Ceramic filter element and method of forming a filter membrane module

Abstract

This invention discloses a ceramic filter element and a method for forming a filter membrane module. The ceramic filter element includes: at least two opposing end surfaces having filter channels; and a surface covered with a potting material, wherein the potting material is an epoxy resin or polyurethane comprising thermoplastic or thermosetting plastics, and the potting material has a penetration depth into the filter element in the range of 0.24 mm to 3.0 mm, a shrinkage rate of less than 1.24% after curing, a tensile strength in the range of 2-65 MPa during curing, and a tensile strength of 55-260 × 10⁻⁶ MPa. ‑6 The coefficient of thermal expansion in the range of / K.

Description

[0001] This application is a divisional application of the application filed on December 20, 2019, with application number 201980085123.0 (international application number PCT / EP2019 / 086824) and entitled "Piece with Reinforced Encapsulating Material". Technical Field

[0002] This disclosure relates to filter membrane modules and ceramic filter elements having enhanced tensile strength, hardness, glass transition temperature, and polymer chain length. Background Technology

[0003] Filter membrane modules typically have a generally cylindrical housing in which a so-called integral component is arranged. This integral component itself has multiple flat and relatively thin filter elements, which are arranged substantially parallel to each other at relatively small distances within the housing and secured by a potting material. Multiple filter channels pass through the filter elements along their longitudinal direction, extending from one end face of the filter element to the other. The filter elements are made of an open-pore ceramic material and have a porous ceramic structure. The inner walls of the filter channels or the outer sides of the filter elements typically have a thin ceramic layer forming the filter membrane.

[0004] EP 3 153 228 A1 describes a potting material whose quality varies in a maximum permissible manner under given conditions. EP 1 803 756 A1 further describes a polyurethane resin that can be used as a potting material. Summary of the Invention

[0005] The filter elements of the filter membrane are mechanically fixed to each other by a potting material. To achieve this arrangement, the filter elements are first positioned relative to each other using an auxiliary device, and then a liquid potting material is poured in. For example, the material is poured into a mold (e.g., silicone material) with a cup-shaped cylindrical shape at the end region of the filter element. The filter element is surrounded by the potting material on its outside, but the end surface of the filter element, for example, covered by a silicone pad, is not wetted. After the potting material has cured, a disc-shaped potting body is placed therein, in which the end portions of the filter element are non-movably mechanically received or held. The potting body and the filter element are integral components as described above.

[0006] For normal operation, the end faces of the filter element should be tightly sealed against both liquids and gases to prevent the filtered liquid from unintentionally entering through the end faces. In quality testing, the fluid-impermeable seal and gas-impermeable seal are tested, ensuring that fluid forced into the filter channels does not flow out through the end faces but instead flows through the perforated material of the filter element to the outside. For this purpose, potting materials are also used, applied, for example, by impregnation or by rolling it onto the end faces in liquid form, and which, upon curing, form a dense coating on the end faces.

[0007] During operation, the liquid to be filtered is forced through the filter channels of the filter element. Contaminants (residues) then deposit within the filter channels on the filter membrane, while the purified liquid (permeate or filtrate) passes through the pores of the ceramic material of the filter membrane and filter element and flows out from its outer side. A potting compound (or casting) provides a seal between the liquid to be purified and the purified liquid (permeate). Furthermore, the potting compound supports the filter element within the housing.

[0008] The potting material is subjected to mechanical, hydraulic, and chemical loads on the operating device. The cured potting material should withstand these stresses throughout the entire service life of the filter membrane module. Furthermore, it is desirable that the liquid potting material be a fluid that flows into the narrow space between the filter elements. Additionally, when the potting material is in a liquid state, the corresponding surfaces of the filter elements should be sufficiently wetted, thereby forming an absolutely impermeable fluid and gas bond between the cured potting material and the filter elements after curing.

[0009] In some embodiments, the filter membrane module includes: at least one ceramic filter element made of a sintered, porous ceramic structure; a potting material for encapsulating the ceramic filter element, the potting material having an uncured state and a cured state; and a housing, wherein the potting material is a thermoplastic or thermosetting plastic having a tensile strength in the cured state in the range of about 2-65 MPa and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion is within the range of / K, and the penetration depth of the potting material in the structure of the filter element is in the range of 0.24mm to 3.0mm, and the shrinkage rate after curing is less than 1.24%.

[0010] The implementation may include one or more of the following: The potting material is an epoxide or polyurethane. The uncured potting material has a viscosity in the range of about 400-4500 mPa·s. The cured potting material has a Shore hardness in the range of about D10-D86. The cured potting material has a Young's modulus in the range of about 20-4000 MPa. The cured potting material has a glass transition temperature in the range of less than about 0°C or greater than about 25°C. The potting material has an activation period in the range of about 7-180 min. The cured potting material has an elongation in the range of about 1-10 or about 70-100. The cured potting material exhibits cohesive fracture behavior relative to itself and other adhesive materials. After immersing the cured potting material in a fluid at 55°C for 18.5 days, the mass change is 5 ± 2% or less, and / or the Shore hardness change is ± 22% or less, and / or the dimensional change is ± 7.0% or less, and / or the Young's modulus change is ± 18% or less, and / or the tensile strength change is ± 15% or less. The potting material comprises polyisocyanate and at least one diol and / or at least one polyol.

[0011] In some embodiments, the ceramic filter element includes at least two opposing end surfaces having filter channels and a surface covered with a potting material, wherein the potting material is an epoxy resin or polyurethane comprising thermoplastic or thermosetting plastics, having a penetration depth into the filter element in the range of 0.24 mm to 3.0 mm, a shrinkage rate of less than 1.24% after curing, a tensile strength in the range of about 2-65 MPa upon curing, and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion in the range of / K.

[0012] The implementation may include one or more of the following: At least one end face is tightly sealed to fluids and / or gases by the potting material. Multiple ceramic filter elements are mechanically connected by the potting material. The ceramic filter elements have segmented shapes, integral shapes, tubular shapes, hollow fiber shapes, or plate shapes.

