Cleaning agent, method for producing cleaning agent, method for producing cleaned article cleaned with cleaning agent, and method for cleaning article

Abstract

To provide a detergent capable of strongly cleaning an object to be cleaned as compared with alkali shower cleaning in which an alkali cleaning liquid containing no solid content is sprayed to the object to be cleaned.SOLUTION: The cleaning agent 10 is sprayed onto the object to be cleaned 12 in order to clean the object to be cleaned 12. The detergent 10 contains an alkaline sodium bicarbonate aqueous solution 38 and glass particles 41. Therefore, in the washing with the detergent 10, the physical detergency of the solid washing component 40 containing the glass particles 41 and the chemical detergency of the alkaline sodium bicarbonate aqueous solution 38 act at the same time. Therefore, for example, as compared with a case where chemical cleaning in which the sodium bicarbonate aqueous solution 38 is sprayed onto the object to be cleaned 12 and physical cleaning in which a mixed fluid of water and the glass particles 41 is sprayed onto the object to be cleaned 12 are performed in order, significantly high detergency can be obtained. Then, for example, it is possible to clean the object to be cleaned 12 with remarkably high detergency as compared with the above-described alkali shower cleaning.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cleaning agent, a method for producing the cleaning agent, a method for producing cleaned items that have been cleaned with the cleaning agent, and a method for cleaning objects to be cleaned. [Background technology]

[0002] Patent Document 1 describes a blasting method in which a blasting medium made up of predetermined particles is sprayed onto an object to be cleaned together with a fluid injection medium. By using this blasting method, the object to be cleaned can be cleaned. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-343435 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the growing interest in protecting the global environment, there has been a strong desire to establish a circular economy that recycles products and materials. For example, in the recycling of automobile parts, a cleaning process is one of the processes required for that recycling. In the cleaning process for recycling automobile parts, various cleaning methods, such as the blasting method described in Patent Document 1, are expected to be used to clean the automobile parts to be recycled.

[0005] However, when recycling automobile parts, dirt is firmly attached to the automobile parts. Therefore, it has been difficult to achieve sufficient cleaning effects with various existing cleaning agents. For example, when an alkaline cleaning solution, which is a mixture of an alkaline concentrate and water, is used as a cleaning agent, the object to be cleaned must be cleaned for a long time. Furthermore, cleaning with an alkaline cleaning solution often results in insufficient removal of dirt, resulting in poor cleanliness. In such cases, the object to be cleaned must be discarded, which places a burden on the environment. The above findings were discovered as a result of detailed studies by the inventors.

[0006] In view of the above, the present disclosure aims to provide a cleaning agent capable of more powerful cleaning than cleaning with the above-mentioned conventional alkaline cleaning solution, a method for producing the cleaning agent, a method for producing articles that have been cleaned with the cleaning agent, and a cleaning method using the cleaning agent. [Means for solving the problem]

[0007] In order to achieve the above object, a cleaning agent according to one aspect of the present disclosure comprises: A cleaning agent (10) to be sprayed onto an object (12) to be cleaned, an alkaline aqueous solution (38); and glass particles (41).

[0008] In this way, when cleaning with the above-mentioned cleaning agent, both the physical cleaning power, which removes dirt by collision of glass particles with the surface of the object to be cleaned, and the chemical cleaning power, which removes dirt from the surface of the object to be cleaned by the chemical action of the alkaline aqueous solution, work simultaneously, making it possible to clean the object to be cleaned with a cleaning power that is significantly higher than that of cleaning with, for example, the above-mentioned conventional alkaline cleaning solution.

[0009] Further, a method for producing a cleaning agent according to another aspect of the present disclosure includes: A method for producing a cleaning agent (10) to be sprayed onto an object (12) to be cleaned, comprising: A method for producing a mixture of sodium bicarbonate particles (42) having an average particle diameter of 200 to 400 μm, glass particles (41) having an average particle diameter of 200 to 400 μm, and water (S101); The method includes mixing the sodium bicarbonate particles, the glass particles, and the water (S102) after setting the ratio (Cs) of the volume of the pre-mixing solid content to the total volume obtained by adding the volume of the pre-mixing solid content including the sodium bicarbonate particles and the glass particles and the volume (Vw) of the water to 10 to 30 vol% and setting the mass ratio (Rg) of the glass particles to the pre-mixing solid content to 50 to 99 mass%.

[0010] Even in this case, the cleaning agent has both physical and chemical detergency at the same time, so that it can clean objects with significantly higher detergency than, for example, conventional alkaline cleaning solutions. Furthermore, compared to when the mass percentage of the glass particles is less than 50 mass %, it is possible to obtain a cleaning agent that has higher physical detergency and, as a result, can clean objects more powerfully.

[0011] Furthermore, a manufacturing method according to another aspect of the present disclosure includes: A manufacturing method for manufacturing a washed item (13) obtained by washing an object to be washed (12), comprising the steps of: Preparing an object to be cleaned (S204); Preparing a cleaning agent (10) containing an alkaline aqueous solution (38) and glass particles (41) (S101, S102); and cleaning the object by spraying the cleaning agent onto the object, and obtaining the object as a cleaned article after cleaning (S205).

[0012] Even in this case, the cleaning agent has both physical and chemical detergency at work simultaneously, making it possible to clean objects with significantly higher detergency than, for example, conventional alkaline cleaning solutions, thereby preventing poor cleanliness of cleaned items.

[0013] Furthermore, a cleaning method according to another aspect of the present disclosure includes: A cleaning method for cleaning an object (12) having dirt (12a) attached thereto, comprising: Preparing an object to be cleaned (S204); Preparing a cleaning agent (10) containing an alkaline aqueous solution (38) and glass particles (41) (S101, S102); and spraying the cleaning agent onto the object to clean it and remove dirt (S205).

[0014] Even in this case, the cleaning agent has both physical and chemical detergency at work simultaneously, making it possible to clean objects with significantly higher detergency than, for example, cleaning with the conventional alkaline cleaning solution.

