Qingdao HuaNuo Maxwarm Commodity Co., Ltd. is a professional foot warmer manufacturer. The foot warmer heating is a process of using iron powder to rust and slowly oxidize to release heat. Iron powder, oxygen, and water vapor work together to release heat. Activated carbon is used to accelerate the reaction rate and convert chemical energy into heat. In order to make the warm paste last longer and continue to generate heat, a mineral material-vermiculite is added to the warm paste to keep it warm.