Composite catheter with end sealed by porous PET (polyethylene terephthalate) film and end sealing method of composite catheter

Abstract

The composite catheter comprises a catheter body, and the catheter body comprises a lining tube, a middle braided tube and a macromolecule outer layer tube with thermal shrinkage deformation performance which are sequentially arranged from inside to outside; pET heat-shrinkable tubes are arranged at the two ends of the catheter body and located between the middle braided tube and the macromolecule outer-layer tube, the melting point of the PET heat-shrinkable tubes is higher than that of the macromolecule outer-layer tube, a plurality of glue passing holes are formed in the surfaces of the PET heat-shrinkable tubes, the PET heat-shrinkable tubes wrap the middle braided tube through the heat-shrinkable technology, and the macromolecule outer-layer tube is attached to the outer wall of the PET heat-shrinkable tubes through the heat-shrinkable technology. And polymer melt generated by heating the polymer outer-layer pipe is welded to the middle braided pipe and / or the lining pipe through the glue passing holes. The end sealing of the catheter is firm, the catheter layers are not easy to layer, and the use safety of the catheter is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical composite catheters, and in particular to a composite catheter with porous PET film end-capping and an end-capping method thereof. Background Art

[0002] Medical composite catheters are widely used in various interventional surgeries, such as cardiovascular, neurovascular and gastrointestinal surgeries. Such catheters are usually composed of a three-layer tubular structure.

[0003] The existing Chinese patent with publication number CN108042897A discloses a composite structure catheter, including an outer layer of polymer tube, a middle layer of a tubular braided mesh or spring mesh and a smooth inner layer; the material of the outer layer of the polymer tube is nylon, block polyetheramide elastomer, polyurethane or silicone rubber; the wall thickness of the distal end of the braided mesh or spring mesh in the middle layer is less than or equal to the wall thickness of the braided mesh or spring mesh body; the inner layer material is polytetrafluoroethylene, or high-density polyethylene, or a block polyetheramide elastomer containing an additive to reduce the friction coefficient.

[0004] However, the composite structure catheter has the following disadvantages: like the existing medical composite catheters on the market, the composite catheter is prone to delamination between adjacent tube layers during storage or use due to oxidation or loose bonding between adjacent layers, resulting in exposure of the braided wires at the end of the braided mesh, making catheter intervention difficult and even causing skin punctures during the intervention process, which urgently needs to be improved. Summary of the invention

[0005] The invention aims to provide a composite conduit with porous PET film end-capping and an end-capping method thereof, which has the effects of firm conduit end-capping, difficulty in delamination between conduit layers and improved safety in use of the conduit.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: a composite conduit with porous PET film end-capping, comprising a conduit body, wherein the conduit body comprises an inner liner tube, an intermediate braided tube and a polymer outer layer tube with heat shrinkage deformation performance, which are arranged in sequence from the inside to the outside;

[0007] PET heat shrink tubes are provided at both ends of the catheter body, located between the middle braided tube and the polymer outer layer tube. The melting point of the PET heat shrink tube is higher than the melting point of the polymer outer layer tube. A plurality of gluing holes are provided on the surface of the PET heat shrink tube. The PET heat shrink tube is wrapped around the outside of the middle braided tube through a heat shrinking process. The polymer outer layer tube is attached to the outer wall of the PET heat shrink tube through a heat shrinking process. The polymer melt generated by the heating of the polymer outer layer tube is welded to the middle braided tube and / or the inner lining tube through the gluing holes.

