preparing the coating liquid. The atomization spraying unit is used for spraying the coating liquid on the tensioned tubular polyester fabric. The spraying method comprises the following steps: tensioning and fixing the tubular polyester fabric; mixing the gelatin / collagen solution and the cross-linking agent solution in real time, atomizing, driving the tubular polyester fabric to make axial and circumferential movements for full-coverage spraying, and drying and sterilizing after cross-linking and solidification. The application effectively solves the problems of easy deformation of the tubular polyester fabric, uneven coating, unstable viscosity of the coating liquid and the like, and is suitable for uniform coating preparation of the anti-bleeding artificial blood vessel.

Description

Technical Field

[0001] This invention relates to the field of surface coating technology for medical textile materials, specifically to an ultrasonic atomization coating spraying device and method for high-density tubular polyester fabrics. Background Technology

[0002] Artificial blood vessels are important medical devices used for replacement, bypass grafting, or shunt of diseased blood vessels in the human body. Currently, high-density polyester filament braided tubular fabrics are widely used in clinical practice. After precision heat setting, they are formed into soft tubular prostheses with a regular spiral wavy structure. Due to the inherent porosity of the braided structure, blood can leak through the vessel wall after implantation. Therefore, the vessel wall must be coated to give it anti-leakage properties and improve biocompatibility.

[0003] Existing coating technologies have the following drawbacks: (1) Uneven coating due to dip coating. Existing technologies mainly use dip coating (immersion method) for coating treatment. For example, Chinese invention patent CN100364620C discloses a collagen pre-coated coating for artificial blood vessels, and CN104027844A discloses a new method for coating artificial blood vessels with astragalus polysaccharide, both of which involve collagen pre-coated coating schemes. The dip coating method relies on the coating liquid to flow naturally under the action of gravity. For tubular fabrics with spiral corrugated structures, the coating thickness difference between the crest and trough is significant, and the measured deviation can reach more than 30%, which seriously affects the uniformity of the anti-bleeding effect.

[0004] (2) Low utilization rate of coating liquid. During the dip coating process, a large amount of coating liquid is not effectively absorbed by the fabric and is lost. The utilization rate is usually less than 40%. When using high-cost biological materials such as gelatin and collagen, the economic efficiency is poor.

[0005] (3) Mandrel-supported spraying method. A rigid mandrel is inserted into the tubular polyester fabric for support, and then the spraying operation is carried out. This method can maintain the tubular shape of the fabric to a certain extent, but due to the gap between the rigid mandrel and the inner wall of the fabric, the fabric may still experience circumferential displacement and local wrinkles during the spraying process; at the same time, the rigid mandrel is difficult to adapt to tubular polyester fabrics with different inner diameters, and its versatility is poor.

[0006] (4) Poor batch-to-batch reproducibility. The dip coating method is affected by multiple factors such as temperature, humidity, immersion time, and lifting speed, resulting in a large coefficient of variation between batches, which makes it difficult to meet the strict requirements for quality consistency in the large-scale production of medical devices.

[0007] (5) The separation of crosslinking and coating processes leads to process complexity and creates a crosslinking gradient. In the prior art, coating and crosslinking are usually carried out in separate steps—the coating is completed first, and then the coating is immersed in a crosslinking agent solution for crosslinking. In this process, the crosslinking agent diffuses from the surface of the coating to the interior, which inevitably creates a spatial gradient of "high crosslinking density on the surface and low crosslinking density in the interior", affecting the overall mechanical properties and degradation behavior of the coating. In addition, the step-by-step process is cumbersome and time-consuming.

[0008] Therefore, there is an urgent need to develop a new coating technology for high-density tubular polyester fabrics to solve the aforementioned problems of existing technologies. Summary of the Invention

[0009] This invention aims to overcome the technical shortcomings of existing dip coating methods, such as uneven coating, low material utilization, unstable quality, and complex step-crosslinking processes. It provides an ultrasonic atomization coating device and method for high-density tubular polyester fabrics. This invention replaces traditional dip coating with atomization spraying, achieving uniform and directional deposition of atomized droplets on the curved surface of the tubular polyester fabric. Furthermore, it employs a two-component instant mixing strategy to resolve the contradiction between the premixing and gelation of the protein-crosslinking agent system and the step-crosslinking gradient, thereby improving coating uniformity, coating liquid utilization, and product quality consistency.

