Manufacturing method of container foil with high corrosion resistance and high oxidation resistance

Abstract

The invention provides a manufacturing method of a high-corrosion-resistance and high-oxidation-resistance container foil. The manufacturing method comprises the following steps: melting an aluminum ingot to obtain molten aluminum; the molten aluminum is put into a smelting furnace to be smelted for the first time, a refining agent is added for refining for 15-25 min, stirring is conducted for 2-5 min, standing is conducted for 15-25 min, the molten aluminum obtained after the first time of smelting is smelted for the second time, a refining agent is added for refining for 15-25 min, stirring is conducted for 5-10 min, and standing is conducted for 15-25 min; carrying out cast rolling; carrying out 2-3 passes of cold rolling on the cast-rolled molten aluminum at the temperature of lower than 60 DEG C to obtain an aluminum foil, and trimming; the trimmed aluminum foil is subjected to finish rolling for three times, the roughness of the aluminum foil obtained through finish rolling is 0.25 micrometer, 0.15 micrometer and 0.1 micrometer respectively, after finish rolling, threading is conducted at the speed of 8 m / min, and spraying is conducted on the surface of the aluminum foil during threading so as to remove rolling oil; aluminum foil is threaded to obtain an aluminum foil roll, and the aluminum foil roll is subjected to air purging to remove rolling oil; and atomized oil is sprayed on the purged aluminum foil, so that the corrosion resistance and the oxidation resistance of the container foil are improved, and meanwhile, accurate surface oil stain control is realized.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a container foil with high corrosion resistance and high oxidation resistance. Background Technology

[0002] This invention relates to the field of aluminum foil manufacturing technology, and in particular to a method and apparatus for manufacturing a container foil with high corrosion resistance and high oxidation resistance. Container foil is widely used in the fields of lunch boxes and stamped containers. With the continuous improvement of application requirements, higher requirements are being placed on the corrosion resistance, oxidation resistance and mechanical strength of containers.

[0003] Currently, the mainstream container foil on the market is made of 8011 aluminum alloy. Although this alloy has good processing performance and is easy to process through lamination, printing, stamping, etc., its strength and corrosion resistance are relatively weak, making it difficult to meet the needs of high-end applications. In addition, during long-term storage and transportation, conventional container foil is prone to surface oxidation, especially in cases where export orders have long lead times, and oxidation problems can lead to serious economic losses.

[0004] To address the problems of poor corrosion resistance, easy oxidation, and unsatisfactory surface oil control in existing technologies, this invention proposes a novel method for manufacturing container foil with high corrosion resistance and high oxidation resistance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for manufacturing container foil with high corrosion resistance and high oxidation resistance, significantly improving the corrosion resistance and oxidation resistance of the container foil, while achieving precise control of surface oil contamination. This objective of the invention is achieved as follows:

[0006] This invention proposes a method for manufacturing a container foil with high corrosion resistance and high oxidation resistance, comprising the following steps: melting aluminum ingots at a temperature of 730-750°C to obtain molten aluminum; placing the molten aluminum in a smelting furnace for a first smelting and adding a refining agent for refining for 15-25 minutes, stirring for 2-5 minutes and letting it stand for 15-25 minutes; smelting the molten aluminum after the first smelting for a second smelting and adding a refining agent for refining for 15-25 minutes, stirring for 5-10 minutes and letting it stand for 15-25 minutes; and placing the molten aluminum in a casting and rolling zone for casting and rolling. The molten aluminum after casting is cold-rolled in 2-3 passes at a temperature below 60 degrees Celsius to obtain aluminum foil. The cold-rolled aluminum foil is then trimmed. The trimmed aluminum foil is then precision-rolled three times, and the roughness of the aluminum foil obtained by precision rolling is 0.25 μm, 0.15 μm, and 0.1 μm, respectively. After precision rolling, the aluminum foil is threaded at a speed of 8 m / min. During threading, the surface of the aluminum foil is sprayed to remove rolling oil. After the aluminum foil is threaded, an aluminum foil roll is obtained. The aluminum foil roll is then air-blown to remove rolling oil. Finally, atomized oil is sprayed onto the air-blown aluminum foil.

[0007] Furthermore, the aluminum ingot comprises, by mass percentage, 0.2-0.4% Si, 0.4-0.7% Fe, 0.2-0.3% Cu, 0.05-0.15% Zr, 0.05-0.1% Ti, 0.02-0.05% B, with the remainder being Al and unavoidable impurities.

[0008] Furthermore, the amount of the refining agent added is 0.5-1.5±0.1 kg per ton of aluminum ingot.

[0009] Furthermore, the step of placing the molten aluminum into the casting and rolling zone for casting and rolling includes: the convexity of the cast and rolled aluminum is 0.3-0.5%, and the process crack edge is within 2mm.

