Liquid leakage sensor and manufacturing method thereof

Abstract

The present invention relates to a method for manufacturing a liquid leakage sensor, and more particularly, to a method for manufacturing a liquid leakage sensor, which is cheap and can be easily manufactured by continuously arranging non-conductive layers and conductive layers and compressing the layers. The method may include: using non-conductive powder to shape a non-conductive mold product having a flat top surface and bottom surface; using conductive raw materials to shape a conductive mold product having a flat top surface and bottom surface; stacking the non-conductive mold products and the conductive mold products alternately up and down on a die; molding a single compressed product by applying pressure up and down to the stacked non-conductive mold products and conductive mold products using a compressor; sintering the compressed mold product; and performing a scraping process on the side of the sintered compressed product to a given thickness.

Description

Technical Field

[0001] The present invention relates to a liquid leakage sensor and a method for manufacturing the same, and more particularly to a liquid leakage sensor which is inexpensive and can be easily manufactured by continuously arranging a non-conductive layer and a conductive layer and then performing a scraping process on a molded product formed by compressing the layers using a press, and a method for manufacturing the same. Background Art

[0002] Korean Patent No. 10-2084721 (capacitive leakage sensor) granted to the present applicant has a structure for detecting various types of leaks of water, conductive and non-conductive chemical solutions, oils, and organic solvents. The structure has a "structure including a base film made of a material having excellent drug resistance and chemical resistance and a pair of conductive wires formed at intervals on a top surface of the base film, the pair of conductive wires being configured to form a capacitance based on the area and interval of the conductive wires, wherein each conductive wire includes three metal layers, a first layer of the lowest layer being formed using copper by etching, a second layer formed on the first layer having a nickel-copper layer formed therein by an electroplating method, and a third layer being formed on the second layer using a gold plating method."

[0003] Therefore, when leaked liquid is introduced into adjacent conductive lines, water, conductive or non-conductive chemical solution, oil, or organic solvent can be determined based on the change in capacitance value.

[0004] The capacitive leakage sensor is also applied to a detection device that detects a liquid leakage state based on a change in conductivity or resistance value of the leaked liquid instead of a capacitance value.

[0005] However, according to such prior art, since the conductive wire is manufactured by forming a conductive metal material such as copper, nickel copper or gold on the top surface of the base using a plating method, the capacitive leakage sensor has very excellent conductivity. However, the capacitive leakage sensor has a problem that the number of times of repeated use is limited, because if the capacitive leakage sensor contacts a chemical solution such as an alkaline solution or an acid solution, it is easily corroded and peeled off, and errors in detection signals often occur due to corrosion, and has the disadvantages that the manufacturing process is very cumbersome and expensive.

[0006] If a conductive wire is formed using a carbon material according to a method such as printing, the conductive wire is less susceptible to chemical solutions than a metal material. In this case, there is a problem that if a protective film is stacked on a base film, the protective film for protecting the conductive wire is easily peeled off due to a step between the base film and the conductive wire.

[0007] <Prior Art Literature>

[0008] 1. Korean Patent No. 10-2084721

[0009] (Capacitive Leak Sensor) Summary of the invention

[0010] An embodiment of the present invention provides a liquid leakage sensor, which is manufactured by: molding a cylindrical compressed product, which is formed by alternately stacking non-conductive mold products and conductive mold products on a cylindrical mold and then compressing the mold products using a compressor, then sintering the compressed product, and then scraping the sintered product along the side of the sintered product to a given thickness; and a manufacturing method thereof.

[0011] In one embodiment, a liquid leakage sensor, wherein a conductive layer is sintered and positioned on a side of a non-conductive layer made of a non-conductive material, and the non-conductive layer and the conductive layer are alternately sintered and positioned at least once.

[0012] Furthermore, in one embodiment, a method for manufacturing a leaking liquid leakage sensor includes: a first step of molding a non-conductive mold article having flat top and bottom surfaces using a non-conductive powder; a second step of molding a conductive mold article having flat top and bottom surfaces using a conductive raw material; a third step of stacking the non-conductive mold articles and the conductive mold articles alternately up and down on a die; a fourth step of molding a single compression article by applying pressure up and down to the stacked non-conductive mold articles and the conductive mold articles using a compressor; a fifth step of sintering the compression mold article; and a sixth step of performing a scraping process on the side of the sintered compression article to a given thickness.

