① Hard foil: aluminum foil that has not been softened (annealed) after rolling, and that there is residue on the surface when it is not degreasing. Therefore, the hard foil must be degreased before printing, lamination, and coating, and it can be used directly if it is used for forming.
② Semi-hard foil: Aluminum foil whose hardness (or strength) is between hard foil and soft foil, usually used for forming.
③ Soft foil: The aluminum foil that has been fully annealed and softened after rolling has a soft material and no residual oil on the surface. Most of the current application areas, such as packaging, lamination, electrical materials,etc.,use soft foils.

① Single-sided smooth aluminum foil: double-rolled aluminum foil, one side is bright after sub-rolling, and the other side is black, such aluminum foil is called one-sided smooth aluminum foil. The thickness of one side light aluminum foil is usually not more than 0.025mm.
② Double-sided smooth aluminum foil: A single rolled aluminum foil, two paintings are in contact with the roll, and the two sides of the aluminum foil are divided into mirror two-sided smooth aluminum foil and ordinary two-sided smooth aluminum foil due to the difference in the surface roughness of the roll. The thickness of the two-sided glossy aluminum foil is generally not less than 0.01mm.

① Plain foil: Aluminum foil without any other processing after rolling, also known as light foil.
② Embossed foil: Aluminum foil with various patterns pressed on the surface.
③ Composite foil: composite aluminum foil formed by laminating aluminum foil, paper, plastic film and cardboard together.
④ Coated foil: aluminum foil coated with various resins or paints on the surface.
⑤ Colored aluminum foil: The surface is coated with aluminum foil of a single color.
⑥ Printing aluminum foil: By printing the aluminum foil with various patterns, patterns, characters or pictures on the surface, it can be one color, up to 12 colors.
Soft aluminum foil can also be further pressed into four-zero foil for high-end decoration.

 The surface of the aluminum foil is extremely clean and hygienic, and no bacteria or microorganisms can grow on its surface.
 Aluminum foil is a non-toxic packaging material, which can be in direct contact with food without any danger of harming human health.
 Aluminum foil is an odorless and odorless packaging material, which will not make the packaged food have any peculiar smell.
 If the aluminum foil itself is not volatile, it and the packaged food will never dry or shrink.
 No matter in high temperature or low temperature, the aluminum foil will not have the phenomenon of grease penetration.
 Aluminum foil is an opaque packaging material, so it is a good packaging material for products exposed to sunlight, such as margarine.
 Aluminum foil has good plasticity, so it can be used to package products of various shapes. Various shapes of containers can also be arbitrarily formed.
 Aluminum foil has high hardness and high tensile strength, but its tear strength is small, so it is easy to tear.
 The aluminum foil itself cannot be heat sealed, and a heatable material, such as Pe, must be applied to its surface to be heat sealed.
 When aluminum foil is in contact with other heavy metals or heavy metals, there may be adverse reactions.

Label printing
Aluminum foil paper belongs to the category of special paper in label printing. Aluminum foil paper labels are mainly laminated aluminum foil paper, including:
1. laminated foil paper
2. bright silver foil
3. matte silver foil
4. matte gold foil
5. semigloss elite fascover

 

 Rolling of aluminum sheets and strips. The thinning of the aluminum strip mainly depends on the rolling force, so the automatic control method of plate thickness is the control method with constant roll gap as the main body of AGC. Even if the rolling force changes, the roll gap can be adjusted at any time to keep the roll gap at a certain value. Thickness can be obtained Consistent sheet and strip. While the aluminum foil is rolled to the middle finish rolling, due to the extremely thin thickness of the aluminum foil, the rolling force is increased during rolling, so that the elastic deformation of the roll is easier than the plastic deformation of the rolled material, and the elastic flattening of the roll cannot be It is neglected that the spring rolling and flattening of the roll determines that the rolling force can no longer play the same role as rolling the sheet. Mainly rely on the adjusted tension and rolling speed.

 Rolling. For ultra-thin aluminum foil with a thickness of less than 0.012mm (the thickness is related to the diameter of the work roll), due to the elastic flattening of the roll, it is very difficult to use a single rolling method, so the double-joint rolling method is used. The method of adding lubricating oil between two aluminum foils and rolling them together (also called stacking). Stacked rolling can not only roll out extremely thin aluminum foils that cannot be produced by single rolling, but also reduce the number of broken strips and improve labor productivity. This process can produce single-sided smooth aluminum foils of 0.006mm to 0.03mm in batches.

 Speed ​​effect. In the process of aluminum foil rolling, the phenomenon that the thickness of the foil decreases with the increase of the rolling degree is called the speed effect. The explanation of the mechanism of the speed effect needs to be further studied, and the reasons for the speed effect are generally believed to have the following three aspects:
1. The friction state between the work roll and the rolling material changes. As the rolling speed increases, the amount of lubricating oil brought in increases, so that the lubrication state between the roll and the rolling material changes. The friction coefficient decreases, the oil film becomes thicker, and the thickness of the aluminum foil decreases.
2. The change of the rolling mill itself. In rolling mills with cylindrical bearings, as the rolling speed increases, the roll necks will float in the bearings, thus causing the two interacting rolls to move toward each other.
3. The processing softens when the material is deformed by rolling. The rolling speed of the high-speed aluminum foil rolling mill is very high. With the increase of the rolling speed, the temperature of the rolling deformation zone increases. It is calculated that the metal temperature in the deformation zone can rise to 200 ° C, which is equivalent to an intermediate recovery annealing, which causes Process softening of rolled materials.

 Determination of the pass processing rate. The determination of the pass processing rate is the core of the rolling process. For pure aluminum series products, the pass processing rate can reach 65%. The first pass after the billet annealing should not be too large. The processing rate is generally about 50%.