In the production of double-sheet foil, the rolling process of aluminum foil is divided into three processes: rough rolling, medium rolling and finishing rolling. From the perspective of process, it can be roughly divided from the thickness of the rolling outlet. The general method is that the outlet thickness is greater than Or equal to 0.05mm for rough rolling, the outlet thickness is between 0.013 and 0.05 for medium rolling, and the single-piece finished product with double-rolled thickness of outlet thickness less than 0.013mm is finish rolling. The rough rolling is similar to the rolling characteristics of the aluminum strip. The thickness control mainly depends on the rolling force and the back tension. The rough rolling processing rate is very small, and the rolling characteristics are completely different from the rolling of the aluminum sheet strip, with aluminum foil rolling. The particularity of the special features are as follows:
1. Aluminum strip rolling. In order to make the aluminum strip thinner mainly depends on the rolling force, the automatic thickness control method is the control method of the constant roll joint as the main body of the AGC. Even if the rolling force changes, the roll gap can be adjusted at any time to maintain a certain value of the roll gap. Consistent sheet strip. Since aluminum foil is rolled to medium finish rolling, since the thickness of the aluminum foil is extremely thin, the rolling force is increased during rolling, and the elastic deformation of the roll is easier than the plastic deformation of the material to be rolled, and the elastic flattening of the roll cannot be performed. Neglected, the rolling and flattening of the roll determines that the rolling force has not been able to function as a rolled sheet in aluminum foil rolling. Aluminum foil rolling is generally carried out under constant pressure without roll gap rolling, and the thickness of the aluminum foil is adjusted. Mainly depends on the adjusted tension and rolling speed.
2, stack rolling. For extremely thin aluminum foils having a thickness of less than 0.012 mm (the thickness is related to the diameter of the work rolls), it is very difficult to use a single-rolling method because of the elastic flattening of the rolls, so the double-rolling method is adopted, that is, A method in which two aluminum foils are filled with lubricating oil and then combined for rolling (also referred to as stack rolling). The lamination rolling can not only roll out extremely thin aluminum foil which cannot be produced by single rolling, but also reduce the number of broken strips and improve labor productivity. This method can mass produce single-sided aluminum foil of 0.006 mm to 0.03 mm.
3. Speed effect. In the aluminum foil rolling process, the phenomenon that the thickness of the foil becomes thinner with the degree of rolling degree is called the velocity effect. The interpretation of the velocity effect mechanism has yet to be studied in depth, and the reasons for the velocity effect are generally considered to have the following three aspects:
1) The friction state between the work roll and the rolled material changes, and as the rolling speed increases, the amount of the lubricating oil is increased, so that the lubrication state between the roll and the rolled material changes. The coefficient of friction is reduced, the oil film becomes thicker, and the thickness of the aluminum foil is reduced.
2) Changes in the rolling mill itself. In a rolling mill with a cylindrical bearing, as the rolling speed increases, the roll neck floats in the bearing, so that the two interacting loaded rolls will move in a mutually abutting direction.
3) The material is softened by processing when it is rolled and deformed. 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 the calculation, the metal temperature of the deformation zone can rise to 200 ° C, which is equivalent to an intermediate recovery annealing. Process softening of rolled materials.