A manufacturing process for a multi-segmentally variable stiffness medical catheter

Abstract

The application discloses a manufacturing process of a medical catheter with multi-section variable hardness, which comprises the following steps: raw material extrusion; mold forming, which shapes the initial shape of the medical catheter, and determines the position and length of the soft tube section a and the hard tube section b on the tube body of the medical catheter; cooling and setting, which performs cooling and setting treatment on the soft tube section a or the hard tube section b for 0.1-2.1 h; modification treatment, which immerses the cooled and set soft tube section a or hard tube section b in modified material for 1.1-8.1 h; and catheter finished product; the manufacturing process is simple and convenient to operate, can make the medical catheter have the characteristics of soft structure and hard structure at the same time, reduces the production cost, and makes the medical catheter have the advantage of hardness gradient, enhances the integrity of the medical catheter, improves the flexibility and mechanical properties of the medical catheter, and is favorable for the long-time and safe use of the medical catheter.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a manufacturing process for a medical catheter with variable rigidity in multiple segments. Background Technology

[0002] Medical catheters are tubular rubber products used in medical procedures, primarily playing an auxiliary role in medical processes. For example, they are used for urinary catheterization and drainage. Balloon dilation catheters can help expand the lumen and improve blood flow. Medical catheters are widely used as common medical consumables and are classified in many ways according to their function, such as infusion catheters, hemodialysis catheters, angiography catheters, catheters for endovascular interventional therapy, nerve system catheters and delivery sheaths, surgical drainage tubes, and flexible endoscope guiding sheaths. With the development of medical devices, the manufacturing processes for medical catheters in different fields also vary.

[0003] The "Preparation Method of Antibacterial Medical Catheter" disclosed in patent CN101406712A is to prepare an antibacterial powder, mix it thoroughly with plastic masterbatch, and then extrude it to obtain a medical catheter with antibacterial function. The medical catheters produced by this process have the same overall performance and overall softness and hardness, that is, the catheter can be made into a soft structure or a hard structure.

[0004] Currently, when manufacturing flexible endoscope guide sheaths / delivery sheaths, these catheters require either actively or passively bending sections. The actively bending sections are mostly soft structures, while the passively bending sections are mostly hard structures. Therefore, the soft and hard structures of the catheters need to be combined using thermofusion welding, ultrasonic welding, or bonding to form a medical catheter. The process of combining these medical catheters is relatively complicated and the production cost is high. The overall performance of the medical catheters is poor, and the thermofusion welded parts are often prone to breakage during use, resulting in a short service life for these types of catheters. Summary of the Invention

[0005] The purpose of this invention is to provide a manufacturing process for a medical catheter with variable hardness in multiple stages, in order to solve the problems mentioned in the background art, such as cumbersome manufacturing steps, high production costs, poor overall catheter performance, and short service life.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A manufacturing process for a multi-segment variable-rigidity medical catheter, comprising at least one flexible tube segment a and at least one rigid tube segment b, includes the following steps: Raw material extrusion involves preheating the raw material, feeding the preheated raw material into an extruder, and then extruding the raw material into a mold. The mold is used to shape the initial shape of the medical catheter, and the positions and lengths of the flexible tube segment a and the rigid tube segment b are determined on the body of the medical catheter. The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is subjected to traction, stretching, and compression retraction. Cooling and shaping: Perform a cooling treatment on flexible tube section a or rigid tube section b for 0.1-2.1 hours. Modification treatment involves immersing the cooled hose segment a or rigid pipe segment b in a modifying material for 1.1-8.1 hours. The modifying material must be prepared as a modification solution at 10-150°C. The modified catheter is dried and cut to size.

[0007] Furthermore, during the cooling process, both the flexible hose segment a and the rigid pipe segment b undergo water cooling simultaneously. The cooling time for the flexible hose segment a is 0.3-1.1 hours, and the cooling time for the rigid pipe segment b is 0.9-1.5 hours.

[0008] Furthermore, after the water cooling time of the flexible tube segment a is 0.3-1.1h, the flexible tube segment a is switched to air cooling. After the water cooling time of the rigid tube segment b is completed, the air cooling of the flexible tube segment a also stops.

[0009] Furthermore, during the modification process, the modifying material is a reinforcing resin, a toughening resin, or a hydrophilic coating, and the hydrophilic coating is made of PET plastic, PC plastic, ABS plastic, PA plastic, or PPO plastic. During modification, the flexible tube segment a or the rigid tube segment b is immersed in a container filled with a modification solution at 20-120°C for 1.5-6 hours.

[0010] Furthermore, the hose segment a is immersed in a toughening resin-modified solution at 30-80°C for 1.6-3 hours.

