The topmost layer of the primary batteries is a metal casing. The metal casing is printed with the necessary information like, Company name, Logo, Manufacturing date etc. Underneath the metal casing is the Zinc anode with protective polythene covering.
Removing the polythene covering shows the Zinc can. When the cell is in use the electrolyte reacts with the Zn container reacts with the Ammonium Chloride to form Zinc Chloride. As a result of the same the thickness of the Zn container reduces and there are chances of leakage of Zinc Chloride which may damage the device. The polythene covering works as an isolating jacket to prevent the leakage of Zinc Chloride and hence protects the device from any damage where the battery is used.
The two plastic rings red and white in color are used as sealant. One ring is placed at the top and the other on the bottom. They prevent any leakages from the top and bottom of the battery.