Extrusion molding die and process for Nafion tube

Abstract

The invention discloses an extrusion molding die and process for a Nafion tube. The extrusion molding die comprises a base, a die cavity, a guide sleeve and a wall thickness adjusting module, the base comprises a tail end feeding port, threads are arranged outside the feeding port and used for being connected with an extruding machine, the die cavity comprises a die core, a forming cavity, an air vent and the like, molten Nafion is preliminarily shaped through the die core, the guide sleeve comprises a guide cavity, a discharging port and the like, and the preliminarily-molten Nafion is subjected to molding and pipe forming through the guide cavity and then is extruded out of the discharging port. The die cavity and the guide sleeve are in contact connection through the two table tops, and the wall thickness of the Nafion tube can be controlled by adjusting a screw of the wall thickness adjusting module. The Nafion tube extrusion mold and process have the advantages of being simple in structure, convenient and fast to switch and the like, the production process is remarkably optimized, the production efficiency is improved, the consistency and quality stability of products of all batches are ensured, and meanwhile the Nafion tube extrusion mold and process are suitable for extrusion molding of other perfluorinated sulfonic acid resin mold materials.

Description

Technical Field

[0001] One or more embodiments of this specification relate to the field of manufacturing materials such as intelligent drive materials, and particularly to a die and process for extrusion molding of Nafion tubes. Background Art

[0002] As a perfluorosulfonic acid ionomer, Nafion's structure is composed of a hydrophobic carbon-fluorine main chain and hydrophilic sulfonic acid group short side chains. This unique chemical structure endows Nafion with remarkable properties, including free cations that can move within the polymer and anions covalently fixed to the main chain, ensuring high selectivity and excellent ionic conductivity. These properties enable Nafion to exhibit extensive application potential in fields such as artificial muscles, fuel cells, and air-conditioning condenser tubes. However, traditional methods for preparing Nafion membranes mainly rely on casting techniques, which not only require custom-made molds for specific applications but also typically produce sheet-like solid products, making it impossible to fabricate Nafion tubes with complex geometries or hollow structures, which to some extent limits its applicability in more practical application fields.

[0003] In traditional minimally invasive interventional surgeries, the common catheters on the market lack the function of guiding. The guide wire is used as a key tool to guide other medical devices to the lesion site. However, its operation depends on the manual manipulation of the operator, which not only increases the dependence on the operator's skill level. In addition, when the guide wire passes through blood vessels in different parts of the human body, due to its hardness and the frictional effect with the vascular intima, it is easy to cause varying degrees of physical damage to the blood vessel wall, ranging from mild local inflammatory reactions to severe complications such as bleeding, thrombosis, and even perforation, thus limiting the application scope and safety of such surgeries.

[0004] The application of IPMC (ionic polymer metal composite) based on Nafion materials in catheter navigation technology can significantly simplify the surgical process and improve the success rate. Compared with the traditional solid form, the tubular hollow structure of Nafion exhibits more excellent performance advantages, not only supporting more flexible direction control but also being applicable to pulsed ablation therapy and drug delivery systems. By manufacturing Nafion tubes using specific processes, the possibility of efficient and large-scale production is achieved while ensuring the required functional characteristics, thereby significantly reducing the manufacturing cost and enhancing the economic feasibility, which has important practical value. Summary of the Invention

[0005] Based on the above technical problems, the purpose of the present invention is to provide a die and process for extrusion molding of Nafion tubes, which can ensure stable production while adjusting the wall thickness of the Nafion tube to guarantee the manufacturing precision and quality of the tube.

