Composite medical catheter with micro-grooves in surface and forming method of composite medical catheter

Abstract

The invention relates to a composite medical catheter with micro-grooves in the surface and a forming method thereof, the composite medical catheter comprises a thin-walled tube, a braid layer and an outer sleeve which are arranged from inside to outside, and the outer surface of the outer sleeve is provided with a micro-groove structure. Compared with the prior art, the composite medical catheter has the advantages that the micro-groove structure is arranged on the outer wall of the composite medical catheter, the binding force between the coating and the surface of the catheter is remarkably improved through the mechanical interlocking effect and the mode of increasing the specific surface area, and the problem that a traditional coating is prone to falling off is solved; through the effect of the heat shrink tube on the surface of the outer sleeve in the catheter forming process, the problem of active groups caused by plasma treatment is avoided and the risk of thrombus formation is reduced due to the adoption of a material reduction thought.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a composite medical catheter with surface microgrooves and its molding method. Background Technology

[0002] In medicine, to perform certain diagnostic and treatment procedures, such as endoscopic examination of the digestive tract, it is necessary to establish channels inside and outside the body cavities. This can be achieved by inserting a medical catheter into the body cavity and then delivering the necessary tools or substances through the catheter. On the one hand, to prevent unnecessary damage to the body cavity during catheter movement, the outer wall of the catheter should obviously be kept as smooth as possible, ensuring that the surface quality of the outer wall meets certain standards. On the other hand, to ensure that the necessary tools or substances can smoothly pass through the medical catheter and reach their target location within the body cavity, the surface quality of the inner wall of the catheter must also meet certain requirements. However, for various reasons, medical catheters may be made of materials of different specifications or materials connected axially (or along the length) of the catheter. This connection must consider not only the surface quality of the outer wall at the connection point, for the reasons mentioned above, but also the surface quality of the inner wall at the connection point to ensure the passage within the lumen at the connection point. In addition, the aforementioned medical catheters extensively utilize polymer materials, commonly including polyurethane, silicone rubber, polyester fiber, polyvinylpyrrolidone, polyetheretherketone, polymethyl methacrylate, polyvinyl alcohol, polylactic acid, and polyethylene.

[0003] In the prior art, surface treatments such as etching are usually performed on the surface of thin-walled tubes to increase their adhesion, thereby making the coating on the surface of the tube firm.

[0004] Chinese invention patent CN115709560A discloses a polymer medical catheter fitting and its molding and connection methods. The molding method for a polymer medical catheter fitting is characterized by the following steps: Step 1, inserting an etched tube from the beginning of the outer cavity tube and extending it from the end of the outer cavity tube; Step 2, sealing the end of the etched tube; Step 3, covering the outside of the outer cavity tube with a heat-shrinkable tube to form a composite tube; Step 4, placing the composite tube from Step 3 in a rheometer, and filling its cavity with fluid from the beginning of the etched tube, the fluid being sufficient to expand the cavity of the etched tube; then heating the rheometer to shrink the heat-shrinkable tube, and under the action of fluid expansion and the outer heat-shrinkable tube, melting the inner wall of the outer cavity tube and bonding it to the outer wall of the etched tube. This solution employs a fluid expansion internal support method, thus eliminating the need to insert a high-precision mandrel into the cavity of the etched tube, reducing processing requirements and improving processing efficiency.

[0005] However, the composite structure of the aforementioned composite catheter is complex, resulting in low production efficiency and high cost. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a composite medical catheter with surface microgrooves and its molding method.

[0007] The above-mentioned problems of the present invention are solved by the following technical solutions: A composite medical catheter with surface microgrooves includes a thin-walled tube, a braided layer, and an outer tube arranged from the inside out, wherein the outer surface of the outer tube has a microgrooved structure.

[0008] A further provision of the above technical solution is that the microgroove structure is a groove provided on the outer surface of the outer sleeve, and the microgroove structure is formed by extrusion within the heat shrink tubing.

[0009] A further setting of the above technical solution is: the microgroove structure is a rectangular groove, an inverted trapezoidal groove, or a V-shaped groove.

