Preparation method of filter element for water purifier, filter element and water purifier

Abstract

A method for preparing a filter element for a water purifier, a filter element and a water purifier, belonging to the technical field of filter medium preparation methods. The preparation method includes the following steps: (S.1): mixing titanium alloy powder, a binder and a plasticizer, and heating and stirring the mixture to obtain a mixed material; (S.2): granulating the mixed material and forming it into a filter element blank; (S.3): degreasing the filter element blank; (S.4): sintering the degreased filter element blank, the sintering temperature is 800~1200℃, and the sintering time is 0.5~0.8 hours. The titanium alloy filter element described in the technical solution of the present invention obtains the effect of smaller filtration resistance while ensuring the filtration accuracy, and at the same time has the filter element strength.

Description

Technical Field

[0001] The invention belongs to the technical field of methods for preparing filter media, and in particular relates to a method for preparing a filter element for a water purifier, a filter element and a water purifier. Background Art

[0002] Titanium alloy filter element is a filter element made by sintering titanium alloy powder as the main raw material. It has the advantages of corrosion resistance, long service life, good bioaffinity, and good antibacterial performance. It is suitable as a filter medium for water bodies.

[0003] Although titanium alloy filter elements have the above advantages, few people have considered the sintering process of titanium alloy in the prior art. The inventor of this application believes that, under the premise of ensuring filtration accuracy, titanium alloy filter elements still have the potential to further reduce filtration resistance and maintain strength. Summary of the invention

[0004] In order to solve the above technical problems, the present application improves the preparation method of the titanium alloy filter element, so as to obtain a filter element with smaller filtration resistance under the premise of ensuring filtration accuracy. One of the purposes of the present invention is to provide a preparation method of a filter element for a water purifier, the second purpose is to provide a corresponding filter element, and the third purpose is to provide a corresponding water purifier.

[0005] The specific technical solution is described below:

[0006] A method for preparing a filter element for a water purifier comprises the following steps:

[0007] (S.1): A step of mixing titanium alloy powder, a binder and a plasticizer, and heating and stirring the mixture to obtain a mixed material;

[0008] The binder comprises a composition of low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer and paraffin, and the plasticizer is octadecyl acrylate;

[0009] (S.2): a step of granulating the mixed material and forming it into a filter element blank;

[0010] (S.3): a step of degreasing the filter element blank;

[0011] (S.4): a step of sintering the degreased filter element blank, wherein the sintering temperature is 800-1200° C. and the sintering time is 0.5-0.8 hours.

[0012] In the above technical solution, the combination of the binder and the plasticizer has excellent fluidity and stability, and the selection range of the sintering temperature is based on the looseness of the titanium alloy filter element after molding. When the sintering temperature is less than 800°C, the filter element is often too loose, and it is difficult to ensure the strength and filtration accuracy of the filter element. When the sintering temperature is greater than 1200°C, the filter element is too dense, resulting in increased filtration resistance.

[0013] The sintering time should not be too long. When the sintering time exceeds 1 hour, the distance between the titanium alloy powder particles is too small, some of the filtering pores are closed, and the filtering pressure is increased.

[0014] Preferably, the titanium alloy powder is industrial high-purity titanium powder with a titanium content greater than 99.4% by mass.

[0015] Preferably, the binder comprises a composition of 25 to 30 parts of low-density polyethylene, 25 to 30 parts of high-density polyethylene, 2 to 10 parts of ethylene-vinyl acetate copolymer and 20 to 25 parts of paraffin wax, and the plasticizer is 2 to 10 parts of octadecyl acrylate.

[0016] In the above technical solution, the binder mainly provides a system with good fluidity, so that the materials are mixed evenly and can maintain the shape of the materials to a certain extent without collapsing, and the plasticizer further improves the fluidity and stability of the material system;

[0017] The inventors have found that the selection and proportioning of the above-mentioned binder and plasticizer can achieve better fluidity and stability, so that the titanium alloy powder can have good strength while optimizing the filtration resistance.

