A process for producing filter bags using meltblown technology and a filtration device.

Abstract

This invention provides a process and filtration device for producing filter bags using meltblown technology, relating to the field of air filtration technology. It solves the technical problem of difficulty in forming pleated filter bags using existing processes. The process for producing filter bags using meltblown technology includes feeding, heated extrusion, filtration, spinning, die forming, electret treatment, and demolding. Feeding and heated extrusion form a flowable melt from the raw material. Spinning then sprays the flowable melt onto a forming mold, which includes a room-temperature mold with circumferentially shaped ribs. The filtration device includes a support device and a meltblown filter bag fitted over the support device. This invention can produce filter bags that match the shape of the forming mold. It is not only simple and efficient, but also produces filter bags with stable morphology and low cost. These filter bags can filter dust, droplets, viruses, etc., exhibiting good filtration effects and a wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of air filtration device technology, specifically to a process for producing filter bags using meltblown technology and a filtration device. Background Technology

[0002] In daily life, meltblown fabric is the core material of masks. In the process of filtering air, it can filter out tiny non-oily particles and effectively block aerosols and virus-containing droplets. In the field of respiratory filtration devices, meltblown fabric is widely used in masks due to its excellent filtration effect. However, due to its flexibility, meltblown fabric often cannot be folded into a specific shape and structure. Existing cylindrical air filter elements are cylindrical in shape with uniform folds on the outer wall. The fold structure is usually achieved by folding. However, when the folding method is directly applied to meltblown fabric, it is often impossible to form folds, which greatly limits the application of meltblown fabric. Summary of the Invention

[0003] One objective of this invention is to provide a process for producing filter bags using meltblown technology, thereby solving the technical problem that it is difficult to form pleated filter bags using existing processes. The preferred technical solution among the many technical solutions provided by this invention offers numerous technical advantages (the room-temperature mold includes an extension section and a connecting section; shaping ribs are set on the connecting section; the extension section and connecting section allow the flowable melt to be formed into an annular installation section and a pleated filter section, respectively used for installation and air filtration; after meltblown forming, a shaping tool is used to shape the filter bag, making its shape and structure more fixed and facilitating subsequent installation; during the meltblown forming process, only the sidewalls and bottom walls of the forming mold are meltblown). The filter bags are formed using spinnerets, creating open-top filter bags for easy installation. After demolding, the process includes sealing the seams using ultrasonic welding, which strengthens the filter bag structure and ensures its integrity, thus guaranteeing its filtration efficiency. The molding die also includes a high-temperature die, with a room-temperature die inside. The molten metal flows through the spinnerets in the high-temperature die and is sprayed onto the room-temperature die, directly producing open-top filter bags without the need for post-sealing. The high-temperature die also effectively prevents the spinnerets from clogging due to molten metal cooling, resulting in superior quality filter bags. See below for details.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention provides a process for producing filter bags using the meltblown method, comprising the following steps:

[0006] (I) Feeding: Inputting raw materials into the feeding device;

[0007] (II) Heated extrusion: The raw material is conveyed to the extrusion device through the feeding device, and the extrusion device extrudes and heats the raw material, so that the raw material is melted into a flowable melt;

[0008] (III) Filtration: The flowable melt produced by extrusion is filtered to remove impurities and particulate matter through a filtration device;

[0009] (IV) Spinning: The filtered flowable melt is sprayed out by a spinneret and falls onto a forming mold. The forming mold includes a room temperature mold. The outer wall of the room temperature mold is uniformly provided with shaped ribs with toothed cross sections. The flowable melt is cooled on the forming mold to form a filter bag that matches the shape of the forming mold.

[0010] (V) Electret: The filter bag is electretted using a corona discharge device;

[0011] (VI) Demolding: Remove the molding mold.

[0012] Preferably, the room temperature mold is divided into an extension section and a connecting section along the axial direction, wherein: the extension section is located at the end of the connecting section, and the shaping rib is located on the connecting section; during the spinning process in step (IV), the flowable melt located at the position of the extension section forms the annular mounting section of the filter bag, and the flowable melt located at the positions of the connecting section and the shaping rib forms the pleated filter section of the filter bag.

[0013] Preferably, after the spinning process in step (IV) is completed, the process further includes die forming, in which a forming tool adapted to the room temperature mold is pressed onto the room temperature mold, and after pressing is completed, the forming tool is removed to obtain the shaped filter bag.

