Introduzione
Surface treatment seems to be a relatively easy task. When the workpiece is placed in a tank and powered on, a layer of film grows out. However, those who have worked on the production line know that the coating effect is completely different with a slight difference in current. In a batch of goods, some parts are bright while others are gray. The problem is often not with the chemical solution, but with the rarely noticed power supply. What affects this layer of film is not only the price of the tank solution and the advanced level of the formula, but also the current in the equipment. If the current is stable, the product will be stable. If the current shakes, the entire batch of products will be scrapped normally. A power supply is usually used for several years, and its reliability in these years directly determines the reputation and rework rate of the production line. Adjustable AC/DC power supply is freeing the electroplating workshop from dependence on the manual dexterity of experienced craftsmen.
Power Requirements of Electroplating and Anodizing Processes
Electroplating requires current, while anodizing requires voltage. Both processes appear to be rectifying, but the requirements for the Alimentazione elettrica are actually opposite. Choosing the wrong direction at the beginning will be in vain for subsequent adjustments. On the electroplating side, chrome plating, zinc plating, and copper plating each have their own characteristics. As the concentration, temperature, and shape of the plating solution change, the current density needs to be adjusted accordingly. If the current is too small, it cannot be plated, and if it is too large, it will burn out the workpiece. The sensitivity of different plating types to current varies greatly. To use the same output to cope with all processes, there is no way to go up the electroplating line, while anodizing has the opposite. It has requirements for the voltage curve. If the boost is too fast, the film will burn out, and if it is too slow, the color will not go up. A production line often needs to perform several processes at the same time, and the power supply only has one output, so it cannot be paid for. So the requirements that electroplating power supplies need to meet can be summarized into three things: stable current, wide voltage range, and low ripple. This may sound simple, but it’s not really something that can be achieved.
Why Adjustable Voltage and Current Control Matters
Old style power supplies have fixed outputs, and if you want to adjust the voltage once, you have to disconnect the wiring. Once it’s fixed, you dare not move it again. The production line has stopped and the delivery time has been delayed, so you have to change one parameter. However, not a single day on the production line is repeated. The workpiece size varies, the hanging density varies, the tank solution ages day by day, the formula is adjusted repeatedly, any variable changes, the ideal output changes, the Alimentazione elettrica cannot be adjusted, and people can only accommodate the equipment. If there is too much accommodation, the quality will gradually become unstable. According to different coating chemical formulas, different formulas are matched and output, and the corresponding current density range varies greatly. Taking nickel plating as an example, more brighteners are added, and the available current window becomes narrower. As the current increases, the coating becomes gray and brittle, and the gloss disappears. The process difference is a few volts or a few amperes, and the results are completely different. There are many types of formulas, and the power supply can only provide a fixed output, so there is no matching. Only the power supply can be adjusted, and the equipment can follow the formula, rather than the formula accommodating the equipment. To maintain consistent surface treatment quality, customers require the same batch of goods with the same color and thickness. However, anodizing is affected by the season, with higher tank temperatures in summer and lower tank temperatures in winter, and the same voltage resulting in different film thicknesses. Batch after batch, temperature differences can occur, leading to color differences and complaints. The function of adjustable power supply is to control this drift and ensure that each pendant falls within the allowable range, allowing different batches of products to match. Not adjusting can only rely on the feel, and only after adjusting can we dare to talk about stability. These two points are ultimately one thing, which is to take the quality out of the state of relying on luck.
Key Features to Look for in a Plating Power Supply
Precise Current Regulation
Precise current regulation is not about the larger the current, but about the more accurate it is. If the regulation accuracy is poor, the thickness of the coating will also decrease, and the scrap rate will directly increase. High demand plating requires strict control over the current, and the current can be stable at the target value without fluctuation, which is truly useful. Only looking at the range without stability is equivalent to not looking at it.
Ripple Control for Uniform Deposition
Ripple control ensures uniform deposition. As long as the ripple is large, the deposition will be uneven. For deep holes, blind holes, and complex shaped workpieces, high ripple will cause blackening of the edges and whitening in the middle. Good workpieces will be damaged in this way, and the coating will become rough, resulting in an increase in porosity and a decrease in corrosion resistance. Low ripple is not a bonus point, but a prerequisite for uniform deposition, and it is also the boundary line for whether high-end orders can be accepted.