[0015] In addition, in each section of the application documents, each element may be assigned a reference number in parentheses. In this case, the reference number merely indicates an example of the correspondence between the element and the specific configuration described in the embodiment described below. Therefore, the present disclosure is not limited in any way by the description of the reference number. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a schematic configuration of a cleaning device used to clean an object to be cleaned in a first embodiment. [Figure 2] 1 is a table showing air pressure, solid volume ratio, cleaning time, and nozzle vibration frequency when cleaning an object to be cleaned in the first embodiment. [Figure 3] 1 is a flowchart showing a manufacturing process of a cleaning agent used to clean an object to be cleaned in the first embodiment. [Figure 4] 3 is a table showing the composition of raw materials of a cleaning agent in the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view schematically illustrating the configuration of the cleaning agent in the first embodiment when all sodium bicarbonate particles are dissolved in water without remaining undissolved. [Figure 6]FIG. 2 is a cross-sectional view schematically illustrating the structure of the cleaning agent in the first embodiment when some of the sodium bicarbonate particles remain undissolved in water. [Figure 7] 4 is a flowchart showing a recycling process including a process of cleaning an object to be cleaned in the first embodiment. [Figure 8] 1A and 1B are diagrams showing enlarged views of the surfaces of an object to be cleaned and an article that has already been cleaned, and also showing a schematic diagram of a method for measuring the brightness of these surfaces in the first embodiment. [Figure 9] FIG. 2 is a diagram showing a photographic image of an object to be cleaned before cleaning, taking a starter center case as an example in the first embodiment. [Figure 10] 10 is a diagram showing a photographic image of a washed article, which is the object to be washed shown in FIG. 9 after being washed. [Figure 11] FIG. 8 is a diagram showing the results of an experiment conducted to obtain the relationship between the cleaning effect in step S205 of FIG. 7 and the glass solid content ratio in the raw materials of the cleaning agent. [Figure 12] FIG. 2 is a cross-sectional view showing an enlarged view of the surface of the object to be cleaned in the first embodiment, and also showing a schematic diagram of the mechanism by which dirt on the surface of the object to be cleaned is removed by a cleaning agent. [Figure 13] FIG. 1 is a diagram showing an outline of the relationship between the kinetic energy of a solid cleaning component during cleaning, the Na concentration in the aqueous sodium bicarbonate solution of the cleaning agent, and the glass solid content ratio in the raw materials of the cleaning agent in the first embodiment. [Figure 14] FIG. 10 is a graph showing the relationship between the number of objects to be cleaned and the cleaning effect, with brightness used as an index value, when the glass solid content ratio is 90% by mass. [Figure 15] FIG. 10 is a graph showing the relationship between the number of objects to be cleaned and the cleaning effect, with brightness used as an index value, when the glass solid content ratio is 0% by mass. [Figure 16] FIG. 10 is a diagram corresponding to FIG. 8, which schematically illustrates a conventional example in which the degree of contamination is determined by visual inspection by an operator. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

[0018] (First embodiment) As shown in FIG. 1, a cleaning agent 10 of this embodiment is sprayed onto an object 12 to be cleaned in order to clean the object 12. In this embodiment, cleaning of the object 12 to be cleaned is performed as one process in recycling automobile parts. Therefore, the object 12 to be cleaned is, for example, a metal part for an automobile removed from a scrapped vehicle and recycled, specifically, a metal part made of iron or aluminum alloy. Examples of the object 12 to be cleaned include an alternator case that was placed in an engine compartment or the center case of an engine starter. Therefore, a large amount of oily dirt 12a adheres to the surface 121 of the object 12 to be cleaned (see FIG. 8) before cleaning. For example, the dirt 12a on the surface 121 of the object 12 to be cleaned contains a large amount of oily dirt.

[0019] The cleaning agent 10 is used in a cleaning device 14 shown in Fig. 1, for example, and is sprayed onto an object 12 to be cleaned within the cleaning device 14. As shown in Fig. 1, the cleaning device 14 is a device for spraying the cleaning agent 10 onto an object 12 to be cleaned housed within the cleaning device 14. The cleaning device 14 includes a cleaning tank 16, a cleaning agent tank 17, a cleaning agent supply pipe 18, an air supply pipe 19, a nozzle 20, and a recovery pipe 22.

[0020] The cleaning tank 16 is a housing capable of accommodating the object 12, and is provided with a door (not shown) or the like so that the object 12 can be taken in and out. The cleaning tank 16 is designed to cover the object 12 while housing it during cleaning. This prevents the sprayed cleaning agent 10 from scattering outside the cleaning tank 16. A rotatable table (not shown) is also provided within the cleaning tank 16. During cleaning, the object 12 is fixed on the table and rotates together with the table.

[0021] The cleaning agent tank 17 is a container for storing the cleaning agent 10. The cleaning agent tank 17 and the cleaning tank 16 are connected via a recovery pipe 22. During cleaning, the cleaning agent 10 that has been sprayed onto the object 12 and accumulated in the cleaning tank 16 is returned to the cleaning agent tank 17 through the recovery pipe 22 as shown by arrow A1 by, for example, a pump (not shown).

[0022] The cleaning agent supply pipe 18 is a pipe that guides the cleaning agent 10 stored in the cleaning agent tank 17 to the nozzle 20. Therefore, one end of the cleaning agent supply pipe 18 is open in the cleaning agent 10 stored in the cleaning agent tank 17, and the other end of the cleaning agent supply pipe 18 is connected to the nozzle 20. The cleaning agent supply pipe 18 is made up of, for example, a flexible hose.

[0023] The air supply pipe 19 is a pipe that guides compressed air Ar from an air supply source, such as a factory facility, to the nozzle 20. Therefore, one end of the air supply pipe 19 is connected to the air supply source, and the other end of the air supply pipe 19 is connected to the nozzle 20. The air supply pipe 19 is made up of, for example, a flexible hose. For example, as shown in FIG. 2 , in this embodiment, compressed air Ar at an air pressure of about 0.4 MPa is supplied to the nozzle 20.

