Alkaline etching process:The degreasing → washing → alkaline etching → rinsing → rinsing → light → washing → washing → oxidation, namely profiles degreasing later, in alkaline etching by alkaline etching treatment to remove the natural oxide film and mechanical pattern, sand, and then after a light tank to remove surface black and gray, can be anodized. The core of the process step is alkaline etching, surface roughness profile, sand, etc. The quality of the process by the decision. For the purpose of leveling the mechanical pattern, which normally takes 12-15 minutes alkali corrosion, aluminum consumption of 40-50Kg / T, alkali consumption of 50Kg / T. Such a high consumption of aluminum, waste of resources and serious environmental problem, increase the cost of wastewater treatment. The process has been used for over 100 years, much of the world still in use ALUMINUM, until the last two years, was gradually replaced by the etching.
Etching process:Etching by a degreasing → washing → → washing → washing → alkaline etching → rinsing → rinsing → light → washing → washing → oxidation composition. After the first etching profile degreasing, after alkaline etching, a light, complete pre-treatment. The core of the process is etching step, to mechanical pattern, sand, such as by etching decision. The biggest advantage is different from the alkaline etching, etching is going strong mechanical pattern, sand, low aluminum consumption, usually 3-5 minutes to complete, alkaline etching aluminum consumption is almost 1 / 8-1 / 6 from efficiency and resource conservation perspective, the etching is undoubtedly a big step forward alkaline etching process. However, environmental issues have become more prominent etching: contaminated with toxic gases escape HF acid bath and washing trough Fˉ of. Fluorides are generally highly toxic, processing more difficult. In addition, the etching process, profiles the appearance of dark black hair, despite the forced continuation of alkaline etching and the light brightens, but still very dark, not only increasing the process has lost its luster, these problems have not yet valid solution.
Polishing process:The degreasing → washing → polishing → washing → washing composition profiles by polishing into the groove after degreasing, 2-5 minutes after polishing, the mirror can be formed, after washing with water can be directly oxidized. The core of the process step is polishing, Wrinkle, mirror polishing is done in the groove. Polished aluminum consumption has a low profile bright advantages, but polished grooves NOx escape, causing serious environmental pollution and operatives of bodily harm, while expensive chemical raw material costs and other factors have hampered the process of promotion.
Throughout the three processes, although with different characteristics, but the disadvantages are also prominent, such as high alkaline etching aluminum consumption, more caustic, low efficiency; etching fluoride pollution, dark profiles; polishing pollution, high cost and so on. These processes are either polluted the environment, or a waste of resources to aluminum, either to reduce the aluminum surface quality, process improvement urgently.