[0006] In the first aspect of the embodiment of the present invention, a mold for extrusion molding of Nafion tubes is proposed. The mold includes: a base (1), a mold cavity (2), a guide sleeve (3), and a wall thickness adjustment module (4);

[0007] The tail end of the base (1) includes a feed inlet (1-1), and the front end face is provided with eight fixing holes (1-3) arranged in a circular pattern. The mold cavity (2) is connected to the front end face of the base (1) by screws;

[0008] The base (1) includes: a feed inlet (1-1), a feed chamber (1-2), and fixing holes (1-3);

[0009] The mold cavity (2) is installed on the front end face of the base (1) by screws. The tapered end of the mold core (2-1) is completely embedded in the feed chamber (1-2). The molding chamber (2-5) is directly connected to the feed chamber (1-2). The feed chamber (1-2) is directly connected to an extruder. The guide sleeve (3) and the mold cavity (2) are positioned by contacting the first table surface (2-7) and the second table surface (3-2);

[0010] The mold cavity (2) includes: a mold core (2-1), a split surface (2-2), threaded holes (2-3), air vents (2-4), a molding chamber (2-5), an air outlet chamber (2-6), a first table surface (2-7), and counterbores (2-8);

[0011] The guide sleeve (3) and the mold cavity (2) are positioned by the first table surface (2-7) and the second table surface (3-2). The pipe orifice of the mold core (2-1) is led out through the guide sleeve (3) to the chamber (3-1). The relative position of the guide sleeve (3) and the mold cavity (2) is determined by rotating the screw in the adjustment hole (4-1) installed on the wall thickness adjustment module (4). The first step surface (3-4) of the guide sleeve (3) is in surface contact with the second step surface (4-3) of the wall thickness adjustment module (4);

[0012] The guide sleeve (3) includes a lead-out chamber (3-1), a second table surface (3-2), a discharge port (3-3), and a first step surface (3-4);

[0013] The wall thickness adjustment module (4) includes an adjustment hole (4-1), a temperature measurement port (4-2), and a second step surface (4-3).

[0014] Preferably, in a mold for extrusion molding of Nafion tubes, the feed inlet (1-1) is connected to the extruder by a threaded connection.

[0015] Preferably, the wall thickness of the Nafion tube is determined by adjusting the tightness of the screw of the wall thickness adjustment module (4).

[0016] Preferably, the mold core (2-1) divides the molten Nafion into two semi-circular tubes through the split surface (2-2) and spliced into a circular tube at the entrance of the outlet chamber (3-1).

[0017] Preferably, the first table surface (2-7) and the second table surface (3-2) are hemispherical convex platforms, and the contact position between the first table surface (2-7) and the second table surface (3-2) is changed by the wall thickness adjustment module (4) to adjust the wall thickness of the Nafion tube.

[0018] Preferably, the mold cavity (2) is circumferentially provided with eight holes. During the assembly process, the counterbore (2-8) cooperates with the fixing hole (1-3) of the base (1), and the threaded hole (2-3) cooperates with the adjustment hole (4-1) of the wall thickness adjustment module (4).

[0019] Preferably, the outer circumferential surface of the mold cavity (2) is provided with a vent hole (2-4) to introduce air with a sufficient flow rate to assist in shaping the molten Nafion mold material.

[0020] Preferably, the front end surface of the wall thickness adjustment module (4) is provided with a temperature measurement port (4-2) into which a temperature measurement probe gun is inserted to obtain the mold temperature in real time.

[0021] The second aspect of the embodiment of the present invention provides a process for the extrusion molding of Nafion tubes, and the process includes:

[0022] 1) Wall thickness adjustment: According to actual usage requirements, adjust the screw of the adjustment hole (4-1) of the wall thickness adjustment module (4). Unscrew it counterclockwise, and the wall thickness at the corresponding position becomes thinner; tighten it clockwise, and the wall thickness at the corresponding position becomes thicker;

[0023] 2) Melting of perfluorosulfonic acid resin particles: The feed port (1-1) of the base (1) is connected to an extruder, the temperature of the extruder is set at 240-280 °C, and the mold is heated to 230-270 °C to melt the perfluorosulfonic acid resin particles and ensure that the material composition distribution after melting is uniform;

[0024] 3) Tube body forming: The rotation speed of the extruder is constant, and at the same time, air with a sufficient flow rate is blown through the vent hole, and the specific shape of the Nafion tube at the outlet is observed at all times until a uniform and continuous tubular melt appears;

[0025] 4) Air cooling: Clamp the head end of the continuous and uniform pipe in step 3 with a high-temperature resistant fixture and pull it for 2-3 m until the pipe is cooled and shaped;

[0026] 5) Pipe material collection: Continue to pull the pipe material that has been completely air-cooled in step 4 to the collector, and the rotation speed of the collector is set by itself.

