A method for treating aluminum powder on the surface of rolled aluminum foil

Abstract

This invention relates to the field of aluminum foil production technology, specifically a method for treating aluminum powder on the surface of rolled aluminum foil. This method effectively removes aluminum powder adhering to the aluminum foil surface by combining physical and chemical treatments, improving the purity and safety of the aluminum foil. It is applicable to industries such as electronics, electrical appliances, and food packaging. The treatment effect of aluminum powder can be further optimized by controlling static electricity elimination during the rolling process, selecting the cleaning solution, and using controlled atmosphere heat treatment conditions. Furthermore, the introduction of quality inspection ensures that there is no residual aluminum powder on the surface of the treated aluminum foil, improving product reliability and safety. This invention provides a new solution for quality control in the aluminum foil production process.

Description

Technical Field

[0001] This invention relates to the field of metal processing technology, and in particular to a method for treating aluminum powder on the surface of rolled aluminum foil, and related technologies for aluminum foil manufacturing and treatment. Background Technology

[0002] During the rolling process, aluminum foil easily produces aluminum powder on its surface due to friction and temperature. The presence of this aluminum powder not only affects the appearance and performance of the aluminum foil but can also interfere with the normal operation of electronic and electrical equipment, and even threaten the safety of food-grade aluminum foil. Traditional treatment methods mainly focus on single physical or chemical means, with limited effectiveness. Currently, the treatment of aluminum powder on the surface of rolled aluminum foil faces the following technical challenges: First, the particle size of aluminum powder varies widely, ranging from nanometers to micrometers, requiring treatment methods to adapt to different particle sizes. Second, the aluminum powder on the aluminum foil surface is tightly bonded to the substrate, making it difficult to remove completely. Furthermore, the treatment process must avoid damaging the aluminum foil surface to prevent affecting its performance. Finally, for food-grade aluminum foil, safety is the primary consideration; therefore, the treatment method must ensure no harmful residues remain.

[0003] To address the aforementioned issues, while some existing technologies attempt to solve the problem of aluminum powder removal from aluminum foil surfaces, they typically suffer from poor treatment results, complex operation, or high costs. For example, some technologies use chemical etching or strong oxidants to remove aluminum powder, but these methods may damage the aluminum foil surface, affecting its appearance and performance. Other technologies focus on improving the cleaning power of the cleaning solution, but often neglect the adhesion between the aluminum powder and the substrate.

[0004] In conclusion, there is currently a lack of a comprehensive method to address the aluminum powder problem on the surface of rolled aluminum foil. Therefore, there is an urgent need to develop a new, efficient, safe, and reliable aluminum powder treatment technology to meet the growing market demand and increasingly stringent technical requirements. Summary of the Invention

[0005] This invention provides a method for treating aluminum powder on the surface of rolled aluminum foil. This method effectively and comprehensively solves the problem of aluminum powder on the surface of rolled aluminum foil, and is a highly efficient, safe, and reliable aluminum powder treatment technology. The method of this invention combines various physical and chemical means to achieve highly efficient treatment of aluminum powder on the surface of rolled aluminum foil. This treatment method not only improves the purity and safety of the product, but is also suitable for industries such as electronics, electrical appliances, and food packaging.

[0006] To solve the technical problem of this invention, the proposed technical solution is: a method for treating aluminum powder on the surface of rolled aluminum foil, the method comprising the following steps:

[0007] (1) A rolling mill with static elimination function is used during the rolling process to reduce the generation of aluminum powder; the static elimination device of the rolling mill can use a heated tungsten filament, thermionic electrons overflow on its surface and are accelerated by a DC power supply. These negatively charged electrons collide with inert gas molecules in the reaction chamber to generate plasma of electrons and ions. The electrons in the plasma neutralize the positive charge on the surface of the aluminum foil under the action of an electric field, thereby eliminating static electricity and reducing the adsorption of aluminum powder.

