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Handboard surface treatment - electroplating process

Jan 12,21

Handboard processing some product processes need to do post-treatment electroplating, in the electroplating process generally includes electroplating before pretreatment, electroplating and plating after treatment of three stages.
Complete process of electroplating:
1, pickling → all-plate copper plating → graphic transfer → acid oil removal → secondary countercurrent rinsing → micro-erosion → secondary pickling → tin plating → secondary countercurrent rinsing
2, countercurrent rinsing → leaching acid → graphic copper plating → two-stage countercurrent rinsing → nickel plating → two-stage water washing → leaching citric acid → gold plating → recovery →2-3 grade pure water washing → drying
Plastic shell plating process
Chemical deoiling → washing → soaking acetone → washing → chemical coarsening washing sensitization → washing → activation → reduction → electroless copper plating → washing bright sulfate copper plating → washing → bright sulfate nickel plating → washing → bright chromium plating → washing drying for inspection.
In the above process, the most prone to failure is bright sulfate copper plating, the phenomenon of poor deep plating ability and burr, rough, etc, to the deep plating ability is poor, should be treated differently, if low current area is not bright, and the high current region is very bright and should be white, can consider to N (ethylene thiourea) is overmuch, adjust the way to go, adding suitable amount of M (2 - mercapto narrowing Cuo truxene) and SP (poly two propane sulfonic acid sodium disulfide), if still no, 10 minutes to stir in 50 ~ 100 ml hydrogen peroxide test plating, if low current area is not bright, high current area is very bright and be bright orange, can consider to whether M too much,The adjustment method is to add an appropriate amount of N and P(polyethylene glycol), if still not, can add 50~100ml of oxygen.Water stirring for 10 minutes, if the low current area is not bright, and the brightness of the high current K is poor, it can be considered whether N or M is too little, the adjustment method is to add the right amount of M or N(can also add the right amount of SP), if the high current area long burr, usually add appropriate SP can be eliminated.If there is fine bremsstrahlung on the surface of the beryllium layer, whether there is bremsstrahlung on the surface of the coating is above or below, then there is too much M, and an appropriate amount of SP can be added to eliminate it. However, if there is bremsstrahlung on the surface of the coating, the reason of copper powder should be considered, and 50ml hydrogen peroxide can be added to eliminate it.
Generally speaking, the bright copper plating solution should be added 50ml hydrogen peroxide at the end of each day.In addition to bright copper plating prone to the above failures, coarsening is also prone to failure, usually for home appliance product shell after coarsening the surface of yellow or white powder.At this point, it should be considered from the following three aspects: First, whether the coarsening temperature  is too high and the time is too long;Two. Whether the sulfuric acid content in the coarsening solution is excessive;Three, the concentration of the organic solvent used before coarsening, whether the temperature is too high, too long.Additional, if the home appliance product shell of rework is coarsely changed again when, easy coarsely changed excessive, cause plating is not bright, should reduce coarsely changed temperature and shorten coarsely changed time appropriately to this, before coarsely changed, give acetone no longer generally.Chemical plating steel, prevent tourne plating solution (i.e., to produce a large number of copper powder), if the solution tourne, then the slot of the plastic shell must rework, all want to mace filter chemical plating solution immediately, at the same time after the chemical copper plating appliances shell, shall generally be immediately plating, but encountered special circumstances, needs to be placed for long, the electrical appliances product shell should be dried and vertical in the dry place preservation, shelf life for 2 days, hanging fixture problems is very important also, hanging fixture of the insulation with bandaging method is not suitable for plastic electroplating, ring, due to our ABS plastic electroplating from coarsening to chemical copper plating does not use hanging fixture,But only in bright copper-bright nickel-bright chrome-bright copper-bright nickel-bright chrome-..., and after beryllium chromium (which then enters the copper plating liquid), the chromium plating liquid carried on the panger will deteriorate the bright copper plating liquid. Similarly, such a bandage insulated panger will pollute the setting liquid and the chromium mask liquid.If restricted by conditions, can only be used in the dressing method, the hanging must be soaked in the water after cleaning for more than ten minutes, in order to make the infiltration of chromium in the dressing Once the bright copper plating solution is slightly polluted, it can be treated with a small current for 1 ~ 2 days.
Electroplating process requirements:
1. There should be good adhesion between coating and substrate metal and between coating and coating;
2. The coating should crystallize fine, smooth and uniform in thickness;
3. The coating shall be of specified thickness and have as few pores as possible;
4. The coating should have the specified indicators, such as brightness, hardness, electrical conductivity, etc.;
5. The plating time and the temperature of the plating process determine the thickness of the coating.The ambient temperature is -10℃ ~ 60℃;
6. Input voltage is 220V±22V or 380V±38V;
7. The maximum working noise of water treatment equipment should not be greater than 80dB(A);
8. Relative humidity (RH) should not be greater than 95%;
9. The COD content of raw water ranges from 100mg/L to 150000mg/L.