[0013] In some embodiments of methods for forming a filter membrane module, the filter membrane module includes: at least one ceramic filter element made of a sintered, porous ceramic structure; a potting material for encapsulating the ceramic filter element, the potting material having an uncured state and a cured state; and a housing, wherein the potting material is a thermoplastic or thermosetting plastic having a tensile strength in the cured state in the range of about 2-65 MPa and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6The method comprises: a coefficient of thermal expansion in the range of / K, and the penetration depth of the potting material into the filter element structure is in the range of 0.24 mm to 3.0 mm, and the shrinkage rate after curing is less than 1.24%. The method includes: filling a container with a mixture of epoxy resin or polyurethane comprising thermoplastic or thermosetting plastic; mechanically stirring the mixture at 22°C for at least 5 minutes; degassing the mixture at 60 mbar for about 8-10 minutes; curing the mixture at 60°C for 8 hours; and curing the mixture at room temperature for 24 hours.

[0014] The implementation may include one or more of the following: Transferring the degassed mixture to a clean mixing container. Mechanically stirring the mixture in the clean mixing container for 3-5 minutes. The mixture comprises diphenylmethane-4,4'-diisocyanate and a polyether polyol. The mixture comprises diphenylmethylene diisocyanate, an aromatic isocyanate prepolymer, and polypropylene glycol. The mixture comprises diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate, and a polyether polyol. The mixture comprises diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate, triethyl phosphate, and diphenyltolyl. The mixture comprises 1,1'-diphenylmethylene diisocyanate, 1,1'-methylenebis(4-phenylisocyanate) homopolymer, and vegetable oil. The mixture comprises a combination of bisphenol A-epimercaprolactone resin and butane.

[0015] The filter membrane module comprises a sintered, porous ceramic filter element, a housing, and a potting material. The potting material is used to encapsulate the ceramic filter element and to mechanically fix and / or seal the end surfaces. The potting material includes thermoplastic or thermosetting materials, such as epoxy resin or polyurethane. Optionally, it may include polyisocyanate and diol or polyol. Examples of polyisocyanates are diphenylmethane diisocyanates, such as diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 2,2'-diphenylmethylene diisocyanate, 1,1'-diphenylmethylene diisocyanate, polymethylene polyphenylisocyanate, o-(p-isocyanobenzyl)phenylisocyanate, 4-methyl-m-phenylene diisocyanate, 1,1'-methylene bis(4-phenylisocyanate) homopolymer, etc. Triethyl phosphate and diphenyltoluene phosphate may also be added. Typical polypropylene glycols are 1,1',1”,1”'-ethylenedinitrotetrapropane-2-ol, 2-ethyl-1,3-hexanediol, polyether polyols, polyester polyols, and propoxylated amines. To obtain a good mixture, diisocyanates can be homogenized with polypropylene glycol derivatives.

[0016] Typically, the penetration depth of the potting material into the ceramic structure of the filter element ranges from approximately 0.24 mm to approximately 3.0 mm. The shrinkage rate of the potting material after curing relative to its uncured state is less than approximately 1.24%.

[0017] The potting material has a tensile strength in the range of about 2-65 MPa and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion is within the range of / K. The material property refers to the fully cured state of the potting material.

[0018] Both ISO 527-1 / 527-2 and ASTM D638 list tensile test methods for determining tensile strength. These two standards are technically equivalent, but they do not produce completely equivalent results because the sample shape, test speed, and methods of determining the results differ in some aspects. The values ​​indicated and required herein refer to the test methods according to the aforementioned ISO standards, including "Plastics—Determination of tensile properties—Part 1: General principles" and "Plastics—Determination of tensile properties—Part 2: Test conditions for molded and extruded mixtures."

[0019] In standardized tensile testing, the results are correlated with a defined withdrawal speed on the test specimen. However, in actual use of components or structures, the stresses that occur can span a wide range of deformation rates. Due to the viscoelastic properties of polymers, changes in mechanical strain rates often result in mechanical properties different from those measured on standard test specimens. Therefore, the property values ​​determined in tensile testing are only applicable to component design to a limited extent, but provide a very reliable basis for material comparisons.

[0020] The values ​​presented herein are applicable to environmental and boundary conditions of 23℃ ± 2℃. High tensile strength means that the material yields only to a minimal extent even under high tensile forces. Due to the high weight of ceramic filter membrane modules, the potting material must at least maintain the weight of the entire unit under all desired operating conditions (e.g., pressure fluctuations, filled filter membrane modules, etc.).

[0021] The coefficient of thermal expansion (or “mean linear coefficient of thermal expansion”) is measured according to DIN 53752:1980-12 Plastics – Tests; Determination of linear coefficient of thermal expansion and ISO 11359-3:2002 Plastics – Thermomechanical analysis (TMA) – Part 3: Determination of penetration temperature. For plastics, thermomechanical analysis (TMA) is helpful in measuring the mean linear coefficient of thermal expansion. A cylindrical or cubic test sample with a planar parallel measuring surface is used. A quartz impression is used to apply a low load (0.1 to 5 g) while thermal expansion is measured simultaneously by an inductive measuring system. The experimental setup is located in an oven heated at a low heating rate (e.g., 3-5 K / min). Based on DIN 53752 or ISO 11359, the mean linear coefficient of thermal expansion (upper equation below) or the differential coefficient of thermal expansion (lower equation) can be determined by the equation given below.

[0022]

[0023]

[0024] The differential coefficient of thermal expansion is determined by the slope ΔL / L0 of the tangent relative to the correlation line. This value is always zero at the beginning of the experiment.

[0025] Typically, the difference in the coefficients of thermal expansion between the materials to be bonded should be as small as possible, so that even if the temperature change (shear) is large, no additional force is applied to the bonded area.

[0026] Typically, uncured potting materials have a viscosity in the range of approximately 400-4500 mPa·s. This has proven particularly advantageous for processing and achieving the desired penetration depth. To determine the viscosity, common and known standardized testing methods can be used, with a temperature of approximately 23 ± 2 °C.

[0027] Shore hardness grade A is used for soft rubbers, while Shore hardness grades C and D are used for elastomers and soft thermoplastics. Temperature plays a crucial role in determining Shore hardness; therefore, measurements must be performed within a limited temperature range of 23 ± 2 °C according to standards. However, a tempering chamber can also be used to determine temperature-dependent hardness. The sample thickness should be at least 6 mm. The hardness is read after the support surface of the hardness tester contacts the test sample for 15 seconds.

[0028] Higher Shore hardness is not suitable for potting materials. Materials with low Shore hardness tend to have high elastic modulus and elongation. Soft materials, such as those with relatively low Shore hardness, exhibit "creep," that is, they plastically deform in response to a constant load applied over a long period of time.