[0018] More preferably, the titanium alloy powder is 15 to 25 parts by mass.

[0019] Preferably, step (S.4) further includes step (S.5): immersing the sintered filter element into a graphene emulsion to dip-coat the graphene, and then allowing the graphene to adhere to the surface and pores of the filter element.

[0020] Further preferably, in step (S.5), the filter element after dip-coating with graphene is first subjected to centrifugal rotation to remove excess graphene emulsion, and then subjected to curing or natural air drying to allow the graphene to adhere to the surface and pores of the filter element.

[0021] In the above technical solution, graphene attached to the surface and pores of the filter element reduces the filtration aperture of the filter element, that is, improves the filtration accuracy of the filter element. Therefore, the filter element attached with graphene is suitable for further precision filtration, usually as the second and / or third stage filtration.

[0022] The first filter element is prepared by the preparation method of the above steps (S.1) to (S.4), that is, the filter element does not include a graphene layer.

[0023] The second filter element is prepared by the above-mentioned preparation method including step (S.5), that is, it includes a filter element containing a graphene layer.

[0024] A water purifier uses a filter element prepared by the preparation method described in any of the above technical solutions for filtration.

[0025] In the preferred technical solution, the water purifier uses the first filter element to perform 1~2 level filtration first, and uses the second filter element to perform subsequent filtration.

[0026] In summary, the technical solution of the present invention has the following main beneficial effects:

[0027] Compared with the prior art, the titanium alloy filter element described in the technical solution of the present invention achieves a smaller filtering resistance effect while ensuring filtering accuracy, and at the same time has a high filter element strength;

[0028] At the same time, the present invention ensures better filter element strength and filtering accuracy through an optimal binder formulation.

[0029] Further or more detailed beneficial effects will be described in detail in conjunction with specific examples in the specific implementation manner. DETAILED DESCRIPTION

[0030] The present invention is further explained with reference to the following embodiments:

[0031] The core technical problem faced by the technical solution of the embodiment of the present application comes from the inventor's accurate understanding of the prior art. Therefore, how to make the titanium alloy filter element obtain a smaller filtration resistance while ensuring the filtration accuracy is a technical problem that the inventor urgently needs to solve.

[0032] At the same time, how to ensure the strength of the filter element is also a technical problem that the inventors are trying to solve simultaneously.

[0033] It should be noted that the embodiments do not constitute a limitation on the protection scope of the claims of the present invention. According to the technical concepts provided / proven by the embodiments, all technical solutions that can be reasonably anticipated by technicians in the relevant technical field should be included in the protection scope of the claims of the present invention.

[0034] The embodiments are described in detail as follows:

[0035] The preparation method of titanium alloy filter element for water purifier is as follows:

[0036] (S.1): According to the weight ratio, 15-25 parts of industrial high-purity titanium powder, 25-30 parts of low-density polyethylene, 25-30 parts of high-density polyethylene, 2-10 parts of ethylene-vinyl acetate copolymer, 20-25 parts of paraffin wax, and 2-10 parts of octadecyl acrylate are mixed, and the mixture is heated to 150-250° C. and kneaded to obtain a mixed material;

[0037] (S.2): using a granulator to granulate the mixed material, and using an injection molding machine to injection-mold the granules into a filter element blank in the shape of a filter element;

[0038] (S.3): Degreasing and pickling the filter element blank at 450~600℃ to remove most of the binder;

[0039] (S.4): The degreased filter element blank is sintered at a temperature of 800-1200°C for a time of 0.5-0.8 hours to obtain a first filter element with nanometer to micrometer-scale pores.

[0040] For some filter elements, step (S.4) also includes step (S.5):

[0041] The sintered filter element is immersed in graphene emulsion to be coated with graphene. The filter element after graphene coating is first centrifuged to remove excess graphene emulsion, and then low-temperature cured or naturally air-dried to allow the graphene to adhere to the surface and pores of the filter element, thereby obtaining the second filter element.