[0013] The non-conductive layer or the conductive powder is made of polytetrafluoroethylene (PTFE), and the conductive layer or the conductive raw material is made of a raw material mixed with PTFE and carbon nanotubes (CNT). BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figures 1 to 3 1 is a diagram for describing steps of manufacturing a liquid leakage sensor according to an embodiment of the present invention.

[0015] Figure 4 is a diagram showing the structure of a liquid leakage sensor according to an embodiment of the present invention.

[0016] Figure 5 is a diagram showing a cross section of a liquid leakage sensor according to an embodiment of the present invention.

[0017] Figure 6 is a diagram showing another form of the liquid leakage sensor.

[0018] Figure 7is a flow chart illustrating a method of manufacturing a liquid leak sensor. DETAILED DESCRIPTION

[0019] The aforementioned objects, features, and advantages are described in detail with reference to the accompanying drawings, so that those skilled in the art to which the present invention pertains can easily practice the technical spirit of the present invention.

[0020] In describing the present disclosure, if a detailed description of the related art related to the present disclosure is deemed to unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0021] As terms used in the present invention, general terms widely used now are selected by considering functions in the present invention, and the terms may be different according to intentions of those skilled in the art, precedents, or the emergence of new technologies.

[0022] In addition, in certain cases, the applicant randomly selects some terms. In this case, the meaning of the corresponding terms will be described in detail in the description part of the corresponding invention.

[0023] Therefore, the terms used in the present invention should not be defined simply based on their names but should be defined based on their substantial meanings and contents over the present invention.

[0024] Hereinafter, embodiments of the present invention are described in detail with reference to the accompanying drawings.

[0025] However, the embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the following embodiments.

[0026] The embodiments of the present invention are provided to those skilled in the art to more fully describe the present invention.

[0027] Figures 1 to 3 1 is a diagram for describing steps of manufacturing a liquid leakage sensor according to an embodiment of the present invention. Figure 4 is a diagram showing the structure of a liquid leakage sensor according to an embodiment of the present invention. Figure 5 is a diagram showing a cross section of a liquid leakage sensor according to an embodiment of the present invention.

[0028] Figure 6 is a diagram showing another form of the liquid leakage sensor. Figure 7 is a flow chart illustrating a method of manufacturing a liquid leak sensor.

[0029] In order to manufacture the liquid leakage sensor according to the embodiment of the present invention, first, Figure 1 As shown, a cylindrical non-conductive molded article having flat top and bottom surfaces is manufactured using non-conductive powder. The non-conductive powder may include polytetrafluoroethylene (PTFE) powder having drug resistance and chemical resistance.

[0030] In addition to PTFE, various materials in powder form, such as fluorinated ethylene propylene copolymer (FEP), perfluoroalkoxy (PFA), and ethylene tetrafluoroethylene (ETFE) may also be used as the non-conductive powder.

[0031] In the embodiment of the present invention, the example using the PTFE powder has been described, but the present invention is not limited thereto.

[0032] The conductive mold product stacked on the non-conductive mold product is molded using PTFE powder and carbon nanotubes (CNTs). After inputting and stirring 10 to 30 wt% of PTFE powder, 1 to 10 wt% of multi-walled carbon nanotubes (MWCNTs), 59.9 to 88.1 wt% of an organic solvent, and 1 to 9 wt% of a metal coupling agent, the organic solvent is removed, and the remaining mixture is dried at a low temperature and formed into a cylindrical shape with flat top and bottom surfaces, similar to the non-conductive mold product.

[0033] CNT is made of carbon and has a tube form with a diameter of nanometer size. CNT has the characteristics of high thermal conductivity / electrical conductivity, high strength and chemical stability. In addition to CNT, materials such as graphene can also be used.

[0034] PTFE has high electrical conductivity, a characteristic of CNTs, while maintaining unique properties through the coupling of PTFE and CNTs.

[0035] like Figure 2 As shown, non-conductive mold articles and conductive mold articles are alternately stacked in a die 100 having a cylindrical shape. A first non-conductive mold article 210 is located on a lower compressor 110 inserted into a lower side of the die 100. A first conductive mold article 220 is stacked on the first non-conductive mold article 210. A second non-conductive mold article 230 is stacked on the first conductive mold article 220.

[0036] Furthermore, the second conductive mold article 240 is stacked on the second non-conductive mold article 230. The third non-conductive mold article 250 is stacked on the second conductive mold article 240.