[0029] Typically, potting materials have Shore hardness in the range of approximately D10-D86. For elastomers or thermoplastic elastomers and thermosetting plastics, Shore hardness is determined according to ISO 7619-1:2010. In the Shore hardness test method, additional devices are used in conjunction with a measuring stage to improve the accuracy of test samples that need to be measured by a contact pressure of 12.5 ± 0.5 N for Shore hardness A or 50 ± 0.5 N for Shore hardness D. The DIN ISO 7619-1 standard, which came into effect in 2012, has extended the standardization of Shore hardness testing to include Shore hardness methods AO (for low hardness values) and AM (for thin elastomer test samples), and provides correction values ​​for indenter geometry at Shore hardness D (R = 30 ± 0.25°). When using contact pressure and a fixed measuring stage, 1 + 0.1 kg replaces 12.5 ± 0.5 N for Shore A hardness, and 5 + 0.5 kg replaces 50 ± 0.5 N for Shore D hardness. In this new standard, the measurement time is extended from 3 seconds to 15 seconds, and the storage time for test samples in standard climate is reduced from 16 hours to 1 hour. For safe hardness values, five separate measurements can now be performed.

[0030] Young's modulus (E) is commonly used in mechanical engineering for strength calculations of metals and plastics. It is often referred to as the modulus of elasticity, tensile modulus, elastic coefficient, elongation modulus, or Young's modulus. It is a parameter representing the degree to which a material yields when a force is applied. Under the same load and geometry, rubber components yield more than steel components. Young's modulus is a proportionality constant between stress σ and strain ε in a solid material within its linear elastic range; that is, the slope of the stress-strain curve within the linear elastic range. If the stress σ and strain ε of a material sample within its linear elastic range are known, then the Young's modulus E is determined as:

[0031] E = Δσ / Δε = const.

[0032] Young's modulus can also be determined graphically from a stress-strain diagram. A stress-strain diagram is a direct result of a tensile test. In a tensile test, a standard test material is subjected to stress, and the resulting strain is then plotted on a graph. In the initial linear elastic region of the curve, Young's modulus can be determined by stress and elongation. In the curve, elastic deformation reaches the yield point, and then plastic deformation reaches the tensile strength. Once the sample begins to neck (as in plastic deformation) and exceeds the maximum elongation, fracture occurs.

[0033] Here, the Young's modulus value refers to a temperature of 23±2℃. The elastic modulus decreases at higher room temperatures.

[0034] Young's modulus and elongation should be as low as possible within the elastic range, and preferably not enter the range of plastic deformation. This improves the dimensional stability of the cured potting compound.

[0035] The potting material has a Young's modulus in the range of approximately 50-4000 MPa. As mentioned above, the determination of tensile strength uses the ISO 527-1 / 527-2 and ASTM D638 tensile testing methods. In standardized tensile tests, the results are shown as being related to a defined tensile rate on the test specimen. However, in actual use of a component or structure, the stresses that occur can be over a wide range of deformation rates. Due to the viscoelastic properties of the polymer, changes in mechanical strain rates often result in mechanical properties different from those measured on standardized test specimens. Therefore, the parameters determined in tensile testing are only applicable to component design to a limited extent, but provide a very reliable basis for material comparisons.

[0036] Encapsulating materials have elongation in the range of approximately 1-10 or approximately 70-100. Elongation is typically detected by a probe. A strain gauge records how strong the strain is within a certain force range, from which the strain can be calculated.

[0037] The glass transition temperature was determined according to ISO 11357-1:2017-02. A heating rate of 20 K / min was used. The test environment was nitrogen (N2). ISO 11357 lists various differential scanning calorimetry (DSC) methods for thermal analysis of polymers and polymer blends, such as thermoplastics (polymers, molding mixtures, and molded products with or without fillers, fibers, or polymer reinforcements), thermosetting materials (hardened or uncured materials with or without fillers, fibers, or reinforcements), and elastomers (with or without fillers, fibers, or reinforcements). ISO 11357 is used to observe and quantify various phenomena or properties of the above materials, such as: physical transitions (glass transition, phase changes such as melting or crystallization, polycrystalline transitions, etc.), chemical reactions (polymerization, crosslinking, and vulcanization of elastomers and thermosetting materials, etc.), oxidative stability, and heat capacity.

[0038] The glass transition temperature should be outside the recommended operating temperature of the diaphragm module. The properties of polyurethane below and above its glass transition temperature are generally significantly different; therefore, materials above the glass transition temperature may be elastic, while the same material below the glass transition temperature may be brittle.

[0039] The potting material has a glass transition temperature in the range of approximately less than 0°C or greater than 25°C.

[0040] The potting material has an activation period ranging from approximately 7 to 180 minutes. The activation period (workability time) is determined according to DIN EN 14022:2010-06. This standard outlines methods for determining the suitability and properties of adhesives, optionally referred to as workability time and activation period. It specifies five procedures for determining the usable time for an application, each of which is specific to the case; particularly important are the flow behavior and reaction rate of the adhesive under discussion. The testing standard is intended for adhesive manufacturers, users of multi-component adhesives, and independent testing laboratories. The values ​​given above are for an ambient temperature of 23 ± 2 °C and a stable, ideal relative humidity of approximately 35%.

[0041] Processing time largely depends on the activation period, and therefore the activation period is directly related to the process time or throughput time. The material must have sufficient fluidity to be applied into the narrow gaps between the individual filter elements. The process time can then be adjusted using process parameters such as temperature.

[0042] Expansion is also an important parameter. This parameter is determined by first determining the weight of a completely dried sample of the potting material, and then immersing a sample of the potting material, which does not need to have a specific shape, in a fluid at 55°C, i.e., an aqueous solution, for 18.5 days. At the end of 18.5 days, the weight of the sample is determined again. The equilibrium threshold Q is calculated according to the following formula:

[0043]

[0044] Where WP is the weight of the dry sample, Ws is the weight of the equilibrium solution, and d p It is the density of the potting material, d s This is the density of the solvent. The parameters used in the formula were measured at a temperature of 23±2℃.

[0045] Water absorption and swelling should be as low as possible, as swelling behavior indicates that the solution has penetrated into the plastic structure (when testing test solutions, such as aqueous solutions, or in actual use with filtered water). If fluids with high or low pH values ​​(e.g., pH 0 or pH 14, pH 2 or pH 12, etc.) remain in the structure for extended periods, there is a risk of faster material “aging.” Material parameters such as elongation, tensile Young’s modulus, and Shore hardness also change with swelling.