[0024] 1 mixes the cleaning agent 10 supplied from the cleaning agent supply pipe 18 with the compressed air Ar supplied from the air supply pipe 19, and sprays the mixed cleaning agent 10 and compressed air Ar toward the object 12 to be cleaned in the cleaning tank 16. Specifically, the nozzle 20 is disposed in the cleaning tank 16 and is supported by the cleaning tank 16 so that it can oscillate while moving the nozzle side up and down as shown by arrow A2. The nozzle 20 is oscillated, for example, by an actuator (not shown). Specifically, during cleaning of the object 12 to be cleaned, the nozzle 20 sprays the cleaning agent 10 while oscillating as shown by arrow A2.

[0025] The cleaning device 14 is as described above, but before cleaning the object 12, the cleaning agent 10 is prepared. The process of preparing the cleaning agent 10, in other words, the process of manufacturing the cleaning agent 10, is shown in FIG.

[0026] To prepare the cleaning agent 10, first, in step S101 of Fig. 3, glass particles 41, sodium bicarbonate particles 42, and water, which are raw materials for the cleaning agent 10, are prepared as shown in Fig. 4. Therefore, the pre-mixing solid content, which is composed of solids to be mixed with water, is the glass particles 41 and sodium bicarbonate particles 42. The sodium bicarbonate particles 42 are particles composed of sodium bicarbonate crystals, and the average particle diameter of the sodium bicarbonate particles 42 is 200 to 400 µm. For example, EB60 manufactured by AGC is used as the sodium bicarbonate particles 42 prepared in step S101, and the average particle diameter of the EB60 is approximately 300 µm. Note that sodium bicarbonate is synonymous with sodium bicarbonate (i.e., NaHCO3).

[0027] The glass particles 41 are spherical particles made of glass, and have an average particle diameter of 200 to 400 μm. As the glass particles 41 prepared in step S101, for example, FGB-60 manufactured by Fuji Manufacturing Co., Ltd. is used, and the average particle diameter of FGB-60 is about 300 μm.

[0028] In this embodiment, for example, the average particle size of the baking soda particles 42 and the average particle size of the glass particles 41 are each calculated as the average value of the particle diameters (i.e., particle sizes) measured for all particles or a predetermined number of samples. The predetermined number of samples is preferably, for example, about 100 or more. The particle sizes of the baking soda particles 42 and the glass particles 41 are each measured particle by particle using a microscope. More specifically, since the baking soda particles 42 are elongated rather than spherical, the particle size of the baking soda particles 42 is measured using a microscope, with the long dimension of the baking soda particles 42 being considered as the particle size of the baking soda particles 42. On the other hand, since the glass particles 41 are spherical, the particle size of the glass particles 41 is measured using a microscope without distinguishing between the long dimension and the short dimension of the glass particles 41.

[0029] In step S101, the solid volume fraction Cs is preferably 10 to 30 vol%, and in this embodiment, for example, 20 vol%, and the glass solid fraction Rg is preferably 50 to 99 mass%, and in this embodiment, for example, 90 mass%.

[0030] The solid volume fraction Cs is the ratio of the volume of the pre-mixing solid content to the total volume obtained by adding the volume of the pre-mixing solid content to the volume of water Vw. Therefore, the solid volume fraction Cs is calculated from the following formula F1 based on the volume Vg of the glass particles 41, the volume Vj of the sodium bicarbonate particles 42, and the volume Vw of the water. Cs=(Vg+Vj) / (Vg+Vj+Vw)×100 (F1)

[0031] The glass solid content ratio Rg is the mass ratio of glass particles 41 to the total solid content before mixing. Therefore, the glass solid content ratio Rg is calculated from the following formula F2 based on the glass particle mass Mg, which is the mass of the glass particles 41, and the sodium bicarbonate particle mass Mj, which is the mass of the sodium bicarbonate particles 42. Unless otherwise specified, the solid content volume ratio Cs and the glass solid content ratio Rg refer to the component ratios before the sodium bicarbonate particles 42, glass particles 41, and water are mixed together. Rg = Mg / (Mg + Mj) × 100 (F2)

[0032] 3, the process proceeds to step S102, in which the sodium bicarbonate particles 42, glass particles 41, and water prepared in step S101 are mixed together. This produces the cleaning agent 10. Specifically, the entire amount of the raw materials prepared in step S101 is mixed together in step S102. That is, the solid volume fraction Cs and glass solid fraction Rg of the raw materials mixed in step S102 are the same as those in step S101.

[0033] As a result of mixing the baking soda particles 42, glass particles 41, and water, some or all of the baking soda particles 42 dissolve in water, causing a chemical change shown in formula F3 below. As a result, the cleaning agent 10 contains an aqueous baking soda solution 38 and glass particles 41, as shown in Figure 5 or 6. For example, if some of the baking soda particles 42 remain undissolved, the cleaning agent 10 will contain the aqueous baking soda solution 38, glass particles 41, and baking soda particles 42. As can be seen from formula F3 below, the aqueous baking soda solution 38 obtained in step S102, i.e., the aqueous baking soda solution 38 obtained by dissolving baking soda in water, is an alkaline aqueous solution. NaHCO3+H2O→Na + +OH - +H2O+CO2 (F3)

[0034] As described above, in step S102, the baking soda particles 42 dissolve in water, and so if all of the baking soda particles 42 are dissolved in water, the solid cleaning ingredient 40 contained in the detergent 10 will consist of glass particles 41 and no baking soda particles 42, as shown in Figure 5. The solid cleaning ingredient 40 of the detergent 10 is the solid component contained in the detergent 10, in other words, the solid component.

[0035] On the other hand, if some of the baking soda particles 42 remain undissolved, the solid cleaning component 40 of the cleaner 10 will be composed of solid baking soda particles 42 and glass particles 41, as shown in Figure 6. However, in this case, since the baking soda particles 42 are originally less in mass than the glass particles 41 before mixing, the baking soda particles 42 will also be less in mass than the glass particles 41 in the solid cleaning component 40.

