Recyclable filter element waterproof dust collection bag and preparation method thereof

Abstract

The invention relates to the field of dust collection bags of dust collectors, in particular to a recyclable filter element waterproof dust collection bag and a preparation method. Comprising a main body plastic part for air with dust and impurities to enter, a bag body detachably connected to the main body plastic part, an HEPA filter element connected to the main body plastic part and used for intercepting the dust and impurities in the bag body, and a supporting framework arranged on the periphery of the HEPA filter element and fixedly connected with peaks at wrinkles of the HEPA filter element. A hydrophobic antibacterial coating formed by combining PTFE micro-nano particles, nano silver ions and a water-based silane coupling agent is arranged on the surface of the HEPA filter element, so that the recycling frequency of the dust collection bag is effectively increased.

Description

Technical Field

[0001] This application relates to the field of vacuum cleaner dust bags, and more particularly to a reusable waterproof dust bag with a filter cartridge and a method for its preparation. Background Technology

[0002] The problems of resource waste and environmental pollution caused by disposable consumer goods are becoming increasingly prominent. For example, traditional dust collection bags are mostly designed for single use and are discarded after use. This not only leads to the excessive consumption of materials such as HEPA filter paper and plastics, but also increases the pressure on solid waste disposal.

[0003] From the perspective of user needs, on the one hand, the demand for dual-use (dry and wet) dust bags is becoming commonplace in scenarios such as homes, car detailing, and small construction sites. This requires dust bags to effectively trap dust, safely collect water, and maintain their performance even when reused. On the other hand, users expect to reduce long-term usage costs through recyclable designs, avoiding the hassle and expense of frequently replacing disposable dust bags.

[0004] A HEPA filter-type waterproof dust collection bag with publication number CN222444006U uses a plastic bag body made of OPP / CPE / PE material to replace the traditional non-woven bag body, and is equipped with a HEPA filter paper filter element, which solves the problems of poor waterproof performance and filtration failure after the traditional non-woven dust collection bag becomes damp.

[0005] However, most of the waterproof dust collection bag filter elements mentioned above have an unsupported pleated structure, which is prone to collapse and deformation after repeated washing, resulting in a serious reduction in filtration area and a low number of cycles. Furthermore, the mud-like residue on the surface of the filter element is difficult to completely remove, and bacteria and odors are easily generated in humid environments. These combined factors cause the dust collection bag to become unusable after multiple water washes. Summary of the Invention

[0006] To effectively increase the number of times dust collection bags can be reused, this application provides a reusable waterproof dust collection bag with a filter element and a method for its preparation.

[0007] Firstly, the reusable waterproof dust collection bag provided in this application adopts the following technical solution.

[0008] A reusable waterproof dust collection bag includes a main plastic part for allowing air carrying dust and debris to enter, a bag body detachably connected to the main plastic part, a HEPA filter element connected to the main plastic part and trapping dust and debris inside the bag, and a support frame disposed around the HEPA filter element and fixedly connected to the peaks at the pleats of the HEPA filter element. The surface of the HEPA filter element is provided with a hydrophobic and antibacterial coating composed of PTFE micro-nano particles, nano silver ions and an aqueous silane coupling agent.

[0009] By adopting the above technical solution, the support frame is fixedly connected to the peaks at the pleats of the HEPA filter element to form a three-dimensional support structure, which effectively resists the impact of external forces during repeated cleaning and disassembly, avoids pleat collapse and deformation, increases the number of times the filter element can be used, and reduces the filtration area.

[0010] The hydrophobic and antibacterial coating increases the contact angle of the filter element surface, reducing the adhesion of mud-like residues, which can be quickly removed by rinsing with water. On the other hand, the nano silver ions have a high antibacterial rate, solving the problems of bacterial growth and odor in humid environments.

[0011] Meanwhile, the support frame is fixed only at the pleated peaks, without obstructing the filter element's filtration surface. The hydrophobic and antibacterial coating is relatively thin and uses micro-nano-sized particle materials, which will not clog the micropores of the HEPA filter paper, ensuring that the filtration accuracy remains at H13 level and the ventilation volume does not decrease excessively.

[0012] Optionally, the support frame is made of shape memory alloy wire with a diameter of 0.08-0.1mm. The support frame includes several horizontal bars arranged along the length direction of the peaks at the pleats of the HEPA filter element, a vertical bar fixedly connected between two adjacent horizontal bars, and an end bar formed at the ends of the horizontal bars and the vertical bars and fixed to the sealing frame of the HEPA filter element. The horizontal bars are fixedly connected to the peaks at the pleats of the HEPA filter element.