[0027] The beneficial effects of the present invention compared with the prior art are:

[0028] The present invention proposes a mold and process for the extrusion molding of Nafion tubes. By introducing a wall thickness adjustment module, the wall thickness of the Nafion tube can be flexibly adjusted, thus reducing the need to remanufacture the mold due to specification changes and further reducing costs. Different from the traditional method, this technology continuously ventilates the inside during the tube forming process, ensuring that the product shape is more uniform and consistent, and improving the product quality. The Nafion tubes produced by this process are applicable to multiple fields such as surgical treatment, flue gas analysis systems, and gas separation and purification. Moreover, due to its unique design and efficient production method, the final product has higher application value and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the overall structure diagram of the Nafion tube extrusion mold of the present invention;

[0030] Figure 2 is the overall cross-sectional view of the Nafion tube extrusion mold of the present invention;

[0031] Figure 3 is Figure 1 the structural schematic diagram of the middle base;

[0032] Figure 4 is Figure 1 the structural schematic diagram of the middle cavity;

[0033] Figure 5 is Figure 1 the structural schematic diagram of the middle guide sleeve;

[0034] Figure 6 is Figure 1 the structural schematic diagram of the middle wall thickness adjustment module;

[0035] Figure 7 is the electron microscope image of a pure Nafion tube with an outer diameter of 1.6 mm and an inner diameter of 1.3 mm developed by the Nafion tube extrusion mold of the present invention;

[0036] Figure 8 is the electron microscope image of a Nafion tube with an outer diameter of 0.8 mm, an inner diameter of 0.6 mm, and a carbon tube content of 0.2 wt% developed by the Nafion tube extrusion mold of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] In this embodiment, the present invention provides a Nafion tube extrusion molding die as shown in Figures 1 to 6 which includes a base (1), a mold cavity (2), a guide sleeve (3), and a wall thickness adjustment module (4).

[0039] The tail end of the base (1) includes a feed inlet (1-1), and the front end face is provided with eight fixing holes (1-3) arranged in a circumferential manner. The mold cavity (2) is connected to the front end face of the base (1) by screws;

[0040] The base (1) includes: a feed inlet (1-1), a feed chamber (1-2), and fixing holes (1-3);

[0041] The mold cavity (2) is installed on the front end face of the base (1) by screws. The tapered end of the mold core (2-1) is completely embedded in the feed chamber (1-2). The forming chamber (2-5) is directly connected to the feed chamber (1-2) through four array holes (2-3). The feed chamber (1-2) leads directly to the outside. The guide sleeve (3) and the mold core (2) are positioned by contacting the first table surface (2-7) and the second table surface (3-2);

[0042] The mold cavity (2) includes: a mold core (2-1), a split surface (2-2), threaded holes (2-3), air vents (2-4), a forming chamber (2-5), an air outlet chamber (2-6), a first table surface (2-7), and a counterbore (2-8);

[0043] Preferably, in some embodiments, the overall stiffness of the finally formed Nafion tube is related to the processing time of the molding material in the mold cavity (2).

[0044] The guide sleeve (3) and the mold cavity (2) are positioned by the first table surface (2-7) and the second table surface (3-2). The pipe orifice of the mold core (2-1) is led out through the outlet chamber (3-1) of the guide sleeve (3). The guide sleeve (3) and the mold cavity (2) are fixed by the upper adjustment holes (4-1) on the wall thickness adjustment module (4). The first step surface (3-4) of the guide sleeve (3) contacts the second step surface (4-3) of the wall thickness adjustment module (4);

[0045] The guide sleeve (3) includes an outlet chamber (3-1), a second table surface (3-2), a discharge port (3-3), and a first step surface (3-4);

[0046] The wall thickness adjustment module (4) includes adjustment holes (4-1), a temperature measurement port (4-2), and a second step surface (4-3).

[0047] Preferably, for a Nafion tube extrusion molding die, the feed inlet (1-1) is threadedly connected to an extruder.