[0010] The technical solution of this invention is as follows: On one hand, the present invention provides an ultrasonic atomization coating spraying device for high-density tubular polyester fabric, including a support unit, a feeding unit, and an atomization spraying unit; the support unit includes a radial expansion fixing member, two end fixing members, and a displacement driving mechanism; the radial expansion fixing member is used to expand inside the tubular polyester fabric to tension the tubular polyester fabric and keep it in a straight and taut state; the two end fixing members are used to fix the two ends of the tensioned tubular polyester fabric; the displacement driving mechanism is used to drive the tensioned tubular polyester fabric to move along its axial direction and rotate circumferentially; the feeding unit is used to prepare the coating liquid; and the atomization spraying unit is used to spray the coating liquid onto the tensioned tubular polyester fabric.

[0011] Preferably, the radial expansion fastener is an inflatable polymer elastic self-expanding body; the two end fasteners are annular pneumatic claws that can uniformly grip the edges of both ends of the tensioned fabric from the outside; the displacement drive mechanism is a ball screw, linear guide or linear servo motor driven by a rotary drive servo motor, which can drive the tensioned tubular polyester fabric to perform axial uniform speed movement and circumferential rotational movement.

[0012] Preferably, the feeding unit includes a storage tank 1 and a storage tank 2, with the first storage tank storing coating liquid A and the second storage tank storing coating liquid B; the first storage tank and the second storage tank are respectively connected to a mixing tank via pipelines.

[0013] Preferably, both storage tank one and storage tank two are equipped with a stirrer, a heating mechanism and a temperature sensor; metering pumps are installed on the pipeline between storage tank one and the mixing tank and on the pipeline between storage tank two and the mixing tank.

[0014] Preferably, coating solution A is a gelatin solution or a collagen solution, and coating solution B is a glutaraldehyde solution or a glyoxal solution; the molecular weight of the gelatin or collagen is 500-100,000 Da; the concentration of gelatin or collagen in coating solution A is 0.5-10 wt.%, and the concentration of glutaraldehyde or glyoxal in coating solution B is 0.05-2 wt.%; the mixing volume ratio of coating solution A and coating solution B is (1-20):1; coating solution A also includes a plasticizer, which is at least one of glycerol and sorbitol, and the amount used is 2-15 wt.% of gelatin or collagen.

[0015] Preferably, the atomizing spraying unit includes an ultrasonic atomizing nozzle, which is connected to the mixing tank via a pipeline. The ultrasonic atomizing nozzle can be fixed above or to both sides of the tensioned tubular polyester fabric.

[0016] Preferably, the ultrasonic atomizing nozzle is a piezoelectric ultrasonic atomizing nozzle; the ultrasonic atomizing nozzle is connected to an air compressor pump.

[0017] On the other hand, the present invention provides a method for ultrasonic atomization coating of high-density tubular polyester fabric, wherein the coating is performed using the aforementioned ultrasonic atomization coating device for high-density tubular polyester fabric, and includes the following steps: S1 Fabric tensioning and fixing: The woven high-density tubular polyester fabric is installed on the support unit, causing it to expand inside the tubular polyester fabric and applying radial tension to the tubular polyester fabric to keep it in a straight and taut state. S2 Coating solution preparation: The coating solution is prepared through the feeding unit; S3 Atomized Spraying: The atomized spraying unit forms the coating liquid into atomized droplets and sprays them onto the outer surface of the tubular polyester fabric. At the same time, the displacement drive mechanism drives the tubular polyester fabric to move axially and rotate circumferentially, so that the atomized droplets of the coating liquid fully cover the outer surface of the tubular polyester fabric. S4 Crosslinking Reaction: After spraying, the tubular polyester fabric coated with the coating liquid is left to stand for crosslinking at 20-50℃ and 30-65% relative humidity for 4-12 hours, so that one of glutaraldehyde and glyoxal reacts with one of gelatin and collagen to form a crosslinked network coating. S5 Drying and Sterilization: The cross-linked tubular polyester fabric is vacuum dried and sterilized to obtain a high-density tubular polyester fabric with a uniform coating.

