JPH09314142A - Oil separator in pretreatment degreasing process of plating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain not only a remarkable improvement in the filtration efficiency of the degreasinbg aqueous solution of a pretreatment process in a plating process but an improvement in reducing the consumption of the solution, an improvement in cleanness of apparatus as a whole, and an improvement in working efficiency. SOLUTION: An oil separator is composed of an overflow part 10, a degreasing tank 11, and a filtration tank 12, and a solution circulating pipe 13, a pump 4, a return valve 15, and a degreasing liquid discharge nozzle 13a are installed between the bottom of the filtration tank 12 and the inside of the degreasing tank 11. In the tank 12, partition plates 12a are installed at regular intervals in the longitudinal direction to the tank 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil separation device used in a degreasing process performed on a work as a pretreatment for plating.

[0002]

2. Description of the Related Art Plating refers to a method of coating with another metal and a formed metal coating layer in order to enhance the beauty, corrosion resistance and hardness of the metal surface. Gold, silver, platinum, brass alloys, etc. are mainly used for decoration plating, but chromium, nickel, etc. are plated for corrosion resistance and hardness, but iron plates are tinned. Tinplate plated with zinc and galvanized galvanized galvanized iron are known. The plating method includes an electroplating method, a hot dip plating method, a metal spraying method, and a vacuum plating method. These plating processing methods will be briefly described. The electroplating method is a method of plating an electric conductor by applying the principle of electrolysis, in which an electric circuit in which the metal to be plated is the cathode and the coating metal is the anode is immersed in an electrolyte solution of a salt solution to perform the plating treatment. Therefore, an insoluble anode such as lead or carbon may be used. As the coating metal,
Besides pure metals such as gold, lead, copper, nickel, zinc, tin, cobalt, cadmium, tungsten and molybdenum, alloys such as brass, bronze and nickel silver are also used. The hot dipping method is a method of immersing a metal to be plated in a molten metal, and zinc, tin, lead, cadmium, aluminum or the like having a relatively low melting point is used. Tin plate and tin plate are often made by this method. The metal spraying method is a method in which a molten metal is wiped with pressurized air. The vacuum plating method includes a metal vapor deposition method and a sputtering method. The metal vapor deposition method heats a metal in a vacuum and causes the vapor to adhere to another object. Plating aluminum or lead on plastic or glass is not recommended. This is an example. In sputtering, when a voltage is applied between electrodes in a vacuum, the residual gas is ionized and the cations collide with the cathode, causing the metal particles of the cathode to scatter, and these are attached to the target. Used as a non-conductive object plating base.

When the plating process is divided into process steps, five processes of polishing, pretreatment, plating, posttreatment, and drying are carried out. Of these, the processes that greatly affect the quality of the plated product are polishing and pretreatment. Is. This process varies depending on the product material, surface condition, shape, etc. For example, in the case of iron products, material, polishing, degreasing, washing, pickling, washing, neutralization, washing, activation, washing, plating, Take steps of washing with water and drying. Among these, in the polishing process, the surface of the product to be plated is polished with an abrasive to finish the surface suitable for plating. The polishing method includes grinder hanging, charcoal barbecue, spatula, brush, lapping, buff polishing, belt polishing, Rotational polishing, vibration polishing, etc. are common, but in some cases sandblasting,
Polishing using liquid honing, shot peening, electrolysis, chemical polishing, etc. is also performed. On the other hand, the pretreatment process is a process for removing stains such as grease, rust, and scratches on the product to make the surface most suitable for plating. Specifically, animal fats and oils attached to the surface of the work to be plated,
Degreasing organic and inorganic stains such as vegetable oils and mineral oils or stains of organic and inorganic mixtures by solvent degreasing, emulsion degreasing, alkaline degreasing, electrolytic degreasing, ultrasonic degreasing, mechanical degreasing, etc. However, these are briefly explained. Solvent degreasing is a method of dissolving and removing oily stains on a plating material using an organic solvent, and is performed as preliminary degreasing for washing oily stains that cannot be completely removed by washing with water.
As the degreasing solvent, gasoline, naphtha, petroleum, carbon tetrachloride, acetone, trichlor, ethylene, perchlorethylene, methylene chloride, etc. are used. Emulsification degreasing is a method of dissolving and emulsifying oily stains on a plating material by using an emulsion degreasing agent composed of a surfactant, a solvent and water, and this is also performed as preliminary degreasing for washing with water. As a solvent, kerosene or trichlene with a small amount of added surfactant is used. In alkaline degreasing, when a product to which a saponifying oil / fat is attached is dipped in an alkaline solvent, the alkali and the saponifying oil / fat are combined to form a water-soluble soap. In this method of saponifying fats and oils adhering to products by utilizing this saponification action, caustic soda, sodium carbonate, sodium silicate, sodium glycolate and the like are used as alkaline degreasing agents. Electrolytic degreasing is a method for removing a small amount of stains remaining on the surface of the product even in preliminary cleaning, and is performed after solvent degreasing, emulsion degreasing and alkaline degreasing. Ultrasonic degreasing is performed in combination with solvent degreasing, alkaline degreasing, and electrolytic degreasing to enhance the cleaning effect, and is often used for degreasing nonferrous metals such as zinc die cast and aluminum.