[0014] Preferably, in step (IV) during the spinning process, the spinning device sprays the filtered flowable melt only onto the sidewalls and bottom wall of the forming mold, and the top of the filter bag formed after cooling is open; after step (VI) demolding, the process also includes a sealing step, in which the seam of the formed filter bag is welded using ultrasonic welding technology.

[0015] Preferably, the molding die (1) further includes a high-temperature die, which is set outside the room temperature die. The high-temperature die is configured as a barrel structure with one end open. The room temperature die is set inside the high-temperature die and forms a barrel-shaped cavity with the inner wall of the high-temperature die. The bottom wall and side wall of the high-temperature die are densely covered with spinnerets, which are connected to the cavity.

[0016] In step (IV), during the spinneret forming process, the flowable melt is sprayed through the spinneret orifice onto the ambient temperature mold and cooled on the ambient temperature mold to form a filter bag with an open top.

[0017] The process for producing filter bags using the meltblown method provided by this invention has at least the following beneficial effects:

[0018] The process for producing filter bags using the meltblown method includes steps (I) feeding, (II) heated extrusion, (III) filtration, (IV) spinning, (V) electret treatment, and (VI) demolding. Steps (I) feeding and (II) heated extrusion process the raw material into a flowable melt. Step (III) filtration effectively removes impurities and larger particles from the melt. Step (IV) spinning allows the flowable melt to form a filter bag that fits the mold. Step (V) electret treatment imparts a protective coating to the formed filter bag. The electric charge increases electrostatic adsorption, ensuring filtration efficiency. The filter bag is then demolded in step (VI) to separate the formed filter bag. This invention uses a molding die containing a room-temperature mold and shaping ribs to produce filter bags that match the shape of the molding die via spinning. Not only do the formed pleated filter bags have excellent filtration performance, effectively filtering dust, aerosols, and isolating droplets, viruses, and other harmful substances in the air, but the melt-blown filter bag production process is also simple, efficient, and produces filter bags with stable morphology, low cost, superior quality, and wide applicability.

[0019] Another objective of this invention is to provide a filtration device to address the technical problem of poor filtration efficiency in existing filtration devices. The preferred technical solution among the various technical solutions provided by this invention offers numerous technical effects (the chamber is equipped with a power supply device and an air extraction device; the power supply device provides electrical energy to the air extraction device; the air extraction device draws air, allowing outside air to enter the chamber after being filtered by a melt-blown filter bag, and then exit through a connecting pipe, resulting in a significant filtration effect; the filtration device also includes a breathing mask, enabling a mobile breathing filtration device that does not affect the user's daily activities while ensuring the filtration level; the breathing mask is designed to cover the area above the eyes and the mouth and nose, or...). Air inlets and exhaust outlets are located below the mouth and nose, serving two purposes: cooling for comfort and ensuring a smooth flow of air, preventing fogging from exhaled steam from obstructing vision. The support system includes a support frame and end caps, with a port at one end for easy installation and maintenance of the power supply and extraction devices. The filter system also includes a sealing ring; the meltblown filter bag has an opening at the top, and the end of the support frame furthest from the end cap is inserted into the meltblown filter bag through this opening. The sealing ring seals the opening of the meltblown filter bag, ensuring a tight seal while facilitating disassembly and assembly. See below for details.

[0020] To achieve the above objectives, the present invention provides the following technical solution:

[0021] The present invention provides a filtration device, including a support device, on the outside of which a meltblown filter bag manufactured by the process of producing meltblown filter bags using the meltblown method is sleeved. The support device is adapted to the meltblown filter bag. The support device has a chamber inside, through which air can pass through the meltblown filter bag and the support device and enter into the chamber.

[0022] Preferably, the chamber is provided with a power supply device and an air extraction device, wherein: the power supply device and the air extraction device are electrically connected; the air extraction device is provided with an air inlet and an air outlet, the air inlet is placed in the chamber, the support device is provided with a connecting pipe, and the air outlet is connected to the connecting pipe.

[0023] Preferably, the filtering device further includes a breathing mask, wherein: an air inlet is provided on the breathing mask at a position above the eyes of the human body, and the connecting pipe is connected to the air inlet; and an exhaust port is provided on the breathing mask at a position corresponding to or below the mouth and nose of the human body.

