Cleaning method of cleaner, manufacturing method of display glass plate, and display glass plate

Abstract

To obtain a display glass plate having a low contamination degree.SOLUTION: A cleaning method of a cleaner 100 for cleaning a display glass plate G with an aqueous cleaning fluid includes: a step 1 in which at least one of a contamination degree of an area of a member forming the cleaner 100 which contacts with the aqueous cleaning fluid and a contamination degree of the aqueous cleaning fluid is measured; and a step 2 in which the cleaner 100 is cleaned when the contamination degree measured in the step 1 does not meet a standard.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for cleaning a cleaning apparatus, and more particularly to a method for cleaning a cleaning apparatus for cleaning glass plates for displays with an aqueous cleaning liquid. The present invention also relates to a glass plate for a display and a method for producing a glass plate for a display. [Background technology]

[0002] Flat Panel Displays (FPDs) used in liquid crystal displays, plasma displays, organic electroluminescence displays, etc. are becoming increasingly high-definition. Accordingly, dense electric circuits are formed on the surfaces of the glass plates used in FPDs during the FPD manufacturing process. Therefore, high cleanliness is required for the glass plates used in FPDs.

[0003] For example, Patent Document 1 discloses a technique for cleaning foreign matter attached to the end face of a glass substrate by polishing with a cleaning liquid in order to achieve a high degree of cleanliness on the surface of the glass substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-188420 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors attempted to manufacture a glass plate for displays by referring to the technique described in Patent Document 1, and found that the surface of the glass plate for displays was highly contaminated in some cases and that improvement in this regard was necessary. The present inventors have studied the above problem and found that the degree of contamination may be high due to the cleaning device.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to obtain a glass plate for displays having a low degree of contamination. [Means for solving the problem]

[0007] As a result of extensive investigation into the above problems, the present inventors have found that the above problems can be solved by the following configuration. [1] A cleaning method for a cleaning device for cleaning a glass plate for a display with an aqueous cleaning liquid, comprising the steps of: a step 1 of measuring at least one of a degree of contamination of an area of ​​a member constituting the cleaning device that comes into contact with the aqueous cleaning liquid and a degree of contamination of the aqueous cleaning liquid; and a step 2 of cleaning the cleaning device if the degree of contamination measured in the step 1 does not satisfy the standard. [2] The method for cleaning a cleaning device according to [1], wherein the contamination level is measured using a microorganism testing device or a microorganism testing kit. [3] The method for cleaning a cleaning device according to [2], wherein the microorganism testing device or the microorganism testing kit is based on any one of the principles of an ATP detection method, a culture method, and a staining method. [4] The microorganism testing device is selected from the group consisting of a luminometer and a bioprotometer; The method for cleaning a cleaning device according to [2] or [3], wherein the microorganism testing kit is selected from the group consisting of a water sampler and an easy plate. [5] The method for cleaning a cleaning apparatus according to any one of [1] to [4], wherein in step 1, a degree of contamination of an area of ​​a member constituting the cleaning apparatus that comes into contact with the aqueous cleaning liquid is measured. [6] The cleaning method for the cleaning device according to any one of [1] to [5], wherein the cleaning device includes a tank for storing an aqueous cleaning liquid, a pipe having one end connected to the tank, and a supply unit connected to the other end of the pipe for supplying the aqueous cleaning liquid to the display glass. [7] A method for producing a glass plate for display, comprising the cleaning method for the cleaning apparatus according to any one of [1] to [6]. [8] The number of tissues containing bacteria with sizes between 0.002 and 2 mm is between 0.0001 and 0.005 per m 2 That is, a glass plate for display. Effect of the Invention

[0008] According to the present invention, a glass plate for a display having a low degree of contamination can be obtained. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a cleaning apparatus for cleaning a glass plate for a display with an aqueous cleaning liquid, which is used in the cleaning method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The following description of the configuration may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.