[0013] Optionally, the mass ratio of PTFE micro / nanoparticles, nano-silver ions, aqueous silane coupling agent, and deionized water in the hydrophobic antibacterial coating is 8:1:3:88.

[0014] Optionally, the PTFE micro / nanoparticles have a particle size of 50-100 nm, and the silver nanoparticles have a particle size of 2-5 nm.

[0015] By adopting the above technical solution, using shape memory alloy wire with a diameter of 0.08-0.1mm, the weight of a single frame does not exceed 0.5g, which does not increase the overall burden of the filter element, nor does it affect the assembly compatibility of the dust collection bag.

[0016] The three-dimensional structure of the horizontal and vertical bars forms a double support along the length and height of the pleats. The shape memory alloy wire has a high elastic recovery rate and can return to its original shape within 1 second after being pressed and deformed, ensuring that the filter element maintains a uniform pleat shape and stable ventilation even after long-term use.

[0017] The mass ratio of 8:1:3:88 ensures that the PTFE micro-nano particles and nano silver ions are evenly dispersed in the coating, which not only ensures that the PTFE forms a continuous hydrophobic film layer, but also allows the nano silver ions to fully contact the bacteria, avoiding the failure of hydrophobic or antibacterial functions due to imbalance of component ratio.

[0018] The addition of water-based silane coupling agent makes the coating adhere strongly to the HEPA filter paper, and it does not peel off even after repeated rinsing, thus solving the problem of easy peeling of traditional coatings.

[0019] The particle size control of PTFE micro and nano particles can form micro-nano-level textures, further improving the hydrophobic effect without clogging the micropores of HEPA filter paper.

[0020] The controlled particle size of nano silver ions results in a large specific surface area and stronger antibacterial activity. Only a small amount is needed to achieve highly efficient antibacterial effects, while avoiding the environmental impact caused by excessive precipitation of silver ions, thus meeting environmental protection requirements.

[0021] Secondly, the method for preparing a reusable waterproof dust collection bag for filter cartridges provided in this application adopts the following technical solution.

[0022] A method for preparing a reusable waterproof dust collection bag for filter cartridges, comprising the following steps:

[0023] S1. The support frame is prefabricated, and the hydrophobic and antibacterial coating liquid is prepared for later use.

[0024] S2. Spray the hydrophobic and antibacterial coating liquid onto both sides of the HEPA filter paper to be formed into pleats and dry it.

[0025] S3. The HEPA filter paper is folded and the support frame is placed into the corresponding sealing frame and the end rod is fixed with glue.

[0026] S4. Place the shaped pleated HEPA filter paper into the sealing frame. First, fix the HEPA filter paper and the support frame with glue, and then fix the HEPA filter paper and the sealing frame to obtain the HEPA filter element.

[0027] S5. The main plastic parts and bag body are manufactured and assembled with the HEPA filter element.

[0028] By adopting the above technical solution, the coating is sprayed first and then the pleats are formed, ensuring that the coating evenly covers both sides of the filter paper, the inside of the pleats, and the gaps. This solves the industry problem of missing coating on the inside of the pleats due to forming first and then spraying, and ensures full coverage of hydrophobic and antibacterial functions.

[0029] The filter element is fixed to the frame and glued in place, which avoids damage to the coating or filter paper when the frame is assembled with the filter element. The glue fixation only applies to the key contact points and does not affect the filter surface or ventilation channel.

[0030] Optionally, after the S1 support frame is initially formed, it is kept at 80°C for 10 minutes and then subjected to an elasticity test after natural cooling.

[0031] Optionally, S2 specifically includes placing HEPA filter paper in a spray chamber and evacuating it to -0.08 MPa, spraying a hydrophobic antibacterial coating liquid at 0.1 MPa, then raising the temperature inside the spray chamber to 45°C and air-drying for 20 minutes to form a hydrophobic antibacterial coating with a thickness of 0.5-1 μm.

[0032] Optionally, in step S5, a 0.3-0.5 μm thick PTFE hydrophobic coating is sprayed onto the surface of the bag and air-dried at 45°C for 10 min.

[0033] Optionally, in S5, the main plastic part is made of PP material, which is dried at 80°C for 2 hours before injection molding. The injection barrel temperature is 180-220°C, the mold temperature is 40-60°C, and the injection pressure is 80-100MPa.