[0042] In this embodiment, the filtration accuracy and porosity of the filter element are measured by the bubble pressure method, and the compressive strength is tested by the method described in Part 3 of GB / T14041.3-2010 Hydraulic filter element.

[0043] Embodiment 1:

[0044] The preparation method of titanium alloy filter element for water purifier is as follows:

[0045] (S.1): According to the mass percentage, 20 parts of industrial high-purity titanium powder (mass content of titanium is greater than 99.4%, average particle size is 3.2-6.5 μm), 25 parts of low-density polyethylene, 25 parts of high-density polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 25 parts of paraffin wax, and 10 parts of octadecyl acrylate are mixed, and the mixture is heated to 180° C. and kneaded to obtain a mixed material;

[0046] (S.2): using a granulator to granulate the mixed material, and using an injection molding machine to injection-mold the granules into a filter element blank in the shape of a filter element;

[0047] (S.3): Degreasing and pickling the filter element blank at 500°C to remove most of the binder;

[0048] (S.4): The degreased filter element blank is sintered at a sintering temperature of 1200°C for 30 minutes to obtain a titanium alloy filter element.

[0049] Embodiment 2:

[0050] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 1 in that:

[0051] In step (S.4), the sintering temperature is 1100°C and the sintering time is 35 minutes.

[0052] Embodiment 3:

[0053] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 1 in that:

[0054] In step (S.4), the sintering temperature is 800°C and the sintering time is 48 minutes.

[0055] Comparative Example 1:

[0056] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 3 in that:

[0057] In step (S.4), the sintering time is 60 minutes.

[0058] The performance parameters of the filter elements prepared in Examples 1 to 3 and Comparative Example 1 are shown in Table 1:

[0059] Table 1 Performance parameters of the filter elements prepared in Examples 1 to 3 and Comparative Example 1

[0060] Serial number Filtration accuracy / μm Compressive strength / Mpa Porosity / % Example 1 1.09 1.10 46 Example 2 1.17 1.08 47 Example 3 1.20 1.01 51 Comparative Example 1 1.13 1.06 37

[0061] As can be seen from Table 1, the filter elements sintered in Examples 1 to 3 have a sintering temperature of 800 to 1200°C and a sintering time of 0.5 to 0.8 h, a filtration accuracy of 1.09 to 1.20 μm, and a compressive strength of 1.01 to 1.10, which can meet the use requirements of the water purifier, especially the porosity, which can reach more than 46%. A larger porosity means that water is easier to pass through the filter element, the resistance of the filter element is lower, and the corresponding water purifier has a smaller energy consumption. The filter element is particularly suitable for 1 to 2 level pre-filtration;

[0062] Compared with Example 3, Comparative Example 1 only increases the sintering time from 48 minutes to 1 hour. Although the filtration accuracy and compressive strength of Comparative Example 1 are improved compared with Example 3, its porosity is greatly reduced from 51% of Example 3 to 37%, which means that the filtration resistance of the filter element is greatly increased and the energy consumption of the water purifier is relatively large. Therefore, preferably, the sintering temperature of the filter element corresponding to the embodiment is preferably 800~1200℃, and the sintering time is preferably 0.5~0.8 hours.

[0063] Embodiment 4:

[0064] The preparation method of titanium alloy filter element for water purifier is as follows:

[0065] (S.1): According to the mass percentage, 25 parts of industrial high-purity titanium powder (mass content of titanium is greater than 99.4%, average particle size is 3.2-6.5 μm), 30 parts of low-density polyethylene, 30 parts of high-density polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 25 parts of paraffin wax, and 10 parts of octadecyl acrylate are mixed, and the mixture is heated to 180° C. and kneaded to obtain a mixed material;

[0066] (S.2): using a granulator to granulate the mixed material, and using an injection molding machine to injection-mold the granules into a filter element blank in the shape of a filter element;

[0067] (S.3): Degreasing and pickling the filter element blank at 500°C to remove most of the binder;

[0068] (S.4): The degreased filter element blank is sintered at a sintering temperature of 800°C for 48 minutes to obtain a titanium alloy filter element.