[0008] By adopting the above technical scheme, the assembled catheter body is heated, and the polymer outer layer tube located in the outermost layer is heated first and transfers the heat inward in sequence. Since the melting point of the polymer outer layer tube is lower than the melting point of the PET heat shrink tube, the polymer outer layer tube melts and produces a polymer melt, so that the middle part of the polymer outer layer tube absorbs heat and is welded with the outer wall of the middle braided tube and the inner liner tube, and the two ends of the polymer outer layer tube melt to produce a polymer melt that passes through the glue hole and is welded with the middle braided tube and the inner liner tube at both ends of the catheter body. At the same time, the polymer outer layer tube and the PET heat shrink tube both have heat shrinkage characteristics, and the polymer outer layer tube and the PET heat shrink tube absorb heat and shrink inward, so that the PET heat shrink tube is tightly wrapped around the outside of the middle braided tube, and the polymer outer layer tube absorbs heat and is tightly wrapped around the middle braided tube and the PE In addition to the T heat shrink tube, the present invention utilizes the inward covering force generated by the heat shrink deformation of the PET heat shrink tube, so that the PET heat shrink tube can firmly cover the middle braided tube outside the inner liner tube, thereby improving the connection firmness and concentricity between the two ends of the middle braided tube and the inner liner tube. At the same time, a plurality of glue holes are opened on the surface of the PET heat shrink tube, so that the polymer melt generated by the heat melting of the polymer outer layer tube can pass through the glue holes and be welded to the outer walls of the middle braided tube and the inner liner tube inside the PET heat shrink tube, thereby improving the connection firmness between the two ends of the polymer outer layer tube and the middle braided tube and the inner liner tube, thereby improving the end sealing firmness of the two ends of the catheter body, preventing the adjacent tube layers of the catheter body from stratifying, and having the effects of firmly sealing the catheter ends, not being easy to stratify between the tube layers, and improving the safety of catheter use.

[0009] The present invention is further configured as follows: the material of the polymer outer layer tube is set to PEBAX, and the material of the inner lining tube is set to PTFE.

[0010] By adopting the above technical solution, the melting point range of PEBAX material is between 120-200°C, and the melting point range of PET material is between 250-260°C. Therefore, it is only necessary to control the temperature range during heat shrink heating between 120-250°C to ensure that the PET heat shrink tube will not melt when the polymer outer layer tube begins to melt. At the same time, the inner lining tube is set to PTFE material, which can make the inner lining tube have sufficient lubricity and biocompatibility.

[0011] The present invention is further configured as follows: a plurality of the glue holes are evenly spaced and arranged on the surface of the PET heat shrink tube.

[0012] By adopting the above technical solution, multiple glue holes are evenly and equidistantly opened on the surface of the PET heat shrink tube, thereby ensuring that the stress distribution of the catheter body in the radial direction is more uniform.

[0013] The present invention is further configured as follows: the diameter of the gluing holes is set between 0.1-0.3 mm, and the hole distance between adjacent gluing holes is set between 1-2 mm.

[0014] By adopting the above technical scheme, when the diameter of the glue hole is too large or the hole spacing is too small, the overall structural strength of the PET heat shrink tube will be reduced, and when the diameter of the glue hole is too small or the hole spacing is too large, the polymer melt formed after the polymer outer layer tube absorbs heat and melts cannot pass through the glue hole smoothly. Therefore, the present invention controls the diameter and hole spacing of the glue hole within an appropriate range.

[0015] Another technical purpose of the present invention is to provide a method for sealing an end of a composite conduit, comprising the following steps:

[0016] S1: Liner pipe preparation: Use degreasing alkali solution to remove oil stains on the outer surface of the liner pipe to ensure that the outer surface of the liner pipe has sufficient adhesion;

[0017] S2: forming the intermediate braided tube: fixing the inner lining tube on a three-dimensional braiding machine, and using the three-dimensional braiding machine to three-dimensionally braid a number of fiber filaments outside the inner lining tube to form an intermediate braided tube;

[0018] S3: Punching holes in PET heat shrink tube: Use punching equipment to evenly open several glue holes on the surface of PET heat shrink tube;

[0019] S4: Sleeve the PET heat shrink tube: Sleeve the PET heat shrink tube obtained in S3 on both ends of the inner liner tube wrapped with the middle braided tube, so that the PET heat shrink tube is aligned with the outer extension of the corresponding end of the inner liner tube;

