Zinc alloy due to easy molding, plasticity, low cost, high processing efficiency, widely used in sanitary ware, bags, shoes and clothing accessories, but the zinc alloy blistering problem has been plagued by hardware factories and electroplating plant friends.
Author: Anna
Zinc alloy due to easy molding, plasticity, low cost, high processing efficiency, widely used in sanitary ware, bags, shoes and clothing accessories, but the zinc alloy blistering problem has been plagued by hardware factories and electroplating plant friends.
To summarize the service of a number of hardware factory plating factory needle on zinc alloy blistering experience compilation, specifically the following aspects:
1. Zinc alloy product design at the beginning, we must take into account the mold feed port and slagging port and exhaust settings. Because the feed and dregs of the workpiece smooth flow does not wrap gas, does not produce water stains, no dark bubbles, directly affects the latter electroplating blistering or not, qualified feed and dregs mold die casting out of the workpiece, the surface is smooth, bright white, no water stains.
2. Mold development should also consider the tonnage of the mold loading machine, pressure, we personally experienced a zinc alloy plating blistering after a hundred 20-30 events. A hardware factory friends to take a few million large single, molds open one out of 8 pieces, regardless of how to solve the plating pre-treatment there is always 20-30% blistering, and finally will be plugged into the mold 4 pieces, changed to a mold out of 4 pieces, and then plated without a bubble.
3. Pre-treatment of the surface of the tumbling solution, polishing paste, oxidized layer is not clean, long there is a rolling light, rolling after the workpiece, the surface is bright many plating plant pickling process employees just pickling down, leading to the surface attached to the tumbling agent is not washed, and long there is blistering. Another rolling light roller polishing plant selected by the rolling agent is also a great relationship, some rolling agent in the surfactant is extremely difficult to wash away.
4. products into the alkali copper (many friends do hardware commonly known as copper bottom) plating tank before the surface of the workpiece is still oxidized film (pickling of the film) waxing, de-oiling of the film is not dealt with net. Therefore, it is very important to remove the film, some years ago, you can also use anti-dyeing salt to remove, now the environmental protection does not allow the discharge of wastewater containing anti-dyeing salt, it is recommended to use LJ-D009 film removal powder, the effect is better than anti-dyeing salt, but also can be returned to the nickel layer and the COD emissions in line with international standards.
5. Alkaline copper plating tank organic matter, impurities, free cyanide is not in the range of the composition of the alkaline copper cylinder, to see if the sodium cyanide is low or sodium hydroxide is high! If you add light agent, beware of light agent is high, alkali copper cylinder cleaning is very critical, it is recommended that 3-5 days carbon treatment once!
6. Alkaline copper cylinder conductivity is also very important, whether the anode is dissolved normal, anode copper plate is sufficient will lead to blistering.
7. Zinc alloy products out of the oven blistering; may be uneven oven temperature leads to that the temperature is too high. Due to the die-casting time is not close, resulting in zinc alloy water stains grain sand easily into the acid, acid and zinc in the case of even if there is a surface plating will still be a chemical reaction, resulting in a large number of hydrogen H when the inside of the air pressure is higher than the atmospheric pressure of a certain degree, coupled with the high temperature will be generated bubbles.