As the core functional layer of aluminum foil tissue paper, the antioxidant properties of aluminum foil directly determine the product's barrier properties, durability, and safety. In natural environments, aluminum foil easily reacts with oxygen and water vapor, leading to oxidation spots, discoloration, and even corrosion on the surface, thus affecting the aluminum foil tissue paper's barrier properties against light, gas, and water. Therefore, through scientific and reasonable antioxidant treatment, a dense protective film can be formed on the aluminum foil surface, effectively slowing down the oxidation process and extending the product's lifespan.
Anodizing is one of the most widely used technologies for antioxidant treatment of aluminum foil. Its principle is to immerse the aluminum foil, acting as the anode, in an acidic electrolyte (such as sulfuric acid solution) through an electrochemical process. After applying an electric current, a uniform and dense alumina film is formed on the aluminum foil surface. This film not only prevents direct contact between oxygen and the aluminum substrate but also significantly improves the aluminum foil's hardness, abrasion resistance, and corrosion resistance. For example, in the production of pharmaceutical aluminum foil, anodizing treatment ensures that the aluminum foil maintains stable barrier properties during long-term storage, preventing the drug from becoming ineffective due to oxidation.
Chemical oxidation utilizes chemical reagents to react with the aluminum foil surface, generating a protective oxide film. Compared to anodizing, chemical oxidation equipment is simpler and easier to operate, but the stability of the film is slightly inferior. Commonly used chemical oxidation reagents include chromic acid solution and phosphoric acid solution. By controlling the reaction time and temperature, oxide films of varying thicknesses can be formed on the aluminum foil surface. For example, in the processing of food packaging aluminum foil, chemical oxidation can enhance the aluminum foil's resistance to acidic or alkaline substances, preventing corrosion from the packaging contents.
Electrophoretic coating technology forms an organic coating on the aluminum foil surface through electrophoretic deposition. Specifically, the aluminum foil is immersed in an electrophoresis tank containing coating material. When an electric current is applied, coating particles are uniformly deposited on the aluminum foil surface. After baking and curing, a dense protective film is formed. This coating not only has good corrosion resistance but also enhances the decorative properties of the aluminum foil, giving it matte, high-gloss, or metallic finishes. In the production of high-end aluminum foil tissue paper, electrophoretic coating is often used to improve the product's appearance and market competitiveness.
Organic coating treatments include methods such as spraying and dip coating. By coating the aluminum foil surface with an organic protective film (such as polyethylene or polypropylene), a physical barrier is formed to prevent oxidation. Spraying is suitable for small-batch, multi-variety production, while dip coating is more suitable for large-scale continuous production. The advantages of organic coating treatments are lower cost, process flexibility, and the ability to adjust the coating thickness and performance according to requirements. For example, in the composite process of aluminum foil tissue paper, organic coatings can enhance the adhesion between the aluminum foil and the tissue paper, preventing interlayer separation.
Passivation treatment involves using chemical reagents to form a thin, dense passivation film on the aluminum foil surface, thereby improving its corrosion resistance. Commonly used passivating agents include phosphoric acid solutions and chromate solutions. By controlling the reaction conditions, a passivation film only a few nanometers to tens of nanometers thick can be formed on the aluminum foil surface. Although thin, this film effectively blocks the penetration of oxygen and water vapor, extending the service life of the aluminum foil. During long-term storage of aluminum foil tissue paper, passivation treatment prevents oxidation and corrosion caused by changes in environmental humidity.
In addition to the professional treatment methods mentioned above, aluminum foil tissue paper can also have its oxidation slowed down during daily use through some simple measures. For example, avoid exposing the aluminum foil tissue paper to high temperature, high humidity, or strong light environments; seal the packaging promptly after use to reduce the contact time between the aluminum foil and air; and avoid using acidic or alkaline cleaning agents when cleaning the aluminum foil surface to prevent damage to the protective film. These measures, though simple, can effectively extend the service life of the aluminum foil tissue paper and maintain its good barrier properties.