[0011] The following describes the meaning of each description in this specification. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] <How to clean the cleaning device> The cleaning method of the cleaning apparatus of the present invention (hereinafter also simply referred to as "the cleaning method") is a method for cleaning an apparatus for cleaning a glass plate for display with an aqueous cleaning liquid, and includes step 1 of measuring at least one of the degree of contamination of an area of ​​a component constituting the cleaning apparatus that comes into contact with the aqueous cleaning liquid and the degree of contamination of the aqueous cleaning liquid, and step 2 of cleaning the cleaning apparatus when the degree of contamination measured in step 1 does not satisfy a standard. The mechanism by which the present cleaning method enables production of glass plates for displays with a low degree of contamination in the cleaning device after cleaning is not entirely clear, but the present inventors speculate as follows. Through investigations by the present inventors, it has been found that contamination of glass plates for displays is caused by contamination of cleaning equipment. As a result of further investigations, the inventors have found that at least one of the degree of contamination of the region of the member constituting the cleaning device that comes into contact with the aqueous cleaning liquid and the degree of contamination of the aqueous cleaning liquid is related to the degree of contamination of the glass plate for display obtained by cleaning using the cleaning device. Therefore, it is considered that the degree of contamination of the glass plate for display can be reduced by cleaning the cleaning device when the degree of contamination exceeds the standard. The cleaning method will now be described. In the following, the glass plate for display is also simply referred to as "glass plate".

[0013] [Process 1] In step 1, at least one of the degree of contamination of an area of ​​a member constituting a cleaning device for cleaning a glass plate for a display with an aqueous cleaning liquid that comes into contact with the aqueous cleaning liquid and the degree of contamination of the aqueous cleaning liquid is measured. First, the cleaning device to which the present cleaning method is applied will be described with reference to the drawings. Fig. 1 is a schematic diagram of a cleaning device for cleaning a glass plate for a display (glass plate) with an aqueous cleaning liquid, which is used in the cleaning method of the present invention. 1 includes a plurality of conveying rollers (not shown) stretched in a direction perpendicular to a conveying direction D (the direction of the white arrow in FIG. 1). As the conveying rollers rotate, the glass sheet G is conveyed in the conveying direction D along the conveying path 10 and passes through an area A1. The area A1 is defined by a housing 30 that is a part of the cleaning apparatus 100.

[0014] The cleaning device 100 is equipped with shower heads 22 as supply units on both sides of the glass sheet G transported along the transport path 10 within the area A1, and an aqueous cleaning liquid is sprayed from the shower heads 22 toward the glass sheet G to clean the surface of the glass sheet G. The shower head 22 is connected to a pipe 32 for supplying an aqueous cleaning liquid from a tank 36, and the pipe 32 is connected to the tank 36. The pipe 32 may have a joint 34 midway.

[0015] The cleaning device 100 is also provided with air knives 24 on both sides of the glass sheet G transported along the transport path 10 in the area A1, and air is blown from the air knives 24 toward the glass sheet G to remove the aqueous cleaning liquid adhering to the surface of the glass sheet G and dry the glass sheet G. In the cleaning device 100, the air knives 24 are installed downstream of the shower head 22 on the transport path 10.

[0016] The cleaning device 100 shown in FIG. 1 may further include, in addition to the area A1, another area having a similar configuration to the area A1. Specifically, for example, the cleaning apparatus 100 may further have, as the other regions, a physical cleaning region for performing physical cleaning of the glass plate G upstream of region A1 on the transport path 10, and a liquid cleaning region for supplying liquid to the surface of the glass plate G to perform cleaning. In the physical cleaning area, for example, physical cleaning is performed by a disk brush while a cleaning liquid (cleaning liquid for physical cleaning) is supplied to the surface of the glass sheet G. Also, in the liquid cleaning area, for example, a liquid cleaning liquid (cleaning liquid for liquid cleaning) is supplied to the surface of the glass sheet G, and the cleaning liquid for physical cleaning attached to the surface of the glass sheet G in the physical cleaning area is removed. As the cleaning liquid (physical cleaning liquid, liquid cleaning liquid), for example, the aqueous cleaning liquid may be used. The other area is defined, for example, by a housing (not shown) different from the housing 30 that defines the area A1. Moreover, an exhaust device (not shown) may be provided in the area A1 and the other areas.

[0017] The cleaning apparatus to which the present cleaning method is applied is not limited to the above-mentioned embodiment, and can be modified as appropriate without departing from the spirit of the present invention. However, the cleaning apparatus supplies an aqueous cleaning liquid to the glass plate in any of its regions to clean the glass plate. For example, the showerhead 22 in the embodiment of FIG. 1 may be replaced with other supplies capable of supplying the aqueous cleaning liquid to the glass sheet.

[0018] The glass plate to be supplied to the cleaning apparatus which is the subject of the present cleaning method is preferably a glass base material cut and chamfered to a desired size, and more preferably a glass plate whose surface, etc., has been polished after cutting and chamfering. That is, the cleaning apparatus which is the subject of the present cleaning method is preferably a cleaning apparatus used in a cleaning step for cleaning a glass plate after a cutting step and a chamfering step of the glass plate, more preferably after a cutting step, a chamfering step and a polishing step of the glass plate.

