A folding filter cartridge and filter
By introducing a membrane tape of the same material as the flow guide layer into the pleated filter element, the problem of weak welding caused by the difference in melting point is solved, and higher welding quality and reliability are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU ZHAOBO FILTRATION TECH CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-06-23
AI Technical Summary
In the existing pleated filter cartridges, the difference in melting points between the filter layer and the flow guiding layer during the hot melt welding process leads to weak welded connections, which are prone to connection defects, affecting sealing performance and service life.
A membrane tape is introduced into the pleated filter element. The membrane tape is made of the same material as the flow guide layer and has a similar melting point. The membrane tape, flow guide layer and filter layer are melted simultaneously by hot melt welding, which increases the welding connection area and ensures the integrity of the weld.
It improves the integrity and quality of welding, reduces the risk of missing joint surfaces due to premature melting of low-melting-point materials, and enhances the reliability of welding.
Smart Images
Figure CN224388196U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of filtration technology, specifically to a pleated filter element and filter. Background Technology
[0002] Pleated filter cartridges have advantages such as large filtration area, large dirt holding capacity, long service life, and high filtration efficiency. They can meet the filtration requirements of industries such as food and beverage processing, chemical industry, and pharmaceutical industry, and are an indispensable component in fluid handling processes.
[0003] A pleated filter element typically includes a coaxially arranged, porous central rod, a housing, and upper and lower end caps fixed to the housing and the two ends of the central rod. A pleated filter medium is arranged around the central rod in the cavity between the central rod and the housing. The pleated filter medium is usually sealed to the upper and lower end caps by heat fusion welding.
[0004] Folded filter media typically include a filter layer and a flow guide layer (support layer) located upstream and downstream of the filter layer. Depending on the actual needs, the filter layer and the flow guide layer may be made of different materials, resulting in different melting points. During the welding heating process, the melting time and degree of melting of the filter layer and the flow guide layer are different, which can easily lead to defects in the welding connection between the filter layer or the flow guide layer and the end cap.
[0005] For example, in a polytetrafluoroethylene (PTFE) pleated filter cartridge, the flow guide layer is typically made of PP material, while the filter layer is made of PTFE material. The melting point of the PTFE filter layer is usually above 300℃, while the melting point of the PP flow guide layer is usually between 130℃ and 180℃. Therefore, the melting point of the flow guide layer is significantly lower than that of the filter layer. During hot-melt welding, the temperature needs to reach above 300℃ for the PTFE filter layer to begin melting. By this time, the PP flow guide layer has already melted. Since liquid melt has a certain fluidity, if the PP flow guide layer melts too early, some of the melt may be lost due to flow, thus compromising the integrity of the welded structure. This results in the flow guide layer failing to form a reliable connection with the end cap, leading to insufficient connection strength.
[0006] Similarly, if the melting point of the filter layer is lower than that of the flow guide layer, hot-melt welding may cause the filter layer to fail to form a reliable connection with the end cap, resulting in seal failure. Utility Model Content
[0007] In order to overcome the shortcomings of the prior art, this utility model provides a pleated filter element and filter.
[0008] The technical solution adopted by this utility model is as follows: a pleated filter element, comprising a central rod coaxially arranged and having a porous structure, a shell, and end caps fixed at the upper and lower ends of the shell and the central rod, wherein a pleated filter medium is provided between the central rod and the shell and distributed around the central rod.
[0009] The folded filter medium includes at least one filter layer and a flow guide layer located upstream and downstream of the filter layer. Two thin film strips are provided between each adjacent filter layer and flow guide layer. The material of the thin film strips is the same as that of the filter layer and the flow guide layer with the lower melting point. The two thin film strips are located at the upper and lower ends respectively. The thin film strips can be thermally welded together with the filter layer, the flow guide layer and the end cap.
[0010] The membrane strip and the flow guiding layer are both made of PP material, while the filter layer is made of PTFE or PES material. Therefore, the melting point of the flow guiding layer is lower than that of the filter layer, while the membrane strip is made of the same material and has the same melting point as the flow guiding layer. During the welding heating process, the membrane strip can melt and fuse with the flow guiding layer simultaneously. This effectively increases the overall melting amount of the PP material flow guiding layer, resulting in a larger welding connection area when the flow guiding layer is welded to the end cap. This reduces the risk of incomplete joint surfaces and weak welds caused by premature melting and flow of low-melting-point materials, thus further ensuring the integrity of the weld and improving the weld quality.
[0011] This utility model also provides a filter that includes the above-described pleated filter element.
[0012] The beneficial effects of this utility model are: by adopting the above solution, during hot melt welding, the film strip can increase the overall melting amount of low melting point materials, thereby reducing the risk of poor welding caused by the flow of low melting point materials after premature melting, thus further ensuring the integrity of the welding and improving the welding quality. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of the folded filter element according to Embodiment 1 of this utility model.
[0014] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the AA direction of the medium-pleated filter element.