[0018] Preferably, in step S3, the axial movement speed of the tubular polyester fabric is 1-20 mm / s, the circumferential rotation speed is 1-60 rpm, and the number of spraying passes is 1-5. While the tubular polyester fabric is rotating, the entire outer surface of the tubular polyester fabric is sprayed from one end to the other, which is counted as one spraying pass.

[0019] Preferably, in step S5, the vacuum drying temperature is 20-50℃.

[0020] This invention uses an ultrasonic atomizing nozzle to form atomized droplets from the instantaneously mixed coating liquid A and coating liquid B. When spraying on the surface of tubular polyester fabric, the atomized droplets can enter the troughs and pores of the fabric threads, achieving uniform deposition on the curved surface.

[0021] The cross-linking reaction between the amino groups in gelatin / collagen and the aldehyde groups in glutaraldehyde / glyoxal initiates immediately after mixing. The viscosity of the mixture increases over time, limiting the spraying window; stepwise cross-linking leads to a cross-linking density gradient problem. This invention employs an "instant mixing before spraying" strategy—the two components are stored and transported independently, mixed in precise proportions the instant they enter the mixing tank, and immediately atomized for spraying. This fundamentally avoids the viscosity increase and gelation problems of the premixed solution during storage and transport. Simultaneously, instant mixing ensures the cross-linking reaction begins the moment the atomized droplets deposit on the fabric surface, eliminating the need for the cross-linking agent to diffuse from the outside into the coating, thus eliminating the cross-linking density gradient caused by diffusion directionality in traditional stepwise cross-linking processes.

[0022] Because tubular polyester fabrics are soft and have a porous woven structure, maintaining a stable tubular shape is essential during spraying to ensure coating uniformity. This invention employs an inflatable, high-molecular-weight elastic self-expanding body to apply radial tension inside the tubular polyester fabric, causing it to expand radially to a straight, round shape. Simultaneously, both ends are fixed, and a displacement drive mechanism propels the fabric to move axially and rotate circumferentially. This "internal radial support + active fabric movement" method enables non-contact, full-coverage, uniform spraying of the moving and rotating fabric's outer surface. It avoids positioning errors that may be caused by nozzle movement and eliminates fabric deformation caused by airflow impact or contact, ensuring uniform coating thickness.

[0023] Compared with the prior art, the present invention has the following advantages: 1. This invention uses an inflatable polymer elastic self-expanding body as a radial expansion fixing component. The soft and easily deformable tubular polyester fabric is tensioned into a straight tubular shape through uniform radial tension, avoiding mechanical damage and local stress concentration caused by rigid mandrel support, and providing a smooth substrate surface for subsequent uniform spraying.

[0024] 2. This invention utilizes atomization spraying technology to atomize the coating liquid into micron-sized uniform droplets. Combined with the axial movement and circumferential rotation of the tubular polyester fabric, it achieves blind-spot-free, full-coverage spraying of the tubular three-dimensional substrate, effectively avoiding problems such as uneven coating and pinhole defects inherent in traditional dip coating and spraying methods. The droplet size distribution generated by ultrasonic atomization is narrow and highly consistent, allowing coating thickness errors to be controlled within a small range.

[0025] 3. The present invention employs a two-component instant mixing supply unit to instantly mix the gelatin / collagen solution (coating liquid A) and the crosslinking agent solution (coating liquid B) before spraying. This avoids the problem of viscosity change over time caused by the gradual occurrence of crosslinking reaction after premixing, ensuring that the components of the mixture are fresh and the viscosity is consistent for each spraying, thereby ensuring the stability of the spraying process and the consistency of coating quality.