[0020] S5: Covering the polymer outer layer tube: Covering the polymer outer layer tube on the middle braided tube with PET heat shrink tubes at both ends to form a multi-layer wrapping material;

[0021] S6: hot melt treatment: the multi-layer wrapping material obtained by S5 is heated by a heating device, so that the PET heat shrink tube is heat-shrinked and wrapped outside the middle braided tube, and the polymer outer tube is heat-shrinked and attached to the outer wall of the PET heat shrink tube. Since the melting point of the PET heat shrink tube is higher than that of the polymer outer tube, the polymer outer tube is melted preferentially relative to the PET heat shrink tube, and the polymer melt generated by the heating of the polymer outer tube is welded to the middle braided tube and / or the inner lining tube through a number of glue holes;

[0022] S7: Cooling and solidifying: cooling and solidifying the composite conduit obtained by S6 through natural cooling or a cooling device to obtain a final composite conduit product;

[0023] S8: Quality inspection: Perform appearance inspection, mechanical property test and microstructure analysis on the composite catheter product processed in S7 to ensure that the various layers of materials in the composite catheter product are well bonded and there is no delamination.

[0024] By adopting the above technical scheme, the oil stains on the outer surface of the inner lining tube can be quickly removed by alkaline washing with oil-removing alkali solution, thereby improving the anti-slip property of the fiber filaments of the middle braided tube wrapped around the outside of the inner lining tube, and at the same time being beneficial to the welding strength between the polymer outer layer tube and the inner lining tube. During the end sealing process, the outer end of the PET heat shrink tube is ensured to be flush with the outer end of the inner lining tube, thereby preventing the fiber filaments of the middle braided tube from being exposed after the end sealing, thereby improving the safety of the composite conduit. In addition, multiple glue holes are evenly opened on the surface of the PET heat shrink tube, which effectively improves the uniformity of the stress distribution of the conduit body in the radial direction. The cooling method of the cooling device can be used to quickly cool the composite assembled conduit body, so that it is solidified to obtain the final composite conduit product. Subsequent quality inspection can ensure the yield rate of the composite conduits entering the market.

[0025] The present invention is further configured as follows: the fiber filaments in step S2 are configured as metal wires, the diameter of the metal wires is configured to be between 0.05-0.2 mm, the fineness is controlled to be between 10-200D, and the braiding density of the intermediate braided tube is configured to be between 10-200PPI.

[0026] The present invention is further configured as follows: the punching device in step S3 is a laser punching machine or a high-precision mechanical punching machine.

[0027] The present invention is further configured as follows: the heating device in step S6 is configured as a hot air gun or a heat shrink machine.

[0028] The present invention is further configured as follows: in step S6, the heating temperature of the heating device is controlled between 100-250° C., and the heating time is controlled between 2-5 min.

[0029] The present invention is further configured as follows: in step S7, the cooling device uses a cooling water tank.

[0030] In summary, the present invention has the following beneficial effects:

[0031] PET heat shrink tubes are correspondingly sleeved on both ends of the inner liner tube wrapped with the middle braided tube, and then a polymer outer tube is sleeved on the middle braided tube sleeved with the PET heat shrink tube. By heating the assembled catheter body, the polymer outer tube located at the outermost layer is heated first and transfers the heat inward in sequence. Since the melting point of the polymer outer tube is lower than the melting point of the PET heat shrink tube, the polymer outer tube melts and produces a polymer melt, so that the middle part of the polymer outer tube absorbs heat and is welded with the outer wall of the middle braided tube and the inner liner tube, and the two ends of the polymer outer tube melt to produce a polymer melt that passes through the glue hole and is welded with the middle braided tube and the inner liner tube at both ends of the catheter body. At the same time, the polymer outer tube and the PET heat shrink tube both have heat shrinkage characteristics, and the polymer outer tube and the PET heat shrink tube absorb heat and shrink inward, so that the PET heat shrink tube is tightly wrapped in the middle braided tube. After absorbing heat, the polymer outer layer tube tightly wraps around the middle braided tube and the PET heat shrink tube. The present invention utilizes the inward wrapping force generated by the heat shrink deformation of the PET heat shrink tube, so that the PET heat shrink tube can firmly wrap the middle braided tube around the inner lining tube, thereby improving the connection firmness and concentricity between the two ends of the middle braided tube and the inner lining tube. At the same time, a plurality of glue holes are opened on the surface of the PET heat shrink tube, so that the polymer melt generated by the heat melting of the polymer outer layer tube can pass through the glue holes and be welded to the outer walls of the middle braided tube and the inner lining tube inside the PET heat shrink tube, thereby improving the connection firmness between the two ends of the polymer outer layer tube and the middle braided tube and the inner lining tube, thereby improving the end sealing firmness of the two ends of the catheter body, and preventing the adjacent tube layers of the catheter body from stratifying. The catheter has the effects of firm end sealing, difficult stratification between tube layers, and improved safety in use of the catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is an internal structure diagram of the present invention, and the polymer outer layer tube is in a cross-sectional state.

[0033] Figure 2 It is an overall exploded view of the present invention.

[0034] Figure 3 It is a longitudinal sectional view of the present invention.

[0035] Figure 4 The present invention Figure 3 A partial enlarged view of area A.

[0036] In the figure: 1. catheter body; 11. lining tube; 12. middle braided tube; 13. PET heat shrink tube; 131. glue hole; 14. polymer outer tube. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] A composite conduit with porous PET membrane end-capping, such as Figure 1-4 As shown, the catheter body 1 includes an inner lining tube 11, an intermediate braided tube 12 and a polymer outer tube 14 with heat shrinkage deformation performance, which are arranged in sequence from the inside to the outside; PET heat shrink tubes 13 are arranged at both ends of the catheter body 1 between the intermediate braided tube 12 and the polymer outer tube 14, and the melting point of the PET heat shrink tube 13 is higher than that of the polymer outer tube 14. A plurality of glue holes 131 are opened on the surface of the PET heat shrink tube 13, and the PET heat shrink tube 13 is wrapped around the intermediate braided tube 1 through a heat shrink process. 2, the polymer outer tube 14 is attached to the outer wall of the PET heat shrink tube 13 through a heat shrink process, and the polymer melt generated by the heat of the polymer outer tube 14 is welded to the middle braided tube 12 and the inner liner tube 11 through the glue hole 131; the material of the polymer outer tube 14 is set to PEBAX, and the material of the inner liner tube 11 is set to PTFE. The melting point range of the EBAX material is between 120-200°C, and the melting point range of the PET material is between 250-260°C, so it is only necessary to adjust the temperature range of the heat shrink heating By controlling the temperature between 120-250°C, it can be ensured that the PET heat shrink tube 13 will not melt when the polymer outer layer tube 14 begins to melt. At the same time, the inner liner tube 11 is set to PTFE material, which can make the inner liner tube 11 have sufficient lubricity and biocompatibility; a plurality of glue holes 131 are evenly spaced on the surface of the PET heat shrink tube 13, so that a plurality of glue holes 131 are evenly spaced on the surface of the PET heat shrink tube 13, thereby ensuring that the stress distribution of the catheter body 1 in the radial direction is more uniform; glue holes 1 The aperture of the gluing holes 131 is set between 0.1-0.3mm, and the hole spacing between adjacent gluing holes 131 is set between 1-2mm. When the aperture of the gluing holes 131 is too large or the hole spacing is too small, the overall structural strength of the PET heat shrink tube 13 will be reduced. When the aperture of the gluing holes 131 is too small or the hole spacing is too large, the polymer melt formed after the polymer outer layer tube 14 absorbs heat and melts cannot pass through the gluing holes 131 smoothly. Therefore, the present invention controls the aperture and hole spacing of the gluing holes 131 within a suitable range.