[0019] As described above, in step 1, at least one of the degree of contamination of the area of ​​the member constituting the cleaning device that comes into contact with the aqueous cleaning liquid and the degree of contamination of the aqueous cleaning liquid is measured. The aqueous cleaning liquid refers to a cleaning liquid made of a liquid that is miscible with water in any ratio, and preferably contains water. The aqueous cleaning liquid in the cleaning device used in the present cleaning method is preferably an alkaline aqueous cleaning liquid, an acidic aqueous cleaning liquid, or water, and more preferably water. The water is preferably pure water, which has a specific electric resistivity of 1 MΩ·cm or more. The alkaline aqueous cleaning solution refers to a solution that contains water and a basic component and has a pH of more than 7.0. Examples of the basic component include inorganic basic components such as ammonia, sodium hydroxide, and potassium hydroxide, and organic basic components such as amine compounds and quaternary ammonium salts. The acidic aqueous cleaning solution refers to a solution that contains water and an acidic component and has a pH of less than 7.0. Examples of the acidic component include inorganic acidic components such as hydrogen chloride, hydrogen fluoride, sulfuric acid, nitric acid, and phosphoric acid, and organic acid components such as carboxylic acid and sulfonic acid.

[0020] Examples of the regions of the components constituting the cleaning device that come into contact with the aqueous cleaning liquid include the shower head 22, the pipe 32, the joint 34, and the inner wall surfaces of the tank 36, as well as the inner wall surface of the housing 30 that defines the area A1 in Fig. 1. The region that comes into contact with the aqueous cleaning liquid is preferably the inner wall surface of the pipe 32 or the tank 36.

[0021] Although there is no particular limitation on the method for measuring at least one of the degree of contamination of the above-mentioned region and the degree of contamination of the aqueous cleaning solution, it is preferable to measure the degree of contamination using a microorganism testing device or a microorganism testing kit. In other words, it is preferable to detect the degree of the amount of microorganisms present as the degree of contamination. When measuring the degree of contamination of the above-mentioned area, the above-mentioned area may be brought into contact with a sampling member, and the sampling member may be used as a sample, or the material adhering to the sampling member may be transferred to another liquid, and the other liquid may be used as a sample. The sampling member is not particularly limited as long as sampling is possible, but it is preferable not to use a member containing a heavy metal that inhibits luminescence, and a member containing the detection target adenosine triphosphate (ATP), adenosine diphosphate (ADP), or adenosine monophosphate (AMP). The area of ​​the region in contact with the sampling member can be appropriately set depending on the degree of contamination, the member or device, etc., but is, for example, 5 cm 2 is preferred. In addition, when the degree of contamination of an aqueous cleaning solution is measured, the degree of contamination may be measured by using the aqueous cleaning solution as a sample. The amount of the aqueous cleaning solution used as the sample can be appropriately set.

[0022] The microorganism test device or the microorganism test kit may be based on the principle of detecting ATP. For example, the amount of ATP contained in a sample can be quantified based on the amount of luminescence generated when reacting with luciferin under the catalytic activity of luciferase, and the amount of ATP can be used to analyze the degree of the presence of microorganisms. The above method is also called an ATP detection method. Luciferase may be natural luciferase or a recombinant luciferase mutant genetically engineered. There is no particular limitation on luciferase as long as it uses ATP as a substrate. When ATP present in a sample is reacted with luciferin under the catalytic activity of luciferase, it is preferable to react in the presence of metal ions such as magnesium, manganese, and calcium. The luciferin is not particularly limited as long as it is recognized as a substrate by the luciferase used, and may be natural luciferin or chemically synthesized luciferin. Also, known luciferin derivatives may be used. The basic structure of luciferin is imidazopyrazinon, and there are many tautomers. Examples of luciferin derivatives include those described in JP 2007-91695 A and JP 2010-523149 A. In addition, ATP, O2, and luciferin are converted into adenosine monophosphate (AMP), pyrophosphate, CO2, and oxyluciferin by luciferase, and light is emitted during the conversion.

[0023] When detecting microorganisms based on the principle of detecting ATP, ATP may be generated from ADP by an enzyme and the amount of ADP converted to ATP may also be detected.Furthermore, ATP may be generated from AMP by an enzyme and the amount of AMP converted to ATP may also be detected.