[0026] 4. The two-component instant mixing and feeding unit of the present invention solves the problem that residual materials cannot be reused during pre-mixing. At the same time, ultrasonic atomization spraying has the characteristics of strong directionality and high droplet utilization, which greatly reduces the waste of coating materials compared with traditional dip coating methods.

[0027] 5. The apparatus and method of the present invention are not only applicable to the gelatin / collagen-glutaraldehyde / glyoxal crosslinking coating system of high-density polyester tubular fabrics, but can also be extended to the functional coating treatment of other tubular flexible substrates, and have broad application prospects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the ultrasonic atomization coating spraying device for high-density tubular polyester fabrics according to the present invention.

[0029] Figure 2 This is a schematic diagram of the spray coating state on the surface of the tubular polyester fabric in this invention.

[0030] In the figure, 1. Tubular polyester fabric; 201. Radial expansion fastener; 202. End fasteners; 203. Displacement drive mechanism; 301. Storage tank one; 302. Storage tank two; 303. Mixing tank; 304. Agitator; 305. Metering pump; 401. Ultrasonic atomizing nozzle; 402. Air compressor pump; 5. Controller. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0032] The following examples illustrate the structure of the spraying device used for ultrasonic atomization coating of high-density tubular polyester fabrics. Figure 1 As shown, it includes a support unit, a feeding unit, and an atomizing spraying unit.

[0033] The support unit includes a radial expansion fastener 201, two end fasteners 202, and a displacement drive mechanism 203. The radial expansion fastener 201 expands inside the tubular polyester fabric 1 to tension it, keeping it straight and taut. The two end fasteners 202 secure the two ends of the tensioned tubular polyester fabric 1. The displacement drive mechanism 203 drives the tensioned tubular polyester fabric 1 to move axially and rotate circumferentially. Specifically, the radial expansion fastener 201 is an inflatable, self-expanding polymer elastic body, such as an inflatable airbag or inflatable elastic tube, with an outer diameter slightly smaller than the inner diameter of the tubular polyester fabric 1 to be processed, facilitating the fitting of the tubular polyester fabric 1 onto the radial expansion fastener 201. The two end fasteners 202 are annular pneumatic grippers. The displacement drive mechanism 203 uses a ball screw driven by a rotary servo motor, with the tensioned tubular polyester fabric 1 connected to the slider of the ball screw.

[0034] The feeding unit is used to prepare the coating liquid, specifically including storage tank 301 (first tank) and storage tank 302 (second tank). Storage tank 301 stores coating liquid A, and storage tank 302 stores coating liquid B. Both storage tanks 301 and 302 are equipped with a stirrer 304, a heating mechanism, and a temperature sensor. The stirrer 304 is used to maintain the homogeneity of the coating liquid. The heating mechanism can be a resistance wire, which, in conjunction with the temperature sensor, maintains the required temperature in storage tanks 301 and 302. Storage tanks 301 and 302 are respectively connected to a mixing tank 303 via pipelines, and a metering pump 305 is installed on the pipelines. Coating liquid A is a gelatin solution or a collagen solution, and coating liquid B is a glutaraldehyde solution or a glyoxal solution.

[0035] The atomizing spraying unit is used to spray a coating liquid onto the tensioned tubular polyester fabric 1. It includes an ultrasonic atomizing nozzle 401 fixed above the tensioned tubular polyester fabric 1, which is connected to a mixing tank 303 via a pipeline. The ultrasonic atomizing nozzle 401 is also connected to an air compressor pump 402 via a pipeline. The air compressor pump 402 supplies compressed air to the ultrasonic atomizing nozzle 401, guiding the atomized coating liquid droplets onto the surface of the tubular polyester fabric 1. Specifically, the ultrasonic atomizing nozzle 401 is a piezoelectric ultrasonic atomizing nozzle 401.

[0036] The above-mentioned annular pneumatic chuck, rotary drive servo motor, ball screw, stirrer 304, resistance wire, temperature sensor, metering pump 305, ultrasonic atomizing nozzle 401, and air compressor pump 402 are electrically connected to the controller 5.

