Automatic control of Eletroplating process

The automatic control of the electroplating process is an important issue in the realization of green electroplating. CHINA has made continuous progress in research in this area. For example, the application of linear potentiometric scanning method in electroplating production research, the application of STD industrial control machine in electroplating, etc. The electroplating control system with STD bus control mechanism can realize the automation of the electroplating industry. The microelectroplating control system includes the electroplating process, the automatic control and measurement of parameters, that is, program control and parameter measurement and control. Through the electroplating line station, plating tank temperature, electroplating current signal acquisition, to achieve multiple driving, a variety of process program control, automatic completion of plating parts in different tanks of various processing and plating, to achieve multiple plating tank temperature, electroplating current, flux inspection, tank inspection, display and temperature control of the tank liquid, to ensure that the electroplating is carried out at a very good temperature, the system is equipped with a clock timing, display, input can realize the selection of electroplating process mode and electroplating line, automatic completion of three ways of data printing.

One of the key issues in automating electroplating is the inspection and monitoring of the plating process. Plating thickness control is the first problem to be solved, because less plating means scrap, and more plating causes waste of energy and materials. There are usually two types of thickness control measurement methods, one is non-destructive thickness measurement method, including electromagnetic method, capacitance method, eddy current method, ray method, gravimetric method, etc., and the other type is loss (damage) measurement method, including coulomb method, metallographic method, dissolution method, etc., commonly known as static measurement method, all after the electroplating process is completed, take out the plating part and then measure its thickness, commonly used testing instruments are! Radiographic Thickness Gauges, eddy current Thickness Gauges, electrolytic Thickness Gauges, "fluorescent Thickness Gauges, etc." An on-line microcomputer control system for the thickness of the electroplating layer has been developed, which is characterized by the simultaneous measurement of plating and the dynamic (or online) random detection of the coating thickness change during the production process. Once the plating is complete, the thickness of the coating is known, which is called dynamic measurement or in-line measurement. The advantage is that any thickness of the coating can be obtained, eliminating the error caused by the manual method of controlling the thickness of the coating based solely on experience (mainly plating conditions such as current and duration). Dynamic on-line thickness measurement adopts computer real-time control, and automatically stops plating when the detected coating thickness reaches a given required thickness, reducing scrap and rework, especially saving precious metals. The system is composed of two parts: the ordinary plating tank and the console, the sensor is built into the tank and the signal is introduced into the console, the console adopts the expanded and flexible STD industrial control bus module structure, and is equipped with a variety of interface circuits, which can easily realize the real-time measurement and control of various process parameters such as the temperature, PH value, current, plating thickness and so on, all of which are displayed on the console panel in the form of numerical values. When the plating is finished, there is an audible and visual alarm to alert the operator, and at the same time, the result is automatically printed and the machine is automatically stopped.

In terms of online control of electroplating quality, it has also developed an electromechanical and chemical intelligent test system, which adopts a self-made 12-bit high-speed A/D and D/A conversion interface board, and is equipped with a 1-128 times programmable amplification circuit. Language compilation software realizes the intelligence of all electrochemical measurement processes from test parameter setting, waveform generation, data acquisition, data processing, screen drawing and graphic printing. Test function: Determination of steady-state polarization curve (potential scanning speed can be as low as 0.1mV/s); Determination of dynamic polarization curve (potentiometric scanning speed 1-20000mV/s continuously adjustable); Cartesian and semi-logarithmic coordinates; Determination of electrode reaction velocity constant and corrosion rate; Differential capacitance and differential capacitance curves were determined by square wave potentiometric method. The screen can display (/electrochemical curves) at the same time.

At present, the application of information technology in the electroplating industry is very active. Through the control of the electroplating production process by microcomputer, the electroplating production can be realized without pollution emissions. Process: electrolytic degreasing - activation - high nickel iron alloy plating - low nickel iron alloy plating - chrome plating - drying. The main functions of the monitoring system: control two cranes and 4 pairs of hooks according to the process flow, and dynamically simulate and display the operation status; Detect and display the temperature of the 5-tank plating solution, control the heating steam solenoid valve, and heat the plating solution when needed; Detection and display of electrolytic degreasing, high nickel iron alloy plating, low nickel iron alloy plating, chrome plating! circuit current, voltage; Display the continuous production time of the production line; Timing or random printing of working parameters (continuous working time, temperature, voltage, current, etc.); After a short-term power failure, the breakpoint can be automatically restored, so that the production line can continue to run according to the process flow from the breakpoint, and the working parameters will be memorized for 4h after the end of operation; Hand over control when manual is needed. The STD286 (bus-type industrial control computer is used as the host of the whole system, and the software is designed into a modular structure, and the main functional modules are: analog acquisition and processing CRY display, temperature control, driving operation monitoring, printout, etc. The addition of STD template can automatically control multiple production lines with completely different processes at the same time.

This paper introduces the system control of the electroplating production line using the NBIU programmable controller (PLC) of the rich ± motor, which is used in the copper and nickel plating process of zinc alloy die castings. Strong anti-interference ability, improve the quality of electroplating. The same system can be used to complete automatic, single-step, single-cycle and manual control, faulty sound and light alarm device, and have the flexibility to change the process flow according to the needs of the site; High control accuracy, small size, low performance price, energy saving. The automatic control part adopts SFC instructions, the control process is clear and concise, and the program structure is simple. Programmable controller (PLC) is a new type of industrial automatic control device that integrates automation technology, computer technology and communication technology.

The transformation of the traditional electroplating process has always been a problem that cannot be ignored in the realization of green electroplating, and the successful example is the microcomputer control of the multi-plating automatic ring electroplating production line. The annular electroplating line is characterized by short cycle time, full load operation, high output, and is suitable for products with mature technology and large batches. Multi-plating, multi-functional, dual-channel cantilever automatic ring electroplating production line microcomputer control according to the introduction can be completed black pearl, red bronze, imitation gold 3 sets of plating process, and can choose thick nickel or thin nickel, electrochemical passivation or non-electrochemical passivation scheme according to the need, and at the same time has 8 sets of working procedures.