[0011] Furthermore, the rigid pipe section b is immersed in a modified resin solution at 40-110°C for 2-5 hours.

[0012] Furthermore, after the flexible tube segment a or rigid tube segment b is immersed in the hydrophilic coating modification solution for 2-3 hours, it is placed in a UV curing machine for curing treatment. The temperature of the hydrophilic coating modification solution is 50-90℃.

[0013] Furthermore, the UV curing machine is connected to a clean air source via a high-pressure tee to purge residual moisture from hose section a or rigid pipe section b, and the airflow of hose section a or rigid pipe section b is checked.

[0014] Furthermore, the preheating temperature of the raw materials is 10-80℃, and the raw materials are any one or more of medical-grade PVC, TPU, TPE, PE, FEP, PEBAX, PA, polyester, polytetrafluoroethylene, polyurethane, PET plastic, and silicone rubber.

[0015] Furthermore, the heating temperature of the extruder is maintained at 100-300℃, and the injection pressure of the extruder is 60-900N.

[0016] The beneficial effects of this invention are: during the extrusion molding process, this invention can use step-by-step cooling and modification solutions to treat the catheter body to produce different parts of the tube with different hardness, so that a single medical catheter has the characteristics of both soft and hard structures, reducing the production cost of medical catheters, and giving the medical catheter the advantage of gradual hardness, enhancing the overall integrity of the medical catheter, improving the flexibility and mechanical properties of the medical catheter, which is conducive to the long-term safe use of the medical catheter. At the same time, the manufacturing process is simple, easy to operate, and suitable for the large-scale production of medical catheters. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 A manufacturing process for a medical catheter with variable stiffness in multiple segments includes the following steps: Raw material extrusion involves preheating the raw material and feeding it into an extruder. The extruder then extrudes the raw material and sends it into a mold. The preheating temperature of the raw material is 50°C. The raw material can be, but is not limited to, medical-grade PVC, TPU, TPE, or PE. The heating temperature of the extruder is maintained at 210°C, and the injection pressure of the extruder is 400N. The mold is used to shape the initial shape of the medical catheter, and the positions and lengths of the flexible tube segment a and the rigid tube segment b are determined on the body of the medical catheter. The pipe wall is homogenized, and the flexible pipe section a or rigid pipe section b is stretched and compressed. Cooling and shaping are performed on either flexible tube segment a or rigid tube segment b. Both flexible tube segment a and rigid tube segment b are simultaneously subjected to water cooling. The cooling time for flexible tube segment a is 0.7 hours, and the cooling time for rigid tube segment b is 1.2 hours. After the 0.7-hour water cooling time for flexible tube segment a, air cooling is applied. After the water cooling time for rigid tube segment b is completed, the air cooling for flexible tube segment a also stops. That is, at this time, flexible tube segment a is still subjected to air cooling for 0.5 hours. The modification process involves immersing the cooled conduit segment (either flexible section a or rigid section b) in a hydrophilic coating modification solution for 2.5 hours (at a temperature of 70°C). Then, the flexible section a or rigid section b is placed in a UV curing machine for curing. The UV curing machine is connected to a clean air source via a high-pressure tee to purge any residual moisture from the flexible section a or rigid section b, and the air permeability is checked. The modification material is a hydrophilic coating, which may be made of, but is not limited to, PET, PC, ABS, PA, or PPO plastic. The modified catheter is dried and cut to obtain a medical catheter with varying hardness in multiple segments.

[0020] Example 2 A manufacturing process for a medical catheter with variable stiffness in multiple segments includes the following steps: Raw material extrusion, wherein the preheating temperature of the raw material is 10℃, and the raw material is, but not limited to, PEBAX, PA, polyester or polytetrafluoroethylene. The heating temperature of the extruder is maintained at 100℃, and the injection pressure of the extruder is 60N. Mold forming, determining the location and length of the segmented flexible tube a and rigid tube b; The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is stretched and compressed. Cooling and shaping: Cooling treatment is performed on flexible section a or rigid section b. Flexible section a and rigid section b are simultaneously cooled by water. The cooling time for flexible section a is 0.3 hours and the cooling time for rigid section b is 0.9 hours. Modification treatment: The cooled hose section a is immersed in a toughening resin modification solution at 30℃ for 1.6 hours; the cooled rigid hose section b is immersed in a reinforcing resin modification solution at 40℃ for 2 hours. Finished catheter: The modified catheter is dried and cut.