[0024] When detecting microorganisms based on the principle of detecting at least one of ATP, ADP, and AMP as described above, the abundance of the microorganisms can be analyzed by measuring the amount of luminescence using a commercially available reagent. Commercially available reagents include, for example, those that detect ATP, and those that detect ATP and / or ADP and AMP. An example of an ATP detector is Lucifer 250 (Kikkoman Biochemifa Corporation). An example of an ATP, ADP, and AMP detector is Lucipack A3 Surface (Kikkoman Biochemifa Corporation), an example of an ATP and AMP detector is Lucifer 250 (Kikkoman Biochemifa Corporation), and an example of an ATP and ADP detector is ELDT-100 (Bioassay Systems Corporation).

[0025] The amount of luminescence produced by luciferase can be detected by a known luminescence measuring device. Examples of the luminescence measuring device include luminometers (Centro LB960 and Lumat3 LB9508 manufactured by Berthold, Lumitester (registered trademark, the same applies below) C-110, Lumitester C-100, Lumitester PD-30, and Lumitester PD-20 manufactured by Kikkoman Biochemifa, and System Sure Plus, EnSURE, and EnSURE Touch manufactured by Nitta Corporation). The luminescence measuring device can measure relative luminescence intensity (RLU), and the amount of ATP and the like in the sample can be evaluated using this value as an index. Note that the luminescence measuring device usually measures the luminescence generated during the conversion of luciferin to oxyluciferin. In addition, examples of the luminescence measuring device include a device equipped with a photomultiplier tube (manufactured by 3M, etc.) and a device equipped with a photodiode (manufactured by Hygena, etc.). The above-mentioned exemplary methods correspond to methods using a microorganism testing device.

[0026] The microorganism testing device or the microorganism testing kit may also be one that cultures the microorganisms contained in the sample and analyzes the amount of the microorganisms present by observing the colonies that are formed. The above method is also called a culture method. The method for observing the colonies that have developed and analyzing the level of the amount of microorganisms present is not particularly limited, and examples thereof include a method selected from the group consisting of a water sampler and Easy Plate (registered trademark) from Kikkoman Biochemifa Co., Ltd. The above-mentioned method corresponds to a method using a microorganism test kit.

[0027] Furthermore, the microorganism testing device or the microorganism testing kit may stain the microorganisms contained in the sample and detect the amount of luminescence from the stained microorganisms. The above method is also called a staining method. The device for detecting the amount of luminescence from the stained microorganisms is not particularly limited, but an example thereof is Bioprola manufactured by Koyo Sangyo Co., Ltd. The above-mentioned method corresponds to a method using a microorganism testing device.

[0028] The glass plate to be cleaned by the cleaning apparatus to which the present cleaning method is applied is, for example, a glass plate used for a flat panel display (FPD: Flat Panel Display) such as a liquid crystal display (LCD: Liquid Crystal Display), a plasma display (PDP: Plasma Display), or an organic light-emitting diode (OLED: Organic Light-Emitting Diode). The glass plate may be of the same material, thickness and size as glass plates generally used for the above-mentioned applications.

[0029] [Process 2] In step 2, if the level of contamination measured in step 1 does not meet the standard, the cleaning device is cleaned. First, in step 2, the contamination level measured in step 1 is compared with a standard to determine whether the contamination level measured meets the standard. The standard can be appropriately set depending on the measurement method. The standard can be appropriately set based on the relationship between the number of defects in the glass plate obtained by cleaning with the cleaning device and the contamination level obtained in step 1. The standard can be appropriately set depending on the location where the contamination level is measured in step 1. The comparison between the standard and the measured contamination level may be performed manually by an operator of the cleaning device, or may be performed by a device connected to the cleaning device. The device is, for example, a personal computer (PC), and is preferably equipped with a recording medium on which the standard value is recorded in advance, an input unit for inputting the contamination level value, and a comparison unit for comparing the standard value with the contamination level value. The comparison unit is, for example, composed of a CPU (Central Processing Unit), a storage device such as a RAM (Random Access Memory) connected to the CPU, an auxiliary storage device such as an SSD (Solid State Drive) connected to the CPU, and a program for operating the CPU.

[0030] The cleaning performed in step 2 is preferably performed on the area of ​​the components constituting the cleaning device that come into contact with the aqueous cleaning liquid. Hereinafter, as the cleaning method of the cleaning device in step 2, a case where cleaning is performed on the components constituting the cleaning device that come into contact with the aqueous cleaning liquid (hereinafter, also simply referred to as "components of the cleaning device" will be described.

