Electroplating tinning unit fluxing tank and control method thereof

Abstract

The application provides a fluxing tank of an electro-tinning unit and a control method thereof. The fluxing tank of the electro-tinning unit comprises a tank body, a drainage pipeline communicated with the bottom of the tank body, a water supplement pipeline communicated with the tank body, a spray beam arranged above the overflow port of the tank body, and a fluxing agent circulating system communicated with the tank body. A drainage valve and an electric conductivity detector are arranged on the drainage pipeline, the electric conductivity detector is arranged between the tank body and the drainage valve, a water supplement valve is arranged on the water supplement pipeline, and the spray beam is used for spraying desalted water in the reverse direction in the upward direction of the strip steel after being opened. The application can meet the normal fluxing process of high tin iron and ensure the cleanliness during the fluxing process of low tin iron, thereby avoiding the occurrence of spot rust defects.

Description

Technical Field

[0001] This application relates to the field of tin electroplating, specifically to a flux bath for tin electroplating units and its control method. Background Technology

[0002] like Figure 1 As shown, tin plating units typically have a vertical immersion flux bath after the rinsing tank. This flux bath is used for surface pretreatment before reflow during the production of high-tin iron, thereby improving surface leveling performance during the reflow process. However, during the production of low-tin iron, such as... Figure 2 As shown, due to the thin tin layer, excessive leveling can cause iron leakage at the peaks, which is detrimental to improving corrosion resistance. During the production of low-tin iron, the flux bath is mainly used to enhance rinsing (water washing) capabilities, clean up residual plating solution, and prevent acidic plating solution from corroding the surface tin layer and causing pitting defects.

[0003] Because existing technologies only consider the normal fluxing process in flux baths, the flux washing process for low-tin iron is not adequately considered. Although it is known that flux washing plays an important role in preventing pitting of low-tin iron, current electroplating tin units do not have the ability to control cleanliness under different belt speeds and product specifications, and do not have self-controlled purification capabilities. Summary of the Invention

[0004] The purpose of this application is to provide a flux bath for an electroplating tin unit and its control method, which can meet the normal fluxing process of high tin iron and ensure the cleanliness of low tin iron molten fluxing process, and has self-control purification capability to avoid pitting defects.

[0005] To achieve the above objectives, in a first aspect, this application provides a fluxing tank for an electroplating tin unit, comprising a tank body, a drain pipe communicating with the bottom of the tank body, a water replenishment pipe communicating with the tank body, a spray beam disposed above the overflow port of the tank body, and a flux circulation system communicating with the tank body. The drain pipe is provided with a drain valve and a conductivity meter, the conductivity meter being disposed between the tank body and the drain valve. The water replenishment pipe is provided with a water replenishment valve. The spray beam is used to spray demineralized water in the reverse direction of the strip steel after being opened.

[0006] During the production of high-tin iron by the electroplating tin unit, the drain valve and water supply valve are closed, the spray beam is closed, and the flux circulation system is turned on;

[0007] During the production of low-tin iron by the electroplating tin unit, the flux circulation system is closed, the spray beam is opened, and the drain valve and water supply valve are opened. The opening duration of the drain valve and water supply valve is determined according to the conductivity K of the liquid detected by the conductivity detector.

[0008] In some embodiments of this application, based on the foregoing scheme, during the production of low-tin iron by the electroplating tin unit, K1 is a first threshold value.

[0009] When K < K1, the opening duration of the drain valve and the water supply valve is 0.

[0010] When K≥K1, the drain valve opens for a second preset time T2 and then closes after every first preset time T1, and the water supply valve opens for a third preset time T3 and then closes.

[0011] In some embodiments of this application, based on the foregoing scheme, during the production of low-tin iron by the electroplating tin unit, the amount discharged by the drain valve is less than the amount replenished by the water replenishment valve.

[0012] In some embodiments of this application, based on the aforementioned scheme, the flow rates of the drain valve and the water supply valve are the same, and the second preset time T2 is less than the third preset time T3.

[0013] In some embodiments of this application, based on the aforementioned scheme, K2 is a second threshold. When K1≤K<K2, the second preset time T2 is linearly related to the conductivity K, and the third preset time T3 is linearly related to the conductivity K. When K≥K2, both the second preset time T2 and the third preset time T3 are constant values.

[0014] In some embodiments of this application, based on the aforementioned scheme, K1 is 50 μS / cm, K2 is 100 μS / cm, when K1≤K<K2, T2=0.2K, T3=0.2K+20; when K≥K2, T2=20s, T3=40s.