[0010] The present invention also provides a method for molding a composite medical catheter, for molding the composite medical catheter of claim 1, comprising the following steps: S1. Heat shrink tubing design: A microgroove structure is formed on the inner surface of the heat shrink tubing. S2. Raw material selection: Fluorinated ethylene propylene granules are selected as raw materials, and stabilizers, plasticizers or other functional additives are added as needed; S3, Raw material extrusion: The raw material is added to the extruder hopper, heated and melted, and then conveyed into the heat shrink tube under the action of the screw; S4. Molding and Cooling: The extruded raw material is formed into a tubular structure with microgrooves inside the heat shrink tubing, and then rapidly cooled and shaped by air cooling or water cooling. S5. Blow molding: The size and shape of tubular objects are adjusted as needed using the blow molding process; S6. Heat Shrinkage Test: Measure the shrinkage rate at different temperatures to ensure the reliability and consistency of the pipes in practical applications.

[0011] A further provision of the above technical solution is that, in step S1, the microgroove structure on the inner surface of the heat shrink tubing is formed by mechanical processing or chemical etching.

[0012] A further setting of the above technical solution is as follows: In step S3, a mandrel is set inside the heat shrink tubing, and an inner thin-walled tube and a braided layer are wrapped on the mandrel, and the extruded material is extruded between the braided layer and the heat shrink tubing.

[0013] A further setting of the above technical solution is: in step S3, while the raw material is being transported into the heat shrink tube through the extruder, the heat shrink tube is simultaneously shrinking under high temperature and high pressure.

[0014] The above technical solution is further configured such that, in step S1, the depth of the microgroove structure ranges from 5 to 50 micrometers, and the width ranges from 10 to 100 micrometers.

[0015] A further setting of the above technical solution is: in step S3, the temperature of the extruder is controlled at 300℃-350℃.

[0016] A further provision of the above technical solution is that, in step S4, during the blow molding process, a cooling process is carried out simultaneously to ensure that the pipe maintains a stable shape during the expansion process.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting a microgroove structure on the outer wall of the composite medical catheter, the adhesion between the coating and the catheter surface is significantly improved through mechanical interlocking effect and increased specific surface area, thus solving the problem of easy peeling off of traditional coatings; 2. By using heat shrink tubing to treat the surface of the outer tube during catheter forming, the "subtractive" approach avoids the problem of active groups caused by plasma treatment, thus reducing the risk of thrombosis. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the composite medical catheter in Example 1.

[0019] Figure 2 This is a schematic diagram of the structure of the heat shrink tubing and composite medical catheter in Example 2.

[0020] The attached diagram is labeled: 100, thin-walled tube; 200. Braided layer; 300, outer sleeve; 301, groove; 400. Heat shrink tubing. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0022] like Figure 1 and Figure 2 As shown in the following embodiments, a composite medical catheter with surface microgrooves and a method for forming the catheter are disclosed.

[0023] Example 1 A composite medical catheter with surface microgrooves includes a thin-walled tube 100, a braided layer 200, and an outer tube 300 arranged from the inside out, wherein the outer surface of the outer tube 300 has a microgrooved structure.

[0024] The above is the basic scheme of this embodiment.

[0025] Specific reference Figure 1 As shown, the thin-walled tube 100 is made of PTFE material as the base material of the conduit. The braided layer 200 is wrapped around the outer periphery of the thin-walled tube 100, providing additional mechanical support to the thin-walled tube 100 and giving the conduit a certain strength. The outer tube 300 covers the outside of the braided layer 200 and protects the braided layer 200 and the thin-walled tube 100.

[0026] The outer wall of the outer tube 300 is provided with a microgroove structure. The purpose is to increase the roughness of the outer wall of the outer tube 300, which will enhance the adhesion when the conduit is coated in the future. The coating is not easy to fall off the surface of the conduit, thereby avoiding equipment failure or complications.

[0027] Specifically, the microgroove structure is a groove 301 provided on the outer surface of the outer sleeve 300, and the microgroove structure is formed by extrusion within the heat shrink tube 400.

[0028] Specific reference Figure 2 As shown, when molding a composite medical catheter, the raw material is extruded into a heat shrink tube 400 with a rough inner wall structure through an extruder, thereby forming an outer surface with grooves 301 that are consistent with the rough inner wall structure of the heat shrink tube 400.

