Galvanized plating machine Video:
A, Concept of galvanized plating machine:
Galvanized plating machine is making the usage of electrolysis, which is a process of forming uniform, dense, combined with good metal or alloy deposited layer on workpieces surface.
Compared with other metals, zinc is relatively cheap and easy plated metal, and also is a low corrosion plating layer, while widely used to protect steel parts, in particular to prevent atmospheric corrosion, as well as used for decoration filed. Plating techniques include: tank plating (or rack electroplating), barrel electro plating (for small parts), automatic plating and continuous plating (for wire, strip).
B, Classification of galvanized plating machine:
At present, our domestic classification according to the plating solution can be divided into 4 categories:
1. Cyanide Zinc plating system:
Because (CN) is highly toxic, so the environmental protection put strict limits in the using of cyanide for galvanization, and constantly promote the reduction of cyanide and develop the replacement of galvanizing bath device, requiring of low cyanide (micro cyanide) plating solution.
With this process, electroplating has good product quality, especially color plated, that can get good color retention after passivation.
2. Zincate galvanized plating machine:
This process is evolved by cyaniding galvanized. At present, there are 2 formation of factions, namely as:
a) Wuhan material “DPE” series;
b) Radio and television “DE” series.
Both are belong to alkaline additives zincate, PH value as 12.5 to 13.
With this technology, the lattice structure of columnar coating, which has good corrosion resistance, suitable for color galvanized.
Note: After the products out of bath -> Washing -> Light (nitric acid + hydrochloric acid) -> Washing -> Passivation -> Washing -> Washing -> Hot dry -> Drying -> Aging (Oven 80 ~ 90 ℃. )
3. Chloride galvanized plating machine:
This process is widely adopted in the electroplating industry, the proportion up to 40%. Passivated (blue and white) can use zinc to replace chromium (comparable with chromium plating), especially after additional water-soluble varnish, a layman is difficult to tell which is galvanized or chrome plating. This process is suitable for white passivation (blue white, silver white).
4. Sulfate galvanized plating machine:
Sulfate galvanized plating machine is suitable for continuous plating (wire, strip, simple and crude large parts and components), with feature of low cost.
C, Electric galvanized plating machine technical processes:
1. Galvanized plating machine process: for example galvanized iron alloy, as follows:
Chemical degreasing → Hot water rinse → Water rinse → Electrolysis degreasing → Hot water rinse → Rinse → Highly corrosive → Rinse→ Electric galvanized iron alloy → Rinse → Rinse → Idemitsu →Passivation → Rinse → drying
2. Galvanized bath solution preparation: Bath solution preparation (in lL example):
(1) Pour 1/3 volume of the purified water into plating tank;
(2) With 1/3 pure water to dissolve sodium hydroxide (dissolution may have a fever, you must be careful);
(3) Use small amount of water mix zinc oxide into a paste type, then add more DI water, stirring well. Add the stirred zinc oxide into dissolved sodium hydroxide slowly, while adding while stirring to fully mixing then add to the plating bath;
(4) When the bath temperature dropped to below 30℃, add 85g of Baser, to stir completely;
(5) Dissove 15mL BaseF into 15g BaseR, then the mixture was added to the plating tank;
(6) Add 4mL of H-O624, stir; add water to the dispensed volume;
(7) Add brightener then stir;
Black passivation technical process:
Washing → lighting → Washing → Black passivation → Washing →After treatment → drying.
D. The factors to infect galvanized plating machine:
(1) Zinc content: If zinc content too high, the narrow range of light, can get a thick thickness of the coating and reduce the iron content; If the zinc content is too low, the wide range of light, to achieve the desired thickness requires a long time, and the high iron content in the coating.
(2) Sodium hydroxide: When the sodium content is too high, high temperature operation easy to cause burnning; when the sodium content is too low, the dispersion capacity is poor.
(3) Effect of iron content: Iron content is too high, the high iron content in the coating, passivation film does not shine; iron content is too low, the low iron content in the coating, corrosion resistance decreases, color leaning to partial olive.
(4) Effect of brightener: Too high, the coating is brittle; low, low current region-free plating, passivation color uneven;
(5) Effect of Temperature:
If temperature is too high, decrease dispersing ability, high iron content in the coating, decrease in corrosion resistance, a passivation film is uneven color, blur; temperature is too low, the high current density area charred, brittle coating, the deposition speed is slow.
(6) Movement the cathode: Must adopt cathode movement. Moving too fast, high-current density zone coating roughness; too slow, may produce airflow, partial area will coating layer.