[0008] (2) Clean the surface of the rolled aluminum foil to remove residual aluminum powder;

[0009] (3) The cleaned aluminum foil is heat-treated in a mixed atmosphere of controlled oxygen and inert gas to oxidize the aluminum powder into stable aluminum oxide at high temperature.

[0010] (4) Conduct quality inspection on the heat-treated aluminum foil to ensure that there is no residual aluminum powder on the surface.

[0011] Preferably, the rolling mill with the electrostatic elimination function in step (1) neutralizes the positive charge on the surface of the aluminum foil by generating negatively charged electrons, thereby reducing the adsorption of aluminum powder;

[0012] The cleaning in step (2) uses a cleaning solution containing surfactants and complexing agents to improve the cleaning effect;

[0013] The heat treatment in step (3) is carried out in a controlled mixed atmosphere of oxygen and inert gas to promote the complete oxidation of aluminum powder.

[0014] The quality inspection in step (4) is performed using a surface morphology analyzer and a metal element analyzer.

[0015] Preferably, the cleaning step in step (2) further includes spraying the aluminum foil surface with a high-pressure water gun to remove finer aluminum powder particles.

[0016] Preferably, in the heat treatment process of step (3), a controlled atmosphere oxidation is used to form a uniform oxide film of a certain thickness on the surface of the aluminum foil. The controlled atmosphere includes a carrier gas component: nitrogen or argon inert gas, a reaction gas: oxygen, and a heat treatment temperature between 200-350°C.

[0017] By using inert gas protection, the oxygen content can be effectively controlled, further protecting the aluminum foil surface from oxidation and maintaining its original metallic properties. At the same time, inert gas protection can also improve the efficiency and quality of heat treatment, providing a better foundation for subsequent performance testing.

[0018] During heat treatment, the concentration or atmosphere of oxygen is controlled to ensure that the aluminum powder is completely oxidized into stable alumina, while preventing the aluminum foil surface from being oxidized. This typically involves using inert gases (such as argon or nitrogen) to create a low-oxygen or oxygen-free environment to protect the aluminum foil.

[0019] Preferably, the heat treatment temperature of step (3) is carried out at 250°C to promote the complete oxidation of aluminum powder and prevent the aluminum foil from being over-heat treated.

[0020] Preferably, the quality inspection in step (4) includes the inspection of the surface roughness, cleanliness and metal element content of the aluminum foil; the quality inspection uses a high-resolution microscope to observe the surface morphology to determine the minute defects and residual aluminum powder on the aluminum foil surface, and the surface morphology detector can observe the fine structure of the aluminum foil surface to determine whether there is residual aluminum powder or other defects; the metal element analyzer is used to detect the metal element content on the aluminum foil surface to ensure that the product quality meets the standards.

[0021] Preferably, in step (2), the cleaning solution is first selected as a weak alkaline aqueous solution of sodium bicarbonate and sodium hydroxide. The aqueous solution of these weak alkaline substances has cleaning and antibacterial functions and is suitable for cleaning metal surfaces. Then, a mixed solution of surfactant, complexing agent and organic acid is used to clean and remove surface oxides. Specifically, the surfactant is sodium dodecyl sulfate and coconut oil diethanolamine, the complexing agent is ethylenediaminetetraacetic acid, and the organic acid is a mixed solution of carboxyethyl thiosuccinic acid and N-(2-hydroxyethyl)ethylenediamine-triacetic acid.

[0022] This solution effectively removes residual aluminum powder. The cleaning solution contains surfactants and complexing agents to improve the removal efficiency of aluminum powder and the cleanliness of the aluminum foil. The cleaning solution is low-foaming to reduce foam generation and residue on the aluminum foil surface during the cleaning process.