[0029] Meanwhile, during the extrusion process, the heat shrink tubing 400 shrinks under high temperature and high pressure, which tightly binds the three-layer structure of the composite conduit.

[0030] Preferably, in this embodiment, the depth of the groove 301 is 5-50 micrometers and the width is 10-100 micrometers.

[0031] Preferably, in this embodiment, the microgroove structure is a rectangular groove, an inverted trapezoidal groove, or a V-shaped groove.

[0032] In other embodiments, the microgroove structure may also be a groove 301 shape with other cross-sections.

[0033] Example 2 This embodiment provides a method for molding a composite medical catheter, the purpose of which is to mold the composite medical catheter described in Embodiment 1. The specific molding method is as follows: Includes the following steps: S1, Heat shrink tubing 400 design: A microgroove structure is formed on the inner surface of the heat shrink tubing 400; S2. Raw material selection: Fluorinated ethylene propylene granules are selected as raw materials, and stabilizers, plasticizers or other functional additives are added as needed; S3, Raw material extrusion: The raw material is added to the extruder hopper, heated and melted, and then conveyed into the heat shrink tubing 400 under the action of the screw; S4. Molding and Cooling: The extruded raw material is formed into a tubular material with a microgroove structure inside the heat shrink tubing 400, and is rapidly cooled and shaped by air cooling or water cooling. S5. Blow molding: The size and shape of tubular objects are adjusted as needed using the blow molding process; S6. Heat Shrinkage Test: Measure the shrinkage rate at different temperatures to ensure the reliability and consistency of the pipes in practical applications.

[0034] Specifically, in step S1, the microgroove structure on the inner surface of the heat shrink tubing 400 is formed by mechanical processing or chemical etching.

[0035] Preferably, in this embodiment, the machining can be selected from electrical discharge machining or laser engraving, the purpose of which is to increase the roughness of the inner surface of the heat shrink tubing 400, the roughness of which ranges from a few micrometers to tens of micrometers.

[0036] The raw material is selected as high-quality fluorinated ethylene propylene granules, which have good thermal stability, mechanical strength and chemical inertness. In addition, appropriate amounts of stabilizers, plasticizers or other functional additives can be added to the fluorinated ethylene propylene as needed to improve its processing performance or the performance of the final product.

[0037] In this embodiment, the purpose is to form the outer sheath 300 of the medical catheter, that is, to form a tube structure with through holes inside. Therefore, in this embodiment, a mandrel is provided inside the heat shrink tube 400, and an inner thin-walled tube 100 and a braided layer 200 are wrapped on the mandrel. The extruded material is extruded between the braided layer 200 and the heat shrink tube 400.

[0038] In the preceding steps, a thin-walled tube 100 is formed, and a braided layer 200 is wrapped around the thin-walled tube 100. In this embodiment, the semi-finished product is placed inside the heat shrink tube 400, so that an annular cavity is formed between the braided layer 200 and the heat shrink tube 400. The extruder extrudes the raw material into the annular cavity, thereby forming the outer tube 300.

[0039] The molding process of the outer tube 300 is a process from liquid to solid. Liquid raw materials are poured between the braided layer 200 and the heat shrink tube 400. The outer surface and the rough inner surface of the heat shrink tube 400 are matched. After the molding and cooling to solidify, the heat shrink tube 400 is removed. That is, a microgroove structure that matches the inner wall of the heat shrink tube 400 is formed on the outer tube 300.

[0040] Based on the above settings, in this embodiment, if it is necessary to form a porous conduit, multiple mandrels are set inside the heat shrink tubing 400, and the raw material is extruded between the mandrels and the heat shrink tubing 400 to form a porous conduit, and the outer surface of the conduit matches the inner wall of the heat shrink tubing 400.

[0041] In this embodiment, the extrusion equipment is preferably a single-screw extruder or a twin-screw extruder, with twin-screw extruders typically providing better mixing and higher output.

[0042] Furthermore, it is necessary to precisely control the temperature of each section of the extruder to ensure that the raw material has good fluidity and uniformity in the molten state, with the preferred temperature being 300°C to 350°C.

[0043] Specifically, in this embodiment, in step S3, while the raw material is being transported into the heat shrink tube 400 through the extruder, the heat shrink tube 400 is simultaneously shrinking under high temperature and high pressure.