Next, an example of a conventional degreasing process will be described. 1 and 2 show an outline of a solvent degreasing device which has been conventionally used. As shown in FIG. 1, a solvent degreasing apparatus as a conventional apparatus includes a degreasing treatment tank 2 having an overflow portion 1 on the side surface that overflows from the water surface to the outside when a certain water level is exceeded, and a filtration provided immediately below the overflow portion 1. The tank 3 is composed of an upper partition plate 3a projecting from the upper surface opening to the liquid surface and a lower partition plate 3b projecting upward from the liquid tank bottom into one inside the liquid tank of the filtration tank 3. One or more sets are provided as a unit. Among these, as shown in FIG. 2, from the bottom of the filtration tank 3, a solution circulation pipe 6 is provided via a pump 4 and a return valve 5.
Is provided and the tip discharge port 6a of the solution circulation pipe 6 is provided.
Is discharged to the liquid surface of the degreasing treatment aqueous solution A stored in the degreasing treatment tank 2. With this configuration, in the conventional alkaline degreasing device, the degreasing treatment aqueous solution A prepared by dissolving the degreasing agent obtained by mixing the caustic soda (sodium hydroxide) and the activator in water is introduced into the degreasing treatment tank 2 and the filtration tank 3. As shown in FIG. 1, a work 7 to which a fat component such as an organic / inorganic substance such as an animal fat / oil oil, a vegetable fat / oil and a mineral fat / oil or an organic / inorganic mixture is applied by depressurization or polishing is used for degreasing treatment. Put in the tank 2. Then, the fat and oil component B attached to the work 7 floats due to the degreasing effect of the degreasing treatment aqueous solution A, and as shown in FIG. 2, an oil and fat layer C is formed on the liquid surface. Therefore, the oil / fat layer C floating on the upper surface of the degreasing-treated aqueous solution A is scraped out to the filtration tank 3 via the overflow portion 1 and eliminated. On the other hand, the degreasing treatment discharge liquid discharged from the overflow section 1 to the filtration tank 3 is, as shown in FIG. 2, separated into the upper partition plate 3a and the lower partition plate 3b of one filtration unit provided inside the filtration tank 3. By passing, the fat and oil component contained in the degreasing treatment discharge liquid is accumulated on the upper partition plates 3a and 3c protruding to the liquid surface of the filtration tank 3 and the liquid surfaces D1 and D2 partitioned by the inner wall surface of the filtration tank. I am trying.

[0005]

However, in the above-mentioned conventional technique, the degreasing treatment discharge liquid dropped from the overflow portion 1 to the filtration tank 3 is formed on the plate surface of the upper partition plate 3a by the impact of dropping the liquid. Since a large amount of blisters are generated on the liquid surface D1 that flows, the oil and fat components to be filtered from the degreased water discharge liquid flow through the inside of the filtration tank 3 without separating into the liquid surface, and then on the liquid surface D1 of the first filtration unit. Substantially no oil and fat components are filtered. Furthermore, the degreasing treatment discharge liquid that has flown along the plate surface of the upper partition plate 3a is also filtered by
Since it will flow laterally when hitting the bottom plate, and will be stopped by hitting the plate surface of the lower partition plate 3b as indicated by arrow a, the degreasing treatment discharge liquid that has been put into the filtration tank 3 is indicated by arrow b. As described above, the upper flow of the lower partition plate 3b meanders from the upper layer flow and overflows to the upper partition plate 3c side forming the next filtration unit. Moreover, since a forced circulating flow is generated by the pump 4 from the downstream side on the liquid surface D2 formed by the plate surface of the upper partition plate 3c, the liquid surface formed by the plate surface of the upper partition plate 3c once There is a fatal problem that the filtration efficiency is extremely poor, because the oil and fat components accumulated on D2 are absorbed by the flow of the degreasing process discharge liquid again because the static state of the liquid surface D2 is hindered by the rapid suction flow by the pump 4. It was Therefore, the present invention has been made to solve the problems of these conventional techniques, and not only dramatically improves the filtration treatment efficiency of the degreasing aqueous solution in the pretreatment step in the plating step, but also the degreasing aqueous solution. Saving of consumption, improvement of cleanliness of the whole equipment,
The first purpose is to achieve improvement in workability, and further,
It eliminates the factors that deteriorate the product quality, such as peeling of the plated film after plating, blistering between the work and the plated film, loss of gloss, uneven plating, and the occurrence of pinholes. The second purpose is to suppress and improve the corrosion resistance.