[0024] Preferably, the support device includes a support frame and an end cap, wherein: the support frame is adapted to the meltblown filter bag, and the meltblown filter bag is detachably sleeved on the support frame; one end of the support frame is provided with a port communicating with the chamber, and the end cap is detachably closed on the port; the connecting pipe is provided on the end cap.

[0025] Preferably, the filtration device further includes a fastening sealing ring, the top of the meltblown filter bag is provided with an opening, one end of the support frame away from the end cap is inserted into the meltblown filter bag along the opening of the meltblown filter bag, the section of the meltblown filter bag located at the opening is fitted on the end cap, and the fastening sealing ring is fitted on the outside of the opening of the meltblown filter bag.

[0026] The filtration device provided by the present invention has at least the following beneficial effects:

[0027] The filtration device includes a support device, on the outside of which is a meltblown filter bag manufactured using the process described above. The support device is adapted to the meltblown filter bag, and a chamber is provided inside the support device. Air can pass through the meltblown filter bag and the support device and enter the chamber. The support device can firmly support the meltblown filter bag. The meltblown filter bag is used to filter air, and the chamber is used to collect and contain the filtered air. The meltblown filter bag produced by the process described above can effectively filter dust and aerosols in the air, and isolate harmful substances such as droplets and viruses, with a significant filtration effect. In addition, the formed meltblown filter bag has a pleated structure, which can effectively increase the air contact area and improve the filtration efficiency. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the spinning process in the production of filter bags using the meltblown method of this invention;

[0030] Figure 2 This is a simplified view of the room temperature mold structure of the present invention;

[0031] Figure 3 This is a simplified view of the high-temperature mold structure of the present invention;

[0032] Figure 4 This is a simplified structural view of the filtration device of the present invention;

[0033] Figure 5 This is a simplified view of the internal structure of the support device of the present invention;

[0034] Figure 6 This is an exploded simplified view of the support device structure of the present invention;

[0035] Figure 7 This is a simplified view of the supporting frame structure of the present invention;

[0036] Figure 8 This is a simplified structural view of the mobile respiratory filtration device of the present invention.

[0037] Figure Labels

[0038] 1. Molding mold; 11. Normal temperature mold; 111. Extension section; 112. Connecting section; 113. Shaping rib; 12. High temperature mold; 121. Spinneret; 2. Meltblown filter bag; 21. Pleated filter section; 22. Annular mounting section; 3. Support device; 31. Support frame; 32. End cap; 4. Fastening sealing ring; 5. Power supply device; 6. Air extraction device; 7. Connecting pipe; 8. Breathing mask; 9. Outer packaging. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] Example 1:

[0041] This invention provides a process for producing filter bags using the meltblown method, comprising the following steps:

[0042] (I) Feeding: PP (polypropylene) material and electret masterbatch are fed into the feeding device in a certain proportion;

[0043] (II) Heated extrusion: The raw material is conveyed to the extrusion device through the feeding device. The mixed raw material is extruded and heated through the extrusion device to melt the raw material into a flowable melt. The heating is carried out by electric heating.

[0044] (III) Filtration: The flowable melt produced by extrusion is filtered by a filtration device to remove impurities and coarser particles;

[0045] (IV) Spinning: The filtered flowable melt is ejected through a spinneret and falls onto the forming mold 1. The spinneret includes an electric hot air device and a spinneret plate, etc. Figure 1 As shown, a high-temperature traction airflow is generated by an electric heating air device, and the high-speed airflow heated by the molten material flows out of the spinneret and impacts the molding die 1 at a specific angle.

[0046] The molding die 1 includes a room temperature mold 11. The outer wall of the room temperature mold 11 is uniformly provided with shaped ribs 113 with toothed cross sections. After the flowable melt is cooled on the molding die 1, it forms a filter bag that matches the shape of the molding die 1. The filter bag includes a pleated filter section. The thickness of the filter bag is 0.8mm to 1mm. The room temperature mold 11 is at room temperature to ensure the smooth electret process.

[0047] (V) Electret: The filter bag is electreted using a corona discharge device. The electret treatment makes the filter material fibers carry an electric charge, increasing the electrostatic adsorption effect.

[0048] (VI) Demolding: Remove the molding mold 1, and the production of meltblown filter bag 2 is completed.