[0036] Next, a process for obtaining a cleaned item 13, which is an item obtained by cleaning the item 12 with the above-described cleaning agent 10, will be described with reference to FIG. 7. As shown in FIG. 7, first, in step S201, pre-cleaned items including the item 12 are collected from the secondhand goods market. The secondhand goods market is a market where pre-cleaned used items are distributed, including automobile dismantler companies. For example, if the pre-cleaned item is an engine starter removed from a scrapped vehicle before cleaning, the item 12 to be cleaned is a starter center case included in the engine starter before cleaning. Also, if the pre-cleaned item is an alternator removed from a scrapped vehicle before cleaning, the item 12 to be cleaned is an alternator case included in the alternator before cleaning. Step S201 in FIG. 7 is followed by step S202.

[0037] In step S202, it is assumed that the object to be cleaned 12 removed from the pre-cleaning article will be cleaned in a subsequent cleaning process, and it is determined whether or not the cleaning process can sufficiently remove the dirt 12a on the object to be cleaned 12. Specifically, in this embodiment, as shown in FIG. 8, brightness measurement is performed on the surface 121 of the object to be cleaned 12 among the pre-cleaning articles. Then, the brightness L * If the measured value of is equal to or greater than a predetermined pre-cleaning brightness judgment value, it is judged that cleaning is possible to sufficiently remove the stains 12a on the object 12 to be cleaned. * If the measured value is less than a predetermined pre-cleaning brightness judgment value, it is judged that cleaning that sufficiently removes the stains 12a on the object 12 to be cleaned is not possible.

[0038] The pre-cleaning brightness determination value is experimentally set in advance so that it can be determined whether or not cleaning is possible depending on the cleaning ability of the cleaning performed in step S205, which will be described later. * The measurement is carried out using, for example, a spectrophotometer 32 as shown in FIG.

[0039] In step S202, if it is determined that the cleaning can sufficiently remove the stains 12a on the object 12 to be cleaned, that is, if the brightness L *If the measured value of is equal to or greater than the pre-cleaning brightness judgment value, the process proceeds to step S204. On the other hand, if it is judged that cleaning is not possible to sufficiently remove the stains 12a on the object 12 to be cleaned, that is, if the brightness L * If the measured value is less than the pre-cleaning brightness determination value, the process proceeds to step S203. * The pre-washed article is discarded when the measured value falls below the pre-washed brightness judgment value.

[0040] In step S204, the pre-cleaned article is disassembled, and the object to be cleaned 12 is taken out from the pre-cleaned article. That is, the object to be cleaned 12 is prepared. After step S204, the process proceeds to step S205.

[0041] In step S205, the cleaning agent 10 is sprayed onto the object 12 to clean the object 12. Therefore, before starting to clean the object 12, the cleaning agent 10 containing the sodium bicarbonate aqueous solution 38 and glass particles 41 is prepared in advance according to the manufacturing process shown in FIG.

[0042] Specifically, in step S205, as shown in Fig. 1, the object 12 to be cleaned is fixed on a table in the cleaning tank 16 of the cleaning device 14. Then, cleaning of the object 12 begins. During cleaning of the object 12, the nozzle 20 of the cleaning device 14 is oscillated as shown by arrow A2, spraying the cleaning agent 10 together with compressed air Ar onto the object 12. At the same time, the object 12 to be cleaned, fixed on a table provided in the cleaning tank 16, rotates in accordance with the rotation of the table.

[0043] This causes the cleaning agent 10 to be sprayed evenly over the entire surface 121 of the object 12. For example, if the object 12 is a case-shaped part, the cleaning agent 10 is sprayed evenly over the entire inner and outer surfaces of the case-shaped part. In step S205, the object 12 is cleaned in this way, thereby removing the dirt 12a adhering to the surface 121 of the object 12.

[0044] When cleaning of the object 12 is complete, the object 12 is removed from the table of the cleaning device 14, and the cleaned object 12 is obtained as a cleaned item 13. For example, Fig. 9 shows the object 12 before cleaning in step S205, in the case where the object 12 is a starter center case. Fig. 10 shows the cleaned item 13, which is the object 12 of Fig. 9 cleaned in step S205.

[0045] For example, in the cleaning in step S205 described above, the cleaning time for spraying the cleaning agent 10 onto the object 12 is 10 seconds, as shown in Fig. 2. The nozzle vibration frequency, which is the number of times the nozzle 20 swings back and forth, is 18 times per 10 seconds. The temperature of the cleaning agent 10 is preferably about 10 to 30°C, and more preferably about 30°C. Step S205 in Fig. 7 is followed by step S206.

[0046] In step S206, it is determined whether the stains 12a have been sufficiently removed from the washed article 13 obtained in step S205. Specifically, the determination in step S206 is also made by measuring the brightness, as in step S202, but the brightness L * The judgment value for step S202 is different.

[0047] That is, in step S206, as shown in FIG. 8, brightness measurement is performed on the surface 131 of the washed article 13. Then, the brightness L * If the measured value of is equal to or greater than a predetermined post-wash brightness judgment value, it is judged that the stain 12a has been sufficiently removed from the washed article 13. * If the measured value is less than a predetermined post-wash brightness judgment value, it is judged that the removal of the stain 12a from the washed article 13 is insufficient.

[0048] The post-wash brightness judgment value is experimentally set in advance so as to be able to judge whether the stain 12a has been sufficiently removed from the washed article 13, in other words, whether the stain 12a has been sufficiently removed by the washing in step S205. That is, the post-wash brightness judgment value is a judgment value for judging whether the washing result in step S205 is good or bad. The post-wash brightness judgment value corresponds to a predetermined judgment value for brightness in the present disclosure. Also, the brightness L in step S206 * The measurement is performed using, for example, the spectrophotometer 32 shown in FIG. 8, in the same manner as in step S202 described above.

[0049] In step S206 of FIG. 7, if it is determined that the stain 12a has been sufficiently removed from the washed article 13, that is, if the brightness L * If the measured value is equal to or greater than the post-washing brightness judgment value, the process proceeds to step S208. In short, in this case, the washed article 13 is judged to be a non-defective product.