[0023] Preferably, it includes the following steps:

[0024] (1) Select an untreated rolled aluminum foil as the starting material and roll it using a rolling mill with electrostatic elimination function. The rolling mill has an electrostatic elimination device during the rolling process. It can use a heated tungsten filament to release thermionic electrons on its surface and accelerate them through a DC power supply. These electrons collide with inert gas molecules in the reaction chamber to generate plasma of electrons and ions. The electrons in the plasma neutralize the positive charge on the aluminum foil surface under the action of an electric field, thereby eliminating static electricity and reducing the adsorption of aluminum powder.

[0025] (2) The rolled aluminum foil is surface cleaned. The cleaning solution is first a weak alkaline aqueous solution of sodium bicarbonate and sodium hydroxide. The aqueous solution of these weak alkaline substances has cleaning and antibacterial functions and is suitable for cleaning metal surfaces. Then, a mixed solution of surfactant, complexing agent and organic acid is used to clean and remove surface oxides. Specifically, the surfactant is sodium dodecyl sulfate and coconut oil diethanolamine, the complexing agent is ethylenediaminetetraacetic acid, and the organic acid is a mixed solution of carboxyethyl thiosuccinic acid and N-(2-hydroxyethyl)ethylenediamine-triacetic acid.

[0026] After pickling, the aluminum foil surface is sprayed with a high-pressure water gun to further enhance the cleaning effect and remove any residual solution from the surface. After cleaning, the aluminum foil surface is dried in a dryer to keep it dry.

[0027] (3) The cleaned aluminum foil is heat-treated by placing it in a controlled oxygen atmosphere (5%-10% by volume) and heating it to 250°C. By controlling the temperature and the controlled atmosphere, a uniform and dense oxide film can be grown on the surface of the aluminum foil to prevent corrosion and uneven oxidation of the aluminum foil surface.

[0028] (4) Quality inspection is carried out on the heat-treated aluminum foil using a surface morphology analyzer and a metal element analyzer. The surface morphology analyzer can observe the fine structure of the aluminum foil surface to determine whether there is residual aluminum powder or other defects; the metal element analyzer is used to detect the metal element content on the aluminum foil surface to ensure that the product quality meets the standards.

[0029] Specifically, the method of the present invention includes the following steps:

[0030] (1) Rolling is performed using a rolling mill with electrostatic elimination function. This mill has an electrostatic elimination device that utilizes a heated tungsten filament. Thermionic electrons escape from the surface of the filament and are accelerated by a DC power supply. These electrons collide with inert gas molecules in the reaction chamber to generate electron-ion plasma. Under the influence of an electric field, the electrons in the plasma neutralize the positive charge on the aluminum foil surface, thereby eliminating static electricity and reducing the adsorption of aluminum powder. A schematic diagram of the electrostatic elimination device is shown below. Figure 1 As shown. This step uses physical means to reduce the generation of aluminum powder at its source.

[0031] (2) The rolled aluminum foil is then surface-cleaned using a cleaning solution containing surfactants. The surfactants can penetrate into the tiny crevices of the aluminum foil surface, thoroughly removing any residual aluminum powder. Furthermore, the cleaning solution has antibacterial properties, further ensuring that microbial contamination on the aluminum foil surface is controlled.

[0032] (3) The cleaned aluminum foil undergoes heat treatment, being heated to a certain temperature in a controlled atmosphere. In this step, the controlled atmosphere includes a carrier gas component (nitrogen, argon, and other inert gases) and an oxidizing component (oxygen). The inert gases are mainly used to dilute the oxygen, controlling its concentration and partial pressure. Nitrogen and argon, as inert gases, reduce the oxygen concentration, thereby controlling the rate and extent of the oxidation reaction. This oxidizes the aluminum foil surface at high temperature into a uniform and dense alumina film, improving the foil's corrosion resistance and surface quality. The aluminum foil heat treatment apparatus and controlled atmosphere conveying device are as follows: Figure 2 As shown.

[0033] Heat treatment is a common method for improving the properties of metals. However, the methods and parameters for obtaining the desired properties vary depending on the metal being treated. In particular, there are no reports on the use of controlled atmospheres for uniform oxidation of aluminum foil.