[0015] In some embodiments of this application, based on the aforementioned scheme, the first preset time T1 is 30 minutes.

[0016] In some embodiments of this application, based on the foregoing scheme, both the drain valve and the water supply valve are solenoid valves.

[0017] In some embodiments of this application, based on the foregoing scheme, a PLC is also included, which is used to control the opening and closing of the drain valve, water supply valve, spray beam, and flux circulation system.

[0018] Secondly, this application also provides a method for controlling the flux bath of an electroplating tin unit, applied to the flux bath of the electroplating tin unit described in the first aspect, comprising:

[0019] Obtain the production information of the tin plating unit;

[0020] If the tin plating unit is producing high-tin iron, the drain valve and water supply valve are closed, the spray beam is closed, and the flux circulation system is turned on.

[0021] If the electroplating tin unit is producing low-tin iron, the conductivity K of the liquid detected by the conductivity meter is obtained, the flux circulation system is controlled to close, the spray beam is opened, and the drain valve and water supply valve are opened. The opening duration of the drain valve and water supply valve is determined according to the conductivity K of the liquid detected by the conductivity meter.

[0022] This application proposes a flux bath and its control method for an electroplating tin unit. This method can satisfy the normal fluxing process for high-tin iron while ensuring cleanliness during the fluxing and rinsing process for low-tin iron, thus preventing pitting defects. Simultaneously, this application does not affect the existing flux circulation system and allows for switching fluxing based on different tin layers. Since low-tin iron should employ a water-flushing process, improving the cleanliness of the fluxing and rinsing process after electroplating and avoiding residual acidic substances on the surface is crucial for preventing pitting defects. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0024] Figure 1 A schematic diagram of the production process flow of an electroplating tin unit;

[0025] Figure 2 A diagram illustrating how excessive leveling during the production of low-tin iron can cause iron leakage at the peaks.

[0026] Figure 3 This is a schematic diagram of the flux bath structure of the tin plating unit in this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The following detailed description of some embodiments of this application will be provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] like Figure 3As shown, this application provides a fluxing tank for an electroplating tin unit, including a tank body 10, a drain pipe 20 connected to the bottom of the tank body 10, a water supply pipe 30 connected to the tank body 10, a spray beam 40 located above the overflow port of the tank body 10, and a flux circulation system 50 connected to the tank body 10. The drain pipe 20 is equipped with a drain valve 21 and a conductivity meter 22. The conductivity meter 22 is located between the tank body 10 and the drain valve 21. The water supply pipe 30 is equipped with a water supply valve 31. The spray beam 40 is used to spray demineralized water in the reverse direction of the strip 60 after being opened.

[0030] During the production of high-tin iron by the electroplating tin unit, the drain valve 21 and the water supply valve 31 are closed, the spray beam 40 is closed, and the flux circulation system 50 is turned on. Thus, during the production of high-tin iron, the flux in the flux circulation system 50 is circulated into the tank 10, that is, the normal high-tin iron fluxing process is carried out to perform surface pretreatment before softening and to improve the surface leveling performance of the softening process.

[0031] During the production of low-tin iron by the electroplating tin unit, the flux circulation system 50 is closed, the spray beam 40 is opened, and the drain valve 21 and water supply valve 31 are opened. The opening duration of the drain valve 21 and water supply valve 31 is determined according to the conductivity K of the liquid detected by the conductivity detector 22.

[0032] It should be noted that during the production of low-tin iron by the electroplating tin unit, the higher the conductivity K of the liquid detected by the conductivity meter 22, the lower the cleanliness of the liquid in the tank 10. In order to rinse away the residual acidic plating solution on the strip steel 60, the drain valve 21 and the water supply valve 31 need to be open for a longer period of time. When the conductivity K is not high, the liquid in the tank 10 can be considered clean, and it is not necessary to open the drain valve 21 and the water supply valve 31.

[0033] Therefore, in some embodiments of this application, during the production of low-tin iron by the electroplating tin unit, K1 is a first threshold value.

[0034] When K < K1, the opening duration of the drain valve 21 and the water supply valve 31 is 0.

[0035] When K≥K1, the drain valve 21 is opened for a second preset time T2 and then closed after every first preset time T1, and the water supply valve 31 is opened for a third preset time T3 and then closed.