[0050] On the other hand, if it is determined that the removal of the stain 12a is insufficient in the washed article 13, that is, if the lightness L * If the measured value is less than the post-wash brightness judgment value, the process proceeds to step S207. In short, in this case, the washed item 13 is judged to be a defective item. Then, in step S207, the washed item 13 judged to be a defective item is discarded.

[0051] In step S208, the cleaned article 13 is subjected to a glass shot. In the glass shot, glass particles are sprayed evenly onto the entire surface 131 of the cleaned article 13 together with high-pressure air. This blows away and removes the dirt 12a remaining on the surface 131 of the cleaned article 13. The glass particles used in this glass shot may be the same as the glass particles 41 contained in the cleaning agent 10, or may be different from the glass particles 41 contained in the cleaning agent 10. After step S208 in FIG. 7, the process proceeds to step S209.

[0052] In step S209, the cleaned item 13 that has been subjected to glass shot is attached to a mating part of a recycled product that includes the cleaned item 13, and the recycled product is assembled. As a result, a recycled product that includes the cleaned item 13 is completed. For example, if the cleaned item 13 is a starter center case, the recycled product is an engine starter. Also, if the cleaned item 13 is an alternator case, the recycled product is an alternator.

[0053] Here, in step S101 of Fig. 3, the glass solid content ratio Rg is set to, for example, 90 mass % as described above. An experiment was conducted to examine the relationship between the cleaning effect and the glass solid content ratio Rg in step S205 of Fig. 7, and the experimental results are shown in Fig. 11. In the experiment of Fig. 11, the object 12 to be cleaned is a starter center case, and the cleaning agent 10 is manufactured according to the process of Fig. 3, except that the glass solid content ratio Rg is changed. Therefore, the solid content volume ratio Cs of the raw materials before mixing into the cleaning agent 10 is, for example, 20 vol %, as described above in the explanation of Fig. 3. Note that the experiment of Fig. 11 is intended to confirm the cleaning effect in step S205 of Fig. 7, so glass shot after cleaning is not performed in the experiment of Fig. 11.

[0054] The vertical axis of Figure 11 is the brightness L. * is an index value that indicates the effectiveness of cleaning, and brightness L * The higher the value, the less soiling 12a there is after cleaning. The points Pw in FIG. 11 show the experimental results, and the lightness L measured on the surface 131 of the cleaned article 13 * The relationship between the glass solid content ratio Rg and the lightness L * is the average value of the measured values ​​at multiple points on the surface 131 of the washed article 13. In addition, the lightness L * Both of these values ​​are within the pre-cleaning brightness range Rbw in FIG.

[0055] From the experimental results represented by the multiple relation points Pw in Fig. 11, it is believed that when the cleaning agent 10 is manufactured according to the process in Fig. 3, the cleaning power of the cleaning agent 10 will be strongest when the glass solids ratio Rg is about "Rg = 90 mass%." Therefore, according to the experimental results in Fig. 11, in order to obtain high cleaning power of the cleaning agent 10, it is believed that the glass solids ratio Rg is preferably 50 to 99 mass%, and more preferably 85 to 95 mass%.

[0056] The experimental results shown in Fig. 11 were obtained because, as shown in Fig. 12, when cleaning is performed using the cleaning agent 10 of this embodiment, dirt 12a on the object 12 is removed by a synergistic effect of the physical and chemical cleaning powers of the cleaning agent 10. The physical cleaning power is the cleaning power that removes dirt 12a by the collision of solid cleaning components 40 of the cleaning agent 10 with the surface 121 of the object 12 as shown by arrow SH. The chemical cleaning power is the cleaning power that removes dirt 12a on the surface 121 of the object 12 by the chemical action of the alkaline sodium bicarbonate aqueous solution 38.

[0057] To be more specific about the physical detergency of the detergent 10, the greater the kinetic energy of the entire solid detergent component 40 of the detergent 10, the greater the physical detergency of the detergent 10. The kinetic energy of the entire solid detergent component 40 is the sum of the kinetic energies Es of the particles 41 and 42, calculated by the following formulas F4 and F5. Es=m×v 2 / 2 (F4) m=(4 / 3)×π×r 3 ×ρ (F5)

[0058] In the above formulas F4 and F5, m is the mass of the particles constituting the solid cleaning component 40, v is the particle velocity, and r is the particle radius, i.e., 1 / 2 of the average particle diameter. ρ is the density of the particles constituting the solid cleaning component 40, and for glass particles 41, ρ=2.5 g / cm 3 " and for sodium bicarbonate particles 42, "ρ = 2.2 g / cm 3When some of the sodium bicarbonate particles 42 remain undissolved, it is assumed that the average particle diameter of the undissolved sodium bicarbonate particles 42 is substantially the same as the average particle diameter of the sodium bicarbonate particles 42 before mixing prepared in step S101 of FIG.

[0059] Here, the glass particles 41 and the sodium bicarbonate particles 42 collide with the stains 12a on the surface 121 of the object 12 while being contained in the sodium bicarbonate aqueous solution 38, so it is thought that the velocity v at the time of collision is the same for both the glass particles 41 and the sodium bicarbonate particles 42. As mentioned above, the density of the glass particles 41 is greater than that of the sodium bicarbonate particles 42. Therefore, as can be seen from the above formulas F4 and F5, the more glass particles 41 there are in the solid cleaning ingredient 40, the greater the kinetic energy of the solid cleaning ingredient 40 during cleaning. The higher the glass solid content ratio Rg in step S101 of FIG. 3, the more glass particles 41 there are in the solid cleaning ingredient 40. Therefore, as shown in FIG. 13, the higher the glass solid content ratio Rg, the greater the kinetic energy of the solid cleaning ingredient 40. In other words, the higher the glass solid content ratio Rg, the greater the physical detergency of the cleaning agent 10.