[0049] As an optional implementation, such as Figure 2 As shown, the ambient temperature mold 11 is divided into an extension section 111 and a connecting section 112 along the axial direction, wherein: the extension section 111 is located at the end of the connecting section 112; the shaping rib 113 is located on the connecting section 112; the cross-sectional shape of the ambient temperature mold 11 is set to be circular, elliptical or oblong, and the annular mounting section 22 and the section structure between adjacent pleats of the formed meltblown filter bag 2 are smoother, which facilitates installation and sealing.

[0050] In step (IV) of the spinning process, the flowable melt located at the extension section 111 forms the annular mounting section 22 of the filter bag, which is mainly used for the installation of the filter bag; the flowable melt located at the connecting section 112 and the shaping rib 113 forms the pleated filter section 21 of the filter bag, the pleated structure of the pleated filter section 21 is adapted to the shaping rib 113, the pleated filter section 21 is mainly used for air filtration, and its pleated structure can effectively increase the contact area with air and improve the filtration efficiency.

[0051] As an optional implementation, after the spinning process in step (IV) is completed, the process further includes die forming, in which a forming tool adapted to the room temperature mold 11 is pressed onto the room temperature mold 11, and after the pressing is completed, the forming tool is removed to obtain the shaped filter bag.

[0052] The shaping tool includes shaping strips adapted to the grooves. Optionally, the shaping tool includes a flexible substrate with a plurality of shaping strips evenly distributed on the flexible substrate. The number of shaping strips is the same as the number of grooves. A shaping groove adapted to the shaping rib 113 is formed between adjacent shaping strips. In use, the flexible substrate is pressed around the mold 11 at room temperature, the shaping rib 113 is accommodated in the shaping groove, and the shaping strip is accommodated in the groove. After pressing is completed, the shaping tool is removed.

[0053] Preferably, the molding step and the electret step are performed simultaneously.

[0054] As an optional implementation, in step (IV) of the spinning process, the spinning device sprays the filtered flowable melt only onto the sidewalls and bottom wall of the forming mold 1, and the top opening of the filter bag is formed after cooling.

[0055] After demolding, the process also includes sealing the filter bag. Ultrasonic welding technology is used to weld the seams of the formed filter bag (such as the junction of the side wall and the bottom wall). During the welding process, the ultrasonic welding device has several support points along the straight line of the filter bag seam, and the ultrasonic welding joint is welded along the seam. Directly spinning the filter bag into the room temperature mold 11 often results in a loosely connected seam (such as the junction of the bottom wall and the side wall). Sealing the filter bag in this step can reinforce the seam and ensure the quality of the filter bag.

[0056] As an optional implementation, the process of producing filter bags using the meltblown method further includes step (VII) inspection operation, in which the filter bags are inspected after demolding in step (VI) and qualified filter bags are selected.

[0057] The filter bags produced by the process of using meltblown technology can be used to manufacture meltblown fabric filter elements, split-type filter devices, mobile filter devices, etc.

[0058] Example 2

[0059] The difference between Example 2 and Example 1 is that, as Figure 3 As shown, the molding die 1 also includes a high-temperature die 12, which is fitted on the outside of the room temperature die 11. The high-temperature die 12 is configured as a barrel structure with one end open. The room temperature die 11 is placed inside the high-temperature die 12 and forms a barrel-shaped cavity between it and the inner wall of the high-temperature die 12. The bottom wall and side wall of the high-temperature die 12 are densely covered with spinnerets 121, which are connected to the cavity.

[0060] In step (IV) during the spinneret forming process, the flowable melt is sprayed through the spinneret 121 onto the ambient temperature mold 11 and cooled on the ambient temperature mold 11 to form a filter bag with an open top.

[0061] During this process, the high temperature of the high-temperature mold 12 can effectively prevent the flowable melt from cooling and blocking the spinneret orifice 121.

[0062] After the filament spinning process is completed, the high-temperature mold 12 is removed, and the filter bag is molded and shaped using the shaping tool.

[0063] Compared to Example 1, Example 2 eliminates the need for a sealing step, making the process simpler and more efficient while ensuring that the produced filter bags meet quality requirements.

[0064] Example 3

[0065] The difference between Example 3 and Example 1 is that the axial dimension of the room temperature mold 11 is longer. During the spin forming process in step (IV), the top and bottom walls of the room temperature mold 11 are not spinned. After the spin forming is completed, the resulting filter bag is open at both ends and is cylindrical.