[0034] Optionally, the bag body is made of any one or more of OPP, CPE and PE, and the bag body is heat-sealed by film with a heat-sealing temperature of 130℃, a pressure of 0.3MPa and a heat-sealing width of 5mm.

[0035] By adopting the above technical solution, the process of holding at 80℃ for 10 minutes combined with natural cooling makes the shape of the memory alloy wire skeleton more complete, the elastic recovery performance stable, and avoids the failure of the wrinkle support due to insufficient skeleton elasticity.

[0036] Vacuum spraying avoids air bubbles in the coating liquid, ensuring a uniform coating without pinholes. Low-pressure spraying at 0.1MPa combined with low-temperature air drying at 45℃ ensures that the coating is ultra-thin and does not clog micropores, while also improving the adhesion between the coating and the filter paper and avoiding damage to the original structure of the HEPA filter paper caused by high-temperature curing.

[0037] The bag surface is additionally coated with a 0.3-0.5μm thick PTFE hydrophobic coating, which upgrades the bag's waterproof performance. It can not only collect water but also prevent muddy sewage from adhering to the inner wall of the bag, making cleaning easier.

[0038] The 45℃ low-temperature air drying process is suitable for bag materials such as OPP / CPE / PE, avoiding bag deformation or performance degradation caused by high temperature.

[0039] PP material is dried at 80℃ for 2 hours to remove moisture, avoiding air bubbles during injection molding. Precise control of barrel temperature, mold temperature and injection pressure ensures the dimensional accuracy of the main plastic part, and guarantees sealing performance and assembly compatibility.

[0040] The combination of a heat-sealing temperature of 130℃, a pressure of 0.3MPa, and a heat-sealing width of 5mm ensures that the heat-sealed part of the bag is firm and leak-free, with high tensile strength, meeting the strength requirements for repeated disassembly and dumping during recyclable use.

[0041] In summary, this application includes at least the following beneficial effects:

[0042] By incorporating a support framework made of shape memory alloy wires at the pleats of the HEPA filter element, combined with a hydrophobic and antibacterial coating made of PTFE micro / nanoparticles, nano-silver ions in a specific mass ratio, water-based silane coupling agent, and deionized water, along with a precise manufacturing process and an adaptable assembly design between the PP main body and the OPP / CPE / PE bag body, this technology achieves both detachable and reusable HEPA filter elements and effectively prevents pleat collapse and filtration area reduction after repeated cleaning through the support framework. The hydrophobic and antibacterial coating significantly reduces the adhesion rate of mud residue and inhibits bacterial growth and odor. At the same time, it ensures that the original filtration accuracy of the filter element and the waterproof performance of the dust collection bag are not affected throughout the process. The hydrophobic coating of the bag body further enhances the waterproof effect. The overall structure has strong adaptability and a controllable manufacturing process, taking into account environmental protection, durability, and user experience. It solves the core pain points of traditional waterproof dust collection bags, such as low reusability, difficult cleaning, and easy odor generation. Attached Figure Description

[0043] Figure 1 This is a structural diagram of the main body of a reusable waterproof dust collection bag with a filter cartridge;

[0044] Figure 2 This is a structural diagram of the HEPA filter element and its supporting frame;

[0045] Figure 3 This is a flowchart illustrating the steps involved in preparing a reusable waterproof dust collection bag for filter cartridges.

[0046] Explanation of reference numerals in the attached drawings: 1. Main plastic part; 2. Bag body; 3. HEPA filter element; 4. Support frame; 41. Horizontal bar; 42. Vertical bar; 43. End bar. Detailed Implementation

[0047] The present application will be further described in detail below with reference to the accompanying drawings.

[0048] This application discloses a reusable waterproof dust collection bag with a filter cartridge, as shown in the reference. Figure 1 It includes a main plastic part 1 for allowing air containing dust and debris to enter, a bag body 2 for containing dust and debris is detachably connected to one side of the main plastic part 1, and a HEPA filter element 3 for preventing dust and debris from flowing out of the bag body 2 along with the air inlet is detachably connected to the same side of the main plastic part 1.