[0046] After immersing the cured potting material in a fluid at 55°C for 18.5 days, the changes in mass were ±2.5% or less, Shore hardness ±22% or less, dimensional change ±7.0% or less, Young's modulus ±18% or less, and tensile strength ±15% or less. For Shore hardness, height, length, and weight, the changes in these parameters between undried, immediately aged samples were compared to the values ​​after drying (ideally equal to the initial values ​​before aging) (non-destructive evaluation). For Young's modulus and tensile strength, the values ​​after drying and aging were compared to the values ​​of unencapsulated samples (non-destructive value determination).

[0047] Cured potting materials exhibit cohesive fracture behavior relative to their own tensile and shear properties and those of other adhesive materials. This fracture behavior also demonstrates favorable material properties.

[0048] For potting materials comprising polyisocyanates and glycols or polyols, it is also possible to include catalysts, particularly organotin complexes. This facilitates the production of potting materials with desired parameters. This is particularly applicable in the case of homogenization of diisocyanates and propylene glycol derivatives as described above.

[0049] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features and advantages will become apparent from the specification, the drawings, and the claims. Attached Figure Description

[0050] Figure 1 It is the longitudinal section passing through the filter membrane module with a housing;

[0051] Figure 2 Is it through Figure 1 An enlarged longitudinal section of a portion of the filter element;

[0052] Figure 3 It passes through line III-III Figure 1 The cross-section of the upper part of the filter membrane module.

[0053] The same reference numerals in different figures denote the same elements. Detailed Implementation

[0054] The ceramic filter element has at least two opposing end faces. Filter channels exist within the filter element, extending longitudinally and leading to the end faces. A portion of the filter element's surface is covered with a potting material. This ceramic filter element has an optimal potting material on at least one surface.

[0055] At least one end surface is sealed with a potting material in a manner that is impermeable to both fluid and gas. During normal operation, this arrangement ensures that contaminated fluid does not enter the filter element through the end surface (passing through the filter element from the inside to the outside along the flow path). Therefore, contaminated fluid only passes through the filter membrane on the inner wall of the filter channel. During quality testing, this impermeable seal to both fluid and gas ensures that, for example, air forced into the filter channel does not flow out through the end face, but instead flows through the perforated material of the filter element to its outside.

[0056] Furthermore, each ceramic filter element is a composite of several ceramic filter elements mechanically linked together by a potting material. The curing of the potting material results in a durable and stable mechanical composite of the filter elements.

[0057] Ceramic filter elements can have segmented shapes, integral shapes, tubular shapes, hollow fiber shapes, or plate shapes. Other shapes are also possible.

[0058] Figure 1 The image shows a filter membrane module 10. The filter membrane module 10 includes a tubular housing 12 with a circular cross-section. Other cross-sections are also possible, such as rectangular, square, or polygonal cross-sections. At both axial ends of the housing 12 are disc-shaped caps 14, which are fixed to be fluid-impermeable. The right cap 14 includes an inlet connection 16 for the fluid to be filtered, and the left cap 14 includes an outlet connection 18 for unfiltered fluid. The housing 12 has an outlet nozzle 20 for the filtered fluid (filtrate or permeate). The housing 12 and caps 14 can be made of metal or plastic, such as fiber composite plastic.

[0059] The integral component 22 is inside the housing 12. Figure 1 The diagram shows six flat filter elements 24, which are elongated, relatively wide vertically in the direction perpendicular to the drawing plane, and relatively narrow vertically. Other cross-sections of the filter elements 24 are also possible. The filter elements 24 are made of sintered, porous ceramic material. The top three of these filter elements 24 are... Figure 3 The plan view shows that the external shape of the filter element 24 conforms to the circular cross-sectional profile of the housing 12, thus making optimal use of the internal volume of the housing 12. In general, the filter element 24 has a trapezoidal cross-section.

[0060] from Figure 3 It can also be seen that multiple filter channels 26 extend through the filter element 24. Figure 1 In this process, these filter channels 26 extend from the front end face 27 of the filter element 24 to the rear end face 29 of the filter element 24. For clarity, in Figure 1In the figure, the reference numerals on the end faces 27 and 29 refer to only one filter element 24. The inner wall of the filter channel 26 is coated with a ceramic filter membrane, which is not shown in the figure.

[0061] The integral component 22 includes a potting body 28 at its respective end face. The potting body is made of a cured liquid potting material. The filter elements 24 are mechanically fixed to each other by the cured potting material. The potting material creates a fluid-impermeable seal for the internal fluid space 30 between the filter elements and a fluid-impermeable seal for the external fluid chamber 32 between the cap 14 and the potting body 28. To ensure a fluid-impermeable seal, additional components, such as seals, may be used.

[0062] To produce the potting compound 28, the filter element 24 is arranged in a desired manner; for example, by means of an auxiliary device removed after the production of the potting compound 28. The filter element 24 is arranged such that its longitudinal direction extends in the axial direction. One end of the composite filter element 24 is placed in a cup-shaped mold of silicone material. The cup-shaped mold is then filled with a curable liquid, which wraps around and completely wets the outer surface of the end portion of the filter element 24. The curable liquid material is a material that hardens or cures over a certain period of time. After curing, the composite of the filter element 24 and the cured material now forms the potting compound 28, which is then removed from the mold.

[0063] Curable materials are used to produce potting compounds 28 and end surface seals 34. Figure 2 A cross-section through the end region of a single filter element 24 is shown. The filter channel 26 provides a corresponding right-side end portion of the right-side front face 27. A curable material is applied to the end face 27, for example, by rolling, brushing, or spraying. Upon curing, an end surface seal 34 is formed. This prevents the fluid to be filtered from entering the filter element 24 directly via the end face 27 and flowing thereout during operation without passing through the filter membrane on the inner wall of the filter channel 26.

[0064] During operation, the fluid to be filtered is introduced into the right external fluid chamber 32 through the right inlet port 16. From there, the fluid flows through the filter channel 26. Unfiltered material is not conveyed through the walls of the filter channel 26 but is deposited there. The filtrate flows through the perforated ceramic material of the filter membrane and filter element 24 to be collected in the internal fluid space 30 and flows through the outlet port 20. Unfiltered fluid can flow out through the outlet port 18 and return to the inlet port 16.

