Multilayer composite filtering membrane based on polytetrafluoroethylene
By adopting a multi-layer composite structure of polytetrafluoroethylene filter membrane, combined with ceramic membrane, ε-polylysine-PCL fiber membrane and graphene filter membrane, the problem of the polytetrafluoroethylene filter membrane being prone to deformation and low thermal conductivity under high pressure is solved, achieving higher filtration efficiency and membrane service life.
Patent Information
- Application Number
- CN202420468312.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-12
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-03-12
AI Technical Summary
The polytetrafluoroethylene filter membrane is prone to deform under the impact of high-pressure water or air flow, resulting in pore expansion, change of pore size distribution and cracking, reducing filtration efficiency. At the same time, its thermal conductivity is low, which easily leads to heat accumulation and microbial growth, resulting in membrane contamination and blockage.
A multi-layer composite filter membrane based on polytetrafluoroethylene is adopted, including polytetrafluoroethylene microporous membrane, first ceramic membrane, ε-polylysine-PCL fiber membrane, graphene filter membrane and second ceramic membrane. Through the combination of multi-layer structure and special materials, the bearing capacity, thermal conductivity and antibacterial activity of the membrane are improved, and scaled and deformation are reduced.
It improves the bearing capacity and deformation resistance of the filter membrane, enhances thermal conductivity, reduces scaling rate and microbial growth, improves filtration efficiency, and extends the service life of the membrane.
Smart Images
Figure CN222586147U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a filtering membrane, in particular to a multi-layer composite filtering membrane based on polytetrafluoroethylene. Background Art
[0002] As people pay more attention to their health and safety, the quality requirements for air and water are getting higher and higher. Polluted air and water need to be filtered to remove odors, bacteria, viruses, particulate matter and other pollutants in the water and air, so as to purify the water and air and protect people's health.
[0003] Among them, membrane filtration is a more commonly used solid-liquid separation filtration method. Membrane filtration is to filter air or water through the membrane pores, intercept impurities and pollutants in the air or water, without chemical changes, and is simple and easy to handle. Polytetrafluoroethylene filter membrane is a microporous membrane made of polytetrafluoroethylene as raw material through calendering, extrusion, biaxial stretching and other methods. The pore size range is between 0.02 microns and 5 microns, and the porosity is above 88%. It has the characteristics of high peel strength, large air permeability, and uniform pore size distribution. Polytetrafluoroethylene filter membrane can be coated on various fabrics and substrates to become a filter material with large air permeability. While maintaining air circulation, it can filter all dust particles including bacteria to achieve the purpose of purification and ventilation. It has high filtration efficiency and can be used in pharmaceuticals, biochemistry, microelectronics, laboratory consumables and other fields.
[0004] However, the texture of the polytetrafluoroethylene filter membrane is relatively soft and its load-bearing capacity is not very high. It is easy to deform under the impact of high-pressure water flow or air flow, which leads to pore expansion, change in pore size distribution, and even cracking, thereby reducing the filtration efficiency. In addition, the thermal conductivity of the polytetrafluoroethylene filter membrane is low. Under high temperature conditions, heat is easy to accumulate and heat up in the polytetrafluoroethylene filter membrane, which will promote the growth of microorganisms and cause them to gather on the membrane. Certain scaling substances will also be decomposed by heat and precipitated in water, and precipitated on the membrane to scale, causing membrane pollution and membrane blockage, hindering the flow of filtered substances and reducing filtration efficiency. Utility Model Content
[0005] The purpose of the utility model is to provide a multi-layer composite filter membrane based on polytetrafluoroethylene. The utility model has the characteristics of being not easily deformed and improving the filtering efficiency.
[0006] The technical solution of the utility model is: a multilayer composite filter membrane based on polytetrafluoroethylene, including a polytetrafluoroethylene microporous membrane, a first ceramic membrane is provided on the lower surface of the polytetrafluoroethylene microporous membrane, an ε-polylysine-PCL fiber membrane is provided on the upper surface of the polytetrafluoroethylene microporous membrane, a graphene filter membrane is provided on the upper surface of the ε-polylysine-PCL fiber membrane, and a second ceramic membrane is provided on the upper surface of the graphene filter membrane.
[0007] In the aforementioned multi-layer composite filtration membrane based on polytetrafluoroethylene, the pore size of the first ceramic membrane is smaller than the pore size of the second ceramic membrane.
[0008] In the aforementioned multi-layer composite filtration membrane based on polytetrafluoroethylene, the polytetrafluoroethylene microporous membrane is provided with conical micropores, and the small pore diameter end of the conical micropores faces the feed end.