[0037] Furthermore, the conductive mold articles and the non-conductive mold articles may be alternately stacked on the third non-conductive mold article 250. In this case, the number of conductive lines formed by the conductive mold articles may be increased as needed.

[0038] When the non-conductive molded article and the conductive molded article are stacked as described above, a single cylindrical compressed article is formed by pressurizing the lower compressor 110 and the upper compressor 120 .

[0039] The compressed product has a state in which the non-conductive mold product and the conductive mold product have not been firmly bonded. Therefore, the non-conductive mold product and the conductive mold product are bonded by sintering. Since the non-conductive mold product is formed using PTFE and the conductive mold product also contains PTFE, the non-conductive mold product and the conductive mold product are easily sintered and bonded by the same material.

[0040] As a result, bonding according to sintering is easily performed only when the non-conductive molded article and the conductive molded article are formed using the same material.

[0041] The steps of pre-molding the non-conductive molded article into a cylindrical shape and inputting the molded non-conductive molded article into the die 100 have been described. However, as another form, PTFE powder may be directly stacked.

[0042] That is, the top surface of the PTFE powder is flattened after the PTFE powder is stacked at the same height instead of the first non-conductive mold article 210. The first conductive mold article 220 is stacked on the PTFE powder. Thereafter, the PTFE powder is stacked on the first conductive mold article 220 and flattened.

[0043] By repeating such steps, non-conductive powder may be stacked instead of non-conductive mold products.

[0044] Thereafter, after a cylindrical compressed product is formed by applying pressure using the lower compressor 110 and the upper compressor 120 and then sintered, the non-conductive powder and the conductive mold product are combined together.

[0045] In the cylindrical compressed product formed as described above, Figure 3 As shown, the first non-conductive layer 310 is formed from the lowermost side by the first non-conductive mold article 210. The first conductive layer 320 is combined and stacked by the first conductive mold article 220. The second non-conductive layer 330 is formed by the second non-conductive mold article. The second conductive layer 340 is combined and stacked by the second conductive mold article 240. The third non-conductive layer 350 is formed by the third non-conductive mold article 250.

[0046] If the cylindrical compressed product is scraped from the outer circumferential surface to a given thickness using a scraper 400, then Figure 4 As shown, the liquid leakage sensor 300 is formed to have a long strip shape.

[0047] That is, the sides of the first non-conductive layer 310, the first conductive layer 320, the second non-conductive layer 330, the second conductive layer 340, and the third non-conductive layer 350 are sintered and bonded laterally. The second non-conductive layer 330 serves as an insulator between the first conductive layer 320 and the second conductive layer 340. The first non-conductive layer 310 and the third non-conductive layer 350 located at the outermost side protect the sides of the first conductive layer 320 and the second conductive layer 340 so that the sides are not exposed to the outside.

[0048] Therefore, if Figure 5 As shown, the first conductive layer 320 and the second conductive layer 340 are positioned in parallel while maintaining a gap therebetween by the second non-conductive layer 330, thereby serving as electrodes. Therefore, when the leaking solution L is located on the top surfaces of the first conductive layer 320 and the second conductive layer 340, the leakage state of the solution L can be detected using a capacitance method, a resistance method, or a conductivity method.

[0049] Since the bottom and top surfaces of the liquid leakage sensor 300 have a flat state by the scraping process, the adhesive member to be attached to the bottom of the liquid leakage sensor 300 can be attached to the bottom surface without being lifted. In addition, the protective film can be closely attached to the top surface.

[0050] That is, as in the prior art, if a conductive line is formed on the top surface of the base film, the protective film is easily lifted and peeled off due to the step between the base film and the conductive line. However, in the embodiment of the present invention, since the non-conductive layers 310, 330, and 350 and the conductive layers 320 and 340 are formed flat at the same height, the protective film can be attached very stably.

[0051] The non-conductive layers 310, 330, and 350 and the conductive layers 320 and 340 contain PTFE, so their surfaces have very smooth lubricity. Therefore, when the leaking solution L is introduced into the top surface, the leaking solution slides easily. This may make it difficult for the leaking solution to be positioned between the conductive layers 320 and 340.

[0052] In order to solve such problems, Figure 5 As shown in (a), the lines 321 and 341 made of PTFE material are backstitched in the length direction of the conductive layers 320 and 340. Therefore, the tops of the backstitched lines 321 and 341 are located higher than the surfaces of the conductive layers 320 and 340.