[0065] The potting material used to produce the potting body 28 or for the end surface seal 34 is a plastic material and may be a thermoplastic or thermosetting plastic, such as an epoxide or polyurethane. The penetration depth of the potting material into the structure of the filter element 24 is in the range of about 0.24 mm to about 3.0 mm, and the shrinkage after curing is less than about 1.24%. In the cured state, the potting material has a tensile strength in the range of about 2-65 MPa and a tensile strength of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion is within the range of / K. Its Shore hardness can be in the range of approximately D10-D86, and its Young's modulus is in the range of approximately 50-4000 MPa. The glass transition temperature can be in the range of approximately less than 0°C or greater than 25°C. Furthermore, the potting material can have an activation period in the range of approximately 7-180 min and an elongation in the range of approximately 1-10 or approximately 70-100. The hardened potting body 28 or the cured end surface seal 34 exhibits cohesive fracture behavior relative to itself and relative to other adhesive or bonding materials in terms of tensile shear properties.

[0066] Generally, all equipment used for producing liquid potting materials should be in good working order, clean, and dry. Oils, greases, and other contaminants that affect adhesion should be removed. Oil-contaminated surfaces that have absorbed oil (e.g., silicone gaskets) should be properly cleaned with an emulsified cleaner. Excess water should be removed from the equipment used. Starting materials should be used at suitable temperatures and should be placed in the processing area and stored there one to two days before use to allow them to acclimatize to environmental conditions. The temperature of the starting material should not exceed 50°C during mixing. Reaction and processing times depend on the ambient temperature, the outlet temperature of the raw materials, and the relative humidity. At lower temperatures, the chemical reaction time is prolonged, which extends the activation period and processing time. Contact between the starting material and water should be avoided until fully cured, as this can lead to decarboxylation or tackiness on the surface, in either case causing the potting material to lose its properties.

[0067] The components should be completely homogenized, and all material should be scraped from the walls and bottom of the mixing container used. Mechanical or electric mixing instead of manual mixing is possible, but should be carried out at a low material infeed rate (e.g., 3 g / s at 25°C) to minimize the introduction of air into the batch.

[0068] To obtain better chemical resistance of the potting material, the mass change of the cured polyurethane resin composite test sample in a fluid (e.g., water, sodium hydroxide, sulfuric acid, glycerol, or hypochlorite) at 55°C for 18.5 days should be ±2.5% or less. A mass change of ±2.0% or less is preferable. Larger mass changes due to chemical stress may indicate that the cured polyurethane casting material dissolves upon contact with the fluid being filtered, or may indicate that the cured polyurethane casting material absorbs a significant amount of water and thus swells during operation.

[0069] Similarly, regarding chemical resistance, the change in Shore hardness of the cured polyurethane composite test sample after immersion in a liquid at 55°C for 18.5 days and subsequently after drying should be ±22% or less. Here and below (where other parameters are mentioned below), the corresponding changes in value (Δ) are measured before removal, immediately after removal in the non-dry state, and after drying. Using the average of 10 samples, the Δ value is determined as follows:

[0070] Measured value (current) = XA, XB or XC

[0071] The average value of measurements before removal = A

[0072] The average value measured after aging and before drying = B

[0073] The average value measured after aging and after drying = C

[0074] Average value A = (XA1 + XA2 + XA3 + ... + XA) n ) / n

[0075] The calculation of averages B and C is similar to that of A.

[0076] The relative change (d) for each individual measurement is then determined by the current measurement and the calculated average.

[0077] dA=(XA-A) / A

[0078] The average of the relative changes is calculated from the relative changes measured individually.

[0079]

[0080] The calculation of the relative change (d) for each individual measurement of B and C is similar to that of dA.

[0081] The average of the relative changes of B and C The calculation is similar to

[0082] The absolute change can now be calculated from the relative results.

[0083]

[0084]

[0085] Δmass, ΔShore hardness, Δlength, Δheight:

[0086] Δ value = (D1, D2) maximum value

[0087] ΔYoung's modulus, Δtensile strength:

[0088] Δ value = maximum value of D2

[0089] Ideally, the value before aging but not drying corresponds to the value after aging and drying. Since the ceramic filter element uses cast material, the cast material itself is always operating in a liquid medium, making this difference meaningful.

[0090] Significant changes in Shore hardness due to chemical stress may indicate that, during operation, changes in the material properties of the polyurethane potting material when it comes into contact with fluids result in products no longer meeting certain required specifications (e.g., resistance to pressure fluctuations).

[0091] Also considering chemical resistance, the dimensional changes (height and length) of the cured polyurethane composite test samples after immersion in a chemical liquid at 55°C for 18.5 days, and in the case where the test samples were subsequently not dried or were dried, should be ±7.0% or less, for example ±2.5% or less. Larger dimensional changes due to chemical stress may cause irreversible damage to the filter membrane module due to the elongation or shrinkage of the polyurethane potting material, leading to filter element damage or leakage of the filter membrane module due to changes in the properties of the adhesive between different materials.

[0092] Similarly, regarding chemical resistance, the change in Young's modulus of a cured polyurethane composite sample after immersion in a chemical fluid at 55°C for 18.5 days and subsequent drying should be ±18% or less. Larger changes in Young's modulus due to chemical stress on the test sample can lead to alterations in material properties that are too high to meet certain product specifications, such as resistance to pressure fluctuations.

[0093] Similarly, regarding chemical resistance, the change in tensile strength of a cured polyurethane composite sample immersed in a chemical fluid at 55°C for 18.5 days, and subsequently dried, should be ±15% or less. Larger changes in tensile strength due to chemical stress can lead to alterations in material properties during operation that are too high to meet certain product specifications, such as resistance to pressure fluctuations.

[0094] Example 1

[0095] Add 39.7 parts by weight of diphenylmethane-4,4'-diisocyanate and 100.3 parts by weight of polyether polyol to a container equipped with a stirrer and thermometer. The reaction is carried out at 22°C. Both components are completely homogenized, with the stirrer operating for at least 5 minutes. The mixture is then degassed at 60 mbar for about 8-10 minutes. The mixed and degassed components are transferred to a clean mixing container. There, the reaction is carried out under vigorous stirring for about 3-5 minutes to obtain a polyurethane resin solution. This is poured into a coated mold. It is then cured at 60°C for 8 hours. After cooling to room temperature, the polyurethane test sample is removed from the mold and then cured at room temperature for 24 hours. The test sample obtained in this way has the following properties (TCE = coefficient of thermal expansion, Tg = glass transition temperature, Δ value describes the change of the corresponding property after 18.5 days in a fluid immersed at 55°C (i.e., the test fluid with possibly different pH values ​​mentioned above):

[0096] Density: 1.18 g / cm³ 3

[0097] Activation period (200g): Approximately 50 minutes

[0098] Viscosity: 400-600 mPa·s

[0099] Shore hardness: D60

[0100] TCE: 117 ppm / K when T < 30℃

[0101] 205 ppm / K at T>40℃

[0102] Tensile strength: 6MPa

[0103] Tg: 31℃

[0104] Young's modulus: 890 MPa

[0105] Δmass: +1.6%

[0106] Shore hardness D: +3.3%

[0107] Δ length: +0.6%

[0108] Δ height: +2.2%

[0109] ΔYoung's modulus: -12%

[0110] ΔTensile strength: +2.6%.