[0009] In the aforementioned polytetrafluoroethylene-based multilayer composite filter membrane, the edges of the polytetrafluoroethylene microporous membrane, the first ceramic membrane, the ε-polylysine-PCL fiber membrane, the graphene filter membrane and the second ceramic membrane are all coated with a U-shaped bonding coating, and the bonding coating respectively wraps the membrane edges of the polytetrafluoroethylene microporous membrane, the first ceramic membrane, the ε-polylysine-PCL fiber membrane, the graphene filter membrane and the second ceramic membrane.
[0010] The aforementioned multi-layer composite filter membrane based on polytetrafluoroethylene further comprises a positioning frame with a U-shaped cross section, wherein the positioning frame is wrapped around the outside of all the adhesive coatings, and a positioning screw is passed through the positioning frame.
[0011] In the aforementioned polytetrafluoroethylene-based multi-layer composite filter membrane, a reinforcing sheet attached to the outer side surfaces of all adhesive coatings is provided inside the positioning frame.
[0012] Compared with the prior art, the beneficial effects of the utility model are:
[0013] The present application of the utility model adopts a multifunctional composite filter membrane with a multi-level structure, wherein the graphene filter membrane has strong thermal conductivity and heat dissipation performance, reduces the accumulation of heat on the membrane surface, reduces the growth of microorganisms, and has an adsorption effect on organic matter and heavy metal substances in sewage, reducing scaling; the incorporation of ε-polylysine in the ε-polylysine-PCL fiber membrane makes the filter membrane have good antibacterial activity, and the biodegradable characteristics of PCL reduce the burden on the environment; the first ceramic membrane and the second ceramic membrane have high strength, which can improve the bearing capacity of the membrane, making the filter membrane less likely to deform; and the ceramic membrane surface contains many negatively charged hydrophilic groups, which give it a higher permeability flux while also reducing the interaction between the membrane surface and dirt, thereby reducing the scaling rate of the membrane and improving the filtration efficiency; in addition, the ceramic membrane is located in the outer layer of the multi-layer composite filter membrane, has good oxidation resistance, and is highly resistant to acid and alkali corrosion, which is convenient for multiple cleanings of the composite filter membrane and increases the number of reuses of the filter membrane. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of the utility model.
[0015] Figure 2 It is a schematic diagram of the structure of a polytetrafluoroethylene microporous membrane.
[0016] The markings in the attached drawings are: 1. first ceramic membrane; 2. polytetrafluoroethylene microporous membrane; 21. conical micropores; 3. ε-polylysine-PCL fiber membrane; 4. graphene filter membrane; 5. second ceramic membrane; 6. bonding coating; 7. positioning frame; 71. positioning screw; 72. reinforcement plate. DETAILED DESCRIPTION
[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.
[0018] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0019] Example:
[0020] like Figure 1-Figure 2 As shown, a multi-layer composite filter membrane based on polytetrafluoroethylene includes a polytetrafluoroethylene microporous membrane 2, a first ceramic membrane 1 is provided on the lower surface of the polytetrafluoroethylene microporous membrane 2, an ε-polylysine-PCL fiber membrane 3 is provided on the upper surface of the polytetrafluoroethylene microporous membrane 2, a graphene filter membrane 4 is provided on the upper surface of the ε-polylysine-PCL fiber membrane 3, and a second ceramic membrane 5 is provided on the upper surface of the graphene filter membrane 4.
[0021] The present application adopts a multifunctional composite filter membrane with a multi-level structure, in which the graphene filter membrane 4 has strong thermal conductivity and heat dissipation properties, reduces the accumulation of heat on the membrane surface, reduces the growth of microorganisms, and has an adsorption effect on organic matter and heavy metal substances in sewage, reducing scaling; the incorporation of ε-polylysine in the ε-polylysine-PCL fiber membrane 3 makes the filter membrane have good antibacterial activity, and the biodegradable properties of PCL reduce the burden on the environment; the first ceramic membrane 1 and the second ceramic membrane 5 have high strength, which can improve the bearing capacity of the membrane, making the filter membrane less likely to deform; and the surface of the ceramic membrane contains many negatively charged hydrophilic groups, which give it a higher permeability flux while also reducing the interaction between the membrane surface and dirt, thereby reducing the scaling rate of the membrane and improving the filtration efficiency; in addition, the ceramic membrane is located in the outer layer of the multi-layer composite filter membrane, has good oxidation resistance, and is highly resistant to acid and alkali corrosion, which facilitates multiple cleaning of the composite filter membrane and increases the number of reuses of the filter membrane.