[0048] Preferably, the wall thickness of the Nafion tube is determined by adjusting the tightness of the screws of the wall thickness adjustment module (4).

[0049] Preferably, the die core (2-1) divides the molten Nafion into two semi-circular tubes through the dividing surface (2-2) and joins them into a circular tube at the entrance of the outlet chamber (3-1).

[0050] Preferably, the first table surface (2-7) and the second table surface (3-2) are hemispherical convex platforms. By changing the contact position between the first table surface (2-7) and the second table surface (3-2) through the wall thickness adjustment module (4), the wall thickness of the Nafion tube is adjusted.

[0051] Preferably, the die cavity (2) is circumferentially arrayed with eight holes. During the assembly process, the counterbore (2-8) cooperates with the fixing hole (1-3) of the base (1), and the threaded hole (2-3) cooperates with the adjustment hole (4-1) of the wall thickness adjustment module (4).

[0052] Preferably, an air vent (2-4) is provided on the outer circumferential surface of the die cavity (2), and air with a sufficient flow rate is introduced to assist in the shaping of the molten Nafion mold material.

[0053] Preferably, a temperature measurement port (4-2) is provided on the front end surface of the wall thickness adjustment module (4). A temperature measurement probe gun is inserted to obtain the mold temperature in real time.

[0054] See Figures 1 to 8 , the second aspect of the embodiment of the present invention provides a process for the extrusion molding of Nafion tubes, which includes:

[0055] 1) Wall thickness adjustment: According to actual usage needs, adjust the screws of the adjustment hole (4-1) of the wall thickness adjustment module (4). Unscrew counterclockwise, and the wall thickness at the corresponding position becomes thinner; tighten clockwise, and the wall thickness at the corresponding position becomes thicker;

[0056] 2) Melting of perfluorosulfonic acid resin particles: The feed port (1-1) of the base (1) is connected to an extruder. The temperature of the extruder is set at 240-280 °C, and the mold is heated to 230-270 °C to melt the perfluorosulfonic acid resin particles and ensure that the material composition distribution after melting is uniform;

[0057] 3) Tube body forming: The rotation speed of the extruder is constant. At the same time, air with a sufficient flow rate is blown through the air vent, and the specific shape of the Nafion tube at the outlet is observed at all times until a uniform and uninterrupted tubular melt appears;

[0058] 4) Air cooling: Clamp the head end of the continuous and uniform pipe in step 3 with a high-temperature resistant fixture and pull it for 2-3 m until the pipe is cooled and shaped;

[0059] 5) Pipe material collection: Continue to pull the pipe material that has been completely air-cooled in step 4 to the collector, and the rotation speed of the collector is determined by itself.

[0060] Preferably, in some embodiments, the product scanning electron microscope is referred to Figure 7 , the process of using a pure Nafion tube with an outer diameter of 1.6 mm and an inner diameter of 1.3 mm developed for the Nafion tube extrusion molding process is as follows:

[0061] First step, installation and preparation: Screw the fully assembled mold tightly onto the extruder along the thread direction of the feed port (1-1), insert the temperature measuring gun into the temperature measuring port (4-2), preheat the extruder and the mold to 240 - 280 °C and 230 - 270 °C respectively, and reserve enough space for the air cooling of the Nafion tube.

[0062] Second step, wall thickness adjustment: Use a hex wrench to adjust the screws of the wall thickness adjustment module (4), measure the distance between the mouth of the guide sleeve (3) and the tube mouth of the die core (2-1) until the wall thickness reaches the target thickness, and then remove the hex wrench.

[0063] Third step, adding the molding material: Adjust the rotation speed of the extruder to 1 - 3 r / min, pour in an appropriate amount of perfluorosulfonic acid resin particles, and blow air into the air vent at the same time.

[0064] Fourth step, pulling out the formed Nafion tube: For the first discharge, it is necessary to wait for 5 - 7 min until the molten molding material fills the mold completely, and the formed Nafion tube is extruded from the tube mouth. Clamp the extruded tube with a high-temperature resistant fixture and uniformly pull the tube body forward by 3 m. Observe the shape of the Nafion tube during this period. The pulling speed is 4 - 20 mm / s, neither too fast nor too slow. If it is too fast, the Nafion tube that is not fully cooled has a risk of fracture; if it is too slow, the extrusion material accumulates at the tube mouth, which is not conducive to extrusion.