[0066] After demolding (VI) is completed, the tubular filter bag is cut.

[0067] After cutting, seal one end of the cut filter bag to obtain a meltblown filter bag 2 with one end open.

[0068] This implementation eliminates the need for a sealing step. Although it adds cutting and sealing steps compared to Embodiments 1 and 2, in actual production, it does not require intermittent starting and stopping of the spinneret as in Embodiments 1 and 2.

[0069] Example 4:

[0070] Example 4 is based on any one of Examples 1 to 3: The present invention provides a filtration device, such as... Figure 4 As shown, the filtration device includes a support device 3, and a meltblown filter bag 2 made using the process of producing filter bags by meltblowing is sleeved on the outside of the support device 3. The support device 3 is adapted to the meltblown filter bag 2, and a chamber is provided inside the support device 3, so that air can pass through the meltblown filter bag 2 and the support device 3 and enter the chamber.

[0071] In use, air enters the chamber through the meltblown filter bag 2, and the chamber collects and contains the filtered air. During this process, the meltblown filter bag 2 can filter out small non-oily particles in the air. When virus-containing droplets approach the meltblown filter bag 2, they are electrostatically attracted to its surface and cannot pass through, providing more comprehensive protection and a more significant filtration effect. At the same time, the meltblown filter bag 2 with a pleated structure formed by the molding die 1 can effectively increase the contact area with air and improve the filtration efficiency.

[0072] As an optional implementation, such as Figure 5 As shown, the chamber is equipped with a power supply device 5 and an air extraction device 6. The power supply device 5 is a portable power source, and the air extraction device 6 includes a fan. The power supply device 5 and the air extraction device 6 are electrically connected. The air extraction device 6 is equipped with an air inlet and an air outlet. A connecting pipe 7 is provided on the support device 3. The air inlet is placed inside the chamber, and the air outlet is connected to the connecting pipe 7.

[0073] The power supply device 5 and the air extraction device 6 are both installed in the chamber. Compared with the existing split-type filter devices, this effectively reduces the space occupied by the device and improves its portability.

[0074] As an optional implementation, the filtering device further includes a breathing mask 8, with an air inlet on the breathing mask 8 corresponding to the forehead of the human body. The air inlet is connected to the connecting pipe 7. An exhaust port is provided on the breathing mask 8 corresponding to the mouth and nose of the human body. A one-way valve is provided at the exhaust port, so that air can only flow from the inside of the breathing mask 8 to the outside through the one-way valve.

[0075] The breathing mask 8 uses an existing mask. Preferably, at least a section of the mask body corresponding to the eye position is made of transparent material. The characteristic of the air inside the breathing mask 8 flowing from top to bottom can effectively prevent the user's exhaled steam from forming fog and affecting vision.

[0076] In use, the power supply device 5 supplies power to the air extraction device 6. Under the action of the air extraction device 6, the outside air is filtered by the meltblown filter bag 2 and enters the chamber. It flows through the air inlet and air outlet of the air extraction device 6 to the connecting pipe 7 and enters the breathing mask 8 through the air inlet. The air in the breathing mask 8 flows from top to bottom and is discharged from the air outlet. During this process, the air flowing from top to bottom in the breathing mask 8 has a cooling effect, making it more comfortable to use. On the other hand, it can effectively prevent the user's exhaled hot steam from forming fog and affecting vision.

[0077] Optionally, such as Figure 8 As shown, the filtration device also includes an outer casing 9, which has several ventilation holes. The meltblown filter bag 2, support device 3, power supply device 5 and air extraction device 6 are all installed inside the outer casing 9. The outer casing 9 can be a shell or a backpack, etc. When the outer casing 9 is set as a backpack, the filtration device forms a backpack-type filtration device.

[0078] As an optional implementation, such as Figure 6 and Figure 7 As shown, the support device 3 includes a support frame 31 and an end cap 32, wherein: the support frame 31 is adapted to the meltblown filter bag 2, and the meltblown filter bag 2 is detachably sleeved on the support frame 31; one end of the support frame 31 is provided with a port communicating with the chamber, and the end cap 32 is detachably covered on the port, and the connecting pipe 7 is provided on the end cap 32; the other end of the support frame 31 is provided with a cover plate, and the power supply device 5 and the air extraction device 6 are provided on the cover plate, and the power supply device 5 and the air extraction device 6 can be installed and removed from the port position, which is convenient for installation and removal.