[0006]

The present invention, which has been made to achieve the above object, is an apparatus used in a degreasing process performed as a pretreatment process for plating, in which a degreasing agent is melted at a constant concentration. The degreasing treatment tank that fills the degreasing treatment aqueous solution and performs the degreasing treatment by inserting the member to be degreased, the inner wall portion of the degreasing treatment tank, the degreasing treatment aqueous solution discharge portion provided at a predetermined position, and the body of the degreasing treatment tank. The upper surface of the part is provided with an opening at a predetermined position to remove the degreasing component floating on the water surface of the degreasing aqueous solution and the overflowing degreasing aqueous solution to the outside, and an overflow part provided near the lower part of the overflowing part, and the degreasing discharged from the overflowing part. A degreasing component filtration tank for filtering the degreasing-treated aqueous solution in which the components are mixed, and a degreasing treatment aqueous solution filtered and discharged in the degreasing-component filtration tank are degreased treated water in the degreasing treatment tank. A circulation path for circulating the liquid discharge portion,
In an oil separation device in a pretreatment degreasing process of plating, which includes a pump provided in the circulation path and a return valve provided in parallel with the pump, the degreasing component filtration tank has an upper surface of the degreasing component filtration tank. A plurality of partition plates formed so as to project from the portion to the bottom, and the lower end side thereof is formed so that a predetermined liquid inflow opening is formed from the bottom of the liquid tank, and a plurality of partition plates are provided at predetermined intervals in the longitudinal direction of the degreasing component filtration tank. The gist is an oil separation device in the pretreatment degreasing step of the plating process, which is characterized in that The liquid inflow opening formed at the bottom by the partition plate provided inside the degreasing component filtration tank may have an area of about 20% of the area of the inner wall surface of the short side surface of the degreasing component filtration tank.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. FIG. 3 (a) is a front view showing the internal structure of an oil separation device that is an embodiment to which the oil separation device is applied in the pretreatment degreasing step of the plating process of the present invention, and FIG. 3 (b) is the oil of the same embodiment. It is a top view showing the principal part of a separation device.
As shown in FIG. 3 (a), the oil separation apparatus of this embodiment has a degreasing tank 11 provided with an overflow portion 10 on the side surface of the tank, which overflows from the water surface to the outside when the water level exceeds a certain level.
And a filtration tank 12 provided directly below the overflow section 10, and further, a solution circulation pipe 13 for circulating the degreasing treatment liquid from the bottom of the filtration tank 12 to the inside of the degreasing treatment tank 11, and a solution circulation pipe 13 connected in series to the solution circulation pipe 13. It is composed of a pump 14 mounted, a return valve 15 communicating in parallel with the solution circulation pipe 13 communicating with the pump 14, and a degreasing treatment liquid discharge nozzle 13a attached to the tip of the solution circulation pipe 13. . Of these, inside the filtration tank 12, as shown in FIG. 3B, a substantially right-angled shape is formed from the long-side liquid tank inner wall surface of the long-side liquid tank inner wall surface that opposes the long-side liquid tank inner wall surface. A partition plate 12a of
A plurality of partition plates 12a are attached in the longitudinal direction of the filtration tank 12 at regular intervals (7 in this embodiment). As is apparent from FIG. 3A, the partition plate 12a is provided so as to project from the upper opening surface to the bottom so as to form a flow space of about 20% of the liquid tank volume at the bottom of the filtration tank 12. .