[0039] The present invention provides a method for sealing an end of a composite catheter, comprising the following steps:

[0040] S1: Preparation of the inner liner 11: Remove the oil stains on the outer surface of the inner liner 11 by using degreasing alkali solution to ensure that the outer surface of the inner liner 11 has sufficient adhesion;

[0041] S2: Forming the intermediate braided tube 12: fixing the inner liner tube 11 on a three-dimensional braiding machine, and using the three-dimensional braiding machine to three-dimensionally braid a plurality of fiber filaments outside the inner liner tube 11 to form the intermediate braided tube 12;

[0042] S3: Punching holes in the PET heat shrink tube 13: using a punching device to evenly open a plurality of glue holes 131 on the surface of the PET heat shrink tube 13;

[0043] S4: Sleeve the PET heat shrink tube 13: Sleeve the PET heat shrink tube 13 obtained by S3 on both ends of the inner liner tube 11 wrapped with the middle braided tube 12, so that the PET heat shrink tube 13 is aligned with the outer extension of the corresponding end of the inner liner tube 11;

[0044] S5: Sleeve the polymer outer layer tube 14: Sleeve the polymer outer layer tube 14 outside the middle braided tube 12 with PET heat shrink tubes 13 wrapped at both ends to form a multi-layer wrapping material;

[0045] S6: hot melt treatment: the multi-layer wrapping material obtained by S5 is heated by a heating device, so that the PET heat shrink tube 13 is heat-shrinked and wrapped outside the middle braided tube 12, and the polymer outer layer tube 14 is heat-shrinked and attached to the outer wall of the PET heat shrink tube 13. Since the melting point of the PET heat shrink tube 13 is higher than that of the polymer outer layer tube 14, the polymer outer layer tube 14 melts preferentially relative to the PET heat shrink tube 13, and the polymer melt generated by the heat of the polymer outer layer tube 14 is welded to the middle braided tube 12 and / or the inner lining tube 11 through a plurality of glue holes 131;

[0046] S7: Cooling and solidifying: cooling and solidifying the composite conduit obtained by S6 through natural cooling or a cooling device to obtain a final composite conduit product;

[0047] S8: Quality inspection: Perform appearance inspection, mechanical property test and microstructure analysis on the composite catheter product processed in S7 to ensure that the various layers of materials in the composite catheter product are well bonded and there is no delamination.

[0048] In this embodiment, the degreasing alkali solution in step S1 is mainly composed of sodium hydroxide, sodium silicate and surfactant. The oil stains on the outer surface of the inner lining tube 11 can be quickly removed by alkali washing with the degreasing alkali solution, thereby improving the anti-slip property of the fiber filaments of the intermediate braided tube 12 wrapped around the outside of the inner lining tube 11, and at the same time, it is beneficial to the welding strength between the polymer outer layer tube 14 and the inner lining tube 11; the fiber filaments in step S2 are set as metal wires, the diameter of the metal wires is set between 0.05-0.2mm, the fineness is controlled between 10-200D, and the braiding density of the intermediate braided tube 12 is set between 10-200PPI; the punching equipment in step S3 adopts a laser punching machine or a high-precision mechanical punching machine; the outer end of the PET heat shrink tube 13 is ensured to be aligned with the outer end of the inner lining tube 11 in step S4 The composite conduit is flush with each other, thereby preventing the fiber filaments of the middle braided tube 12 from being exposed after the end sealing is completed, thereby improving the safety of the composite conduit. In addition, multiple glue holes 131 are evenly opened on the surface of the PET heat shrink tube 13, which effectively improves the uniformity of the stress distribution of the conduit body 1 in the radial direction. The cooling method of the cooling device can achieve rapid cooling and cooling of the composite assembled conduit body 1, so that it is solidified to obtain the final composite conduit product. Subsequent quality inspection can ensure the yield of the composite conduit entering the market; the heating device in step S6 is set to a hot air gun or a heat shrink machine; the heating temperature of the heating device in step S6 is controlled between 100-250°C, and the heating time is controlled within 2-5min; the cooling device in step S7 adopts a cooling water tank.