[0037] Example 1 The ultrasonic atomization coating method for high-density tubular polyester fabric 1 in this embodiment includes the following steps: S1 Fabric Tensioning and Fixing: High-density tubular polyester fabric 1 (inner diameter 30mm, length 200mm) is sequentially ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes each, and then vacuum dried at 50℃ for 2 hours. The dried tubular polyester fabric 1 is then placed around the inflatable airbag. Inflation of the airbag applies uniform radial tension to the fabric, keeping it straight and taut. Then, the annular pneumatic clamps are activated to evenly grip the edges of the tensioned fabric and the inflatable airbag from the outside.

[0038] S2 preparation of coating liquid: Coating solution A: Weigh gelatin (molecular weight approximately 100,000 Da) and dissolve it in deionized water to prepare a gelatin solution with a concentration of 0.5 wt.%. Add glycerin at a mass of 2% of the gelatin as a plasticizer and stir until homogeneous.

[0039] Coating solution B: Dissolve glutaraldehyde in deionized water to prepare a glutaraldehyde solution with a concentration of 0.05 wt.%.

[0040] Coating liquid A and coating liquid B are placed in storage tank 301 and storage tank 302 respectively, heated to 50°C and continuously stirred to keep warm.

[0041] S3 Instant Mixing and Ultrasonic Atomization: Start metering pump 305 to deliver coating liquid A and coating liquid B to mixing tank 303 at a volume ratio of 20:1 for instant mixing. The mixture immediately enters piezoelectric ultrasonic atomizing nozzle 401 and is atomized into uniform droplets at a frequency of 60kHz.

[0042] S4 Full Coverage Spraying: Compressed air (0.2 MPa) is introduced into the piezoelectric ultrasonic atomizing nozzle 401 to guide the atomized droplets to the outer surface of the tubular polyester fabric 1 (e.g., Figure 2 (As shown). At the same time, the displacement drive mechanism 203 is activated, driving the tubular polyester fabric 1 to move axially at a speed of 1 mm / s and rotate circumferentially at a speed of 1 rpm to perform full-coverage spraying, with two spraying passes.

[0043] S5 Crosslinking Reaction: After spraying, the tubular polyester fabric 1 coated with the mixture is left to crosslink at 20℃ and 30% relative humidity for 12 hours to allow glutaraldehyde and gelatin to undergo a crosslinking reaction (e.g., Figure 2 (As shown).

[0044] S6 Drying and Sterilization: The cross-linked tubular polyester fabric 1 is vacuum dried at 50°C for 4 hours and then sterilized with ethylene oxide to obtain a high-density tubular polyester fabric 1 with a uniform gelatin cross-linked coating, which is a blood-proof artificial blood vessel.

[0045] Example 2 The ultrasonic atomization coating method for high-density tubular polyester fabric 1 in this embodiment includes the following steps: S1 Fabric Tensioning and Fixing: A high-density tubular polyester fabric 1 (inner diameter 8mm, length 400mm) was sequentially ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes each, and then vacuum-dried at 50℃ for 2 hours. The dried tubular polyester fabric 1 was then placed around the outer periphery of the inflatable airbag. Inflation of the airbag applied uniform radial tension to the fabric, keeping it straight and taut. Then, the annular pneumatic clamps were activated to evenly grip the edges of the tensioned fabric and the inflatable airbag from the outside.

[0046] S2 preparation of coating liquid: Coating solution A: Weigh out collagen (molecular weight of 500 Da) and dissolve it in deionized water to prepare a collagen solution with a concentration of 10 wt.%. Add sorbitol, which accounts for 15% of the collagen protein mass, as a plasticizer and stir evenly.

[0047] Coating solution B: Dissolve glyoxal in deionized water to prepare a 2 wt.% glyoxal solution.

[0048] Coating liquid A and coating liquid B are placed in storage tank 301 and storage tank 302 respectively, heated to 50°C and continuously stirred to keep warm.

[0049] S3 Instant Mixing and Ultrasonic Atomization: Start metering pump 305 to deliver coating liquid A and coating liquid B to mixing tank 303 at a volume ratio of 1:1 for instant mixing. The mixture immediately enters piezoelectric ultrasonic atomizing nozzle 401 and is atomized into uniform droplets at a frequency of 40kHz.