[0060] Next, to explain the chemical cleaning power of the cleaning agent 10 in detail, the sodium bicarbonate aqueous solution 38 of the cleaning agent 10 contains sodium ions (i.e., Na + ) exists. The sodium ions then separate the dirt 12a from the surface 121 of the object 12 to be cleaned through a chemical reaction shown in the following formula F6. R in the following formula F6 stands for an alkyl group, and RCOOH on the left side corresponds to the oil content of the dirt 12a. Na + +RCOOH→RCOONa (F6)

[0061] As can be seen from the above formula F6, the Na concentration, which is the concentration of sodium ions in the aqueous solution of sodium bicarbonate 38, is an index value for the chemical detergency of the cleaning agent 10; the higher the Na concentration, the stronger the chemical detergency of the cleaning agent 10. The Na concentration of this aqueous solution of sodium bicarbonate 38 will be saturated if the amount of sodium bicarbonate particles 42 mixed with the water is sufficient to saturate the sodium ions. However, if the amount of sodium bicarbonate particles 42 is insufficient to saturate the sodium ions, the Na concentration will decrease as the number of sodium bicarbonate particles 42 decreases.

[0062] Therefore, as shown in Figure 13, in a low ratio region B1 where the glass solid content ratio Rg is equal to or less than a certain boundary value Xrg, the Na concentration reaches a saturated concentration and becomes constant. In a high ratio region B2 where the glass solid content ratio Rg exceeds the boundary value Xrg, the Na concentration decreases as the glass solid content ratio Rg increases. If the glass solid content ratio Rg is 100% by mass, the sodium bicarbonate particles 42 are not mixed as a raw material, and the Na concentration becomes zero. In the experiment shown in Figure 11, the boundary value Xrg in Figure 13 is approximately 50% by mass.

[0063] For these reasons, it is believed that the experimental results indicated by the multiple relation points Pw in FIG. 11 are due to the synergistic effect of the physical and chemical detergency of the cleaner 10, as described above.

[0064] 14 and 15 show the results of an experiment different from that of FIG. 11. In FIGS. 14 and 15, similarly to FIG. 11, the vertical axis shows the brightness L * is used, and the scale of the vertical axis is the same between Figures 14 and 15.

[0065] In both Figures 14 and 15, the horizontal axis indicates the number of washing machines that washed the object 12, and the vertical axis indicates the lightness L measured on the surface 131 of the washed article 13, which is the object 12 that was washed last among the number of washing machines. * The lightness L in Figs. * The broken line La in Fig. 14 shows the relationship between the number of units cleaned and the lightness L when the glass solid content ratio Rg is 90 mass %.* The solid line Lb in Figure 15 shows the relationship between the number of units cleaned and the lightness L when the glass solid content ratio Rg is 0 mass%. * It represents the relationship between

[0066] As a result of the experiment in FIG. 14, when the glass solid content ratio Rg was 90 mass %, the glass particles 41 and the sodium bicarbonate particles 42 were not refined regardless of the number of washing machines. * was almost constant regardless of the number of washing units. In contrast, as a result of the experiment in FIG. 15, when the glass solid content ratio Rg was 0 mass %, the sodium bicarbonate particles 42 were confirmed to be finer when the number of washing units slightly exceeded 40. The measured lightness L * This is presumably because the physical detergency of the cleaner 10 decreases as the size of the sodium bicarbonate particles 42 decreases.

[0067] 14 and 15, it is believed that mixing glass particles 41 into the cleaning agent 10 is effective for ensuring a certain degree of continuous use of the cleaning agent 10. Note that in the experiments shown in Figs. 14 and 15, glass shot was not performed after cleaning, as in the experiment shown in Fig. 11.

[0068] As described above, in this embodiment, as shown in Figures 1 and 12, the cleaning agent 10 is sprayed onto the object 12 to clean it. The cleaning agent 10 contains an alkaline sodium bicarbonate aqueous solution 38 and glass particles 41. Therefore, during cleaning with the cleaning agent 10, the physical cleaning power of the solid cleaning component 40 containing the glass particles 41 and the chemical cleaning power of the alkaline sodium bicarbonate aqueous solution 38 work simultaneously.

[0069] Therefore, in this embodiment, a significantly higher cleaning power can be obtained compared to, for example, a case where chemical cleaning in which a sodium bicarbonate aqueous solution 38 is sprayed onto the object 12 and physical cleaning in which a mixed fluid of water and glass particles 41 is sprayed onto the object 12 in sequence. Furthermore, it is possible to clean the object 12 with a significantly higher cleaning power compared to, for example, conventional alkaline shower cleaning. The conventional alkaline shower cleaning is a cleaning method in which, for example, an alkaline aqueous solution containing no solids and at about 60°C is sprayed onto the object 12.

[0070] Furthermore, the conventional alkaline shower cleaning requires a cleaning time of about 45 minutes, despite the cleaning power being inferior to that of the cleaning of this embodiment shown in Figures 3 and 7, whereas the cleaning time of this embodiment is 10 seconds as described above. In other words, the cleaning time of this embodiment can be significantly reduced compared to the conventional alkaline shower cleaning.

[0071] In this embodiment, the number of uncleaned articles discarded in step S203 and the number of cleaned articles 13 discarded in step S207 in the process of Fig. 7 were almost zero. In contrast, in the conventional alkaline shower cleaning described above, the ratio of articles discarded in steps S203 and S207, i.e., the defective rate, was about 60%. In addition, it was confirmed that the dirt 12a was removed from the cleaned articles 13 cleaned in step S205 of Fig. 7 in this embodiment to such an extent that the subsequent glass shot in step S208 was deemed unnecessary.

[0072] From these facts, it can be seen that the present embodiment provides a significantly higher cleaning power than the conventional alkaline shower cleaning described above. In addition, in the present embodiment, it is possible to eliminate any or all of the steps of determining whether cleaning is possible in step S202, determining whether the cleaning is good or bad in step S206, and glass shot in step S208.

[0073] (1) According to this embodiment, the aqueous solution contained in the detergent 10 is a sodium bicarbonate aqueous solution 38. As shown in Figures 5 and 6, the solid cleaning component 40 contained in the detergent 10 is composed of glass particles 41 and solid sodium bicarbonate particles 42 that are present in a smaller amount by mass than the glass particles 41, or is composed of only glass particles 41 without containing sodium bicarbonate particles 42. In other words, the mass proportion of glass particles 41 in the solid cleaning component 40 exceeds 50 mass%.