[0036] Specifically, in order to meet the overflow requirements of the tank 10, the amount discharged by the drain valve 21 is less than the amount replenished by the water supply valve 31.

[0037] In some embodiments of this application, the flow rates of the drain valve 21 and the water supply valve 31 are the same, and the second preset time T2 is less than the third preset time T3.

[0038] Specifically, K2 is the second threshold. When K1≤K<K2, the second preset time T2 is linearly related to the conductivity K, and the third preset time T3 is linearly related to the conductivity K. When K≥K2, both the second preset time T2 and the third preset time T3 are constant values.

[0039] Specifically, both the drain valve 21 and the water supply valve 31 are solenoid valves.

[0040] Optionally, the drainage pipe 20 drains the liquid into the pit.

[0041] Specifically, the flux bath of the electroplating tin unit also includes a PLC (Programmable Logic Controller), which is used to control the opening and closing of the drain valve 21, the water supply valve 31, the spray beam 40, and the flux circulation system 50. In specific implementation, the PLC is pre-programmed with corresponding control programs to control the opening and closing of the drain valve 21, the water supply valve 31, the spray beam 40, and the flux circulation system 50.

[0042] In this application, the term "low tin iron" refers to a tin layer content of less than 5.6 g / m².

[0043] In one specific embodiment, based on the actual production process, the volume of liquid in the tank 10 is 5 m³, the flow rate of both the drain valve 21 and the water supply valve 31 is 1.5 m³ / h, and the flow rate of the spray beam 40 is 3.5 m³ / h. During the production of low-tin iron by the electroplating tin unit, the drain valve 21 automatically opens once every 30 minutes, each time for 10-20 seconds. After the drain valve 21 closes, the water supply valve 31 immediately opens for 30-40 seconds (to meet the overflow requirements of the tank 10), and the spray beam 40 sprays demineralized water, maintaining a constantly open mode. In this application, the focus is on setting the drainage and water supply durations in the PLC's preset program according to the volume of the tank 10, the conductivity test results, and a certain slope (linear relationship). The higher the conductivity K test value, the longer the opening time of the drain valve 21 and the water supply valve 31. When the conductivity K is below 50 μS / cm, the water replenishment and drainage programs will not be triggered; when the conductivity K is above 100 μS / cm, the maximum drainage time is set to 20 seconds and the water replenishment time to 40 seconds.

[0044] In this specific embodiment, K1 is 50 μS / cm, K2 is 100 μS / cm, when K1 ≤ K < K2, T2 = 0.2K, T3 = 0.2K + 20; when K ≥ K2, T2 = 20s, T3 = 40s. The first preset time T1 is 30min.

[0045] The electroplating tin-plating unit flux tank provided in this application upgrades, optimizes, and modifies existing electroplating tin-plating unit flux tanks. It adds water supply pipes, drainage pipes, and corresponding drain valves and water supply valves, and installs a conductivity meter on the drainage pipes. Furthermore, it adds a set of counter-current spray demineralized water jet beams in the upward direction of the strip. During the production of high-tin iron, the drain valves and water supply valves are closed, the spray beams are closed, and the flux circulation system is open. During the production of low-tin iron, the flux circulation system is closed, the spray beams are open, and the drain valves and water supply valves are open. The opening duration of the drain valves and water supply valves is determined based on the conductivity of the liquid detected by the conductivity meter. This satisfies both the normal fluxing process for high-tin iron and ensures the cleanliness of the low-tin iron fluxing water washing process, avoiding pitting defects. Meanwhile, this application does not affect the original flux circulation system and can solve the problem of inaccurate cleanliness control in the original flux bath during the water fluxing process in the production of low-tin iron. It can realize the ability to switch fluxes according to different tin layers. Since low-tin iron should adopt a water fluxing process, improving the cleanliness of the flux water wash after electroplating and avoiding the residue of acidic substances on the surface after plating is of great significance for preventing pitting defects.

[0046] Based on the same inventive concept, this application also provides a control method for the flux bath of an electroplating tin unit, applied to the flux bath of the electroplating tin unit in the foregoing embodiments, comprising:

[0047] Step S1: Obtain the production information of the tin plating unit;

[0048] Step S2: During the production of high-tin iron by the electroplating tin unit, the drain valve and water supply valve are closed, the spray beam is closed, and the flux circulation system is turned on;

[0049] Step S3: During the production of low-tin iron by the electroplating tin unit, the conductivity K of the liquid detected by the conductivity detector is obtained, the flux circulation system is shut down, the spray beam is opened, and the drain valve and water supply valve are opened. The opening duration of the drain valve and water supply valve is determined according to the conductivity K of the liquid detected by the conductivity detector.