[0031] Methods for cleaning the cleaning device include, for example, physical cleaning, chemical cleaning, and sterilization. Physical cleaning refers to cleaning aimed at physically removing contamination, and examples of such cleaning include scrubbing with a cleaning tool, washing with running water, and ultrasonic cleaning. In physical cleaning, it is preferable to bring a cleaning solution W described later into contact with the components of a cleaning device. Chemical cleaning refers to cleaning that aims to remove contamination by chemical action by bringing cleaning liquid W into contact with the components of the cleaning device. For example, there is a soaking method in which the components of the cleaning device are brought into contact with cleaning liquid W for a certain period of time. Sterilization is a process in which the components of a cleaning device are placed in an environment that is difficult for microorganisms to grow in, thereby reducing the number of microorganisms. Examples of sterilization include boiling, heat and pressure sterilization, ultraviolet irradiation, and drying in a dryer. Note that chemical cleaning and physical cleaning may be combined to perform the cleaning in step 2. Furthermore, the cleaning in step 2 may be performed multiple times, or different types of cleaning methods may be used for each step.

[0032] The cleaning tool is not particularly limited, and any commonly used tool can be used. Examples of the cleaning tool include sponges, brushes, scrubbing brushes, dishcloths, and paper towels. The cleaning liquid W used in the cleaning in the above step 2 is not particularly limited, and any known cleaning liquid can be used. Examples of the cleaning liquid W include an alcohol-based solvent, a liquid containing peracetic acid, an aqueous hypochlorous acid solution, an ammonia solution, a liquid containing an antibacterial agent, and a liquid containing a surfactant. The surfactant is not particularly limited, and any known surfactant can be used, including, for example, cationic surfactants, anionic surfactants, amphoteric surfactants, and nonionic surfactants. The antibacterial agent is not particularly limited, and known antibacterial agents can be applied, such as silver compounds, isothiazolinone-based antibacterial agents, triazine-based antibacterial agents, imidazole-based antibacterial agents, pyridine-based antibacterial agents, azole-based antibacterial agents, iodine-based antibacterial agents, and pyrithione-based antibacterial agents.

[0033] The cleaning in step 2 may be cleaning with disassembly (COP), which is performed by disassembling the cleaning equipment, or cleaning in place (CIP), which is performed without disassembling the cleaning equipment.

[0034] After carrying out the cleaning in step 2, the cleaning device may be rinsed with the aqueous cleaning solution.

[0035] Also, cleaning in step 2 may be performed, and a determination may be made as to whether or not the contamination level measured again in step 1 satisfies the predetermined standard. If the result of the determination is that the contamination level does not satisfy the predetermined standard, cleaning in step 2 may be performed again. Furthermore, after cleaning in step 2 is performed again, a determination may be made as to whether or not the contamination level measured in step 1 satisfies the predetermined standard. Step 2 and step 1 may be repeated, and the cleaning in step 2 and the measurement of the contamination level in step 1 may be repeated until a predetermined standard is satisfied. In addition, when step 2 is performed two or more times, it is also preferable to adopt a different washing method or washing conditions from the previous washing for the second or subsequent washings in step 2. For example, the type of the above-mentioned washing method, washing time, number of washings, type of washing solution W used, concentration of washing solution W, supply amount of washing solution W, type of washing tool, etc. may be appropriately changed. Also, the degree of contamination may be measured in step 1, and only those areas that do not meet a predetermined standard may be cleaned in step 2.

[0036] According to the present cleaning method, a glass plate for a display having a low degree of contamination can be produced in a cleaning device after cleaning, and a glass plate for a display having a low degree of contamination can be obtained. A glass plate for a display having a low degree of contamination is useful because a denser electric circuit can be formed on the glass plate for a display, and a higher-definition FPD can be obtained.

[0037] <Display glass plates> The glass plate for display of the present invention has a number of tissues containing bacteria having a size of 0.002 to 2 mm of 0.0001 to 0.005 pieces / m 2 It is. The glass plate for displays of the present invention (hereinafter also referred to as "glass plate of the present invention") has a small number of tissues including bacteria, and can form a denser electric circuit. If the size of the bacteria-containing tissue exceeds 2 mm, the wiring, etc. formed on the glass plate for display is likely to break. Also, if the size of the bacteria-containing tissue is less than 0.002 mm, it is difficult to detect it as a foreign body, and if wiring, etc. is formed on the glass plate for display with the foreign body remaining, the properties of the electric circuit are likely to vary. The number of tissues containing bacteria was 0.005 / m 2 If the number of bacteria-containing tissues is more than 0.0001 / m, the wiring formed on the glass plate for displays is likely to break. 2 If the amount is less than this, it will be difficult to detect it as a foreign matter, and if wiring or the like is formed on a glass plate for a display with the foreign matter remaining thereon, the properties of the electric circuit will be likely to vary.