[0079] The support frame 31 is configured as a column frame, which is adapted to the meltblown filter bag 2. Its outer wall is uniformly configured with strip-shaped toothed supports in the circumferential direction. The strip-shaped toothed supports are adapted to the pleated structure of the pleated filter section 21. Ventilation holes are provided on the strip-shaped toothed supports.

[0080] Optionally, the end cover 32 is provided with a wiring port, which is electrically connected to the power supply device 5 via a connector. By connecting a charging cable to the wiring port, the power supply device 5 can be charged.

[0081] As an optional implementation, the filtration device further includes a fastening sealing ring 4. The top of the meltblown filter bag 2 has an opening. When installing the meltblown filter bag 2, the end of the support frame 31 away from the end cap 32 is inserted into the meltblown filter bag 2 through the opening. After insertion, the section of the meltblown filter bag 2 located at the opening is just fitted over the outside of the end cap 32. The meltblown filter bag 2 is a consumable part and needs to be replaced regularly. The insertion installation method greatly simplifies the disassembly and assembly process of the filtration device and facilitates the replacement of the meltblown filter bag 2. The fastening sealing ring 4 is fitted over the outside of the opening of the meltblown filter bag 2. On the one hand, the fitting method makes the disassembly and assembly process convenient and quick, and on the other hand, the fastening sealing ring 4 has a good sealing effect.

[0082] The fastening sealing ring 4 is made of silicone, which has good heat and cold resistance and a long service life.

[0083] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A process for producing filter bags using meltblown technology, characterized in that, The process for manufacturing pleated meltblown fabric filter cartridges includes the following steps: (I) Feeding: Inputting raw materials into the feeding device; (II) Heated extrusion: The raw material is conveyed to the extrusion device through the feeding device, and the extrusion device extrudes and heats the raw material, so that the raw material melts into a flowable melt; (III) Filtration: The flowable melt produced by extrusion is filtered to remove impurities and particulate matter through a filtration device; (IV) Spinning: The filtered flowable melt is sprayed out by the spinneret and falls onto the forming mold (1). The forming mold (1) includes a room temperature mold (11). The outer wall of the room temperature mold (11) is uniformly provided with shaped ribs (113) with toothed cross sections. The flowable melt is cooled on the forming mold (1) to form a filter bag that matches the shape of the forming mold (1). The ambient temperature mold (11) is divided into an extension section (111) and a connecting section (112) along the axial direction, wherein: the extension section (111) is located at the end of the connecting section (112), and the shaping rib (113) is located on the connecting section (112); during the spin forming process in step (IV), the flowable melt located at the position of the extension section (111) forms the annular mounting section (22) of the filter bag, and the flowable melt located at the positions of the connecting section (112) and the shaping rib (113) forms the pleated filter section (21) of the filter bag; The molding die (1) further includes a high-temperature die (12), which is fitted on the outside of the room temperature die (11). The high-temperature die (12) is configured as a barrel structure with one end open. The room temperature die (11) is set inside the high-temperature die (12) and forms a barrel-shaped cavity with the inner wall of the high-temperature die (12). The bottom wall and side wall of the high-temperature die (12) are densely covered with spinnerets (121), which are connected to the cavity. In the spinneret forming process in step (IV), the flowable melt passes through the spinnerets (121) and is sprayed onto the room temperature die (11), and is cooled on the room temperature die (11) to form a filter bag with an open top. (V) Electret: The filter bag is electretted using a corona discharge device; (VI) Demolding: Remove the molding mold (1).

2. The process for producing filter bags using the meltblown method according to claim 1, characterized in that, After the spinning process in step (IV) is completed, the process also includes die forming. A forming tool adapted to the room temperature mold (11) is used to press onto the room temperature mold (11). After pressing is completed, the forming tool is removed to obtain the shaped filter bag.

3. The process for producing filter bags using the meltblown method according to any one of claims 1-2, characterized in that, During the spinning process in step (IV), the spinning device sprays the filtered flowable melt only onto the side wall and bottom wall of the forming mold (1), and the filter bag formed after cooling has an opening at the top. After demolding in step (VI), the process also includes sealing the end by welding the seams of the formed filter bag using ultrasonic welding technology.

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