[0034] (4) Quality inspection is carried out on the heat-treated aluminum foil using a surface morphology analyzer and a metal element analyzer. The surface morphology analyzer can observe the fine structure of the aluminum foil surface to determine whether there is residual aluminum powder or other defects; the metal element analyzer is used to detect the metal element content on the aluminum foil surface to ensure that the product quality meets the standards.

[0035] Beneficial effects:

[0036] The processing method of this invention achieves highly efficient treatment of aluminum powder on the surface of rolled aluminum foil by combining various physical and chemical methods. This method not only improves the purity and safety of the product but is also applicable to industries such as electronics, electrical appliances, and food packaging. Compared with existing technologies, the method of this invention has higher processing efficiency and better reliability, providing a new solution for quality control in the aluminum foil production process.

[0037] The processing method of the present invention has the following advantages:

[0038] 1. Rolling using a rolling mill with electrostatic elimination function: This step aims to reduce the positive charge on the surface of the aluminum foil, thereby reducing the adsorption of aluminum powder. This is a physical means of solving the aluminum powder problem at its source. Using a rolling mill with electrostatic elimination function is mainly to reduce the accumulation of charge on the metal surface, thereby reducing dust adsorption.

[0039] 2. Surface cleaning of the rolled aluminum foil: This process removes impurities and contaminants from the surface. Cleaning with a cleaning solution containing surfactants removes residual aluminum powder and other impurities. This step is a necessary follow-up treatment to ensure the cleanliness of the aluminum foil surface.

[0040] 3. The cleaned aluminum foil undergoes heat treatment: The aluminum powder is oxidized into stable alumina at high temperature, with controlled oxygen atmosphere and temperature to avoid over-oxidation or heat damage. By heating to a certain temperature in a controlled oxygen atmosphere, the aluminum powder can be oxidized into stable alumina at high temperature, thus completely transforming the aluminum powder through a chemical reaction. This step is a crucial process, aiming to solve the aluminum powder problem from a chemical perspective.

[0041] 4. Quality Inspection of Heat-Treated Aluminum Foil: Comprehensive inspection is performed using a surface morphology analyzer and a metal element analyzer to assess the quality of the aluminum foil surface. This comprehensive inspection using these instruments allows for the evaluation of the aluminum foil surface quality and performance, ensuring product compliance with standards. This step is a crucial part of quality control and assurance.

[0042] These four steps are performed separately, but they are closely linked and interdependent. The correct sequence and coordination are key to ensuring the effectiveness and reliability of the entire process.

[0043] This invention provides a method for effectively addressing the problem of aluminum powder on the surface of rolled aluminum foil through a combination of multiple means and carefully designed steps. These steps include using a rolling mill with electrostatic elimination capabilities, surface cleaning, heat treatment, and quality inspection. These steps target the prevention and treatment of aluminum powder on the aluminum foil surface, aiming to improve the quality and performance of the aluminum foil. This invention addresses the problem of aluminum powder on the surface of rolled aluminum foil in the specific scenario of aluminum foil rolling, thereby improving the quality and performance of the aluminum foil.

[0044] The processing method of this invention can effectively remove aluminum powder from the surface of rolled aluminum foil under different conditions. Through a multi-step processing combining physical and chemical methods, it not only improves the purity and safety of the product but also provides a more comprehensive and efficient solution for actual production. Among the embodiments, Example 7 exhibits the best overall performance indicators compared to other examples: Al powder residue detection is 0.1%, conductivity is 0.162 S·m⁻¹, flexural strength is 281 MPa, tensile strength is 308 MPa, elongation is 15%, corrosion resistance is excellent (no flaky rust spots), and surface roughness Ra is 0.09 μm. Attached Figure Description

[0045] Figure 1 Schematic diagram of static electricity elimination device

[0046] Figure 2 Schematic diagram of aluminum foil heat treatment equipment and controlled atmosphere conveying equipment Detailed Implementation

[0047] Example 1

[0048] The specific steps for treating aluminum powder on the surface of rolled aluminum foil are as follows:

[0049] (1) Select a roll of untreated rolled aluminum foil as the starting material. First, roll it using a rolling mill with electrostatic elimination function. During the rolling process, an electrostatic elimination device is used to generate negative charges to neutralize the positive charges on the surface of the aluminum foil, reducing the adsorption of aluminum powder. This step can effectively reduce the generation of aluminum powder and lay a good foundation for subsequent processing.