[0010] Furthermore, the step of obtaining an aluminum foil roll by threading the aluminum foil and then air-blowing the aluminum foil roll to remove the rolling oil includes: when air-blowing the aluminum foil roll, blowing in both directions towards the sides of the aluminum foil roll.

[0011] Furthermore, before spraying the atomizing oil onto the purged aluminum foil, the process includes annealing and slitting and rewinding.

[0012] Furthermore, the atomizing oil includes: stamping oil.

[0013] Compared with the prior art, the beneficial effects of the present invention are: through the improvement of materials and manufacturing methods, the effective removal of rolling oil and the precise control of oil film thickness are achieved, which effectively solves the oxidation problem of aluminum foil during long-term storage, increases the yield rate, and is particularly suitable for long-cycle application scenarios such as foreign trade orders. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a process for manufacturing a container foil with high corrosion resistance and high oxidation resistance. Detailed Implementation

[0015] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0016] Please refer to Figure 1This invention provides a method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil, comprising the following steps: melting aluminum ingots at 730-750°C to obtain molten aluminum; placing the molten aluminum in a smelting furnace for a first smelting and refining with a refining agent for 15-25 minutes, stirring for 2-5 minutes and letting it stand for 15-25 minutes; smelting the molten aluminum a second time and refining with a refining agent for 15-25 minutes, stirring for 5-10 minutes and letting it stand for 15-25 minutes; placing the molten aluminum in a casting and rolling zone for casting... Rolling; The cast-rolled molten aluminum is cold-rolled 2-3 times at a temperature below 60 degrees Celsius to obtain aluminum foil. The cold-rolled aluminum foil is trimmed. The trimmed aluminum foil is then precision rolled three times. The roughness of the aluminum foil obtained by precision rolling is 0.25um, 0.15um and 0.1um respectively. After precision rolling, the aluminum foil is threaded at a speed of 8m / min. During threading, the surface of the aluminum foil is sprayed to remove rolling oil. After threading, the aluminum foil is rolled into an aluminum foil roll. The aluminum foil roll is then air-blown to remove rolling oil. Atomized oil is sprayed onto the air-blown aluminum foil.

[0017] The container foil manufactured using this embodiment has the following properties after testing: tensile strength ≥180MPa, which is about 25% higher than that of conventional 8011 aluminum alloy; yield strength ≥150MPa; elongation ≥8%; no red rust after salt spray test for ≥72 hours; no visible oxidation after storage at 40℃ and 90%RH for 6 months; roughness controlled at about 0.1μm; and ink thickness of 9-12nm. Therefore, the method of this embodiment effectively controls surface oil and oxidation.

[0018] In this embodiment, the aluminum ingot comprises, by mass percentage, 0.2-0.4% Si, 0.4-0.7% Fe, 0.2-0.3% Cu, 0.05-0.15% Zr, 0.05-0.1% Ti, 0.02-0.05% B, with the remainder being Al and unavoidable impurities; the amount of refining agent added is 0.5-1.5±0.1 kg per ton of aluminum ingot; the molten aluminum is then placed in the casting and rolling zone for casting and rolling, including: the convexity of the cast and rolled aluminum is 0.3-0.5%, and the process crack edge is within 2 mm.

[0019] In the demonstrative first smelting, the prepared raw materials were completely melted at 740±5℃ to form molten aluminum. A forklift was used for stirring during the smelting process at a speed of 40 rpm to ensure a uniform melt. For the first refining, a refining agent of 0.2% by weight of the molten aluminum was added to the molten aluminum for 20±2 minutes, with stirring maintained for 3 minutes at a speed of 50 rpm to ensure sufficient contact and reaction between the refining agent and the molten aluminum. After refining, the mixture was allowed to stand for 20 minutes to allow impurities to float to the surface. For the second smelting, the temperature of the molten aluminum after the first refining was adjusted to 745±5℃ for a second smelting. Then, for the second refining, 0.2% by weight of the refining agent was added again. A 0.2% refining agent was used, the refining time was extended to 22±2 minutes, the stirring time was extended to 8 minutes, and the stirring speed was increased to 60 rpm. After refining, the mixture was allowed to stand for 20 minutes. During casting and rolling, the casting and rolling temperature was controlled at 700±10℃, and the casting and rolling speed was set to 1.2 m / min. Cold rolling was divided into three passes, mainly to reduce the material's translucency and homogenize the microstructure, achieving complete recrystallization and good elongation properties. The first pass had a reduction rate of 45±2%, a rolling speed of 2.5 m / s, and a rolling force controlled at 850±50 kN. A 4% concentration emulsion was used for cooling and lubrication, with the emulsion temperature controlled at 45±2°C and a flow rate of [missing information]. The second pass reduction rate was 35±2%, the rolling speed was 3.0 m / s, the rolling force was controlled at 700±50 kN, the emulsion concentration was adjusted to 3.5%, the temperature was 42±2°C, and the flow rate was... The third pass reduction rate was 25±2%, the rolling speed was 3.5 m / s, the rolling force was controlled at 550±50 kN, the liquid concentration was 3%, the temperature was 40±2°C, and the flow rate was... After each finishing roll, online roughness testing is performed, and the edges are trimmed to remove burrs for further processing.