[0021] Example 3 A manufacturing process for a medical catheter with variable stiffness in multiple segments includes the following steps: Raw material extrusion, wherein the preheating temperature of the raw material is 80℃, and the raw material is, but not limited to, medical grade TPU, PA, polyurethane or PET plastic, the heating temperature of the extruder is maintained at 300℃, and the injection pressure of the extruder is 900N. Mold forming, determining the location and length of the segmented flexible tube a and rigid tube b; The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is stretched and compressed. Cooling and shaping: Cooling treatment is performed on flexible section a or rigid section b. Flexible section a and rigid section b are simultaneously cooled by water. The cooling time for flexible section a is 1.1 hours and the cooling time for rigid section b is 1.5 hours. After modification, the cooled hose segment a or rigid tube segment b is immersed in a hydrophilic coating modification solution for 3 hours. The temperature of the hydrophilic coating modification solution is 90℃. The solution is then placed in a UV curing machine for curing. The UV curing machine is connected to a clean air source through a high-pressure tee to purge the residual moisture from hose segment a or rigid tube segment b. The air permeability of hose segment a or rigid tube segment b is then checked. The modified material is a hydrophilic coating, which may be made of, but is not limited to, PET plastic, PC plastic, ABS plastic, PA plastic, or PPO plastic. The modified catheter is dried and cut to size.

[0022] Example 4 A manufacturing process for a medical catheter with variable stiffness in multiple segments includes the following steps: Raw material extrusion, wherein the preheating temperature of the raw material is 40℃, the raw material is, but is not limited to, PET plastic, the heating temperature of the extruder is maintained at 150℃, and the injection pressure of the extruder is 450N; Mold forming, determining the location and length of the segmented flexible tube a and rigid tube b; The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is stretched and compressed. Cooling and shaping are performed on either flexible hose section a or rigid hose section b. Both flexible hose section a and rigid hose section b are simultaneously subjected to water cooling. The cooling time for flexible hose section a is 0.9 hours, and the cooling time for rigid hose section b is 1 hour. After the 0.9-hour water cooling time for flexible hose section a, air cooling is applied. After the water cooling time for rigid hose section b is completed, the air cooling for flexible hose section a also stops. At this point, flexible hose section a has undergone 0.1 hours of air cooling. Modification treatment: The cooled hose segment a was immersed in a toughening resin modification solution at 50°C for 2.2 hours. Finished catheter: The modified catheter is dried and cut.

[0023] Example 5 A manufacturing process for a medical catheter with variable stiffness in multiple segments includes the following steps: Raw material extrusion, wherein the preheating temperature of the raw material is 20℃, the raw material is, but not limited to, silicone rubber, the heating temperature of the extruder is maintained at 120℃, and the injection pressure of the extruder is 300N; Mold forming, determining the location and length of the segmented flexible tube a and rigid tube b; The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is stretched and compressed. Cooling and shaping are performed on either flexible hose section a or rigid hose section b. Both flexible hose section a and rigid hose section b are simultaneously subjected to water cooling. The cooling time for flexible hose section a is 0.5 hours, and the cooling time for rigid hose section b is 1.1 hours. After the 0.5-hour water cooling time for flexible hose section a, air cooling is applied. After the water cooling time for rigid hose section b is completed, the air cooling for flexible hose section a also stops. At this point, flexible hose section a has undergone 0.6 hours of air cooling. Modification treatment: The cooled rigid pipe section b is immersed in a 75°C reinforced resin modification solution for 3.5 hours. The modified catheter is dried and cut to size.

[0024] The manufacturing process parameters for Examples 1-5 described above are shown in the table below: Table 1: Manufacturing Process and Usage Examples of Multi-Segment Variable Rigidity Medical Catheters - Process Parameter Table The medical catheters manufactured using the production processes of Examples 1-5 all have the following effects: the production cost of the medical catheters is low, and the medical catheters have the advantage of gradual hardness change, allowing a single medical catheter to have the characteristics of both soft and hard structures, which enhances the overall integrity of the medical catheter, improves its flexibility, mechanical properties and biocompatibility, and under the action of the modified solution, can enhance the wear resistance and lubrication properties of the medical catheters, which is conducive to the long-term safe use of the medical catheters.

[0025] The wall homogenization mentioned in Examples 1-5 involves traction, stretching, and compression retraction of the flexible tube segment a or rigid tube segment b. This traction, stretching, and compression retraction homogenizes the wall of the medical catheter, resulting in a more robust catheter wall structure, a smoother inner wall, greater permeability, prevention of foreign objects from accumulating on the inner wall, reduced likelihood of blockage during use, and extended service life. This facilitates long-term and safe use of the medical catheter.

[0026] It should be noted that the modified material is, but is not limited to, reinforced resin, toughening resin or hydrophilic coating. Other materials such as polymers are also used as modified materials to prepare the modified solution, which is also applicable to the embodiments of the present invention. The hydrophilic coating is, but is not limited to, PET plastic, PC plastic, ABS plastic, PA plastic or PPO plastic; the polymer material is, but is not limited to, plastic, fiber or coating.

