With the continuous development of the times, food heating packs have been widely used by us, but how many types of food heating packs do we know?

1. Quicklime. Also known as calcium oxide, it produces slaked lime only after contact with water, also known as calcium hydroxide. It releases a large amount of heat when it comes into contact with water, and is the main source of heat for heating packs.

2. Diatomaceous earth and activated carbon. They are typical adsorbents. The loose and porous structure is conducive to the adhesion of various useful ingredients, which can fully contact with water and produce chemical reactions.

3. Salts such as sodium carbonate and calcium chloride.

4. Iron powder and aluminum powder. They can release a small amount of heat by reacting with oxygen, and form a “galvanic battery” effect with activated carbon, water, and salt; they release heat through oxidation-reduction reactions to achieve continuous heating.

After adding water to the heating pack, the heating pack will heat up when it comes into contact with water, and the temperature can reach above 150°C, and the steam temperature can reach 200°C. When steaming food, the temperature is usually maintained for about 20 minutes.

Traditional convenience foods need to be soaked in boiling water before they can be eaten. Some special groups, such as those who go on field expeditions, travel, etc., cannot eat them without boiling water. Self-heating rice does not require boiling water or electricity when eaten. Open the outer packaging and pour the dirty water bag inside on the heating bag. The water and heating bag automatically mix and heat up, steam the rice and dishes, and they can be eaten in 8-15 minutes. The self-heating lunch box is actually the result of the reaction between the water bag in the lunch box and the heating agent wrapped in non-woven fabric. Once the plastic strip is opened, the water bag will be broken. At this time, the heating agent will react chemically with water, causing the heating agent to dissipate heat evenly and generate heat up to 120°C. After 5-8 minutes, the temperature of the food reaches 55°C-70°C, and delicious food can be eaten at this time. The self-heating boxed meal generates heat energy by the chemical reaction of the heating agent, and heats the food through the thermal reaction, which is similar to the principle of heating rice on the heater. While pursuing convenience, the quality, hygiene and shelf life of food are also the key to convenience food. The food in the self-heating lunch box is sterilized at 125℃ and then vacuum packed in the lunch box. When eating, the food can be heated after 5-8 minutes.