[0050] S4 Full Coverage Spraying: Compressed air (0.2 MPa pressure) is introduced into the piezoelectric ultrasonic atomizing nozzle 401 to guide the atomized droplets to the outer surface of the tubular polyester fabric 1. At the same time, the displacement drive mechanism 203 is activated to drive the tubular polyester fabric 1 to move axially at a speed of 20 mm / s and rotate circumferentially at a speed of 60 rpm to perform full coverage spraying, with 5 spraying passes.

[0051] S5 Crosslinking Reaction: After spraying, the tubular polyester fabric 1 coated with the mixture is left to crosslink at 50°C and 65% relative humidity for 4 hours to allow glyoxal and collagen to undergo a crosslinking reaction.

[0052] S6 Drying and Sterilization: The cross-linked tubular polyester fabric 1 is vacuum dried at 20°C for 6 hours and then sterilized with ethylene oxide to obtain a high-density tubular polyester fabric 1 with a uniform collagen cross-linked coating, which is a blood-proof artificial blood vessel.

[0053] Example 3 The ultrasonic atomization coating method for high-density tubular polyester fabric 1 in this embodiment includes the following steps: S1 Fabric Tensioning and Fixing: A high-density tubular polyester fabric 1 (inner diameter 18mm, length 400mm) was sequentially ultrasonically cleaned with deionized water and anhydrous ethanol for 15 minutes each, and then vacuum-dried at 50℃ for 2 hours. The dried tubular polyester fabric 1 was then placed around the outer periphery of an inflatable elastic tube. Inflation of the tube applied uniform radial tension to the fabric, keeping it straight and taut. Then, the annular pneumatic clamps were activated to evenly grip the edges of the tensioned fabric and the inflatable elastic tube from the outside.

[0054] S2 preparation of coating liquid: Coating solution A: Weigh gelatin (molecular weight 5000 Da) and dissolve it in deionized water to prepare a gelatin solution with a concentration of 3 wt.%. Add 7.5% glycerin by weight of gelatin as a plasticizer and stir evenly.

[0055] Coating solution B: Dissolve glutaraldehyde in deionized water to prepare a glutaraldehyde solution with a concentration of 1 wt.%.

[0056] Coating liquid A and coating liquid B are placed in storage tank 301 and storage tank 302 respectively, heated to 50°C and continuously stirred to keep warm.

[0057] S3 Instant Mixing and Ultrasonic Atomization: Start metering pump 305 to deliver coating liquid A and coating liquid B to mixing tank 303 at a volume ratio of 10:1 for instant mixing. The mixture immediately enters piezoelectric ultrasonic atomizing nozzle 401 and is atomized into uniform droplets at a frequency of 50kHz.

[0058] S4 Full Coverage Spraying: Compressed air (0.2MPa pressure) is introduced into the piezoelectric ultrasonic atomizing nozzle 401 to guide the atomized droplets to the outer surface of the tubular polyester fabric 1. At the same time, the displacement drive mechanism 203 is activated to drive the tubular polyester fabric 1 to move axially at a speed of 10mm / s and rotate circumferentially at a speed of 30rpm to perform full coverage spraying, with 3 spraying passes.

[0059] S5 Crosslinking Reaction: After spraying, the tubular polyester fabric 1 coated with the mixture is left to stand for 8 hours at 30°C and 50% relative humidity to allow glutaraldehyde and gelatin to undergo a crosslinking reaction.

[0060] S6 Drying and Sterilization: The cross-linked tubular polyester fabric 1 is vacuum dried at 35°C for 5 hours and then sterilized with ethylene oxide to obtain a high-density tubular polyester fabric 1 with a uniform gelatin cross-linked coating, which is a blood-proof artificial blood vessel.

