1. The dripping time is too short, the consumption of the medicament is too large, and the yield is too low. Therefore, although the polishing process is so simple, the cost is all the pre-oxidation treatment technology! Up to 6000-8000 yuan / ton. After the aluminum door profile leaves the polishing liquid, the dripping time in the air generally should not exceed 30 seconds, otherwise flow marks will appear and waste will be generated. The problem of flow marks in polished materials is a world problem that plagues the aluminum door profile processing industry. Such a short dripping time is bound to cause two serious consequences: one is that the consumption of chemicals is too large, even as high as 400-600kg/ton, and about 800Kg of caustic soda treatment wastewater is added for such high waste acid treatment! The yield is too low, generally less than 70%, and most of the scrap is caused by flow marks or flowers, which further increases production costs.
2, can not sand, to mechanical grain. With the successful development of the chemical polishing mirror polishing process in our institute, the above problems have been satisfactorily solved. During the molding process of the aluminum door profile, there are many mechanical marks on the surface. After the tri-acid polishing process, the grain is more obvious, which seriously affects the appearance quality of the aluminum door profile. In addition to pretreatment with less efficient mechanical methods (such as sand blasting, machine polishing), in recent decades, no mature technology has been developed that uses chemical methods for de-graining and sanding, and then polishing. Restricted the promotion of polishing technology.
3. The decomposition of nitric acid is too fast, a large amount of yellow smoke is seriously polluted, and the treatment cost is expensive. Nitric acid is a strong oxidant. Under high temperature conditions, it encounters aluminum alloy profiles, which are highly reductive metals. The rapid decomposition rate is unimaginable: a large amount of yellow smoke overflows like a fire, and it is difficult to extract the wind. It is even harder to absorb completely! In addition, fluctuations in the concentration of nitric acid will inevitably result in alternating bright and dark surfaces of polished aluminum door profiles with low yield.
4, the oxidation is seriously lost, the quality is greatly reduced. How to reduce oxidative loss of light is another world problem! Tri-acid polishing can generally form a mirror surface. Once anodized, the gloss is greatly reduced.