[0111] The activation period is long. This is because any two-component curing process is an exothermic reaction that releases energy in the form of heat. Curing itself depends on temperature. Therefore, the larger the quantity used, the more heat is released, and the faster the two components cure. Conversely, the smaller the quantity used, the longer the curing process takes.

[0112] Example 2

[0113] Add 50.5 parts by weight of a mixture of diphenylmethylene diisocyanate (concentration between 50-75%), aromatic isocyanate prepolymer (concentration between 25-50%), and 99.5 parts by weight of polypropylene glycol to a container equipped with a stirrer and thermometer. The reaction is carried out at 22°C. Both components are completely homogenized by stirring for at least 5 minutes. The mixture is then degassed at 60 mbar for approximately 8-10 minutes. All the premixed and degassed components are then transferred to a clean mixing container. There, the reaction is carried out under vigorous stirring for approximately 3-5 minutes to obtain a polyurethane resin solution. This solution is poured into a coated mold to prepare test samples. These are then cured at 60°C for 8 hours. After cooling to room temperature, the polyurethane test samples are removed from the molds. They are then allowed to cure at room temperature for an additional 24 hours. The test samples obtained in this way have the following characteristics (TCE = coefficient of thermal expansion; Tg = glass transition temperature; Δ value describes the change in the corresponding properties of the fluid immersed at 55°C (i.e., the test fluid with possibly different pH values ​​mentioned above) after 18.5 days):

[0114] Density: 1.08 g / cm³ 3

[0115] Activation period (150g): approximately 15 minutes

[0116] Viscosity: 1100-1300 mPa·s

[0117] Shore hardness: D58

[0118] TCE: 85 ppm / K at T<0℃

[0119] 206 ppm / K at T>50℃

[0120] Tensile strength: 14MPa

[0121] Tg: 36℃

[0122] Young's modulus: 550 MPa

[0123] Δmass: +1.7%

[0124] Shore hardness D: +5.4%

[0125] Δ length: +0.38%

[0126] Δheight: +0.5%

[0127] ΔYoung's modulus: -12%

[0128] ΔTensile strength: -14.3%.

[0129] Example 3

[0130] Add 50.5 parts by weight of diphenylmethane-2,4'-diisocyanate (concentration between 5-10%), diphenylmethane-4,4'-diisocyanate (concentration between 10-25%), diphenylmethane diisocyanate (concentration between 65-85%), and 100 parts by weight of polyether polyol to a container equipped with a stirrer and thermometer. The first three components are premixed and added to the hardener as a homogeneous mixture. The reaction is carried out at 22°C. The two components are completely homogenized by operating the stirrer for at least 5 minutes. The mixture is then degassed at 60 mbar for about 8-10 minutes. Transfer all the premixed and degassed components to a clean mixing container. There, the reaction is carried out under vigorous stirring for about 3-5 minutes to obtain a polyurethane resin solution. Pour it into a coated mold to make test samples. Then cure it at 60°C for 8 hours. After cooling to room temperature, remove the polyurethane test samples from the mold and then cure them at room temperature for 24 hours. Test samples obtained in this manner have the following properties (TCE = coefficient of thermal expansion, Tg = glass transition temperature; Δ value describes the change in the corresponding properties of a fluid immersed at 55°C (i.e., the test fluid with possibly different pH values ​​mentioned above) after 18.5 days):

[0131] Density: 1.14 g / cm³ 3

[0132] Activation period (150g): Approximately 60 minutes

[0133] Viscosity: 400-600 mPa·s

[0134] Shore hardness: D50

[0135] TCE: 116 ppm / K when T < 25℃

[0136] 220ppm / K at T>40℃

[0137] Tensile strength: 10 MPa

[0138] Tg: 28℃

[0139] Young's modulus: 230 MPa

[0140] Δmass: +2.2%

[0141] ΔShore Hardness D: -12%

[0142] Δ length: +0.5%

[0143] Δ height: +2.4%

[0144] ΔYoung's modulus: -18%

[0145] ΔTensile strength: -15%.

[0146] Example 4

[0147] Add 16 parts by weight of a mixture of diphenylmethane-2,4'-diisocyanate (25-50% concentration), diphenylmethane-4,4'-diisocyanate (25-50% concentration), and diphenylmethane diisocyanate (isomers and homologues, 20-25% concentration) and 100.2 parts by weight of a mixture of triethyl phosphate and diphenyltoluene phosphate in a polyester / polyether polyol to a container equipped with a stirrer and thermometer. The reaction is carried out at 22°C. The two components are completely homogenized by stirring for at least 5 minutes. The mixture is then degassed at 60 mbar for approximately 8-10 minutes. All the premixed and degassed components are transferred to a clean mixing container. There, the reaction is carried out under vigorous stirring for approximately 3-5 minutes to obtain a polyurethane resin solution. This solution is poured into a coated mold to prepare test samples. These are then cured at 60°C for 8 hours. After cooling to room temperature, the test samples were removed from the mold and then cured at room temperature for 24 hours. Test samples obtained in this manner exhibit the following properties (TCE = coefficient of thermal expansion, Tg = glass transition temperature; Δ value describes the change in the corresponding properties of a fluid immersed at 55°C (i.e., the test fluid with potentially different pH values ​​mentioned above) after 18.5 days):

[0148] Density: 1.52 g / cm³ 3

[0149] Activation period (250g): Approximately 45 minutes

[0150] Viscosity: 600-900 mPa·s

[0151] Shore hardness: D40

[0152] TCE: 55 ppm / K at T < -20℃

[0153] M / K at T>-5℃

[0154] Tensile strength: 7MPa

[0155] Tg: -4℃

[0156] Young's modulus: 20 MPa

[0157] Δmass: -2.1%

[0158] ΔShore Hardness D: -21%

[0159] Δ length: -1.1%

[0160] Δ height: -6.6%

[0161] ΔYoung's modulus: -14.3%

[0162] ΔTensile strength: -4.7%.

