German customer ordered chemical etching machines

In Aug 2022, HOT SALES, etching machines are packed for delivering to customer in Germany.

When we used chemical etching machine， how can we control the dosage of chemical reagents, let's read this passage.

In etching processing, hydrochloric acid is an important additive potion. But how much is appropriate, this must have a benign understanding. Both acidity and acidity have a great influence on product quality. The amount of hydrochloric acid can be measured by the pH value. The following is the analysis:

During the etching process, attention should be paid to the control of the pH value of the solution. Since HF will volatilize in acidic conditions, it is easy to cause poisoning to the staff and pollution to the ambient atmosphere. Theoretically, using an etching solution with a moderately low acidity for metal etching is more conducive to increasing the texture roughness. However, from the practical application point of view, if higher roughness is required, the pH value of the solution needs to be lower (set solution pH=3.5 as the reference value); if the luminosity of the texture is required to be higher and the texture is thinner, The pH of the solution is higher. In order to etch a satisfactory surface effect, it is important to control the proper acidity of the solution during the etching process. Too high pH value, such as greater than 4.5, although the luminosity is improved, it is not easy to form a uniform texture, and the roughness is low; when the pH value is 5-6 and after natural aging, it will slow down the etching of aluminum at room temperature and even to not etch aluminum. Then increase the pH value of the solution until it is alkaline. At this time, the solution only performs extensive stainless steel etching on the aluminum material, and cannot form a texture effect with a certain roughness (for example, when the pH value is adjusted to 6-6.5 by selecting a suitable pH value adjuster It has a good effect on the etching of aluminum alloys). The low pH value is easy to form texture and the roughness is large; but when the pH value is too low, such as less than 2.5, the texture roughness will not increase but may decrease. In a solution with higher acidity, NH4 HF: There will be a change in chemical equilibrium as follows.

NH4 HF2 -NH4F+HF (3-10)

The higher the acidity of the solution, the higher the concentration of NH4HF: and the higher the temperature, the greater the tendency for the equilibrium to shift to the right. BF in the solution is easy to volatilize, especially in the case of heating, the volatilization is even worse, which causes poisoning to the environment and the staff, and at the same time, it is easy to cause the aluminum alloy workpiece to be over-corroded and the workpiece to be etched and scrapped. When we process non-joint etching, car welcome pedals, film etching, and etching film, scrapping has occurred. The volatilization of HF in the solution leads to an increase in the loss of effective fluorine in the solution, which reduces the effectiveness of the solution and increases the production cost.

Effect of Solution pH on Texture Etching

And too low pH value cannot increase the texture roughness of the aluminum alloy surface, but accelerate the etching rate of the solution to the aluminum material, increase the loss of aluminum workpieces, and increase the consumption of the solution, causing unnecessary waste.