The operation of the oil separating apparatus of the present embodiment having the above structure will be described with reference to the drawings. FIG. 4 is an explanatory view of the operation of the oil separation device of this embodiment. First, a degreasing treatment aqueous solution A in which caustic soda (sodium hydroxide) and an activator are mixed is put into the degreasing treatment tank 11, the filtration tank 12, and the solution circulation pipe 13. Next, in the pressing or polishing process, the work is coated with the oil / fat component such as the organic / inorganic / organic / inorganic mixture such as animal fat, vegetable fat and mineral fat, and the fat component adhering to the work is removed. The oil / fat layer C is formed so as to float on the liquid surface of the degreasing-treated aqueous solution. In this state, the pump 14 shown in FIG. 3A is driven to start the circulation operation of the degreasing treatment aqueous solution. Then, the circulating liquid is discharged from the degreasing treatment liquid discharge nozzle 13a protruding on the upper surface of the degreasing treatment tank 11 to the liquid surface of the degreasing treatment aqueous solution A, floating on the liquid surface of the degreasing treatment aqueous solution A, and the oil layer C is circulated. Overflow part 10 gradually
The first partition plate 12a of the filtration tank 12 that has been pushed out to
It falls on the liquid surface F1 formed by. Then, the dropped degreasing treatment discharge liquid flows through the bottom portion of the filtration tank 12 and into the solution circulation pipe 13 as shown by an arrow 16. During this period, the oil and fat components contained in the degreasing treatment discharge liquid are separated from the main stream flowing at a constant flow rate through the bottom of the filtration tank 12 as shown by arrow 17, and are separated by the partition plate 12a to form the liquid level F1. From the liquid surface to the liquid surface F8 are sequentially floated and deposited. Due to this action, the oil separation apparatus of this embodiment succeeded in obtaining various effects as shown below. By allowing the degreasing treatment discharge liquid discharged from the overflow section 10 to be circulated at a constant flow rate inside the filtration tank, separation and suspension of the degreasing components from the degreasing treatment discharge liquid are facilitated, and filtration of the filtration tank is facilitated. The processing efficiency has improved dramatically. When the circulation operation of the degreasing process is started from the eight liquid levels F1 to F8 divided by the seven partition plates 12a provided in the filtration tank 12, the overflow section 10
From the liquid level F1 near the liquid circulation pipe 13 to the liquid level F near the solution circulation pipe 13
Since the degreasing components are sequentially deposited over 8, it becomes possible to easily grasp the amount of the accumulated fats and oils components and to determine the removal time, and improve the efficiency of the maintenance and inspection work of the device. The oil separation device of the present embodiment can be easily applied to any size device from a small device to a large plant and the same effect can be obtained, so that an economical device having a wide range of applications is realized. . By introducing this device, it is possible to eliminate factors that deteriorate product quality, such as peeling of the plated film after plating, generation of blisters between the work and the plated film, deterioration of gloss, and uneven plating. become. By introducing this device, it becomes possible to suppress the generation of pinholes and improve the corrosion resistance. The introduction of this device has made it possible to keep the factory clean. With the introduction of this device, there is almost no deterioration in the quality of the product after plating, and many defective products are produced in the process of production, and it is almost impossible to damage the plating industry costly. It was

The oil separation device in the pretreatment degreasing step of the plating process of the present invention is not limited to the oil separation device of the above embodiment, and various variations applying the technical idea of the present invention are conceivable. . For example, in order to optimize the flow rate of the degreasing treatment effluent flowing through the inside of the filtration tank 12, a flow rate measurement sensor is provided inside the filtration tank 12, and the signal from this flow rate measurement sensor is read into the microcomputer. The microcomputer can also be applied to a fully automatic oil separation device that feedback-controls the opening degree of the return valve 15 according to an algorithm of a program stored in advance.

[0010]