[0053] Therefore, the leaked solution L is positioned between the reverse-sewn lines 321 and 341. As a result, since the leaked solution L flows down, the conductive layers 320 and 340 can detect the leaked solution L very easily.

[0054] The lines 321 and 341 may be reverse-sewn in the length direction of the conductive layers 320 and 340. Figure 5 As shown in (b), the lines 321 and 341 may be formed at the outer edge portions of the conductive layers 320 and 340 , ie, in the length direction between the first conductive layer 320 and the first non-conductive layer 310 and between the second conductive layer 340 and the third non-conductive layer 350 .

[0055] Wires 321 and 341 have been described as being made of PTFE material, but may be formed using various materials other than PTFE, such as fluorinated ethylene propylene copolymer (FEP), perfluoroalkoxy (PFA), or ethylene tetrafluoroethylene (ETFE) having drug resistance and chemical resistance.

[0056] Figure 6 3 is a diagram showing another form of the liquid leakage sensor 300. The liquid leakage sensor 300 may have a structure in which conductive layers 320 and 340 are positioned in parallel on both sides of a second non-conductive layer 330.

[0057] In this case, since the second non-conductive layer 330 is located between the two conductive layers 320 and 340 functioning as electrodes, the two conductive layers 320 and 340 can maintain a given interval and can be insulated. Figure 5 The five layers shown, however, may have only three layers, namely, two conductive layers 320 and 340 and a second non-conductive layer 330. Therefore, the manufacturing cost may be greatly reduced.

[0058] Furthermore, the conductive layers 320 and 340 may be reverse-stitched by lines 321 and 341 in the length direction thereof.

[0059] An advantage of the liquid leakage sensor and the manufacturing method thereof according to an embodiment of the present invention is that the liquid leakage sensor can be manufactured inexpensively and very easily because a non-conductive mold product made of PTFE and a conductive mold product made of PTFE and CNT are alternately stacked on a die having a cylindrical shape, the non-conductive mold product and the conductive mold product are compressed by a compressor to form a single cylindrical compressed product, and the compressed product is sintered and scraped along the side of the mold product to a given thickness.

[0060] Furthermore, there are advantages in that, since the non-conductive wire and the conductive wire are sintered, peeling does not occur as in the related art, and chemical resistance and chemical resistance are very excellent.

[0061] The above has described a specific part of the content of the present invention. For ordinary technicians in this field, such detailed description is only a preferred embodiment, and it is obvious that the scope of the present invention is not limited by such detailed description.

[0062] Accordingly, it shall be deemed that the true scope of the present invention is defined by the appended claims and their equivalents.

[0063] Description of Reference Numerals

[0064] 100: Die 110: Lower compressor

[0065] 120: Upper compressor 210, 230, 250: Non-conductive mold

[0066] 220, 240: Conductive mold 300: Liquid leakage sensor

[0067] 310, 330, 350: non-conductive layer

[0068] 320, 340: Conductive layer

[0069] 400: Scraping machine.

Claims

1. A method for manufacturing a leaking liquid leak sensor, comprising: The first step is to alternately stack non-conductive powder and conductive mold products made of conductive raw materials on a die. The second step is to form a single compressed product by applying pressure up and down to the stacked non-conductive powder and the conductive mold product using a compressor; The third step: sintering the compressed product; and Fourth step: performing scraping processing on the side surface of the sintered compressed product to a given thickness.

2. The method according to claim 1, characterized in that: The non-conductive powder is polytetrafluoroethylene powder, and The conductive raw material is a mixture of polytetrafluoroethylene powder and carbon nanotubes, or a mixture of polytetrafluoroethylene powder and graphene, or a mixture of polytetrafluoroethylene, carbon nanotubes and graphene.

3. The method according to claim 1, characterized in that: When the non-conductive powder and the conductive molded article are alternately stacked in multiple layers, the non-conductive powder is located at the uppermost side.

4. The method according to claim 1, characterized in that: When the non-conductive powder and the conductive molded article are alternately stacked in multiple layers, the conductive molded article is located at the lowest side and the highest side.

5. The method according to claim 1, further comprising the step of reverse-stitching a thread having chemical resistance and chemical resistance in a length direction of the conductive mold product after the scraping process.

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