[0074] Therefore, while the chemical cleaning power of the sodium bicarbonate aqueous solution 38 is obtained, the physical cleaning power can be increased by increasing the amount of glass particles 41, which have a higher density than the sodium bicarbonate particles 42. As a result, the cleaning power of the cleaner 10 can be enhanced by the synergistic effect of the chemical cleaning power and the physical cleaning power.

[0075] (2) Furthermore, according to this embodiment, the object 12 to be cleaned is, for example, a metal part for an automobile to be recycled. Therefore, the cleaning agent 10 containing the sodium bicarbonate aqueous solution 38 and the glass particles 41 can exert a good cleaning effect.

[0076] (3) According to this embodiment, glass particles 41, sodium bicarbonate particles 42, and water are prepared in step S101 of Fig. 3, with the glass particles 41 having an average particle diameter of 200 to 400 µm and the sodium bicarbonate particles 42 also having an average particle diameter of 200 to 400 µm. In step S101, the solid volume fraction Cs is set to 10 to 30 vol%, and the glass solid fraction Rg is set to 50 to 99 mass%. The glass particles 41, sodium bicarbonate particles 42, and water are then mixed in step S102 of Fig. 3. Therefore, as shown in the experimental results of Fig. 11, the synergistic effect of the chemical cleaning power of the sodium bicarbonate aqueous solution 38 and the physical cleaning power of the solid cleaning component 40 allows the cleaning agent 10 to exert a high cleaning power on the object 12 to be cleaned.

[0077] (4) Furthermore, according to this embodiment, the glass solid content ratio Rg of the raw materials prepared in step S101 of Fig. 3 is set to, for example, 90 mass %. That is, in the process of Fig. 3, the glass solid content ratio Rg is set to 85 to 95 mass %, and then glass particles 41, sodium bicarbonate particles 42, and water are mixed together. Therefore, as shown in the experimental results of Fig. 11, it is possible to maximize or nearly maximize the detergency of the cleaning agent 10.

[0078] (5) According to this embodiment, in step S206 of FIG. 7, the brightness L of the surface 131 of the washed article 13 is * is measured. And the lightness L * If the measured value is equal to or greater than a predetermined post-wash brightness judgment value, the washed article 13 is judged to be a non-defective product.

[0079] Regarding the conventional technology, in both the determinations in steps S202 and S206, the degree of soiling is determined visually by an operator 80, as shown in Fig. 16. In contrast, in this embodiment, the degree of soiling is determined by measuring brightness as described above, so that it is possible to reduce variations in determinations made by operators 80.

[0080] (Second embodiment) Next, a second embodiment will be described. In this embodiment, differences from the first embodiment will be mainly described. Furthermore, parts that are the same as or equivalent to the first embodiment will be omitted or simplified. This also applies to the following embodiments.

[0081] In this embodiment, the manufacturing process of the cleaning agent 10 shown in Fig. 3 is different from that of the first embodiment. Specifically, in this embodiment, in step S101 shown in Fig. 3, glass particles 41 and a sodium bicarbonate aqueous solution 38 are prepared as raw materials for the cleaning agent 10. However, this prepared sodium bicarbonate aqueous solution 38 is an aqueous solution in which sodium bicarbonate is dissolved until saturated, in other words, a saturated aqueous solution of sodium bicarbonate. Furthermore, in this embodiment, sodium bicarbonate particles 42 are not prepared, so the glass solid content ratio Rg is 100 mass%.

[0082] For confirmation, the average particle size of the glass particles 41 and the solid volume fraction Cs in this embodiment are the same as those in the first embodiment. In addition, the saturated aqueous solution of sodium bicarbonate referred to here is not limited to an aqueous solution in which the Na concentration is exactly the same as the saturated concentration, but also includes an aqueous solution in which the Na concentration is slightly lower than the saturated concentration but is approximately the same as the saturated concentration in consideration of practical use.

[0083] In step S102 of Fig. 3, the glass particles 41 prepared in step S101 are mixed with the sodium bicarbonate aqueous solution 38. This completes the cleaning agent 10. The sodium bicarbonate aqueous solution 38 contained in this completed cleaning agent 10 is the saturated aqueous solution of sodium bicarbonate prepared in step S101, and the solid cleaning component 40 is composed of glass particles 41 without containing sodium bicarbonate particles 42. Since the glass particles 41 are insoluble in water, the volume fraction of the glass particles 41 in the cleaning agent 10 is the same as the solid volume fraction Cs of the raw materials. The process of Fig. 7 is the same in this embodiment as in the first embodiment.

[0084] According to this embodiment, the aqueous baking soda solution 38 contained in the detergent 10 is a saturated aqueous baking soda solution. The solid cleaning component 40 contained in the detergent 10 is composed of glass particles 41, without any baking soda particles 42. Therefore, by using a saturated aqueous baking soda solution, the chemical cleaning power of the aqueous baking soda solution 38 can be maximized. At the same time, since a large amount of glass particles 41, which have a higher density than the baking soda particles 42, can be mixed into the detergent 10, it is easy to increase the physical cleaning power of the solid cleaning component 40. As a result, the cleaning power of the detergent 10 can be enhanced by the synergistic effect of the chemical and physical cleaning powers.

[0085] For example, in this embodiment, the experimental results shown by the relation point Pws in FIG. 11 were obtained in the cleaning in step S205 in FIG. 7. According to the experimental results, the lightness L indicated by the relation point Pws in this embodiment * is the lightness L indicated by the plurality of relation points Pw obtained by changing the glass solid content ratio Rg in the first embodiment. *Therefore, it is considered most preferable to form the cleaning agent 10 from a saturated aqueous solution of sodium bicarbonate and glass particles 41, as in this embodiment, in order to obtain a high cleaning effect.

[0086] Except for the points described above, this embodiment is the same as the first embodiment. In this embodiment, the same effects as those of the first embodiment can be obtained from the configuration common to the first embodiment.

