Aluminum Mirror Sheet for Cosmetic Packaging
The aluminum mirror sheets are the raw materials for high-end cosmetic bottle caps. The general requirements for mirror aluminum sheets are high brightness after anodizing, good coloring effect, smooth surface after stamping, low ear-making rate, etc.
The common choice is 1070 H12 aluminum mirror sheet. Due to the high content of Si and Fe impurities in the composition, the 1070H12 products are prone to segregation during casting and subsequent production, resulting in uneven grain size of the material. After anodizing and electroplating, it is prone to have surface defect.
During the manufacturing process of the mirror aluminum cover, the aluminum plate needs to be electrolytically polished and anodized and colored. Because the mirror aluminum cover needs electrochemical treatment on the aluminum plate during the manufacturing process, it has a greater impact on the chemical composition of the aluminum plate. Therefore, the lower the impurity content in the aluminum plate, the better.
In this way, after the aluminum plate is electrolytically polished and anodized, it can achieve higher color brightness and uniform oxidation color. In order to get better performance, Haomei Aluminum adjusts the composition of the polished aluminum sheet and regulates the production process. It includes the following steps:
(1) Smelting: Put 30-40 tons of aluminum ingots with a purity of ≥99.9% into the smelting furnace, and smelt for 4-6 hours to obtain molten aluminum with a melt temperature of 720-750°C. The molten aluminum is stirred at 720-750°C for 5 minutes: After the smelting is completed, use the nitrogen and chlorine mixture to refine the aluminum liquid for 30-40 minutes and remove the surface scum in the static furnace. The temperature of the static furnace is controlled at 710-730℃;
(2) Casting: The molten aluminum is introduced into the casting device from the static furnace through the launder, the depth of the molten aluminum introduced into the launder from the static furnace is controlled to be 250~300mm, and the depth of the molten aluminum in the flow plate above the casting device is controlled to be 200~250mm. The process uses an automatic liquid level control system to control the liquid level in the casting device: during the casting process, a dual titanium wire feeder device is used to add 6-12kg of titanium wire to the molten aluminum;
(3) Milling surface: the single-side milling amount of the large surface is ≥15mm; the thickness of the aluminum alloy ingot after milling is 610mm;
(4) Homogenizing heat treatment of the ingot;
(5) Hot rolling: hot rolling the aluminum alloy ingots processed in step (4), and using emulsion to lubricate and cool the aluminum alloy ingots during the hot rolling process;
(6) Cold rolling: cold-rolling the coil after hot rolling;
(7) Annealing: the aluminum alloy finished product processed in step (6) is subjected to intermediate annealing treatment, and foil rolling is performed after annealing treatment:
(8) Finishing and packaging: thepolished aluminum sheet processed in step (8) is subjected to finishing treatment and packaging into storage.
Original source: https://www.hm-alu.com/a/aluminum-mirror-sheet-for-cosmetic-packaging.html