Definition and classification of aluminum foil
Aluminum foil refers to thin strips of aluminum and aluminum alloys with a thickness of ≤0.2mm. Its hot stamping effect is similar to that of pure silver foil, so it is also called fake silver foil. Due to the soft texture of aluminum, good ductility and silvery white luster, if the rolled sheet is mounted on offset paper with sodium silicate and other substances to make aluminum foil, it can also be printed. Aluminum foil is generally classified according to thickness, state and use.
According to the thickness: any aluminum foil greater than 0.012mm is called a single foil, and less than or equal to 0.012mm is called a double foil; there is also a thickness with a 0 after the decimal point called a single zero foil, and two 0 after the decimal point is called a foil Double foil.
According to the state: it can be divided into full hard foil, soft state foil, semi-hard foil, 3/4 hard foil, 1/4 hard foil. Full hard foil refers to the foil that is not annealed after rolling (fully annealed coil and >75% cold rolling); soft state foil refers to the foil that is fully annealed after cold rolling; where the tensile strength of aluminum foil is between full hard The semi-hard foil between the foil and the soft foil; the 3/4 hard foil whose tensile strength is between the full-hard foil and the semi-hard foil; the tensile strength of the aluminum foil is between the soft-state foil and the semi-hard foil The one between the foils is called 1/4 hard foil.
According to the surface state: it can be divided into single-sided glossy foil and double-sided glossy foil. Aluminum foil rolling is divided into single-sheet rolling and double-column rolling. During single-sheet rolling, both sides of the foil are in contact with the roll surface, and both sides have a bright metallic luster, which is called double-sided light foil. During double-rolling, only one side of each foil is in contact with the roller, the side in contact with the roller is bright, and the two sides in contact with each other between the aluminum foils are dark. This kind of foil is called single-sided glossy foil. The minimum thickness of double-sided smooth aluminum foil mainly depends on the diameter of the work roll, usually not less than 0.01mm, the thickness of single-sided smooth foil is usually not more than 0.03mm, and the current minimum thickness can reach 0.004mm.
Features of aluminum foil
- Small specific gravity, large specific surface, and low cost of use;
- High conductivity;
- Good contact thermal conductivity and strong radiation heat insulation;
- Good air tightness;
- High strength ratio;
- Corrosion resistant in everyday environment;
- Good cold deformation performance;
- Not magnetized;
Aluminum foil is widely used in the following industries
Beverage industry: composite packaging made of aluminum foil, paper and PE and other multi-layer materials together is an ideal packaging material for soft drinks with long shelf life, low cost of use and low environmental impact in the world today. The surface quality, pinhole, unfolding performance and other quality indicators of aluminum foil have a great impact on the shelf life and appearance quality of beverage packaging. Therefore, the quality requirements of aluminum foil for soft beverage packaging are extremely strict.
Flexible packaging: With the improvement of people's living standards and the acceleration of the pace of life, the way of food supply has changed, and there are more and more convenient foods with long shelf life. Since the preservation period of aluminum foil and plastic composite bags is about five times longer than that of plastic bags of the same thickness, the flexible packaging aluminum foil market has broad prospects and the demand is growing rapidly. Household aluminum foil is suitable for food preservation, barbecue, aviation, hotel catering and kitchen cleaning. Products are available in roll and block packaging. It has a very good effect in food cooking for freezing, fresh-keeping, baking, etc. In the refrigerator or freezer, the aluminum foil can be wrapped on the food, the aluminum foil can maintain its shape, and avoid fish, vegetables, fruits, dishes. Water loss, and prevent the leakage or mixing of taste, both hygienic and convenient. The steel grating factory uses aluminum foil to separate the high-temperature charcoal fire and smoking, which can prevent the food from being scorched and cause carcinogens, which is a healthier eating method. This product complies with the national food hygiene standards, and is packaged in a color box with a cutting saw blade, which is easy to use and beautiful. Now the household aluminum foil and aluminum foil containers produced by Aibang have been exported overseas in large quantities.
Gold card packaging: With the rapid development of the packaging industry, the level of my country's packaging industry has entered the world's advanced ranks. Most of my country's high-end cosmetics, cigarettes, liquor and other products are packaged with gold cards that are composited with aluminum foil and cardboard. Gold card packaging not only has certain fresh-keeping and moisture-proof performance, but also has a beautiful and luxurious surface, which greatly improves the grade of the product.
Cigarette packaging: my country is a big country in the production and consumption of cigarettes. Although the consumption ratio of aluminum foil for cigarette packaging is decreasing year by year due to the rapid development of other industries, it is still the main consumer of double zero foil. Aluminum foil in cigarette packaging materials plays an important role in preserving fragrance and preventing moisture.
Capacitors: In recent years, my country's electronics and power industries have developed rapidly. Due to its small specific gravity, large specific surface and high conductivity, aluminum foil has become the best material for manufacturing film capacitors and is used in electronics and power industries.
Construction industry: In China, aluminum foil is used as thermal insulation material outside the central air-conditioning pipeline. In developed countries and regions, steel grating factories also use aluminum foil, plastic and woven fiber composite materials as the thermal insulation layer of building roofs. This material It has good thermal insulation effect and long service life, making it an ideal building material.