[0069] Embodiment 5:

[0070] The preparation method of titanium alloy filter element for water purifier is as follows:

[0071] (S.1): According to the mass percentage, 15 parts of industrial high-purity titanium powder (mass content of titanium is greater than 99.4%, average particle size is 3.2-6.5 μm), 25 parts of low-density polyethylene, 25 parts of high-density polyethylene, 2 parts of ethylene-vinyl acetate copolymer, 20 parts of paraffin wax, and 2 parts of octadecyl acrylate are mixed, and the mixture is heated to 180° C. and kneaded to obtain a mixed material;

[0072] (S.2): using a granulator to granulate the mixed material, and using an injection molding machine to injection-mold the granules into a filter element blank in the shape of a filter element;

[0073] (S.3): Degreasing and pickling the filter element blank at 500°C to remove most of the binder;

[0074] (S.4): The degreased filter element blank is sintered at a sintering temperature of 800°C for 48 minutes to obtain a titanium alloy filter element.

[0075] Embodiment 6:

[0076] The preparation method of titanium alloy filter element for water purifier is as follows:

[0077] (S.1): According to the mass proportion, 20 parts of industrial high-purity titanium powder (mass content of titanium is greater than 99.4%, average particle size is 3.2-6.5 μm), 27 parts of low-density polyethylene, 27 parts of high-density polyethylene, 5 parts of ethylene-vinyl acetate copolymer, 23 parts of paraffin wax, and 5 parts of octadecyl acrylate are mixed, and the mixture is heated to 180° C. and kneaded to obtain a mixed material;

[0078] (S.2): using a granulator to granulate the mixed material, and using an injection molding machine to injection-mold the granules into a filter element blank in the shape of a filter element;

[0079] (S.3): Degreasing and pickling the filter element blank at 500°C to remove most of the binder;

[0080] (S.4): The degreased filter element blank is sintered at a sintering temperature of 800°C for 48 minutes to obtain a titanium alloy filter element.

[0081] Comparative Example 2:

[0082] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 6 in that:

[0083] The mass fraction of ethylene vinyl acetate copolymer was adjusted to 28 parts, and no paraffin was added.

[0084] Comparative Example 3:

[0085] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 6 in that:

[0086] The mass fraction of paraffin wax was adjusted to 28 parts, and ethylene vinyl acetate copolymer was not added.

[0087] The performance parameters of the filter elements prepared in Examples 4 to 6 and Comparative Examples 2 to 3 are shown in Table 2:

[0088] Table 2 Performance parameters of filter elements prepared in Examples 4 to 6 and Comparative Examples 2 to 3

[0089] Serial number Filtration accuracy / μm Compressive strength / Mpa Porosity / % Example 4 1.20 1.03 51 Example 5 1.22 1.00 52 Example 6 1.21 1.01 51 Comparative Example 2 1.40 0.95 49 Comparative Example 3 1.47 0.85 50

[0090] As can be seen from Table 2, Examples 4 to 6 using the binder and plasticizer formulation of low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, paraffin wax, and octadecyl acrylate have good performance in filtration accuracy, compressive strength, porosity, etc., and are relatively stable;

[0091] Comparative Example 2 is compared with Example 6, in which ethylene vinyl acetate copolymer is used to replace paraffin wax. The filtration accuracy and compressive strength parameters of Comparative Example 2 are obviously inferior to those of Example 6, and the porosity is equivalent to that of Example 6.

[0092] Comparative Example 3, compared with Example 6, uses paraffin instead of ethylene vinyl acetate copolymer, and its filtration accuracy and compressive strength parameters are also significantly inferior to those of Example 6, and its porosity is equivalent to that of Example 6;

[0093] This may be because the combination of ethylene vinyl acetate copolymer and paraffin wax has a synergistic effect in enhancing the uniformity and stability of material distribution. The lack of either one will have an adverse effect on the performance of the filter element.

