Electroplating Tanks: What are the different types of tanks used in the electroplating process?

Electroplating tanks are used to hold plating solutions for processes such as galvanizing, copper plating, nickel plating, and gold plating. The movable cathode electroplating tank consists of a steel tank lined with soft PVC plastic, a conductive device, steam-heating tubes, and a cathode-moving mechanism. The tank body can also be made with a steel lining reinforced by rigid polyvinyl chloride. The choice of tank structure depends on the properties and temperature of the plating solution. So, regarding electroplating tanks: What types of plating tanks are there in the electroplating process?

Electroplating Tanks: What are the different types of tanks used in the electroplating process?

1. Cold-water tank: Typically, this is a rectangular container made by welding carbon steel or by welding rigid PVC plastic sheets. The upper part of the tank is equipped with an overflow port, while the lower part has a drain port. The overflow port is used to remove surface impurities from the water, and the drain port is provided for changing the water and cleaning the tank; in some cases, however, no drain port may be installed. The tanks used for acid pickling are made of plastic. If the inner walls of carbon-steel tanks are lined with rubber or fiberglass-reinforced plastic, such lining is necessary.

2. Hot-water tank: Similar to the cold-water tank, except that it is equipped with heating facilities and has a slightly larger overflow port. The hot-water tank is welded from carbon steel. If corrosion protection is required, it can be lined with soft plastic, fiberglass-reinforced plastic, or rubber sheets. Such lined electroplating tanks are commonly used because they not only offer rigidity and strength but also exhibit excellent corrosion resistance.

3. Acidic Solution Plating Tanks: Acidic solutions are highly corrosive, so plating tanks made of carbon steel must undergo anti-corrosion treatment. The inner lining can be made of soft PVC plastic sheets, PP, PTFE, fiberglass-reinforced plastic, or hard rubber sheets (Sl001). Welding with rigid PVC plastic sheets is also an option. Heating tubes can be made of titanium or fluoroplastic materials.

4. Electrochemical degreasing tank and alkaline plating tank: Since the alkaline solution can be made from corrosion-resistant fluoroplastics, these tanks exhibit excellent corrosion resistance.

5. Chemical Degreasing Tank (Alkaline Tank): The solution in this tank is alkaline, and the operating temperature ranges from 70 to 80°C. The tank is typically made of carbon steel; due to the high temperature, the outer wall of the tank must be equipped with a thermal insulation layer.

6. Cathode-moving electroplating tank: According to the requirements of the electroplating process, for degreasing processes involving galvanizing, copper plating, nickel plating, and other similar operations, the cathode needs to move continuously in a horizontal reciprocating motion or vertically up and down. Horizontal movement is suitable for various types of electroplating tanks, while vertical movement is ideal for degreasing tanks. Therefore, it is necessary to install a device on the electroplating tank that enables the cathode to move. It should be noted that the cathode-moving device must be effectively insulated from the support structure.

7. Chrome-plating tanks: Depending on the application, they can be designed in rectangular or cylindrical shapes. Rectangular tanks are ideal for chrome plating decorative parts and offer a large loading capacity; cylindrical tanks are suitable for mechanical parts with large dimensions and high requirements for coating thickness. For functional chrome plating (hard chrome) applications—such as rods, shafts, and bushings—four to six anodes are installed on the tank body, and four to six anode plates are mounted on the base. This configuration helps prevent the plated parts from developing oval or conical shapes.

The current density used in chrome plating is relatively high; therefore, the volume of the plating solution should be designed according to the power supply’s load capacity. The electric charge passing through the solution typically does not exceed 1.5 A/L. The tank can be constructed by welding carbon steel, which then requires corrosion protection treatment. Typically, chrome-plating solutions are lined with lead sheets or lead-titanium alloys. For composite chrome-plating solutions, electrodes can be coated with a 70010 or 30010 tin alloy to provide lead lining, thereby enhancing the corrosion resistance of the lining layer.