Aluminum Foil Factory

What are the main process steps in the production of aluminum foil? For example, what are the key links from aluminum ingots to finished products?

The production process of aluminum foil includes the following main process steps, and it needs to go through multiple complex processes and treatments from aluminum ingots to finished products:

1. Melting and casting of aluminum ingots
The aluminum ingots are first heated to the melting point and melted in a furnace.
The molten aluminum liquid is degassed and filtered to remove impurities and gases.
The aluminum liquid is cast into large aluminum ingots (usually flat or cylindrical) for subsequent processing.
2. Hot rolling process
The aluminum ingots are preheated to a certain temperature (about 400°C to 500°C) and then repeatedly rolled through a hot rolling mill.
The purpose of hot rolling is to gradually reduce the thickness of the aluminum ingot to obtain a preliminarily formed aluminum sheet.
3. Cold rolling process
The hot-rolled aluminum sheet is further rolled through a cold rolling mill to make its thickness reach a finer range.
Cold rolling not only further thins the material, but also improves the surface finish and mechanical properties of the aluminum foil.
4. Intermediate annealing (optional)
If the aluminum sheet hardens or loses ductility during rolling, an intermediate annealing can be performed.
Annealing heats the aluminum foil to the appropriate temperature to restore ductility.
5. Foil rolling
The cold-rolled aluminum sheet is passed through a dedicated foil rolling mill for final rolling to produce aluminum foil with a thickness between 0.004 and 0.2 mm.
Depending on demand, double-layer rolling (overlap rolling) can be performed to improve efficiency while reducing the risk of material breakage.
6. Surface treatment and slitting
Depending on the application, the aluminum foil is coated, oiled or otherwise surface treated (such as anti-corrosion treatment or enhanced hydrophilicity).
The aluminum foil is cut to the required width and length and wound into rolls for easy transportation and use.
7. Final annealing
The finished aluminum foil usually requires final annealing to further improve flexibility and processability while eliminating residual stress.
8. Quality inspection and packaging
The finished aluminum foil undergoes strict quality inspections (including thickness, surface finish, mechanical properties, etc.).
After passing the test, it is packaged and prepared for shipment.

How does the thickness, ductility and corrosion resistance of aluminum foil affect its performance in different application scenarios?

The thickness, ductility and corrosion resistance of aluminum foil are the key factors affecting its performance in different application scenarios. The following is a specific analysis:

1. The influence of thickness
Food packaging
Thinner aluminum foil (such as 6-10 microns) is often used for disposable food packaging (such as candy, chocolate, tablets, etc.) because it is lightweight and provides good barrier properties.
Thicker aluminum foil (such as 20-40 microns) is suitable for food containers or sealed packaging for ovens because it has higher strength and puncture resistance.
Building insulation
In the construction field, thicker aluminum foil is used in sandwich insulation materials to reflect heat and provide excellent thermal insulation.
Industrial use
Industrial aluminum foil is usually thicker (50 microns and above) and is suitable for scenarios such as cable shielding, radiators and lithium battery separators to ensure high mechanical strength and conductivity.

2. The influence of ductility
Flexible packaging
Highly ductile aluminum foil is suitable for foldable or flexible packaging (such as beverage packages, pharmaceutical blister packaging, etc.) because it can withstand multiple bends without breaking.
Composite materials
In composite packaging, aluminum foil is usually used in combination with plastics and paper. Aluminum foil with good ductility is easy to composite and can provide excellent sealing effect.
Molded containers
Aluminum foil with good ductility is used to make food containers or trays, and can be pressed into complex shapes by molds without being easily torn.

3. The influence of corrosion resistance
Food preservation
The corrosion resistance of aluminum foil enables it to effectively block moisture, light, oxygen and other pollutants, extending the shelf life of food.
Medical packaging
Medical grade aluminum foil requires high corrosion resistance to ensure that it will not be affected by moisture or chemicals during transportation and storage.
Industrial applications
In the fields of cable shielding and chemical industry, aluminum foil needs to resist moisture and chemicals in the air to ensure long-term performance stability.

4. Overall performance
Food cooking
Aluminum foil with moderate thickness (10-20 microns), good corrosion resistance and high temperature resistance is suitable for cooking and food storage, such as barbecue and oven packaging.
Energy industry
High conductivity and ductility make aluminum foil an important material in industries such as lithium batteries and capacitors, while its corrosion resistance helps to extend the life of equipment.
Aerospace
Aluminum foil is used as a thermal insulation layer or electronic shielding in aerospace, requiring uniform thickness, durability and good oxidation resistance.