[0020] In this embodiment, after the aluminum foil is threaded to obtain an aluminum foil roll, the aluminum foil roll is air-blown to remove the rolling oil, which includes: when air-blowing the aluminum foil roll, blowing in both directions towards the sides of the aluminum foil roll; before spraying atomized oil on the air-blown aluminum foil, the step further includes: annealing and slitting and rewinding.

[0021] Specifically, an oiling device was designed based on the existing slitting machine. This fully enclosed device allows for internal oil circulation and repeated use. It has two spray beams: an upper beam and a lower beam. Each beam consists of multiple nozzles, which are electrically controlled by a separately programmed PLC. Each nozzle has a solenoid valve switch to control its angle at 45°, with a gap of 30-60mm. The spray pattern is atomized, ensuring even distribution of oil on the aluminum foil surface. Excess oil drips from the foil into an oil collection tank, where it is then pumped out by a centrifugal pump. The filter is a mesh filter that is cleaned regularly. Without affecting the slitting machine's function, the cleaning and spraying device is installed at the uncoiler position of the slitting machine. The cleaning and spraying device is a sealed cover, with the spray beam fixed to it. The two ends of the spray beam are the oil inlets. The oil used is a stamping oil, which adheres to the aluminum foil surface, preventing contact between the aluminum substrate and oxygen in the air, thus preventing oxidation. Furthermore, the stamping oil facilitates stamping by downstream customers, reducing friction during stamping and protecting the stamping equipment.

[0022] It should be noted that atomized oil includes stamping oil. The nozzle of stamping oil uses a specially designed atomizing nozzle to produce a uniform and fine oil mist. The spray angle of the nozzle and the diameter of the atomized particles directly affect the quality of the oil film, which can ensure the uniformity of spraying across the entire width of the aluminum foil and avoid edge effects.

[0023] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for manufacturing a container foil with high corrosion resistance and high oxidation resistance, characterized in that, The process includes the following steps: melting aluminum ingots at 730-750°C to obtain molten aluminum; placing the molten aluminum in a smelting furnace for the first smelting, adding a refining agent and refining for 15-25 minutes, stirring for 2-5 minutes and letting it stand for 15-25 minutes; smelting the molten aluminum a second time, adding a refining agent and refining for 15-25 minutes, stirring for 5-10 minutes and letting it stand for 15-25 minutes; placing the molten aluminum in a casting and rolling zone for casting and rolling; cold rolling the cast and rolled aluminum in 2-3 passes at a temperature below 60°C to obtain aluminum foil; trimming the edges of the cold-rolled aluminum foil; performing three finishing rolls on the trimmed aluminum foil, with the resulting aluminum foil having roughnesses of 0.25µm, 0.15µm, and 0.1µm respectively; threading the foil at a speed of 8m / min after finishing rolls, spraying the aluminum foil surface during threading to remove rolling oil; After the aluminum foil is threaded onto the tape, an aluminum foil roll is obtained. The aluminum foil roll is then purged with air to remove the rolling oil. Spray atomized oil onto the purged aluminum foil.

2. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 1, characterized in that, The aluminum ingot comprises, by mass percentage, 0.2-0.4% Si, 0.4-0.7% Fe, 0.2-0.3% Cu, 0.05-0.15% Zr, 0.05-0.1% Ti, 0.02-0.05% B, with the remainder being Al and unavoidable impurities.

3. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 2, characterized in that, The amount of the refining agent added is 0.5-1.5±0.1 kg per ton of aluminum ingot.

4. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 3, characterized in that, The step of placing the molten aluminum into the casting and rolling zone for casting and rolling includes: the convexity of the cast and rolled aluminum is 0.3-0.5%, and the process crack edge is within 2mm.

5. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 1, characterized in that, The process of threading aluminum foil to obtain an aluminum foil roll and then air-blowing the aluminum foil roll to remove rolling oil includes: when air-blowing the aluminum foil roll, blowing in both directions towards the sides of the aluminum foil roll.

6. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 5, characterized in that, The steps before spraying atomized oil onto the purged aluminum foil include annealing and slitting and rewinding.

7. The method for manufacturing a highly corrosion-resistant and highly oxidation-resistant container foil according to claim 1, characterized in that, The atomizing oil includes: stamping oil.

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