[0094] Embodiment 7:

[0095] The method for preparing a titanium alloy filter element for a water purifier is different from that of Example 6 in that:

[0096] The method further comprises the step (S.5): immersing the filter element sintered in the step (S.4) into a graphene emulsion to coat the filter element with graphene, first subjecting the filter element coated with graphene to centrifugal rotation to remove excess graphene emulsion, and then subjecting the filter element to low temperature curing or natural air drying to allow the graphene to adhere to the surface and pores of the filter element, thereby obtaining a graphene filter element;

[0097] Specifically, firstly, nanometer (30-200 nm) graphite powder is added to ethanol, stirred and ultrasonically treated to mix evenly, then the solution is filtered through a 2000-3000 mesh filter to remove large agglomerates, and the filtrate is dispersed in deionized water or pure water and ultrasonically treated to obtain a nanometer multilayer graphene emulsion (solid-liquid ratio is controlled at 2-10:90-98);

[0098] The titanium alloy filter element prepared in Example 6 was immersed in the graphene emulsion for 5-10 minutes to allow the emulsion to completely enter the gap of the filter element. The filter element was then taken out from the emulsion and placed on a rotating table for drying (rotation number 40-60rpm, drying for 20-40s), and excess emulsion was removed under the action of centrifugal force. The filter element was then placed in a dust-free environment at a temperature of 20-35°C, a humidity of 40-65%, and a wind speed of 1-5m / s, and naturally air-dried and cured for 24-36 hours to obtain a graphene filter element.

[0099] The performance parameters of the graphene filter element prepared in Example 7 are: filtration accuracy 0.76 μm, compressive strength 1.01 Mpa, porosity 47%. The filter element can be used for precision filtration after 1~2 level filter elements, that is, suitable for 3 level and above filtration.

[0100] The embodiment part also relates to a water purifier, which uses the filter element described in Example 6 for first-stage filtration and the filter element described in Example 7 for second-stage filtration.

[0101] In the description of this specification, the description with reference to the terms "embodiment", "basic embodiment", "preferred embodiment", "other embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0102] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0103] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a filter element for a water purifier, It is characterized in that The steps include: (S.1): A step of mixing titanium alloy powder, a binder and a plasticizer, and heating and stirring the mixture to obtain a mixed material; The binder comprises a composition of low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer and paraffin, and the plasticizer is octadecyl acrylate; The binder comprises a composition of 25 to 30 parts of low-density polyethylene, 25 to 30 parts of high-density polyethylene, 10 parts of ethylene-vinyl acetate copolymer and 20 to 25 parts of paraffin wax in terms of weight percentage, and the plasticizer is 2 to 10 parts of octadecyl acrylate; (S.2): a step of granulating the mixed material and forming it into a filter element blank; (S.3): a step of degreasing the filter element blank; (S.4): a step of sintering the degreased filter element blank, wherein the sintering temperature is 800-1200° C. and the sintering time is 0.5-0.8 hours.

2. The preparation method according to claim 1, Features: The titanium alloy powder is industrial high-purity titanium powder with a titanium content greater than 99.4%.

3. The preparation method according to claim 1, Features: The titanium alloy powder is present in an amount of 15 to 25 parts by mass.

4. The preparation method according to claim 1, Features: The step (S.4) further includes the step (S.5): immersing the sintered filter element into a graphene emulsion to dip-coat the graphene, and then allowing the graphene to adhere to the surface and pores of the filter element.

5. The preparation method according to claim 4, Features: In step (S.5), the filter element after dip-coating with graphene is first subjected to centrifugal rotation to remove excess graphene emulsion, and then cured or naturally air-dried to allow the graphene to adhere to the surface and pores of the filter element.

6. Filter element, Features: Prepared by the preparation method according to any one of claims 1 to 3.

7. Filter element, Features: Prepared by the preparation method described in claim 4 or 5.

8. Water purifier, Features: Filtration is performed using the filter element prepared by the preparation method according to any one of claims 1 to 5.

9. Water purifier, Features: Use the filter element described in claim 6 to first perform 1~2 level filtration, and use the filter element described in claim 7 to perform subsequent filtration.