[0049] Reference Figure 2The HEPA filter element 3 is detachably connected to a support frame 4. The support frame 4 is made of shape memory alloy wire with a diameter of 0.08-0.1mm. The support frame 4 includes several horizontal bars 41 arranged along the length of the peaks at the pleats of the HEPA filter element 3, vertical bars 42 fixedly connected between two adjacent horizontal bars 41, and end bars 43 formed at the ends of the horizontal bars 41 and vertical bars 42 and fixed to the sealing frame of the HEPA filter element 3. The horizontal bars 41 are fixedly connected to the peaks at the pleats of the HEPA filter element 3, and the vertical bars 42 are directly opposite the valleys at the pleats of the HEPA filter element 3. The end of the end bar 43 away from the connected horizontal bars 41 or vertical bars 42 is close to the inner surface of the sealing frame of the bag body 2 and the HEPA filter element 3, so that the end bar 43 can be tightly connected to the sealing frame.

[0050] The surface of the HEPA filter element 3 is also coated with a hydrophobic and antibacterial coating, which is composed of PTFE micro / nano particles, nano silver ions, aqueous silane coupling agent, and deionized water in a mass ratio of 8:1:3:88. The PTFE micro / nano particles have a particle size of 50-100 nm, and the nano silver ions have a particle size of 2-5 nm.

[0051] This application also discloses a method for preparing a reusable waterproof dust collection bag for filter cartridges, referring to... Figure 3 Specifically, it includes the following steps.

[0052] S1. The support frame 4 is prefabricated, and the hydrophobic antibacterial coating liquid is prepared for use.

[0053] For the fabrication of the support frame 4, alloy wire made of nickel-titanium shape memory alloy with a diameter of 0.08-0.1 mm, preferably 0.09 mm, is selected to ensure support strength without increasing the overall weight of the filter element or affecting the ventilation volume. According to the design dimensions of the HEPA filter element 3, crossbars 41 and longitudinal bars 42 are processed using a micro-bending machine. The crossbars 41 match the outer contour of the pleats in the HEPA filter element 3, and one crossbar 41 can be placed at 15 mm intervals along the length of the pleat peaks. The longitudinal bars 42 are straight and evenly distributed between adjacent crossbars 41. The intersections of the crossbars 41 and longitudinal bars 42 are fixed by laser spot welding, with the weld diameter within 0.3 mm, forming the support frame 4 and ensuring a stable and secure structure.

[0054] The formed support frame 4 is placed in a constant temperature oven and kept at 80℃ for 10 minutes. Then it is taken out and allowed to cool naturally to room temperature. After cooling, an elasticity test is performed. The edge of the frame is held with tweezers and pressed until 50% of the deformation is achieved. The frame must be released and completely return to its original shape within 1 second without permanent deformation. Frames that fail the test are scrapped and remade.

[0055] To prepare the hydrophobic antibacterial coating solution, first prepare the raw materials: PTFE micro / nano particles with a particle size of 50-100nm, preferably 80nm; silver nanoparticles with a particle size of 2-5nm, preferably 3nm; an aqueous silane coupling agent (KH-550 is acceptable); and deionized water. Accurately weigh each raw material according to the mass ratio 8:1:3:88. Take 8g of PTFE micro / nano particles, 1g of silver nanoparticles, 3g of aqueous silane coupling agent, and 88g of deionized water, and add them sequentially to a beaker.

[0056] Place the beaker in an ultrasonic disperser with a power setting of 300W and a frequency setting of 40kHz, and disperse for 20 minutes to ensure that the PTFE micro-nano particles and nano silver ions are uniformly dispersed without agglomeration. After preparation, seal and store for later use to avoid contamination by impurities.

[0057] S2. Spray the hydrophobic and antibacterial coating liquid onto both sides of the HEPA filter paper to be formed into pleats and dry it.

[0058] Select H13 grade HEPA filter paper, cut it to the designed size, and blow both sides of the filter paper with clean compressed air at a pressure of 0.1 MPa for 30 seconds each to remove surface dust and moisture, ensuring coating adhesion. Lay the cut HEPA filter paper flat in the spray chamber of the vacuum spraying equipment, close the chamber door and start the vacuum pump to evacuate to -0.08 MPa, maintain this vacuum for 5 minutes to expel air from the pores of the filter paper, facilitating coating liquid penetration.

[0059] Pour the prepared hydrophobic and antibacterial coating liquid into the storage tank of the spraying equipment, turn on the spraying function, adjust the nozzle orifice diameter to 0.1mm and the spraying pressure to 0.1MPa, so that the coating liquid is evenly sprayed on both sides of the HEPA filter paper in the form of ultra-fine droplets, ensuring that no area of ​​the filter paper is missed, especially the area that will form wrinkles later.