[0050] The rolling mill with static elimination function, such as Figure 1 It can utilize a heated tungsten filament, where thermionic electrons overflow from its surface and are accelerated by a DC power supply. These electrons collide with inert gas molecules in the reaction chamber to generate plasma of electrons and ions. Under the action of an electric field, the electrons in the plasma neutralize the positive charge on the aluminum foil surface, thereby eliminating static electricity and reducing the adsorption of aluminum powder.

[0051] (2) Next, the rolled aluminum foil is surface-cleaned. The cleaning solution is initially a weakly alkaline aqueous solution of sodium hydroxide and sodium bicarbonate, with sodium hydroxide content of 1%-3% and sodium bicarbonate content of 2%-4%. This weakly alkaline aqueous solution has cleaning and antibacterial properties, suitable for cleaning metal surfaces. Then, a weakly acidic solution (citric acid 1%-3% and acetic acid 0.5%-2%) is used to remove surface oxides. This solution effectively removes residual aluminum powder. After pickling, a high-pressure water jet is used to spray the aluminum foil surface, further enhancing the cleaning effect and removing any residual solution. After cleaning, the aluminum foil is dried using a dryer to keep the surface dry.

[0052] (3) Next, a heat treatment step is performed. The heat treatment apparatus is as follows: Figure 2 As shown, the cleaned aluminum foil is placed in a controlled oxygen atmosphere (using inert gases such as argon or nitrogen to create a low-oxygen or oxygen-free environment to protect the aluminum foil) and heated to a certain temperature, such as 300℃. By controlling the temperature and the controlled atmosphere, a uniform and dense oxide film can be promoted to grow on the surface of the aluminum foil, preventing corrosion and uneven oxidation of the aluminum foil surface.

[0053] (4) Finally, a quality inspection step is performed. The surface of the aluminum foil is observed using a surface morphology analyzer to determine whether there is residual aluminum powder or other defects; at the same time, the metal element content on the surface of the aluminum foil is detected using a metal element analyzer to ensure that the product quality meets the standards. If the test results meet the requirements, the processed aluminum foil is packaged or further processed; if it does not meet the requirements, cleaning and heat treatment steps must be repeated.

[0054] Example 2

[0055] Based on Example 1 above, the controlled atmosphere heat treatment is replaced with ordinary air atmosphere heat treatment. Other steps are the same as in Example 1.

[0056] Example 3

[0057] Based on Example 1 above, an ultrasonic process is added to the pickling process. The high-frequency vibration of ultrasound can generate strong impact force and eddy current effect, which can more thoroughly remove oxides and impurities from the surface of the object. Other steps are the same as in Example 1.

[0058] Example 4

[0059] Based on Example 3 above, the pickling solvent was changed to a mixed solution containing surfactant, complexing agent and organic acid: sodium dodecyl sulfate (0.5%-1% by mass), diethanolamine cocoate (1%-2% by mass) surfactant, and ethylenediaminetetraacetic acid (0.1-0.3% by mass) complexing agent, and carboxyethyl thiosuccinic acid (0.1-0.3% by mass) and N-(2-hydroxyethyl)ethylenediamine-triacetic acid (0.1-0.3% by mass) organic acid, to remove surface oxides. Other steps were the same as in Example 3.