As described above in detail, the oil separation device in the pretreatment degreasing process of the plating process of the present invention is a device used in the degreasing process performed as the pretreatment process of the plating process, and the degreasing agent is used. A degreasing treatment tank that fills the degreasing treatment solution melted at a certain concentration and performs the degreasing treatment by introducing the degreasing target material, the inner wall of the degreasing treatment tank, and the degreasing treatment solution discharge part provided at a predetermined position, and the degreasing treatment An opening is provided at a predetermined position on the upper surface of the body of the tank to provide an overflow part for removing the degreasing component floating on the water surface of the degreasing aqueous solution and the overflowing degreasing aqueous solution to the outside, and an overflow part near the lower part of the overflowing part for discharging from the overflow part. The degreasing component filtering tank that filters the degreasing-treated aqueous solution mixed with the degreasing component and the degreasing-treated aqueous solution that has been filtered by the degreasing component filtering tank and discharged A circulation path for circulating the liquid discharge portion,
The degreasing component filtration tank of the oil separation device in the pretreatment degreasing process for plating, which includes a pump installed in the circulation path and a return valve arranged in parallel with the pump, includes a top portion to a bottom portion of the degreasing component filtration tank. A plurality of partition plates are provided so as to project from the bottom of the liquid tank so that a predetermined liquid inflow opening is formed from the bottom of the liquid tank, and a plurality of partition plates are provided at predetermined intervals in the longitudinal direction of the degreasing component filtration tank. The liquid inflow opening formed at the bottom by the partition plate provided inside the tank is about 20% of the area of the inner wall surface of the short side surface of the degreasing component filtration tank, and the present invention has the following effects. Can be obtained. (1) Degreasing treatment It becomes easier to separate and float degreasing components from the discharged liquid, and the filtration treatment efficiency of the filtration tank is dramatically improved. (2) The amount of accumulated oil and fat components can be easily grasped and the time to remove it can be easily determined, and the efficiency of equipment maintenance and inspection work has improved. (3) Oil content brought into the wastewater treatment process is reduced, and B
We can expect OD reduction. (4) Since the same effect can be obtained by easily applying to any size device from a small device to a large plant, an economical device having a very wide range of application is realized. In addition, as a result of secondary introduction of the present invention, (5) peeling of the plating film after plating, generation of blisters between the work and the plating film, deterioration of gloss, and nonuniform plating It becomes possible to eliminate the factors that deteriorate the quality of the product such as. (6) It becomes possible to suppress the generation of pinholes and improve the corrosion resistance. (7) It has become possible to keep the factory clean. (8) There is almost no deterioration in the quality of the product after the plating treatment, and a large number of defective products are generated in the product under production, and the cost of the metal surface treatment industry is hardly damaged. . It was an epoch-making invention that succeeded in obtaining a number of primary and secondary effects, the technical effect on the industry was enormous, and the benefit to the entire industry was immeasurable. There is.

[Brief description of drawings]

FIG. 1 is an explanatory view of a solvent degreasing device showing a specific degreasing process as a conventional technique of an oil separation device in a pretreatment degreasing process of plating processing of the present invention.

FIG. 2 is an explanatory view of a solvent degreasing device showing a specific degreasing process as a conventional technique of an oil separation device in a pretreatment degreasing process of plating processing of the present invention.

FIG. 3 is a front view (a) showing an internal structure of an oil separation device, which is an embodiment to which an oil separation device is applied in a pretreatment degreasing step of the plating process of the present invention, and a plan view of main parts of the oil separation device. is there.

FIG. 4 is an operation explanatory view of an oil separation device that is an embodiment to which the oil separation device is applied in the pretreatment degreasing step of the plating process of the present invention.

[Explanation of symbols]

1,10 Overflow part 2,11 Degreasing tank 3,12 Filtration tank 3a, 3c Upper partition plate 3b Lower partition plate 4,14 Pump 5,15 Return valve 6,13 Solution circulation pipe 7 Workpiece 12a Partition plate 13a Tip discharge port A Degreasing treatment aqueous solution B, C Oil and fat component D1, D2, F1, F2, F3, F4, F5, F6, F
7, F8 liquid level

Claims (2)

[Claims] 1. A device used in a degreasing process performed as a pretreatment process for plating, which is filled with a degreasing treatment aqueous solution in which a degreasing agent is melted at a constant concentration, and a member to be degreased is charged to perform the degreasing treatment. The degreasing treatment tank to be performed, the degreasing treatment aqueous solution discharge part provided at a predetermined position on the inner wall of the degreasing treatment tank, and the opening on the upper surface of the body of the degreasing treatment tank at a predetermined position, floating on the water surface of the degreasing treatment solution An overflow section for removing the degreasing component and the overflowed degreasing aqueous solution to the outside, and a degreasing component filtering tank provided near the lower part of the overflow section for filtering the degreasing aqueous solution mixed with the degreasing component discharged from the overflow section, and the degreasing unit. A circulation path that circulates the degreasing aqueous solution that has been filtered and discharged in the component filtering tank to the degreasing aqueous solution discharge section of the degreasing tank, and is installed in the circulation path. In the oil separation device in the pretreatment degreasing process for plating, which consists of a pump and a return valve installed in parallel with the pump, the degreasing component filtration tank is provided with a protrusion from the top to the bottom of the degreasing component filtration tank. The lower end of the partition plate is formed so that a predetermined liquid inflow opening is formed from the bottom of the liquid tank.
An oil separation device in a pretreatment degreasing step of plating, wherein a plurality of degreasing component filtration tanks are provided at predetermined intervals in a longitudinal direction. 2. The liquid inflow opening formed at the bottom by a partition plate provided inside the degreasing component filtration tank has an area of about 20% of the area of the inner wall surface of the short side of the degreasing component filtration tank. The oil separation device in the pretreatment degreasing step of the plating process according to claim 1.