In the production of double foil, the rolling of aluminum foil is divided into three processes: rough rolling, intermediate rolling, and finishing rolling. From a technological point of view, it can be roughly divided from the thickness of the rolling exit. The general method is that the exit thickness is greater than Or equal to 0.05mm is rough rolling, the exit thickness is between 0.013 and 0.05 is intermediate rolling, and the single finished product and the double rolled product with the exit thickness less than 0.013mm are finished rolling. The characteristics of rough rolling are similar to the rolling characteristics of aluminum plate and strip. The thickness control mainly depends on the rolling force and post tension. The thickness of the rough rolling is very small, and its rolling characteristics are completely different from the rolling of aluminum plate and strip. It has aluminum foil rolling. The particularity of, its characteristics mainly include the following aspects:
(1) Aluminum strip rolling. To make the aluminum strip thinner mainly depends on the rolling force, so the automatic thickness control method is the constant roll gap as the main control method of the 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 to obtain the thickness. Consistent plate and strip. When aluminum foil is rolled to medium-finish rolling, because the thickness of aluminum foil is extremely thin, the rolling force is increased during rolling, which makes it easier for the roll to produce elastic deformation than the material being rolled. The elastic flattening of the roll is not possible. Ignored, the elastic rolling and flattening of the rolls determines that in aluminum foil rolling, the rolling force can no longer play the same role as the rolled plate. Aluminum foil rolling is generally roll-free rolling under constant pressure conditions to adjust the thickness of the aluminum foil. Mainly depends on the adjusted tension and rolling speed.
(2) Stack 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-sheet rolling method, so the double rolling method is used, that is, the The method of adding lubricating oil between two aluminum foils and then rolling them together (also called stack rolling). Stack rolling can not only produce ultra-thin aluminum foil that cannot be produced by single rolling, but also reduce the number of strip breaks and increase labor productivity. Using this process, single-sided smooth aluminum foil of 0.006mm to 0.03mm can be mass-produced.
(3) Speed effect. In the process of aluminum foil rolling, the phenomenon that the thickness of the foil thins with the rise of the rolling system is called the speed effect. The explanation of the speed effect mechanism still needs to be studied in depth. The reasons for the speed effect are generally considered to have the following three aspects:
1) The friction state between the work roll and the rolled material changes. As the rolling speed increases, the amount of lubricating oil introduced increases, so that the lubrication state between the roll and the rolled material changes. The friction coefficient decreases, the oil film becomes thicker, and the thickness of the aluminum foil decreases accordingly.
2) Changes in the rolling mill itself. In a rolling mill with cylindrical bearings, as the rolling speed increases, the roll neck will float in the bearing, so that the two interacting and loaded rolls will 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. As the rolling speed increases, the temperature of the rolling deformation zone increases. According to calculations, the metal temperature in the deformation zone can rise to 200°C, which is equivalent to an intermediate recovery annealing. The processing softening phenomenon of rolled materials.