[0015] Figure 3 for Figure 2 Enlarged diagram of point B in the middle.
[0016] Figure 4 This is a cross-sectional structural diagram of the folded filter medium according to Embodiment 1 of this utility model.
[0017] Figure 5This is a schematic diagram of the unfolded folded filter medium according to Embodiment 1 of this utility model.
[0018] Figure 6 This is a schematic diagram of the structure of the filter in Embodiment 2 of this utility model. Detailed Implementation
[0019] The embodiments of this utility model will be further described below with reference to the accompanying drawings. Example 1
[0020] like Figures 1-5 As shown, a pleated filter element includes a central rod 1, a housing 2, an upper end cap 3, a lower end cap 4, and a pleated filter medium 5.
[0021] Both the central rod 1 and the outer shell 2 are hollow and have porous surfaces. The central rod 1 and the outer shell 2 are coaxially arranged, and the upper end cover 3 and the lower end cover 4 are respectively fixedly arranged at the upper and lower ends of the central rod 1 and the outer shell 2.
[0022] The folded filter medium 5 is folded to form pleats, and its two ends are sealed and welded together to form a ring structure. It is positioned between the central rod 1 and the outer shell 2. The upper and lower ends of the folded filter medium 5 are respectively sealed to the upper end cap 3 and the lower end cap 4. The folded filter medium 5 includes a filter layer 51 and flow guiding layers 52 located upstream and downstream of the filter layer 51. Two thin film strips 53 are provided between each adjacent filter layer 51 and flow guiding layer 52, with the two thin film strips 53 located at the upper and lower ends respectively. The filter layer 51, flow guiding layer 52, and thin film strips 53 are all heat-fused to the end caps. Of course, the filter layer 51 is not limited to one layer, but can be configured as a multi-layer structure, with the filter layer and flow guiding layer arranged alternately.
[0023] The filter layer 51 is made of PTFE, which has a melting point of approximately 300°C. The flow guiding layer 52 and the film strip 53 are both made of PP, which has a melting point of approximately 130°C-180°C. Therefore, the melting points of the flow guiding layer and the film strip are lower than the melting point of the filter layer.
[0024] During the welding heating process, the film strip 53 can melt and fuse with the flow guide layer 52 at the same time. This is equivalent to increasing the overall melting amount of the PP material of the flow guide layer by the film strip 53. This allows the flow guide layer 52 to have a larger welding connection area when welding with the end cap. This reduces the risk of the connection surface being missing or the welding not being firm due to the flow of the PP material flow guide layer 52 after it melts too early. This further ensures the integrity of the welding and improves the welding quality.
[0025] Of course, the material of the filter layer 51 is not limited to PTFE, but can also be other materials such as PES. The material of the flow guiding layer 52 is not limited to PP, but can also be other materials such as PFA and PVDF. The material of the membrane tape 53 is not necessarily the same as that of the flow guiding layer, but is the same as the one with the lower melting point in the filter layer and the flow guiding layer. In this way, during the hot melt welding process, the membrane tape can increase the overall melting amount of the low melting point material, thereby reducing the risk of missing joint surfaces and weak welding caused by the flow of the low melting point material after it melts too early. This further ensures the integrity of the welding and improves the welding quality. Example 2
[0026] like Figure 6 As shown, a filter includes a filter housing and a pleated filter element disposed within the filter housing, wherein the pleated filter element is the pleated filter element described in Embodiment 1.
[0027] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0029] Please note to all technical personnel: Although this utility model has been described according to the specific embodiments above, the inventive concept of this utility model is not limited to this utility model. Any modification that utilizes the concept of this utility model will be included within the scope of protection of this patent right.
Claims
1. A pleated filter element, comprising a central rod (1) coaxially arranged and having a porous structure, a housing (2) and end caps fixed at the upper and lower ends of the housing and the central rod, wherein a pleated filter medium (5) is provided between the central rod (1) and the housing (2) and distributed around the central rod (1); Its features are: The folded filter medium (5) includes at least one filter layer (51) and a flow guide layer (52) located upstream and downstream of the filter layer (51). Two thin film strips (53) are provided between each adjacent filter layer (51) and flow guide layer (52), and the two thin film strips (53) are located at the upper and lower ends respectively. The filter layer (51), flow guide layer (52), and thin film strips (53) can be heat-fused to the end cap. The material of the thin film strip (53) and the filter layer (51) are the same as the one with the lower melting point in the flow guiding layer (52).
2. The pleated filter element according to claim 1, characterized in that: The melting point of the flow guiding layer (52) is lower than that of the filter layer (51), and the film strip (53) is made of the same material as the flow guiding layer (52).
3. The pleated filter element according to claim 1, characterized in that: Both the thin film strip (53) and the flow guiding layer (52) are made of PP material.
4. The pleated filter element according to claim 1, characterized in that: The filter layer (51) is made of PTFE or PES material.
5. A filter, characterized in that: It includes the pleated filter element as described in any one of claims 1-4.