[0060] Example 5

[0061] Based on Example 4 above, the order of the static elimination process and the cleaning process was reversed. First, an alkaline wash was performed using a weakly alkaline aqueous solution. Then, ultrasonic cleaning was performed using a mixed solution containing surfactants, complexing agents, and organic acids. Next, a high-pressure water jet was used to spray the aluminum foil surface, further enhancing the cleaning effect and removing any residual solution. After cleaning, the aluminum foil surface was dried using a dryer. Then, it was rolled using a rolling mill equipped with static elimination functionality, with the static elimination device used during the rolling process. Following this, controlled atmosphere heat treatment was performed, and finally, a quality inspection step was conducted.

[0062] Example 6

[0063] Based on the above embodiment 4, the static elimination device of the rolling mill is removed, and the other steps are the same as in embodiment 4.

[0064] Example 7

[0065] Based on Example 4 above, the heat treatment temperature of the controlled atmosphere was reduced to 250°C, and the other steps were the same as in Example 4.

[0066] The specific steps for treating aluminum powder on the surface of rolled aluminum foil are as follows:

[0067] (1) Select a roll of untreated rolled aluminum foil as the starting material. First, roll it using a rolling mill with electrostatic elimination function. During the rolling process, an electrostatic elimination device is used to generate negative charges to neutralize the positive charges on the surface of the aluminum foil, reducing the adsorption of aluminum powder. This step can effectively reduce the generation of aluminum powder and lay a good foundation for subsequent processing.

[0068] The aforementioned rolling mill with electrostatic elimination function can utilize a heated tungsten filament, where thermionic electrons overflow from its surface and are accelerated by a DC power supply. These electrons collide with inert gas molecules in the reaction chamber to generate plasma of electrons and ions. Under the action of an electric field, the electrons in the plasma neutralize the positive charge on the aluminum foil surface, thereby eliminating static electricity and reducing the adsorption of aluminum powder.

[0069] (2) Then, the rolled aluminum foil is surface-cleaned. The cleaning solution is initially a weakly alkaline aqueous solution of sodium bicarbonate and sodium hydroxide, with sodium hydroxide having a mass fraction of 1%-3% and sodium bicarbonate having a mass fraction of 2%-4%. These weakly alkaline aqueous solutions have cleaning and antibacterial functions, suitable for cleaning metal surfaces. Then, a mixed solution of surfactants, complexing agents, and organic acids is used: sodium dodecyl sulfate (mass fraction 0.5%-1%), diethanolamine cocoate (mass fraction 1%-2%) as surfactants, and ethylenediaminetetraacetic acid (mass fraction 0.1-0.3%) as a complexing agent. The organic acids are carboxyethyl thiosuccinic acid (mass fraction 0.1-0.3%) and N-(2-hydroxyethyl)ethylenediamine-triacetic acid (mass fraction 0.1-0.3%) to remove surface oxides. This solution can effectively remove residual aluminum powder.

[0070] Adding an ultrasonic process during pickling allows the high-frequency vibrations of ultrasound to generate powerful impact and eddy current effects, which can more thoroughly remove oxides and impurities from the surface of the object. Other steps are the same as in Example 1.

[0071] After pickling, a high-pressure water jet is used to spray and clean the aluminum foil surface, further enhancing the cleaning effect and removing any residual solution. After cleaning, the aluminum foil surface is dried using a dryer.

[0072] (3) Next, a heat treatment step is performed. The cleaned aluminum foil is placed in a controlled oxygen atmosphere, with nitrogen as the inert gas and oxygen accounting for 5%-10% by volume, and heated to a certain temperature of 250℃. By controlling the temperature and the controlled atmosphere, a uniform and dense oxide film can be promoted to grow on the surface of the aluminum foil, preventing corrosion and uneven oxidation of the aluminum foil surface.