[0049] The basic working principle of the present invention is: PET heat shrink tubes 13 are correspondingly sleeved at both ends of the inner liner tube 11 wrapped with the middle braided tube 12, and then a polymer outer layer tube 14 is arranged outside the middle braided tube 12 sleeved with the PET heat shrink tube 13, wherein the material of the polymer outer layer tube 14 is set to PEBAX, and the material of the inner liner tube 11 is set to PTFE. By heating the assembled catheter body 1, the polymer outer layer tube 14 located at the outermost layer is heated first and transfers the heat inward in sequence. Since the melting point of the polymer outer layer tube 14 is low, the heat transfer of the heat to the inner layer is greatly improved. At the melting point of the PET heat shrink tube 13, the polymer outer tube 14 melts and produces a polymer melt, so that the middle of the polymer outer tube 14 absorbs heat and is welded to the outer wall of the middle braided tube 12 and the inner liner tube 11, and the two ends of the polymer outer tube 14 melt to produce a polymer melt that passes through the glue hole 131 and is welded to the middle braided tube 12 and the inner liner tube 11 at both ends of the catheter body 1. At the same time, the polymer outer tube 14 and the PET heat shrink tube 13 both have heat shrink properties, and the polymer outer tube 14 and the PET heat shrink tube 13 absorb heat and are welded to the outer wall of the middle braided tube 12 and the inner liner tube 11. The PET heat shrink tube 13 is tightly wrapped around the middle braided tube 12 by shrinking inward, and the polymer outer layer tube 14 is tightly wrapped around the middle braided tube 12 and the PET heat shrink tube 13 after absorbing heat. The present invention utilizes the inward wrapping force generated by the PET heat shrink tube 13 after heat shrinkage deformation, so that the PET heat shrink tube 13 can firmly wrap the middle braided tube 12 around the inner liner tube 11, thereby improving the connection firmness and concentricity between the two ends of the middle braided tube 12 and the inner liner tube 11. At the same time, a plurality of glue holes 13 are opened on the surface of the PET heat shrink tube 13 1, so that the polymer melt produced by the heat melting of the polymer outer layer tube 14 can pass through the glue hole 131, and be welded with the outer wall of the middle braided tube 12 and the inner liner tube 11 inside the PET heat shrink tube 13, thereby improving the connection firmness between the two ends of the polymer outer layer tube 14 and the middle braided tube 12 and the inner liner tube 11, thereby improving the end sealing firmness of the two ends of the catheter body 1, preventing the adjacent tube layers of the catheter body 1 from being delaminated, and having the effects of firmly sealing the catheter end, not being easy to delaminate between the tube layers, and improving the safety of catheter use.

[0050] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A composite conduit with porous PET film end-capping, comprising a conduit body (1), characterized in that: The catheter body (1) comprises an inner lining tube (11), an intermediate braided tube (12) and a polymer outer layer tube (14) having heat shrinkage deformation performance, which are arranged in sequence from the inside to the outside; A PET heat shrink tube (13) is provided at both ends of the catheter body (1) between the intermediate braided tube (12) and the polymer outer layer tube (14); the melting point of the PET heat shrink tube (13) is higher than the melting point of the polymer outer layer tube (14); a plurality of glue holes (131) are provided on the surface of the PET heat shrink tube (13); the PET heat shrink tube (13) is wrapped around the outside of the intermediate braided tube (12) through a heat shrinking process; the polymer outer layer tube (14) is attached to the outer wall of the PET heat shrink tube (13) through a heat shrinking process; and the polymer melt generated by the heating of the polymer outer layer tube (14) is welded to the intermediate braided tube (12) and / or the inner lining tube (11) through the glue holes (131).