[0087] (Other embodiments) (1) In each of the above-described embodiments, steps S202, S206, and S208 are not essential in the process of Fig. 7, and any or all of these steps may be omitted. Note that if step S202 is omitted, step S203 is also omitted, and if step S206 is omitted, step S207 is also omitted.

[0088] (2) In the second embodiment described above, the solid cleaning ingredient 40 in the cleaner 10 completed in step S102 of Fig. 3 is composed of glass particles 41 without containing sodium bicarbonate particles 42. However, this is just one example. For example, the solid cleaning ingredient 40 may contain a small amount of sodium bicarbonate particles 42 in addition to the glass particles 41. In other words, the solid cleaning ingredient 40 may be composed of glass particles 41 and solid sodium bicarbonate particles 42 that are less in mass proportion than the glass particles 41.

[0089] (3) In the second embodiment described above, the sodium bicarbonate aqueous solution 38 contained in the cleaning agent 10 is a saturated aqueous solution of sodium bicarbonate, and therefore the sodium concentration in the sodium bicarbonate aqueous solution 38 is the saturated concentration. However, this is just one example. The sodium bicarbonate aqueous solution 38 contained in the cleaning agent 10 may be an aqueous solution whose sodium concentration is slightly lower than the saturated concentration, for example, an aqueous solution whose sodium concentration is 90% or more of the saturated concentration.

[0090] (4) In the above-described embodiments, the alkaline aqueous solution contained in the cleaning agent 10 is the sodium bicarbonate aqueous solution 38 obtained by dissolving sodium bicarbonate in water, but this is just one example. The alkaline aqueous solution may be an aqueous solution obtained by dissolving a material other than sodium bicarbonate in water.

[0091] (5) The present disclosure is not limited to the above-described embodiments and can be implemented in various modifications. Furthermore, in each of the above-described embodiments, it goes without saying that elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0092] Furthermore, in each of the above embodiments, when numerical values ​​such as the number, values, amounts, and ranges of components of the embodiments are mentioned, they are not limited to the specific numbers, except when it is particularly clearly stated that they are essential or when they are clearly limited to a specific number in principle, etc. Furthermore, in each of the above embodiments, when the material, shape, positional relationship, etc. of components are mentioned, they are not limited to the material, shape, positional relationship, etc., except when it is particularly clearly stated or when they are clearly limited to a specific material, shape, positional relationship, etc. in principle, etc. [Explanation of symbols]

[0093] 10. Cleaning Agents 12 Items to be washed 38 Sodium bicarbonate solution (alkaline solution) 41 Glass particles

Claims

1. A cleaning agent (10) to be sprayed onto an object (12) to be cleaned in order to clean the object, an alkaline aqueous solution (38); and glass particles (41).

2. the alkaline aqueous solution is an aqueous solution of sodium bicarbonate, 2. The cleaning agent according to claim 1, wherein a solid component (40) contained in the cleaning agent is composed of the glass particles and sodium bicarbonate particles (42) in a mass ratio smaller than that of the glass particles, or is composed of the glass particles without containing the sodium bicarbonate particles.

3. the alkaline aqueous solution is a saturated aqueous solution of sodium bicarbonate; 2. The cleaning agent according to claim 1, wherein a solid component (40) contained in the cleaning agent is composed of the glass particles and sodium bicarbonate particles in a mass ratio smaller than that of the glass particles, or is composed of the glass particles without containing the sodium bicarbonate particles.

4. 4. The cleaning agent according to claim 1, wherein the object to be cleaned is a metal part for an automobile.

5. A method for producing a cleaning agent (10) to be sprayed onto an object (12) to be cleaned, comprising: A method for producing sodium bicarbonate particles (42) having an average particle diameter of 200 to 400 μm, glass particles (41) having an average particle diameter of 200 to 400 μm, and water (S101); and mixing the sodium bicarbonate particles, the glass particles, and the water (S102) after setting a ratio (Cs) of the volume of the pre-mixing solid content to a total volume obtained by adding a volume of the pre-mixing solid content including the sodium bicarbonate particles and the glass particles and a volume (Vw) of the water to 10 to 30 vol % and setting a mass ratio (Rg) of the glass particles to the pre-mixing solid content to 50 to 99 mass %.

6. 6. The method for producing a cleaning agent according to claim 5, wherein the mixing includes mixing the sodium bicarbonate particles, the glass particles, and the water in a mass ratio of 85 to 95 mass%.

7. A manufacturing method for manufacturing a washed item (13) obtained by washing an object to be washed (12), comprising the steps of: Preparing the object to be cleaned (S204); Preparing a cleaning agent (10) containing an alkaline aqueous solution (38) and glass particles (41) (S101, S102); and cleaning the object to be cleaned by spraying the cleaning agent onto the object to be cleaned, and obtaining the object to be cleaned after cleaning as the cleaned article (S205).

8. Providing the cleaning agent comprises: Preparing sodium bicarbonate particles (42) having an average particle diameter of 200 to 400 μm, the glass particles having an average particle diameter of 200 to 400 μm, and water (S101); 8. The method according to claim 7, further comprising: mixing the sodium bicarbonate particles, the glass particles, and the water in a ratio (Cs) of 10 to 30 vol% of the volume of the pre-mixing solid content relative to the total volume of the pre-mixing solid content including the sodium bicarbonate particles and the glass particles and the water; and mixing the sodium bicarbonate particles, the glass particles, and the water in a ratio (Rg) of 50 to 99 mass% of the volume of the pre-mixing solid content.

9. After obtaining the washed article, the brightness (L * 9. The manufacturing method according to claim 7, further comprising measuring the brightness of the washed article, and determining that the washed article is a non-defective product if the brightness is equal to or greater than a predetermined determination value (S206).

10. A cleaning method for cleaning an object (12) having dirt (12a) attached thereto, comprising: Preparing the object to be cleaned (S204); Preparing a cleaning agent (10) containing an alkaline aqueous solution (38) and glass particles (41) (S101, S102); and spraying the cleaning agent onto the object to clean the object and remove the dirt (S205).

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