[0022] The pore size of the first ceramic membrane 1 is smaller than the pore size of the second ceramic membrane 5 .
[0023] The polytetrafluoroethylene microporous membrane 2 is provided with conical micropores 21, and the small pore end of the conical micropores 21 faces the feed end. The filtered material flows from the small pore end of the conical micropores 21 to the large pore end, reducing the flow resistance and accelerating the flow speed and filtering efficiency of the filtered material.
[0024] The edges of the polytetrafluoroethylene microporous membrane 2, the first ceramic membrane 1, the ε-polylysine-PCL fiber membrane 3, the graphene filter membrane 4 and the second ceramic membrane 5 are coated with a U-shaped bonding coating 6, which respectively wraps the membrane edges of the polytetrafluoroethylene microporous membrane 2, the first ceramic membrane 1, the ε-polylysine-PCL fiber membrane 3, the graphene filter membrane 4 and the second ceramic membrane 5. The bonding coating 6 is arranged on the edge of each layer of the membrane, on the one hand, to strengthen the connection strength between the layers of the membrane, and on the other hand, to protect the corners of each layer of the membrane to prevent the corners of the filter membrane from being damaged or warped, thereby affecting the use.
[0025] The utility model further comprises a positioning frame 7 with a U-shaped cross section, the positioning frame 7 is wrapped around the outside of all the adhesive coatings 6, and a positioning screw 71 is provided on the positioning frame 7. The positioning frame 7 is used to fix each layer of the membrane, further enhancing the structural stability of the composite filter membrane, and the positioning screw 71 is used to facilitate the positioning, adjustment and installation between the composite filter membrane and the filter device.
[0026] The interior of the positioning frame 7 is provided with a reinforcing sheet 72 attached to the outer side of all the bonding coatings 6. The reinforcing sheet 72 is made of a graphene sheet, a metallic glass sheet or an aerogel sheet. The reinforcing sheet 72 is provided to protect and fix the sides of each layer of the filter membrane as a whole, thereby reducing the tensile deformation of the filter membrane.
[0027] The parts not described in detail in the present invention are prior art and thus will not be described in detail here.
Claims
1. A multi-layer composite filter membrane based on polytetrafluoroethylene, characterized in that: The invention comprises a polytetrafluoroethylene microporous membrane (2), wherein a first ceramic membrane (1) is provided on the lower surface of the polytetrafluoroethylene microporous membrane (2), an ε-polylysine-PCL fiber membrane (3) is provided on the upper surface of the polytetrafluoroethylene microporous membrane (2), a graphene filter membrane (4) is provided on the upper surface of the ε-polylysine-PCL fiber membrane (3), and a second ceramic membrane (5) is provided on the upper surface of the graphene filter membrane (4).
2. The multi-layer composite filtration membrane based on polytetrafluoroethylene according to claim 1, characterized in that: The pore size of the first ceramic membrane (1) is smaller than the pore size of the second ceramic membrane (5).
3. The multi-layer composite filtration membrane based on polytetrafluoroethylene according to claim 1, characterized in that: The polytetrafluoroethylene microporous membrane (2) is provided with conical micropores (21), and the small-diameter end of the conical micropores (21) faces the feed end.
4. The polytetrafluoroethylene-based multi-layer composite filtration membrane according to claim 1, characterized in that: The edges of the polytetrafluoroethylene microporous membrane (2), the first ceramic membrane (1), the ε-polylysine-PCL fiber membrane (3), the graphene filter membrane (4) and the second ceramic membrane (5) are all coated with a U-shaped bonding coating (6), and the bonding coating (6) respectively wraps the membrane edges of the polytetrafluoroethylene microporous membrane (2), the first ceramic membrane (1), the ε-polylysine-PCL fiber membrane (3), the graphene filter membrane (4) and the second ceramic membrane (5).
5. The polytetrafluoroethylene-based multi-layer composite filtration membrane according to claim 4, characterized in that: It also comprises a positioning frame (7) with a U-shaped cross section, wherein the positioning frame (7) is wrapped around the outside of all the adhesive coatings (6), and a positioning screw (71) is passed through the positioning frame (7).
6. The polytetrafluoroethylene-based multi-layer composite filtration membrane according to claim 5, characterized in that: The interior of the positioning frame (7) is provided with a reinforcing sheet (72) attached to the outer side surfaces of all the adhesive coatings (6).