2. The composite conduit with porous PET membrane end-capping according to claim 1, characterized in that: The material of the polymer outer layer tube (14) is set to PEBAX, and the material of the inner lining tube (11) is set to PTFE.

3. The composite conduit with porous PET membrane end-capping according to claim 1, characterized in that: A plurality of the glue holes (131) are arranged at equal intervals on the surface of the PET heat shrink tube (13).

4. The composite conduit with porous PET membrane end-capping according to claim 3, characterized in that: The diameter of the glue holes (131) is set between 0.1-0.3 mm, and the hole distance between adjacent glue holes (131) is set between 1-2 mm.

5. A method for sealing the end of a composite conduit according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Preparation of the inner lining pipe (11): removing oil stains on the outer surface of the inner lining pipe (11) by using an oil-removing alkali solution to ensure that the outer surface of the inner lining pipe (11) has sufficient adhesion; S2: forming the intermediate braided tube (12): fixing the inner lining tube (11) on a three-dimensional braiding machine, and using the three-dimensional braiding machine to three-dimensionally braid a plurality of fiber filaments outside the inner lining tube (11) to form the intermediate braided tube (12); S3: Punching holes in the PET heat shrink tube (13): using a punching device to evenly open a number of glue holes (131) on the surface of the PET heat shrink tube (13); S4: Sleeve the PET heat shrink tube (13): Sleeve the PET heat shrink tube (13) obtained by S3 onto the two ends of the inner lining tube (11) wrapped with the middle braided tube (12), so that the outer extensions of the corresponding ends of the PET heat shrink tube (13) and the inner lining tube (11) are aligned; S5: Covering the polymer outer layer tube (14): Covering the polymer outer layer tube (14) on the outside of the middle braided tube (12) with PET heat shrink tubes (13) wrapped at both ends to form a multi-layer wrapping material; S6: hot melt treatment: using a heating device to heat the multi-layer wrapping material obtained by the S5 process, so that the PET heat shrink tube (13) is heat-shrink wrapped around the middle braided tube (12), and the polymer outer layer tube (14) is heat-shrink attached to the outer wall of the PET heat shrink tube (13). Since the melting point of the PET heat shrink tube (13) is higher than the melting point of the polymer outer layer tube (14), the polymer outer layer tube (14) melts preferentially relative to the PET heat shrink tube (13). The polymer melt generated by the heat of the polymer outer layer tube (14) is welded to the middle braided tube (12) and / or the inner lining tube (11) through a plurality of glue holes (131); S7: Cooling and solidifying: cooling and solidifying the composite conduit obtained by S6 through natural cooling or a cooling device to obtain a final composite conduit product; S8: Quality inspection: Perform appearance inspection, mechanical property test and microstructure analysis on the composite catheter product processed in S7 to ensure that the various layers of materials in the composite catheter product are well bonded and there is no delamination.

6. The method for sealing the end of a composite conduit according to claim 5, characterized in that: The fiber filaments in step S2 are set as metal wires, the diameter of the metal wires is set between 0.05-0.2 mm, the fineness is controlled between 10-200D, and the braiding density of the intermediate braided tube (12) is set between 10-200PPI.

7. The method for sealing the end of a composite conduit according to claim 5, characterized in that: The punching equipment in step S3 is a laser punching machine or a high-precision mechanical punching machine.

8. The method for sealing the end of a composite conduit according to claim 5, characterized in that: The heating device in step S6 is set to be a hot air gun or a heat shrink machine.

9. The method for sealing the end of a composite conduit according to claim 5, characterized in that: In step S6, the heating temperature of the heating device is controlled between 100-250° C., and the heating time is controlled between 2-5 min.

10. The method for sealing the end of a composite conduit according to claim 5, characterized in that: In step S7, the cooling device adopts a cooling water tank.

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