Qingdao HuaNuo Maxwarm Commodity Co., Ltd. is a professional hand warmer manufacturer. The principle of a hand warmer is:
Hand warmers uses iron oxidation exothermic reaction to generate heat. In fact, it is based on the principle of oxygen-absorbing corrosion of iron in moist air. At the same time, using the strong adsorption of activated carbon, water vapor is stored in the loose structure of activated carbon, and the water vapor is liquefied into water droplets.
When the water comes into contact with air and iron powder, it reacts relatively quickly under the catalysis of sodium chloride to produce iron hydroxide and release heat. The oxidation reaction speed of iron under natural conditions is slow. To accelerate the reaction, we need to increase the surface area of iron.
With water, salt, and activated carbon to form a galvanic battery to promote the reaction, the required temperature of the heating bag can be obtained, which becomes the heat source of the heating bag. The raw material layer in the warm pads can continuously release heat within 12-20 hours under the action of oxygen in the air. This reaction process starts from the opening of the package.