1. Technical Features and Advantages of Alloy Aluminum Plates and Other Aluminum Alloy Profiles
(1) Technical Features of Alloy Aluminum Plates and Other Aluminum Alloy Profiles: Smokeless mirror polishing has characteristics such as no yellow smoke, no streaks, low cost, low consumption, low equipment investment, high brightness, high stability, high efficiency, and high yield. It overcomes the bottlenecks and defects of traditional polishing techniques, successfully achieving large-scale production of 11-meter-long chemical-polished materials as well as automated line chemical polishing. Smokeless mirror polishing technology is an upgraded replacement of ordinary tri-acid and electrolytic polishing and represents the development direction of chemical polishing technology for alloy aluminum plates and other aluminum alloy profiles.
(2) The technical advantages of alloy aluminum plates and other aluminum alloy profiles are as follows:
1) No yellow smoke: Smokeless mirror polishing fundamentally solves the problem of large amounts of yellow smoke generated by triple-acid polishing. It can save a significant amount of environmental treatment costs and clears the main obstacle for the widespread use of chemical polishing.
2) No streaks: Smokeless polishing technology completely solves the problem of polishing streaks and enables fully automatic production of 11-meter-long polished materials, making polishing as easy to operate as alkali etching.
3) High brightness: Due to the use of new polishing components, smokeless polishing increases brightness by 20%–30% compared to triple-acid polishing and electrolytic polishing, making it the brightest polishing technology currently available.
4) Low consumption: The consumption of smokeless mirror polishing agents can be reduced by 60%–70% compared to electrolytic polishing (500–700 kg/t of material).
5) High yield: Almost no defects are generated during the smokeless mirror polishing process, resulting in a very high product yield.
6) High production efficiency: Smokeless polishing allows for large-scale hanging of materials, and multiple rows can be polished at once; there is no waste material in polishing, making production efficiency at least twice that of triple-acid polishing and 6–9 times that of electrolytic polishing.
7) Stable bath solution: The smokeless mirror polishing bath requires almost no adjustment and can operate stably for a long time, paving the way for large-scale industrialized and automated production of chemically polished aluminum materials.
8) Stable brightness: Polished materials from different production batches maintain stable brightness because the bath is not adjusted.
2. Analysis of Process Flow and Key Operating Points
(1) Explanation of Tank Positioning:
1) The smokeless mirror polishing tank is fronted by a completely enclosed exhaust wall, preventing external natural wind from reducing exhaust efficiency, which is conducive to all-weather production during rainy or foggy days.
2) The width of the smokeless mirror polishing tank is over 1.6 meters, enhancing the tank liquid's buffer capacity to absorb smoke, which is conducive to large-scale batch production.
(2) Explanation of Tank Liquid Functions:
1) Wax and Scale Removal Tank: This tank contains a new type of mild alkaline wax and scale remover, which can remove mechanical polishing wax and residual heavy grease without corroding aluminum alloy. It is easy to operate.
2) Smokeless Mirror Polishing Tank: This tank contains multiple components, rich in strong oxidizers, which can perform mirror polishing on aluminum alloy. Compared with other polishing technologies, this tank has the following characteristics:
① Absolutely no yellow smoke, stable brightness: This bath contains a sufficient amount of smoke suppressants, completely preventing the formation of yellow smoke. Since the strong oxidizer decomposes slowly, its concentration is more stable than that of the triple-acid bath, resulting in much smaller differences in brightness between different batches of aluminum alloys compared to triple-acid polishing.
② Increased brightness: The brightness of chemical polishing is not only related to the concentrations of phosphoric acid and nitric acid and the temperature, but also to the water content of the polishing solution. The higher the water content, the lower the brightness. In triple-acid polishing solutions, the phosphoric acid content can be as high as 80% (with a water content of 15%), resulting in a water content in the polishing solution of less than 12%. Such high water content inevitably reduces the brightness of the polished material. In the preparation process of smoke-free mirror polishing solutions, water content is concentrated at a high temperature for a long time, with water content as low as 5%, which significantly increases the brightness of the mirror-polished material.
③ Can drip for a long time: Considering that the chemical polishing reaction is too intense, for aluminum alloys leaving the bath, the dripping time cannot exceed 20 seconds, otherwise a large amount of polishing solution is carried into the rinse bath, making the polished material too costly. The smoke-free mirror polishing solution contains a sufficient amount of corrosion inhibitor, protecting the aluminum alloy when it leaves the bath, allowing it to drip in the air for any length of time without damaging the material or leaving drip marks. This can save more than 70% of the polishing solution.
④ Automatic Ash Removal: When aluminum alloy is impure or the polishing solution has aged, the aluminum material often develops a layer of black ash on the surface after three-acid polishing, which is difficult to remove by conventional methods and seriously affects the quality of the polished material. In smokeless mirror polishing tanks, ash-removing components are added to automatically eliminate polishing ash.
⑤ High Yield: Since the mirror polishing tank addresses issues such as color difference, streaks, pattern defects, and polishing ash, the product yield is significantly increased. This consequently reduces costs and improves production efficiency.
3) Bright-preserving oxidation tank. This tank is set up for two main purposes:
① Pre-forming chemical oxide film: The bright-preserving oxidation tank can generate an oxide film of a certain thickness while completely preserving the original brightness. Before aluminum alloy is anodized from a mirror-polished surface, it can first pass through the bright-preserving oxidation tank to pre-form a certain thickness of chemical oxide film. This prevents pitting or pattern formation in the washing tank before oxidation, improves the yield, and also reduces brightness loss during anodizing.
② Fine removal of polishing residue: There are two sources of polishing residue: one is inclusions in the aluminum alloy, and the other is aging of the polishing solution. Polishing residue is difficult to remove by conventional methods and can severely affect the appearance quality of polished materials. Although a smoke-free mirror polishing tank contains a residue remover that can eliminate the majority of polishing residue, a small amount may still remain. The bright-preserving oxidation tank can thoroughly remove polishing residue, thereby ensuring the quality of polished materials.