[0163] Example 5

[0164] Add 54 parts by weight of 1,1'-diphenylmethylene diisocyanate (concentration between 30-60%) and 1,1'-methylenebis(4-phenylisocyanate) homopolymer (concentration between 10-30%) and 100 parts by weight of a mixture of 5-15% diol and 0.5-1.5% fatty acid-based vegetable oil to a container equipped with a stirrer and thermometer. The reaction is carried out at 22°C. Both components are completely homogenized by stirring for at least 5 minutes. The mixture is then degassed at 60 mbar for approximately 8-10 minutes. The entire amount of the premixed and degassed components is transferred to a clean mixing container. There, the reaction is carried out under vigorous stirring for approximately 3-5 minutes to obtain a polyurethane resin solution. This solution is poured into a coated mold to prepare test samples. It is then cured at 80°C for 16 hours. After cooling to room temperature, the polyurethane test samples are removed from the mold and then cured at room temperature for 24 hours. Test samples obtained in this manner have the following properties (TCE = coefficient of thermal expansion, Tg = glass transition temperature, Δ value describes the change in the corresponding properties of the fluid immersed at 55°C (i.e., the test fluid with possibly different pH values ​​mentioned above) after 18.5 days):

[0165] Density: 1.05 g / cm³ 3

[0166] Activation period (200g): Approximately 60 minutes

[0167] Viscosity: 2000 mPa·s

[0168] Shore hardness: D10

[0169] TCE: Unmeasurable

[0170] Tensile strength: 6.2 MPa

[0171] Tg: -20℃

[0172] Young's modulus: 150 MPa

[0173] Δmass: +0.8%

[0174] Shore hardness D: -14.3%

[0175] Δ length: -0.1%

[0176] Δ height: -2.5%

[0177] ΔYoung's modulus: -10%

[0178] ΔTensile strength: +8.5%.

[0179] Example 6

[0180] Add 100 parts by weight of bisphenol A-epiochlorohydrin resin (average molecular weight <700) and 1,4-bis(2,3-epoxypropoxy)butane and 50.2 parts by weight of a mixture of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (45-50%), alkyl polyamine (35-40%), polyaminoamide adduct (10-15%), and 1,2-diaminoethane (1-5%) to a container equipped with a stirrer and thermometer. The reaction is carried out at 22°C. Both components are completely homogenized by stirring for at least 5 minutes. The mixture is then degassed at 60 mbar for approximately 15 minutes. All of the premixed and degassed components are transferred to a clean mixing container. There, the reaction is carried out under vigorous stirring for approximately 5 minutes to obtain an epoxy resin solution. This solution is poured into a coated mold to prepare test samples. These are then cured at 80°C for 2 hours. After cooling to room temperature, the epoxy resin test samples were removed from the mold and then cured at room temperature for 24 hours. The test samples thus obtained have the following properties (TCE = coefficient of thermal expansion; g = glass transition temperature; Δ value describes the change in the corresponding properties after 18.5 days in a fluid at an immersion temperature of 55°C (i.e., the test fluid with possibly different pH values ​​mentioned above):

[0181] Density: 1.08 g / cm³ 3

[0182] Activation period (250g): Approximately 120 minutes

[0183] Viscosity: 500-1000 mPa·s

[0184] Shore hardness: D80

[0185] TCE: 90 ppm / K when T < 50℃

[0186] 190ppm / K at T>60℃

[0187] Tensile strength: 59MPa

[0188] Tg: 52℃

[0189] Young's modulus: 3800MPa

[0190] Δmass: +2.5%

[0191] ΔShore Hardness D: -8%

[0192] Δ length: +0.9%

[0193] Δ Height: +1.25%

[0194] ΔYoung's modulus: -4.3%

[0195] ΔTensile strength: -9.1%.

[0196] Many embodiments have been described. However, it should be understood that various modifications can be made without departing from the spirit and scope of this disclosure. Therefore, other embodiments are within the scope of the following claims.

[0197] The following subjects and aspects of the present invention are described:

[0198] 1. A filter membrane module, comprising:

[0199] At least one ceramic filter element made of a sintered, porous ceramic structure;

[0200] A potting material for encapsulating the ceramic filter element, the potting material having an uncured state and a cured state; and

[0201] case;

[0202] The potting material is a thermoplastic or thermosetting plastic, which, in the cured state, has a tensile strength in the range of about 2-65 MPa and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion in the range of / K, and

[0203] The penetration depth of the potting material into the structure of the filter element is in the range of 0.24 mm to 3.0 mm, and the shrinkage rate after curing is less than 1.24%.

[0204] And / or preferably, the potting material is an epoxy or polyurethane.

[0205] And / or preferably, the potting material in the uncured state has a viscosity in the range of about 400-4500 mPa·s, and / or preferably, the potting material in the cured state has a Shore hardness in the range of about D10-D86, and / or preferably, the potting material in the cured state has a Young's modulus in the range of about 20-4000 MPa, and / or preferably, the potting material in the cured state has a glass transition temperature in the range of less than about 0°C or greater than about 25°C, and / or preferably, the potting material has an activation period in the range of about 7-180 min, and / or preferably, the potting material in the cured state... The potting material has an elongation in the range of about 1-10 or about 70-100, and / or preferably, the potting material in the cured state has cohesive fracture behavior relative to itself and other adhesive materials, and / or preferably, after immersing the potting material in the cured state in a fluid at a temperature of 55°C for 18.5 days, the mass change is 5 ± 2% or less, and / or the Shore hardness change is ± 22% or less, and / or the dimensional change is ± 7.0% or less, and / or the Young's modulus change is ± 18% or less, and / or the tensile strength change is ± 15% or less, and / or preferably, the potting material comprises a polyisocyanate and at least one diol and / or at least one polyol.

[0206] 2. Ceramic filter elements, including:

[0207] At least two oppositely arranged end surfaces with filter channels, and

[0208] Surface covered with potting material,

[0209] The potting material is an epoxy resin or polyurethane comprising thermoplastic or thermosetting plastics, having a penetration depth into the filter element in the range of 0.24 mm to 3.0 mm, a shrinkage rate of less than 1.24% after curing, a tensile strength in the range of about 2-65 MPa during curing, and a tensile strength of about 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion is within the range of / K, and / or preferably, at least one end face is tightly sealed to the fluid and / or gas by the potting material, and / or preferably comprises a plurality of ceramic filter elements mechanically connected by the potting material, and / or preferably, the ceramic filter elements have a segmented shape, an integral shape, a tubular shape, a hollow fiber shape, or a plate shape.

