Aluminum Foil Heating Speed
The following factors should be considered to determine the heating speed of aluminum foil:
(1) The larger the width and diameter of the foil roll, the worse the thermal uniformity of the foil roll. If the heating speed is too fast, the temperature difference between the surface and the core of the aluminum foil roll is likely to be too large. The volume changes of the surface and the core will be quite different, which will generate a great thermal stress, which will make the surface of the wave roll bulge and ridge. The effect on the heating speed of aluminum foil above 0.02mm is not obvious, while the heating speed of thin foil below 0.02mm should be appropriately reduced. Low-speed heating is also helpful to prevent the adhesion of aluminum foil.
(2) Rapid heating is easy to obtain a fine and uniform structure and improve its performance, such as 3A21 alloy aluminum foil. In order to prevent local coarse grains and uneven grains that are easy to occur during annealing, rapid heating is usually used.
(3) In actual production, the heating speed should be increased as much as possible under the premise of ensuring quality.
(4) Annealing furnaces with axial flow fans, due to the fast air circulation and uniform temperature, the heating speed can be appropriately increased. At present, most aluminum foil annealing furnaces are air circulation resistance furnaces, with a furnace capacity of 10-30t, with automatic temperature control, over-temperature alarm and other functions, and the uniformity of furnace gas temperature is below ±5°C.