[0027] It should be noted that the UV curing machine, UV curing machine connected to a clean air source via a high-pressure tee, extruder, water cooling, and air cooling mentioned in the embodiments are all conventional equipment and processes in the conduit manufacturing process. Their structure and principle are well-known technologies in the market, so they will not be described in detail here.

[0028] This manufacturing process for multi-segment variable-rigidity medical catheters enables the production of multi-segment medical catheters with flexible tubing segment A and rigid tubing segment B. This is suitable for applications such as flexible endoscope guiding sheaths, ureteral catheters, ureteral stents, central venous catheters, hemodialysis catheters, catheter sheaths, angiography / guiding catheters, aspiration catheters, pressure extension tubes, gastric tubes, double-lumen gastric tubes, drainage tubes, and ablation catheters. These types of catheters require a portion of the tube body to be rigid segment B and a portion to be flexible tubing segment A. This design facilitates the practical use of the medical catheters. Different catheters can be produced using only different raw materials and different extrusion molds. Furthermore, the length, position, and number of flexible tubing segment A and rigid tubing segment B can be adjusted according to the actual needs of the medical catheter, making its use more convenient.

[0029] Application example: For example, a ureteral stent made using the manufacturing process of this multi-segment variable-rigidity medical catheter has two ends set as flexible segment a structure. Flexible segment a serves as a connection between the urinary bladder system and the renal pelvis system, while rigid segment b serves as a bridge connecting the two flexible segments a, thus better guiding the discharge of urine.

[0030] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. In the present invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to fixed connections or detachable connections.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for a medical catheter with variable rigidity in multiple segments, the medical catheter comprising at least one flexible tube segment a and at least one rigid tube segment b, characterized in that, Includes the following steps: Raw material extrusion involves preheating the raw material, feeding the preheated raw material into an extruder, and then extruding the raw material into a mold. The mold is used to shape the initial shape of the medical catheter, and the positions and lengths of the flexible tube segment a and the rigid tube segment b are determined on the body of the medical catheter. The pipe wall is homogenized, and the flexible pipe section a or the rigid pipe section b is subjected to traction, stretching, and compression retraction. Cooling and shaping: Perform a cooling treatment on hose section a or rigid pipe section b for 0.1-2.1 hours. Modification treatment involves immersing the cooled hose segment a or rigid pipe segment b in a modifying material for 1.1-8.1 hours. The modifying material must be prepared as a modification solution at 10-150°C for use. The modified catheter is dried and cut into finished products. During the cooling process, both the flexible hose section a and the rigid pipe section b are simultaneously subjected to water cooling. The cooling time for the flexible hose section a is 0.3-1.1 hours, and the cooling time for the rigid pipe section b is 0.9-1.5 hours. After the water cooling time for hose section a is 0.3-1.1 hours, the air cooling treatment for hose section a is switched to air cooling. After the water cooling time for rigid pipe section b is completed, the air cooling of hose section a also stops.

2. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 1, characterized in that: During the modification process, the modified material is a reinforcing resin, a toughening resin, or a hydrophilic coating. The hydrophilic coating is made of PET plastic, PC plastic, ABS plastic, PA plastic, or PPO plastic. During modification, the flexible tube section a or the rigid tube section b is immersed in a container filled with a modification solution at 20-120°C for 1.5-6 hours.

3. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 2, characterized in that: The hose segment a is immersed in a toughening resin-modified solution at 30-80℃ for 1.6-3 hours.

4. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 2, characterized in that: The rigid pipe section b is immersed in a reinforced resin modified solution at 40-110℃ for 2-5 hours.

5. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 2, characterized in that: After the flexible tube segment a or rigid tube segment b is immersed in the hydrophilic coating modification solution for 2-3 hours, it is placed in a UV curing machine for curing treatment. The temperature of the hydrophilic coating modification solution is 50-90℃.

6. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 5, characterized in that: The UV curing machine is connected to a clean air source via a high-pressure tee to purge residual moisture from hose section a or rigid pipe section b, and the airflow of hose section a or rigid pipe section b is checked.

7. The manufacturing process of the multi-segment variable stiffness medical catheter according to claim 1, characterized in that: The preheating temperature of the raw materials is 10-80℃, and the raw materials are any one or more of the following: medical grade PVC, TPU, TPE, PE, FEP, PEBAX, PA, polyester, polytetrafluoroethylene, polyurethane, PET plastic, and silicone rubber.

8. The manufacturing process of the medical catheter with multi-segment variable stiffness according to claim 1, characterized in that: The extruder's heating temperature is maintained at 100-300℃, and its injection pressure is 60-900N.

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