Ramping and Pulse Plating Capability
Many high demand plating types now use pulses instead of constant currents to control the growth rhythm of crystal nuclei. The resulting layer is dense and bright, and can accommodate deep and blind holes with forward and reverse pulses. If the power step response cannot keep up, pulse plating cannot be achieved.
Sizing a Power Supply for Your Plating Line
When selecting a Alimentazione elettrica, the first step is to calculate the load. Calculate the current of the largest slot and the most fully loaded string of workpieces on the production line, and leave a certain margin. If the margin is too small, the power supply will be fully loaded for a long time, shorten its lifespan, increase faults, and leave too much. Money is spent, and most of the time it is not used up, which is also a waste. Calculate the load based on peak value, not average value. When the production line is busy, what is often missing is that point. The second step is to confirm the process. Is the production line mainly based on constant current or requires constant voltage? Should pulse be used? Will the products become more complex in the future? Will new plating be added? The power supply usually takes seven or eight years. Choosing the wrong one now will cause a lot of trouble in the future. If you want to replace it, it will be like shutting down the production line and starting over. The third step is to examine the enterprise, including whether the after-sales response is fast, whether spare parts can be supplied in a timely manner, whether debugging can be supported, and how to determine the quality assurance. These cannot be seen from the brochure, only when there is a malfunction can they be truly seen. For devices such as power supplies, parameters are important, and the service behind them is more important.
Domande frequenti
Q1:What type of power supply is used for electroplating?
A1:Electroplating generally uses DC power supplies with lower voltage and higher current. In terms of rectification, high-frequency switching power supplies are more popular than old-fashioned thyristors because of their high efficiency, low ripple, and small size. Special coatings such as pulse plating and precious metal plating are required, so choose power supplies with corresponding pulse functions. When selecting, leave enough voltage range and do not get stuck at the lower limit.
Q2:How do you calculate power supply size for anodizing?
A2:First, determine the maximum workpiece area, multiply it by the required current density of the process to obtain the peak current, and then multiply it by the working voltage to obtain the power. After calculating, do not rush to place an order. Leave a margin of about 1.2 times to prevent the tank solution from being unable to withstand temperature and concentration fluctuations. Anodizing has requirements for voltage rise speed, and this should also be considered when calculating capacity.
Q3:Why is low ripple important in plating power supplies?
A3:The ripple size directly determines the degree of deposition uniformity. A large ripple will cause the coating to become rough, the porosity to increase, the corrosion resistance to deteriorate, and the gloss to be difficult to maintain. For decorative and functional coatings, low ripple is the basic requirement and cannot be chosen arbitrarily. Only when the ripple can be controlled can the yield be stable.
Q4:Can adjustable power supplies handle pulse plating?
A4:Sure, but with the premise that the key is whether the step response of the power supply is fast enough and the ripple is low enough. Being able to adjust is just the most basic requirement. A power supply that can truly withstand pulse coating has another set of requirements for control logic, output dynamics, and response speed. Before purchasing, it is best to take an actual workpiece for trial plating, not just look at the parameter table.
Conclusione
Although the Alimentazione elettrica is not the facade of the production line, it affects the quality. If the facade is slightly poor, at most it will not look good, and if there is a quality problem, the entire production line will be affected. Adjustable AC/DC power supply eliminates the need for manual operation in electroplating and anodizing production. Each layer of coating has a standard to follow, and selecting the right one can bring efficiency, improve yield, save every kilowatt hour and ton of material used in recent years, and establish a quality reputation in front of customers. The equipment is constantly upgrading and the technology is constantly subdividing. The threshold of power supply will be raised sooner or later. Instead of trying to be cheap, it is better to find a manufacturer that can handle the details. di WEHO accumulation and efforts in this direction, from stable output to after-sales service, can withstand production line inspections and are worthy of being included in the supplier list.