[0065] Fifth step, collecting the tube material: Continue to pull the air-cooled tube material to the collector, observe in real time, and avoid the Nafion tube material being wound into the rotating collecting wheel.

[0066] Preferably, in some embodiments, the product scanning electron microscope is referred to Figure 8 , the process of using a Nafion tube with an outer diameter of 0.8 mm, an inner diameter of 0.6 mm, and a carbon tube content of 0.2 wt% developed for the Nafion tube extrusion molding process is as follows:

[0067] First step, pretreatment of the molding material: Weigh the corresponding mass of multi-walled carbon nanotubes and perfluorosulfonic acid resin particles using a precision balance, put the weighed carbon nanotubes and perfluorosulfonic acid resin particles into a sealed bag made of polypropylene material with good barrier properties, and shake it well to make them mix evenly.

[0068] Step 2, Installation and Preparation: Screw the fully assembled mold tightly onto the extruder along the thread direction of the feed inlet (1-1). Insert the temperature measuring gun into the temperature measuring port (4-2). Preheat the extruder and the mold to 240-280°C and 230-270°C respectively, leaving enough space for the air cooling of the Nafion tube.

[0069] Step 3, Wall Thickness Adjustment: Use a hex wrench to adjust the screws of the wall thickness adjustment module (4). Measure the distance between the opening of the guide sleeve (3) and the tube opening of the die core (2-1) until the wall thickness reaches the target thickness, and then remove the hex wrench.

[0070] Step 4, Adding Molding Material: Adjust the rotation speed of the extruder to 1-3 r / min, pour in the molding material particles fully mixed in Step 1, and blow air into the air vent at the same time.

[0071] Step 5, Pulling out the Molded Nafion Tube: For the first discharge, wait for 5-7 min until the molten molding material fills the mold. The molded Nafion tube is extruded from the tube opening. Clamp the extruded tube with a high-temperature resistant fixture and uniformly pull the tube body forward by 3 m. Observe the shape of the Nafion tube during this period. The pulling speed is 4-20 mm / s, which should not be too fast or too slow. If it is too fast, there is a risk of breakage of the not fully cooled Nafion tube. If it is too slow, the extrusion material accumulates at the tube opening, which is not conducive to extrusion.

[0072] Step 6, Tube Material Collection: Continue to pull the fully air-cooled tube material to the collector and observe it in real time to prevent the Nafion tube material from being entangled in the rotating collection wheel.

[0073] The beneficial effects of the present invention compared with the prior art are:

[0074] The present invention provides a mold and process for the extrusion molding of Nafion tubes. By introducing a wall thickness adjustment module, the wall thickness of the Nafion tube can be flexibly adjusted, thus reducing the need to remanufacture the mold due to specification changes and further reducing costs. Different from the traditional method, this technology continuously ventilates the inside during the tube forming process, ensuring that the product shape is more uniform and improving the product quality. The Nafion tubes produced by this process are not only applicable to multiple fields such as surgical treatment, gass preprocessors, flue gas analysis systems, and gas separation and purification, but also due to their unique design and efficient production method, the final products have higher application value and market competitiveness.