[0060] After spraying, maintain the vacuum state in the spray chamber and raise the temperature inside the chamber to 45℃. Maintain this temperature for 20 minutes to allow the coating liquid to cure and form a hydrophobic antibacterial coating with a thickness of 0.5-1μm. After drying, remove the filter paper and test the coating adhesion according to GB / T 9286-1998 standard. It must reach at least level 4B, meaning no coating peeling. Simultaneously, use a contact angle meter to test the contact angle of the filter paper surface; it must be at least 115°. Products that fail to meet the standard should be re-sprayed.

[0061] S3. The HEPA filter paper is folded and the corresponding sealing frame of the support frame 4 is placed in and the end rod 43 is fixed with glue.

[0062] After the HEPA filter paper has been sprayed and dried, it is placed into a pleating mold. The mold is used to press the filter paper to form uniform pleats, ensuring that the pleats are consistent in shape and free from twisting or damage.

[0063] A PP frame is selected, with a sealing ring on the outside. A micro dispensing machine is used to apply food-grade silicone sealant to the points where the end rod of the support frame 4 contacts the sealing frame.

[0064] S4. Place the shaped pleated HEPA filter paper into the sealing frame. First, fix the HEPA filter paper and the support frame with 4 dots of glue, and then fix the HEPA filter paper and the sealing frame to obtain the HEPA filter element 3.

[0065] Place the shaped pleated HEPA filter paper into the sealed frame, so that each horizontal bar 41 of the support frame 4 fits the peak of the pleat of the HEPA filter paper, and each vertical bar 42 is directly opposite the two adjacent peaks of the HEPA filter paper pleat, without obstructing the filter surface of the filter element.

[0066] Food-grade silicone adhesive is applied to the key points where the support frame 4 contacts the HEPA filter element 3, with a maximum application amount of 0.01g per point and a maximum bonding area of ​​0.5mm. 2 / point, only to achieve the fixing function, does not clog the filter paper pores.

[0067] Place the HEPA filter element 3 and the support frame 4 assembly after dispensing the adhesive into a 50℃ constant temperature oven and cure for 20 minutes. After cooling, take it out and manually pull the folds lightly to check that the support frame 4 is not loose and the folds are not collapsed, to ensure that the support is effective.

[0068] A ring of food-grade hot melt adhesive is applied to the edge of the HEPA filter paper on the inner side of the frame and maintained at 120°C for 15 seconds to fix the HEPA filter paper to the sealing frame, forming a complete HEPA filter element 3.

[0069] S5. The main plastic part 1 and the bag body 2 are manufactured and assembled with the HEPA filter element 3.

[0070] Select food-grade PP material and place it in a drying oven at 80℃ for 2 hours to remove moisture and prevent air bubbles from forming after injection molding. Add the dried PP material to the injection molding machine and set the injection parameters: barrel temperature 180-220℃ (front section 180℃, middle section 200℃, rear section 220℃), mold temperature 40-60℃ (preferably 50℃), injection pressure 80-100MPa (preferably 90MPa), holding pressure 60MPa, and holding time 15s.

[0071] The main plastic part 1 is injection molded using a special mold. After injection molding, the mold is opened after cooling for 30 seconds. The main plastic part 1 is removed, the gate and burrs are removed, and the size tolerance of the mounting groove is checked to be within 0.1mm to ensure that it is compatible with the HEPA filter element 3.

[0072] Select PE material with a thickness of 0.1mm as the base material for bag body 2. Alternatively, OPP material, CPE material, or a composite film of these three materials can be used as needed. Place the film into a heat sealing machine and set the heat sealing parameters: temperature 130℃, pressure 0.3MPa, and heat sealing width 5mm. Heat seal the sides and bottom of the film, leaving a top opening for connection with the main plastic part, forming the prototype of bag body 2.

[0073] Prepare a 5% PTFE hydrophobic coating solution and spray it evenly on the inner and outer surfaces of the bag body 2 using conventional spraying methods. The coating thickness is controlled at 0.3-0.5μm. After spraying, place the bag body in a 45℃ constant temperature oven and air dry for 10 minutes to enhance the waterproof and stain-resistant performance of the bag body.

[0074] Install a slot at the top opening edge of the bag body 2 that matches the buckle structure of the main plastic part 1 to ensure that the connection is detachable and reliably sealed.