[0210] 3. A method for forming a filter membrane module, the filter membrane module comprising: at least one ceramic filter element made of a sintered, porous ceramic structure; a potting material for encapsulating the ceramic filter element, the potting material having an uncured state and a cured state; and a housing, wherein the potting material is a thermoplastic or thermosetting plastic having a tensile strength in the cured state in the range of about 2-65 MPa and a tensile strength in the range of about 55-260 × 10⁻⁶ MPa. -6 The method comprises: a coefficient of thermal expansion in the range of / K, a penetration depth of the potting material into the structure of the filter element in the range of 0.24 mm to 3.0 mm, and a shrinkage rate after curing of less than 1.24%.

[0211] The container is filled with a mixture of epoxy resin or polyurethane containing thermoplastic or thermosetting plastics.

[0212] The mixture was mechanically stirred at 22°C for at least 5 minutes.

[0213] Degas the mixture at 60 mbar for approximately 8-10 minutes;

[0214] The mixture was cured at 60°C for 8 hours;

[0215] The mixture is cured at room temperature for 24 hours, and / or preferably, this includes transferring the degassed mixture to a clean mixing container, and / or preferably, this includes mechanically stirring the mixture in the clean mixing container for 3-5 minutes, and / or preferably, the mixture comprises diphenylmethane-4,4'-diisocyanate and polyether polyol, and / or preferably, the mixture comprises diphenylmethylene diisocyanate, aromatic isocyanate prepolymer and polypropylene glycol, and / or preferably, the mixture comprises diphenylmethane-2,4'-diisocyanate. The mixture comprises cyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate and polyether polyol, and / or preferably, the mixture comprises diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate, triethyl phosphate and diphenyltolyl, and / or preferably, the mixture comprises 1,1'-diphenylmethylene diisocyanate, 1,1'-methylenebis(phenylisocyanate) homopolymer and vegetable oil, and / or preferably, the mixture comprises a combination of bisphenol A-epimericol resin and butane.

Claims

1. A ceramic filter element, comprising: At least two oppositely arranged end surfaces with filter channels; as well as Surface covered with potting material, The potting material is an epoxy resin or polyurethane comprising thermoplastic or thermosetting plastics. The potting material has a penetration depth into the filter element ranging from 0.24 mm to 3.0 mm, a shrinkage rate of less than 1.24% after curing, a tensile strength in the range of 2-65 MPa during curing, and a tensile strength of 55-260 × 10⁻⁶ MPa. -6 The coefficient of thermal expansion in the range of / K.

2. The ceramic filter element according to claim 1, wherein, Uncured potting materials have a viscosity in the range of 400-4500 mPa·s.

3. The ceramic filter element according to claim 1, wherein, The potting material in the cured state has a Shore hardness in the range of D10-D86.

4. The ceramic filter element according to claim 1, wherein, The potting material in the cured state has a Young's modulus in the range of 20-4000 MPa.

5. The ceramic filter element according to claim 1, wherein, The potting material in the cured state has a glass transition temperature in the range of less than 0°C or greater than 25°C.

6. The ceramic filter element according to claim 1, wherein, The potting material has an activation period in the range of 7-180 min.

7. The ceramic filter element according to claim 1, wherein, The potting material in the cured state has an elongation in the range of 1-10 or 70-100.

8. The ceramic filter element according to claim 1, wherein, The potting material in the cured state exhibits cohesive fracture behavior relative to itself and other adhesive materials.

9. The ceramic filter element according to any one of claims 1 to 8, wherein, After immersing the cured potting material in a fluid at 55°C for 18.5 days, the mass change is ±2.5% or less, and / or the Shore hardness change is ±22% or less, and / or the dimensional change is ±7.0% or less, and / or the Young's modulus change is ±18% or less, and / or the tensile strength change is ±15% or less.

10. The ceramic filter element according to any one of claims 1 to 8, wherein, The potting material includes polyisocyanate and at least one polyol.

11. The ceramic filter element according to claim 10, wherein, The polyol is a diol.

12. The ceramic filter element according to claim 1, wherein, At least one end face is tightly sealed to the fluid and / or gas by the potting material.

13. The ceramic filter element according to claim 1, comprising a plurality of ceramic filter elements mechanically connected by the potting material.

14. The ceramic filter element according to any one of claims 1, 12, and 13, wherein, The ceramic filter element has a segmented shape, an integral shape, a tubular shape, a hollow fiber shape, or a plate shape.

15. A method of forming a filter membrane module, the filter membrane module comprising: At least one ceramic filter element made of a sintered, porous ceramic structure; a potting material for encapsulating the ceramic filter element, the potting material having an uncured state and a cured state; and a housing, wherein the potting material is a thermoplastic or thermosetting plastic having a temperature of 55-260 × 10⁻⁶ in the cured state. -6 The method comprises: a coefficient of thermal expansion within the range of / K, a penetration depth of the potting material into the structure of the filter element within the range of 0.24 mm to 3.0 mm, and a shrinkage rate after curing of less than 1.24%. The container is filled with a mixture of epoxy resin or polyurethane containing thermoplastic or thermosetting plastics. The mixture is mechanically stirred at 22°C for at least 5 minutes; Degas the mixture at 60 mbar for 8-10 minutes; The mixture was cured at 60°C for 8 hours; The mixture was cured at room temperature for 24 hours.

16. The method of claim 15, further comprising transferring the degassed mixture into a clean mixing container.

17. The method of claim 15, comprising mechanically stirring the mixture in a clean mixing container for 3-5 minutes.

18. The method according to any one of claims 15 to 17, wherein, The mixture comprises diphenylmethane-4,4'-diisocyanate and polyether polyol.

19. The method according to any one of claims 15 to 17, wherein, The mixture comprises diphenylmethylene diisocyanate, aromatic isocyanate prepolymer, and polypropylene glycol.

20. The method according to any one of claims 15 to 17, wherein, The mixture comprises diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate, and polyether polyol.

21. The method according to any one of claims 15 to 17, wherein, The mixture comprises diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane diisocyanate, triethyl phosphate, and diphenyltolyl.

22. The method according to any one of claims 15 to 17, wherein, The mixture comprises 1,1'-diphenylmethylene diisocyanate, 1,1'-methylene bis(4-phenylisocyanate) homopolymer, and vegetable oil.

23. The method according to any one of claims 15 to 17, wherein, The mixture comprises a combination of bisphenol A-epiochlorohydrin resin and butane.

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