[0073] (4) Finally, a quality inspection step is performed. The surface of the aluminum foil is observed using a surface morphology analyzer to determine whether there is residual aluminum powder or other defects; at the same time, the metal element content on the surface of the aluminum foil is detected using a metal element analyzer to ensure that the product quality meets the standards. If the test results meet the requirements, the processed aluminum foil is packaged or further processed; if it does not meet the requirements, cleaning and heat treatment steps must be repeated.

[0074] Comparative Example 1

[0075] The same aluminum sheet raw materials of the same specifications and quality as those in the example were selected, and aluminum foil was obtained through a conventional rolling process, that is, without the heat treatment and cleaning process in Example 1, and without the static elimination process.

[0076] The rolled aluminum foils of Examples 1-7 of this invention were tested. Metal element content was determined according to GB / T 32560-2016 "Methods for Surface Quality Assessment of Rolled Aluminum and Aluminum Alloy Sheets," using a metal element analyzer. Corrosion resistance was tested using a salt spray test according to YS / T 439-2001 "Technical Requirements for Aluminum Foil Quality." Electrical conductivity was determined according to GB / T 32560-2016 "Methods for Surface Quality Assessment of Rolled Aluminum and Aluminum Alloy Sheets." Tensile properties were determined according to GB / T 228-2010 "Metallic Materials - Tensile Testing at Room Temperature." Other testing methods, such as surface morphology observation, were performed using a surface morphology analyzer or a high-resolution microscope. The performance indicators of Examples 1-7 of this invention are summarized in Table 1.

[0077] Table 1 Product Performance Indicators

[0078]

[0079]

[0080] 1. Example 1: The residual Al powder content was 0.4%, the conductivity was 0.147 S·m⁻¹, and the flexural strength was...

[0081] The tensile strength is 276 MPa, the elongation is 14%, and the corrosion resistance is good (only small rust spots on the surface, no obvious flaky rust spots). The surface roughness Ra is 0.16 μm. This example shows good performance in all indicators, especially good corrosion resistance.

[0082] 2. Example 2: Al powder residue was detected at 0.5%, conductivity was 0.143 S·m⁻¹, and flexural strength was...

[0083] The aluminum foil exhibits a tensile strength of 285 MPa, an elongation of 15%, and good corrosion resistance (only small rust spots on the surface, no flaky rust spots). The surface roughness Ra is 0.16 μm. This embodiment shows slightly lower performance in all indicators compared to Example 1, but the controlled atmosphere heat treatment results in better overall performance than conventional heat treatment.

[0084] 3. Example 3: Al powder residue was detected at 0.3%, conductivity was 0.152 S·m⁻¹, and flexural strength was...

[0085] The aluminum foil exhibits a tensile strength of 296 MPa, an elongation of 14%, and good corrosion resistance (only small rust spots on the surface, no flaky rust spots), with a surface roughness Ra of 0.12 μm. This embodiment demonstrates good performance across all indicators, particularly high conductivity and flexural strength. Compared to Example 1, the addition of an ultrasonic process improves the surface quality of the aluminum foil.

[0086] 4. Example 4: Al powder residue was detected at 0.1%, conductivity was 0.145 S·m⁻¹, and flexural strength was...

[0087] The tensile strength was 278 MPa, the elongation was 16%, the corrosion resistance was average (small areas of flaky rust on the surface), and the surface roughness Ra was 0.13 μm. This example showed better performance in Al powder residue detection compared to Example 1, mainly due to replacing the ordinary weak acid solution with a mixed solution containing surfactants, complexing agents, and organic acids.

[0088] 5. Example 5: Al powder residue was detected at 0.4%, conductivity was 0.146 S·m⁻¹, and flexural strength was...

[0089] The tensile strength is 275 MPa, the elongation is 17%, and the corrosion resistance is good (only small rust spots on the surface, no flaky rust spots). The surface roughness Ra is 0.15 μm. This example demonstrates...

[0090] Compared to Example 4, which changed the static elimination and cleaning processes, it performed slightly worse in terms of Al powder residue.

[0091] 6. Example 6: Al powder residue was detected at 0.3%, conductivity was 0.153 S·m⁻¹, and flexural strength was...

