What materials make good sealing gaskets for alkaline dry batteries?

The zinc/manganese dioxide combination in alkaline dry batteries is composed of zinc powder and manganese dioxide. The zinc powder provides more surface area for chemical reactions and lowers the internal resistance of the battery. The manganese dioxide prevents gassing in the battery and a plastic gasket is placed between the anode and cathode to prevent leaks.

To make a good sealing gasket for an alkaline dry battery, it is important to choose a material that is strong, flexible, and alkaline-resistant. One good material for this purpose is polypropylene resin, which is a common plastic material. However, this material has limitations. It is not impact-resistant, and can be damaged by a sharp object.

For instance, the resin used to make a gasket must be highly impact-resistant and have high flexibility. For this, it is important to select a material with an Izod impact value of at least 80.

The testing process used for evaluating alkaline dry battery safety valves involves intentionally generating reactant gas in a battery. The current generated by this process is relatively high and the pressure generated by the battery can build up quickly. This method tests the safety valve's ability to function when the pressure of the reactant gas increases.