[0075] The HEPA filter element 3 prepared in S4 is embedded into the mounting groove of the main plastic part 1, ensuring that the sealing ring of the HEPA filter element 3 frame is sealed and fits the mounting groove of the main plastic part 1 without gaps.

[0076] The formed bag body 2 is connected to the buckle structure on the back of the main plastic part 1 through the slot. Press it until the buckle is fully engaged to ensure that the bag body 2 and the main plastic part 1 are sealed together. The rear dust suction port and the rear air outlet are fully connected to the inside of the bag body 2 without any obstruction.

[0077] In addition, activated carbon filter cotton is installed on the side of the main plastic part 1 located away from the bag body 2 on the HEPA filter element 3. It is pressed and attached to absorb odors and improve the user experience.

[0078] The specific embodiments and comparative examples in Table 1 below further illustrate the design. In Embodiment 1, the dust collection bag was prepared according to the method described in this application; in Embodiment 2, no supporting frame was provided; and in Embodiment 3, no hydrophobic antibacterial coating was provided. The detection methods for the indicators involved in Table 1 are as follows.

[0079] Pre-dust / post-dust filtration performance and ventilation volume:

[0080] In the pre-dust testing procedure, the dust collection bags of the three embodiments were installed on the test fixture to simulate the working environment of the vacuum cleaner. The inlet air pressure was set to 0.2 MPa, consistent with the actual working pressure of the vacuum cleaner. The filtration efficiency for 0.3 μm particles was tested using a filtration efficiency tester, and the average value was taken after three consecutive tests. The air volume was measured using an airflow tester, with the unit being m³ / s. 3 / h, test 3 times consecutively and take the average value.

[0081] The post-dust testing procedure involves injecting a fixed amount of A2 dust (5g) into each dust collection bag using a dust generator to simulate dust accumulation under moderate usage intensity. Maintaining an inlet pressure of 0.2MPa, the pre-dust testing procedure is repeated, and the post-dust filtration efficiency and ventilation volume are recorded.

[0082] Collapse deformation after multiple cleanings:

[0083] Pour 500 mL of simulated muddy wastewater into the dust collection bag and let it stand for 10 minutes. Perform a backwash using a standard cleaning device at a water pressure of 0.15 MPa for 3 minutes. After rinsing, place the bag in a 45°C constant temperature oven to air dry for 30 minutes, completing one cycle. Repeat the above cycle 50 times to simulate the number of times the core can be reused.

[0084] The morphology of the filter element pleats was observed using a stereomicroscope. Ten pleats were randomly selected, and the peak height of the pleats before and after 50 cleanings was measured, which is the vertical distance between the highest and lowest points of the pleats, in mm.

[0085] The fold height change rate is calculated as (peak height before cleaning - peak height after 50 cleanings) / initial peak height × 100%, and the average value of 10 folds is taken.

[0086] Residual amount of debris after cleaning:

[0087] Inject 500 mL of simulated muddy wastewater (containing 50 g of A2 dust) into each dust collection bag and let it stand for 10 minutes. Perform one backwash following the above cleaning procedure and collect all the rinsing wastewater. Place the rinsed dust collection bags in a 60℃ constant temperature oven to dry to constant weight, and record this as m1. Disassemble the filter element and ultrasonically clean it with deionized water at a power of 300W for 5 minutes, collecting the ultrasonic cleaning solution. Dry the ultrasonically cleaned filter element again to constant weight, and record this as m2.

[0088] The residual impurity rate is calculated as (m1-m2) / 50g×100%, where m1-m2 is the amount of residue on the surface of the filter element that has not been rinsed.

[0089] Table 1:

[0090]

[0091] Example 1 shows the least reduction in post-dust filtration efficiency and a much lower ventilation rate than Examples 2 and 3, indicating that the support frame 4 can prevent wrinkles and collapses caused by dust accumulation, and the hydrophobic coating can reduce dust adhesion, thus ensuring smooth airflow and stable filtration accuracy.

[0092] Example 2, without the support frame 4, showed a high rate of change in pleat height and severe reduction in filtration area after 50 washes. In contrast, Examples 1 and 3, which included the support frame 4, had smaller deformation rates, demonstrating that the support frame 4 helps to solve the problem of filter element collapse and deformation.

[0093] Example 3, without a hydrophobic antibacterial coating, had a residue rate 4.9 times that of Example 1, indicating that the hydrophobic coating can significantly reduce the adhesion of dust to the filter element surface and reduce cleaning residue. Example 2, lacking the supporting frame 4, experienced some dust retention due to wrinkles and collapse, resulting in a slightly higher residue rate than Example 1.