[0075] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A die for Nafion tube extrusion molding, characterized in that: include: A base (1), a mold cavity (2), a guide sleeve (3) and a wall thickness adjustment module (4); The rear end of the base (1) includes a feed port (1-1), and the front end surface is provided with eight fixing holes (1-3) arranged in a circumference, and the mold cavity (2) is connected to the front end surface of the base (1) by screws; The base (1) comprises: a feed port (1-1), a feed chamber (1-2) and a fixing hole (1-3); The mold cavity (2) is mounted on the front end surface of the base (1) by means of screws, the cone at the end of the mold core (2-1) is completely embedded in the feed chamber (1-2), the molding chamber (2-5) is directly connected to the feed chamber (1-2), the feed chamber (1-2) is directly connected to the extruder, and the guide sleeve (3) and the mold cavity (2) are contacted and positioned by the table top 1 (2-7) and the table top 2 (3-2); The mold cavity (2) comprises: a mold core (2-1), a dividing surface (2-2), a threaded hole (2-3), a vent (2-4), a molding chamber (2-5), an air outlet chamber (2-6), a table top (2-7), and a countersunk hole (2-8); The guide sleeve (3) and the mold cavity (2) are positioned by table top 1 (2-7) and table top 2 (3-2); the nozzle of the mold core (2-1) is guided out of the cavity (3-1) through the guide sleeve (3); the relative position of the guide sleeve (3) and the mold cavity (2) is determined by rotating a screw installed in an adjustment hole (4-1) on a wall thickness adjustment module (4); and the step surface 1 (3-4) of the guide sleeve (3) is in surface contact with the step surface 2 (4-3) of the wall thickness adjustment module (4); The guide sleeve (3) comprises a guide chamber (3-1), a second table surface (3-2), a material outlet (3-3), and a first step surface (3-4); The wall thickness adjustment module (4) comprises an adjustment hole (4-1), a temperature measuring port (4-2), and a second step surface (4-3).

2. A die for Nafion tube extrusion molding according to claim 1, characterized in that: The feed port (1-3) is connected to the extruder via threads.

3. A die for Nafion tube extrusion molding according to claim 1, characterized in that: The wall thickness of the Nafion tube is determined by adjusting the tightness of the screws of the wall thickness adjustment module (4).

4. A die for Nafion tube extrusion molding according to claim 1, characterized in that: The mold core (2-1) divides the molten Nafion into two semicircular tubes through a dividing surface (2-2), which are spliced ​​into a circular tube at the entrance of the outlet chamber (3-1).

5. The die for Nafion tube extrusion molding according to claim 1, characterized in that: The table top 1 (2-7) and the table top 2 (3-2) are hemispherical raised tables, and the contact position between the table top 1 (2-7) and the table top 2 (3-2) is changed by a wall thickness adjustment module (4) to adjust the wall thickness of the Nafion tube.

6. The die for Nafion tube extrusion molding according to claim 1, characterized in that: The mold cavity (2) has eight holes in a circumferential array. During assembly, the countersunk hole (2-8) cooperates with the fixing hole (1-3) of the base (1), and the threaded hole (2-3) cooperates with the adjusting hole (4-1) of the wall thickness adjusting module (4).

7. According to the die for Nafion tube extrusion molding as described in claim 1, the outer circumferential surface of the mold cavity (2) is provided with vents (2-4) for introducing sufficient flow of air to assist in shaping the molten Nafion mold material.

8. According to the Nafion tube extrusion molding die of claim 1, the front end surface of the wall thickness adjustment module (4) is provided with a temperature measuring port (4-2), into which a temperature measuring probe gun is inserted to obtain the mold temperature in real time.

9. The die for Nafion tube extrusion molding according to claim 1, characterized in that: include: 1) Adjustment of pipe wall thickness: According to actual use needs, adjust the screw of the adjustment hole (4-1) of the wall thickness adjustment module (4) and turn it counterclockwise to make the wall thickness thinner in the corresponding direction; Tighten clockwise, and the wall thickness in the corresponding direction will become thicker; 2) Melting of perfluorosulfonic acid resin particles: the feed port (1-1) of the base (1) is connected to an extruder, the temperature of the extruder is set at 240-280° C., the mold is heated to 230-270° C., the perfluorosulfonic acid resin particles are melted, and the material composition after melting is ensured to be evenly distributed; 3) Tube molding: The extruder speed is kept constant, and sufficient air flow is blown into the vent. The specific shape of the Nafion tube at the outlet is always observed until a uniform and uninterrupted tubular melt appears. 4) Air cooling: Use a high temperature resistant clamp to clamp the continuous and uniform pipe head in step 3, and pull it for 2 to 3 meters until the pipe is cooled and shaped; 5) Pipe material collection: The pipe material that has been completely air-cooled in step 4 is further pulled to the collector, and the speed of the collector is self-determined.

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