Aluminum foil rolling produces plastic deformation under the conditions of roll-free rolling. At this time, the rolling mill frame is elastically deformed and the rolls are elastically flattened.
When the thickness of the rolled piece reaches a smaller and more limited thickness h. When the rolling pressure has no effect, it is very difficult to make the rolled piece thinner. Usually two pieces of aluminum foil are stacked and rolled. For thin aluminum boxes 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 rolls, it is very difficult to use a single sheet rolling method, so the double rolling method is used to Lubricating oil is added between the two aluminum boxes, and then they are rolled together (also called stack rolling). Stack rolling can not only produce thinner aluminum that cannot be produced by single-sheet rolling, but also reduce the number of strip breaks and improve labor productivity. Using this process can mass produce 0.006-0.03mm single-sided light aluminum foil.
Laminated aluminum foil has dark and bright sides. Sometimes in order to improve production efficiency or to obtain a dark side aluminum box, the thicker aluminum foil can also be laminated. The main functions of stack rolling are:
(1) A finished box material with a thinner thickness (0.05mm thinner) can be obtained.
(2) Due to the relatively large unevenness of the dark surface of the aluminum foil, it is more firmly compounded with the material.
(3) Overlap rolling can reduce the risk of foil breakage and increase the yield.
(4) Improve production efficiency (at the same rolling speed, it is twice as fast as single foil rolling).
Before double rolling, the aluminum foil must be trimmed. Otherwise, the two foils of the double foil will be inseparable or broken after rolling due to the uneven edges, resulting in waste.