[0050] In summary, this application provides a fluxing tank for an electroplating tin unit and its control method. The fluxing tank includes a tank body, a drainage pipe connecting to the bottom of the tank body, a water replenishment pipe connecting to the tank body, a spray beam located above the overflow port of the tank body, and a flux circulation system connecting to the tank body. The drainage pipe is equipped with a drainage valve and a conductivity meter, which is located between the tank body and the drainage valve. The water replenishment pipe is equipped with a water replenishment valve. The spray beam is used to spray demineralized water in the reverse direction of the strip's upward movement after being opened. This application can satisfy the normal fluxing process for high-tin iron while ensuring the cleanliness of the low-tin iron fluxing process, avoiding pitting defects. It can effectively improve the cleanliness of low-tin iron fluxing, avoid pitting defects during low-tin iron production, meet the iron quality requirements of protein beverages such as Lulu, and prevent economic losses of over 500,000 yuan annually due to complaints about rust quality issues.

[0051] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A flux bath for an electroplating tin unit, characterized in that, The system includes a tank, a drainage pipe connecting to the bottom of the tank, a water supply pipe connecting to the tank, a spray beam located above the overflow port of the tank, and a flux circulation system connecting to the tank. The drainage pipe is equipped with a drainage valve and a conductivity meter, with the conductivity meter located between the tank and the drainage valve. The water supply pipe is equipped with a water supply valve. The spray beam is used to spray demineralized water in the reverse direction of the strip's upward movement after being opened. During the production of high-tin iron by the electroplating tin unit, the drain valve and water supply valve are closed, the spray beam is closed, and the flux circulation system is turned on; During the production of low-tin iron by the electroplating tin unit, the flux circulation system is closed, the spray beam is opened, and the drain valve and water supply valve are opened. The opening duration of the drain valve and water supply valve is determined according to the conductivity K of the liquid detected by the conductivity detector.

2. The flux bath of the tin plating unit according to claim 1, characterized in that, During the production of low-tin iron by the electroplating tin unit, K1 is the first threshold value. When K < K1, the opening duration of the drain valve and the water supply valve is 0. When K≥K1, the drain valve opens for a second preset time T2 and then closes after every first preset time T1, and the water supply valve opens for a third preset time T3 and then closes.

3. The flux bath of the tin plating unit according to claim 2, characterized in that, During the production of low-tin iron by the electroplating tin unit, the amount discharged by the drain valve is less than the amount replenished by the water supply valve.

4. The flux bath of the tin plating unit according to claim 3, characterized in that, The flow rates of the drain valve and the water supply valve are the same, and the second preset time T2 is less than the third preset time T3.

5. The flux bath of the tin plating unit according to claim 4, characterized in that, K2 is the second threshold. When K1≤K<K2, the second preset time T2 is linearly related to the conductivity K, and the third preset time T3 is linearly related to the conductivity K. When K≥K2, both the second preset time T2 and the third preset time T3 are constant values.

6. The flux bath of the tin plating unit according to claim 5, characterized in that, K1 is 50 μS / cm, K2 is 100 μS / cm, when K1≤K<K2, T2=0.2K, T3=0.2K+20; when K≥K2, T2=20s, T3=40s.

7. The flux bath of the tin plating unit according to claim 2, characterized in that, The first preset time T1 is 30 minutes.

8. The flux bath of the tin plating unit according to claim 1, characterized in that, Both the drain valve and the water supply valve are solenoid valves.

9. The flux bath of the tin plating unit according to claim 1, characterized in that, It also includes a PLC, which is used to control the opening and closing of the drain valve, water supply valve, spray beam, and flux circulation system.

10. A method for controlling the flux bath of a tin plating unit, characterized in that, The flux bath used in the tin plating unit as described in any one of claims 1 to 9 comprises: Obtain the production information of the tin plating unit; If the tin plating unit is producing high-tin iron, the drain valve and water supply valve are closed, the spray beam is closed, and the flux circulation system is turned on. If the electroplating tin unit is producing low-tin iron, the conductivity K of the liquid detected by the conductivity meter is obtained, the flux circulation system is controlled to close, the spray beam is opened, and the drain valve and water supply valve are opened. The opening duration of the drain valve and water supply valve is determined according to the conductivity K of the liquid detected by the conductivity meter.

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