[0044] To avoid premature molding of the raw material, in this embodiment, the extrusion process of the raw material is carried out in a high temperature and high pressure environment. The raw material is injected into the heat shrink tube 400. At the same time, the heat shrink tube 400 shrinks under high temperature and high pressure, compressing the three-layer composite medical catheter structure. During the compression process, the excess part of the raw material used to form the outer tube 300 is squeezed out, and the part left in the heat shrink tube 400 is the formed outer tube 300.

[0045] Preferably, in this embodiment, the depth of the microgroove structure ranges from 5 to 50 micrometers, and the width ranges from 10 to 100 micrometers.

[0046] That is, the multiple grooves 301 forming the microgroove structure are grooves 301 with different depths and widths.

[0047] In this embodiment, in step S3, the temperature of the extruder is controlled at 300℃-350℃.

[0048] In this embodiment, in step S4, cooling is performed simultaneously during the blow molding process to ensure that the tube maintains its shape stability during expansion.

[0049] Blow molding is typically used for specific applications where the size and shape of the tube are fine-tuned. A blow molding machine uses air pressure to inflate the extruded tube blank to the desired diameter and wall thickness. Simultaneous cooling is performed during the blow molding process to ensure the tube maintains its shape during expansion.

[0050] In this embodiment, after the composite medical catheter is formed, its shrinkage performance needs to be measured. By using testing equipment to measure the shrinkage rate at different temperatures, the reliability and consistency of the formed composite medical catheter in practical applications can be ensured.

[0051] Preferably, in this embodiment, the shrinkage temperature range is 120°C to 180°C, and the shrinkage rate is 50% to 70%.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A composite medical catheter with surface microgrooves, characterized in that: It includes a thin-walled tube (100), a braided layer (200), and an outer tube (300) arranged from the inside out, wherein the outer surface of the outer tube (300) has a microgroove structure.

2. The composite medical catheter with surface microgrooves according to claim 1, characterized in that: The microgroove structure is a groove (301) provided on the outer surface of the outer sleeve (300), and the microgroove structure is formed by extrusion within the heat shrink tube (400).

3. The composite medical catheter with surface microgrooves according to claim 1 or 2, characterized in that: The microgroove structure is a rectangular groove, an inverted trapezoidal groove, or a V-shaped groove.

4. A method for molding a composite medical catheter, used to mold the composite medical catheter of claim 1, characterized in that: Includes the following steps: S1, Heat shrink tubing (400) design: A microgroove structure is formed on the inner surface of the heat shrink tubing (400); S2. Raw material selection: Fluorinated ethylene propylene granules are selected as raw materials, and stabilizers, plasticizers or other functional additives are added as needed; S3, Raw material extrusion: The raw material is added to the extruder hopper, heated and melted, and then conveyed into the heat shrink tube (400) under the action of the screw; S4. Molding and Cooling: The extruded raw material is formed into a tubular material with a microgroove structure in the heat shrink tube (400), and is rapidly cooled and shaped by air cooling or water cooling. S5. Blow molding: The size and shape of tubular objects are adjusted as needed using the blow molding process; S6. Heat Shrinkage Test: Measure the shrinkage rate at different temperatures to ensure the reliability and consistency of the pipes in practical applications.

5. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S1, the microgroove structure on the inner surface of the heat shrink tubing (400) is formed by mechanical processing or chemical etching.

6. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S3, a mandrel is placed inside the heat shrink tube (400), and an inner thin-walled tube (100) and a braided layer (200) are wrapped around the mandrel. The extruded material is extruded between the braided layer (200) and the heat shrink tube (400).

7. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S3, while the raw material is being transported into the heat shrink tube (400) through the extruder, the heat shrink tube (400) is simultaneously shrinking under high temperature and high pressure.

8. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S1, the depth of the microgroove structure ranges from 5 to 50 micrometers, and the width ranges from 10 to 100 micrometers.

9. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S3, the temperature of the extruder is controlled at 300℃-350℃.

10. The method for forming the composite medical catheter according to claim 4, characterized in that: In step S4, cooling is performed simultaneously during the blow molding process to ensure that the tube maintains its shape stability during expansion.

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