[0038] In the glass plate of the present invention, the tissue containing bacteria refers to a tissue containing one or more bacteria, and includes a single bacterium and a biofilm formed by the bacteria. The size of a single bacterium is often about 2 μm. The size of a biofilm is often about 0.1 to 2 mm. The tissue containing bacteria is preferably a biofilm.

[0039] The number of tissues containing the bacteria is determined as follows. First, a multi-beam surface defect inspection machine scans at specified intervals to identify the location and size of defects on the glass plate. From the scanned defects, defects measuring 0.002 to 2 mm in size are extracted, and the extracted defect locations are observed under an optical microscope. The number of defects that are determined to be tissues containing bacteria as a result of observation under the optical microscope is counted. The number of defects is multiplied by the ratio of the total area of ​​the scanned area and the unscanned area to the scanned area to determine the number of tissues containing bacteria (unit: pieces / m2) on the glass plate. 2 ) is calculated. In addition, the above-mentioned determination of whether or not a tissue contains bacteria using an optical microscope is performed by first obtaining a relationship between characteristic points of an observation image such as transmittance and shape when observing a defect in advance and whether or not the defect contains bacteria. Based on the above relationship, it is determined whether or not the tissue contains bacteria from the characteristic points of the transmittance and shape of the defect.

[0040] <Method of manufacturing glass plate for display> The method for producing a glass plate for display of the present invention includes a cleaning method using the above-mentioned cleaning apparatus of the present invention. That is, the method for producing a glass plate for display of the present invention is a method for producing a glass plate by using a cleaning apparatus that has been cleaned by the above-mentioned cleaning method for a cleaning apparatus of the present invention. The method for producing a glass plate for display of the present invention preferably comprises a cutting step of cutting a glass plate from a glass plate as a base material, a chamfering step of chamfering the cut surface of the cut glass plate, and a cleaning step of cleaning the glass plate that has been subjected to the chamfering step. In the cleaning step, a cleaning device that has been cleaned by the cleaning method for the cleaning device of the present invention described above is used. The above-mentioned glass plate of the present invention can be produced by the method of producing a glass plate for displays of the present invention. [Explanation of symbols]

[0041] 10 Transport path 22 Shower head (supply section) 24 Air Knife 30 Case 32 Piping 34 Joints 36 Tank 100 Cleaning equipment A1 area D Conveying direction G Glass plate

Claims

1. A method for cleaning a cleaning apparatus for cleaning a glass plate for a display with an aqueous cleaning liquid, comprising the steps of: A step 1 of measuring at least one of a degree of contamination of an area of ​​a member constituting the cleaning device that comes into contact with the aqueous cleaning liquid and a degree of contamination of the aqueous cleaning liquid; and if the degree of contamination measured in step 1 does not satisfy a standard, a step 2 of cleaning the cleaning apparatus.

2. 2. The method for cleaning a cleaning device according to claim 1, wherein the measurement of the degree of contamination is carried out using a microorganism testing device or a microorganism testing kit.

3. 3. The method for cleaning a cleaning device according to claim 2, wherein the microorganism testing device or the microorganism testing kit is based on any one of the principles of an ATP detection method, a culture method, and a staining method.

4. The microbiological testing device is selected from the group consisting of a luminometer and a bioprotometer; The method for cleaning a cleaning device according to claim 3 , wherein the microorganism test kit is selected from the group consisting of a water sampler and an easy plate.

5. 5. The method for cleaning a cleaning apparatus according to claim 1, wherein in the step 1, a degree of contamination of an area of ​​a member constituting the cleaning apparatus that comes into contact with the aqueous cleaning liquid is measured.

6. 5. The cleaning method for a cleaning device according to claim 1, wherein the cleaning device includes a tank for storing an aqueous cleaning liquid, a pipe having one end connected to the tank, and a supply unit connected to the other end of the pipe for supplying the aqueous cleaning liquid to the display glass.

7. A method for producing a glass plate for a display, comprising the cleaning method for the cleaning apparatus according to any one of claims 1 to 4.

8. The number of tissues containing bacteria with a size of 0.002 to 2 mm is 0.0001 to 0.005 / m ２ That is, a glass plate for display.

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