[0061] Comparative Example 1 Comparative Example 1 uses a traditional dip-coating method to coat the surface of a high-density tubular polyester fabric 1: Coating solution A and coating solution B are prepared according to the method of step S2 in Example 1, and the two are directly premixed at a volume ratio of 20:1 to obtain a premixed gelatin-glutaraldehyde mixture; then, the high-density tubular polyester fabric 1 of the same specifications as in Example 1 is directly immersed in the premixed gelatin-glutaraldehyde mixture for 10 minutes, and after being taken out, it is allowed to stand for crosslinking at 20°C and 30% relative humidity for 12 hours, then vacuum dried at 50°C for 4 hours, and then sterilized with ethylene oxide.

[0062] Comparative Example 2 The difference from Example 1 is that an air spray gun is used to spray the premixed gelatin-glutaraldehyde mixture onto the surface of the tubular polyester fabric 1.

[0063] Comparative Example 3 The difference from Example 1 is that instead of using an inflatable airbag to tension the tubular polyester fabric 1, a mandrel is used for support.

[0064] The impermeable artificial blood vessels prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following methods: 1) Coating Uniformity: Ten samples, each weighing approximately 0.1 g, were randomly selected at different positions every 20 mm along the axial direction of the tubular polyester fabric 1 coated with gelatin. After drying to constant weight, the samples were weighed using an analytical balance with an accuracy of 0.01%. The weighed samples were then treated in a 0.1 M NaOH aqueous solution at 50°C for 2 hours to completely hydrolyze the gelatin. The treated samples were then neutralized with acid and thoroughly washed with water, and finally dried to constant weight before being weighed. For the i-th sample, the coating amount is equal to the percentage of the mass difference before and after alkali treatment relative to the mass of the fabric substrate. .

[0065] in, The coating amount (%) for the i-th sample; The constant weight (g) of the i-th sample before alkali treatment; The constant weight (g) of the i-th sample after alkali treatment and drying is the mass of the pure fabric substrate.

[0066] Coating uniformity is evaluated using the coefficient of variation (CV) of the coating amount across all samples, also known as the relative standard deviation (RSD). A smaller CV value indicates a more uniform coating. .

[0067] Where S is the standard deviation of the coating amount for all samples: .

[0068] The arithmetic mean of the coating amount for all samples: .

[0069] in, The total number of samples (here, n=10).

[0070] 2) Anti-bleeding performance: Water permeability test was conducted in accordance with ISO 7198 "Cardiovascular implants - Tubular grafts".

[0071] 3) Coating material utilization rate: Based on the quantity required for dip coating, prepare coating liquid of the same mass. After coating, weigh the remaining mass of the mixed coating liquid and the mass of the unmixed coating liquid. The material utilization rate is calculated by dividing the mass of the coating liquid sprayed on the fabric by the total mass of the premixed coating liquid.

[0072] Table 1 Performance test results of the anti-bleeding artificial blood vessels of Examples 1-3 and Comparative Examples 1-3

[0073] As can be seen from the results in Table 1, the present invention, through the synergistic effect of tensioning the tubular polyester fabric 1, atomized spraying, and two-component instant mixing and feeding, significantly outperforms the prior art in terms of coating uniformity, anti-bleeding performance, and material utilization.

[0074] In summary, this invention enables uniform tensioning of tubular polyester fabric 1, precise and controllable full-coverage spraying, and stable supply of coating liquid properties. The resulting anti-bleeding artificial blood vessel coating is uniform and dense, exhibiting excellent anti-bleeding performance and biocompatibility. The device of this invention has a reasonable structure and controllable operation, and the method and process are stable and reproducible, making it suitable for industrial-scale application in the fields of medical textile materials and artificial blood vessel manufacturing.

Claims

1. An ultrasonic atomization coating spraying device for high-density tubular polyester fabrics, characterized in that, Includes a support unit, a material supply unit, and an atomizing spraying unit; The support unit includes a radial expansion fixing member (201), two end fixing members (202), and a displacement driving mechanism (203). The radial expansion fixing member (201) is used to expand inside the tubular polyester fabric (1) to tension the tubular polyester fabric (1) and keep it in a straight and taut state. The two end fixing members (202) are used to fix the two ends of the tensioned tubular polyester fabric (1). The displacement driving mechanism (203) is used to drive the tensioned tubular polyester fabric (1) to move along its axial direction and rotate circumferentially. The feeding unit is used to prepare the coating liquid; The atomizing spraying unit is used to spray coating liquid onto the tensioned tubular polyester fabric (1).

2. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 1, characterized in that, The radial expansion fixing member (201) is an inflatable polymer elastic self-expanding body; the two end fixing members (202) are annular pneumatic claws; the displacement driving mechanism (203) is a ball screw, linear guide or linear servo motor driven by a rotary drive servo motor.

3. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 1, characterized in that, The feeding unit includes a storage tank 1 (301) and a storage tank 2 (302). The storage tank 1 (301) stores coating liquid A, and the storage tank 2 (302) stores coating liquid B. The storage tank 1 (301) and the storage tank 2 (302) are respectively connected to a mixing tank (303) through pipelines.

4. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 3, characterized in that, Both storage tank 1 (301) and storage tank 2 (302) are equipped with a stirrer (304), a heating mechanism and a temperature sensor; metering pumps (305) are installed on the pipeline between storage tank 1 (301) and mixing tank (303) and on the pipeline between storage tank 2 (302) and mixing tank (303).

5. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 3, characterized in that, The coating solution A is a gelatin solution or a collagen solution, and the coating solution B is a glutaraldehyde solution or a glyoxal solution; the molecular weight of the gelatin or collagen is 500-100,000 Da; the concentration of gelatin or collagen in coating solution A is 0.5-10 wt.%, and the concentration of glutaraldehyde or glyoxal in coating solution B is 0.05-2 wt.%; the mixing volume ratio of coating solution A and coating solution B is (1-20):1; coating solution A also includes a plasticizer, which is at least one of glycerol and sorbitol, and the amount used is 2-15 wt.% of gelatin or collagen.

6. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 1, characterized in that, The atomizing spraying unit includes an ultrasonic atomizing nozzle (401), which is connected to the mixing tank (303) via a pipeline.

7. The ultrasonic atomization coating spraying device for high-density tubular polyester fabric as described in claim 6, characterized in that, The ultrasonic atomizing nozzle (401) is a piezoelectric ultrasonic atomizing nozzle (401); the ultrasonic atomizing nozzle (401) is connected to an air compressor pump (402).

8. A method for ultrasonic atomization coating of high-density tubular polyester fabric, characterized in that, The coating process using the ultrasonic atomization coating device for high-density tubular polyester fabrics as described in any one of claims 1-7 includes the following steps: S1 Fabric tensioning and fixing: The woven high-density tubular polyester fabric (1) is installed on the support unit, so that it expands inside the tubular polyester fabric (1) and applies radial tension to the tubular polyester fabric (1) to keep it in a straight and taut state. S2 Coating solution preparation: The coating solution is prepared through the feeding unit; S3 Atomized Spraying: The coating liquid is atomized into droplets and sprayed onto the outer surface of the tubular polyester fabric (1) through the atomized spraying unit. At the same time, the displacement driving mechanism (203) drives the tubular polyester fabric (1) to move along the axial direction and rotate circumferentially, so that the atomized droplets of the coating liquid are fully covered and sprayed onto the outer surface of the tubular polyester fabric (1). S4 crosslinking reaction: After spraying, the tubular polyester fabric (1) coated with the coating liquid is left to crosslink for 4-12 hours at 20-50℃ and 30-65% relative humidity. S5 Drying and sterilization: The cross-linked tubular polyester fabric (1) is vacuum dried and sterilized to obtain a high-density tubular polyester fabric (1) with a uniform coating.

9. The ultrasonic atomization coating method for high-density tubular polyester fabric as described in claim 8, characterized in that, In step S3, the axial movement speed of the tubular polyester fabric (1) is 1-20 mm / s, the circumferential rotation speed is 1-60 rpm, and the number of spraying passes is 1-5.

10. The ultrasonic atomization coating method for high-density tubular polyester fabric as described in claim 8, characterized in that, In step S5, the vacuum drying temperature is 20-50℃.

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