[0092] The tensile strength is 273 MPa, the elongation is 15%, and the corrosion resistance is good (only small rust spots on the surface, no flaky rust spots). The surface roughness Ra is 0.12 μm. Compared with Example 4, which removed the static eliminator, this example performs worse in all aspects.

[0093] 7. Example 7: Al powder residue was detected at 0.1%, conductivity was 0.162 S·m⁻¹, and flexural strength was...

[0094] The surface temperature was 281 MPa, the tensile strength was 308 MPa, the elongation was 15%, the corrosion resistance was excellent (no flaky rust spots), and the surface roughness Ra was 0.09 μm. Compared with Example 4, this example reduced the heat treatment temperature and improved its overall performance indicators, resulting in the best overall performance.

[0095] As can be seen from the above embodiments, the processing method of the present invention can effectively remove aluminum powder from the surface of rolled aluminum foil under different conditions. Through a multi-step processing procedure combining physical and chemical methods, not only can the purity and safety of the product be improved, but a more comprehensive and efficient solution is also provided for actual production. Among these, Example 7 exhibits the best overall performance compared to other examples, with an Al powder residue detection rate of 0.1%, a conductivity of 0.162 S·m⁻¹, a flexural strength of 281 MPa, a tensile strength of 308 MPa, an elongation of 15%, excellent corrosion resistance (no flaky rust spots), and a surface roughness Ra of 0.09 μm.

[0096] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method of treating surface aluminum powder of rolled aluminum foil, characterized by: Includes the following steps: (1) Select an untreated rolled aluminum foil as the starting material and roll it using a rolling mill with electrostatic elimination function. The rolling mill has an electrostatic elimination device during the rolling process. It uses a heated tungsten filament, thermionic electrons overflow on its surface and are accelerated by a DC power supply. These electrons collide with inert gas molecules in the reaction chamber to generate plasma of electrons and ions. The electrons in the plasma neutralize the positive charge on the aluminum foil surface under the action of an electric field, thereby eliminating static electricity and reducing the adsorption of aluminum powder. (2) The rolled aluminum foil is surface cleaned. The cleaning solution is first a weak alkaline aqueous solution of sodium bicarbonate and sodium hydroxide. The aqueous solution of these weak alkaline substances has the functions of cleaning and antibacterial, and is suitable for cleaning metal surfaces. Then, a mixed solution of surfactant, complexing agent and organic acid is used to clean and remove surface oxides. Specifically, the surfactant is sodium dodecyl sulfate and coconut oil diethanolamine, the complexing agent is ethylenediaminetetraacetic acid, and the organic acid is a mixed solution of carboxyethyl thiosuccinic acid and N-(2-hydroxyethyl)ethylenediamine-triacetic acid. After pickling, the aluminum foil surface is sprayed with a high-pressure water gun to further enhance the cleaning effect and remove any residual solution from the surface. After cleaning, the aluminum foil surface is dried in a dryer to keep it dry. (3) The cleaned aluminum foil is heat-treated. The cleaned aluminum foil is placed in a controllable oxygen atmosphere with an oxygen volume ratio of 5%-10% and nitrogen as the inert gas. It is heated to 200-350℃. By controlling the temperature and the controllable atmosphere, a uniform and dense oxide film can be grown on the surface of the aluminum foil to prevent corrosion and uneven oxidation of the aluminum foil surface. (4) Conduct quality inspection on the heat-treated aluminum foil using a surface morphology detector and a metal element analyzer. The surface morphology detector is used to observe the fine structure of the aluminum foil surface to determine whether there is residual aluminum powder or other defects. The metal element analyzer is used to detect the metal element content on the aluminum foil surface to ensure that the product quality meets the standards.

2. The method of treating rolled aluminum foil surface aluminum powder according to claim 1, characterized by: The heat treatment in step (3) is carried out at a temperature of 250°C.

Images