[0094] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A reusable waterproof dust collection bag for filter cartridges, characterized in that: The device includes a main plastic part (1) for allowing air containing dust and debris to enter, a bag body (2) detachably connected to the main plastic part (1), a HEPA filter element (3) connected to the main plastic part (1) and trapping dust and debris inside the bag body (2), and a support frame (4) located around the HEPA filter element (3) and fixedly connected to the peaks at the folds of the HEPA filter element (3). The surface of the HEPA filter element (3) is provided with a hydrophobic and antibacterial coating composed of PTFE micro-nano particles, nano silver ions and water-based silane coupling agent.

2. The reusable waterproof dust collection bag for filter cartridges according to claim 1, characterized in that: The support frame (4) is made of shape memory alloy wire with a diameter of 0.08-0.1mm. The support frame (4) includes several horizontal bars (41) arranged along the length of the peak at the fold of the HEPA filter element (3), a vertical bar (42) fixedly connected between two adjacent horizontal bars (41), and an end bar (43) formed at the end of the horizontal bars (41) and the vertical bar (42) and fixed to the sealing frame of the HEPA filter element (3). The horizontal bars (41) are fixedly connected to the peak at the fold of the HEPA filter element (3).

3. The reusable waterproof dust collection bag for filter cartridges according to claim 1, characterized in that: The mass ratio of PTFE micro / nanoparticles, nano-silver ions, aqueous silane coupling agent, and deionized water in the hydrophobic antibacterial coating is 8:1:3:

88.

4. The reusable waterproof dust collection bag for filter cartridges according to claim 3, characterized in that: The PTFE micro / nanoparticles have a particle size of 50-100 nm, and the silver nanoparticles have a particle size of 2-5 nm.

5. A method for preparing a reusable waterproof dust collection bag for filter cartridges, comprising manufacturing a reusable waterproof dust collection bag for filter cartridges as described in any one of claims 1-4, characterized in that: Specifically, the steps include the following: S1. The support frame (4) is pre-formed and the hydrophobic antibacterial coating liquid is prepared for use. S2. Spray the hydrophobic and antibacterial coating liquid onto both sides of the HEPA filter paper to be formed into pleats and dry it. S3, the HEPA filter paper is folded and the support frame (4) is placed into the corresponding sealing frame and the end rod (43) is fixed with glue. S4. Place the shaped pleated HEPA filter paper into the sealing frame. First, fix the HEPA filter paper and the support frame (4) with glue, and then fix the HEPA filter paper and the sealing frame to obtain the HEPA filter element (3). S5. The main plastic part (1) and the bag body (2) are manufactured and assembled with the HEPA filter element (3).

6. The method for preparing a reusable waterproof dust collection bag for filter cartridges according to claim 5, characterized in that: After the S1 support frame (4) is initially formed, it is kept at 80°C for 10 minutes and then naturally cooled for an elasticity test.

7. The method for preparing a reusable waterproof dust collection bag for filter cartridges according to claim 5, characterized in that: S2 specifically includes placing HEPA filter paper in a spray chamber and evacuating it to -0.08MPa, spraying a hydrophobic antibacterial coating liquid at 0.1MPa, then raising the temperature inside the spray chamber to 45°C and air-drying for 20 minutes to form a 0.5-1μm thick hydrophobic antibacterial coating.

8. The method for preparing a reusable waterproof dust collection bag for filter cartridges according to claim 5, characterized in that: In S5, a PTFE hydrophobic coating of 0.3-0.5 μm thickness is sprayed onto the surface of the bag body (2) and air-dried at 45°C for 10 min.

9. The method for preparing a reusable waterproof dust collection bag for filter cartridges according to claim 5, characterized in that: The main plastic part (1) in S5 is made of PP material, which is dried at 80℃ for 2 hours and then injection molded. The injection cylinder temperature is 180-220℃, the mold temperature is 40-60℃, and the injection pressure is 80-100MPa.

10. A method for preparing a reusable waterproof dust collection bag for filter cartridges according to claim 5, characterized in that: The bag body (2) is made of any one or more of OPP, CPE and PE. The bag body (2) is heat-sealed by film with a heat-sealing temperature of 130℃, a pressure of 0.3MPa and a heat-sealing width of 5mm.

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