A self-heating can, is essentially an enhanced version of the more commonly and widely used food can. These cans have double chambers, with the outer chamber surrounding the inner one. The chamber which is on the inner side of the can holds the beverage or food and the outer chamber packs chemicals that, when combined, undergo exothermic reaction. As soon as the user wants to warm the drink or food inside the can, a ring is pulled on the can which causes a break in the barrier, separating the chemicals contained in the outer chamber. The drink or food becomes hot as soon as the reaction causes heat, which in turn, is absorbed by the contents.
For general consumers and campers, who do not have access to fire, microwave oven or stove, self-heating cans prove to be a boon. This technology is, however, not very common yet. As self heating cans are more costlier than the traditional cans, these are not as popular. In addition, the former also doesn't always ensure even heating of the beverage or food.
History of Self-Heating Cans
The predecessor self-heating can, the self heating tin, was invented in the year 1897 by the Russian engineer Fedorov. Around 1900, the tins start being produced commercially especially for explorers and mountaineers. During World War II, these tins were manufactured in limited quantities for the Russian Army. Over the years, the tins evolved and took the form of modern day self-heating cans.
The popularity of cans went down after the 1940s but a resurge was seen in America in 2006. Since then, self heating cans have been around. These are available for purchase in supermarkets, sports shops, bakeries, etc.
Types of Self Heating Cans
A self-heating can is broadly divided into two categories - one is the traditional variant with chemicals in the chamber on the outer side and food or beverage in the inner chamber, and the other is a newer, more modern variant that holds the beverage or food in the outer chamber and the chemicals are contained in the inner chamber. While the former, more traditional design is more in use and more known to people, the newer version is actually an upgrade and promises better quality. The new design is more efficient and it also reduces the excessive heating of the can's exterior. The older version tends to get too hot on the outside, making handling difficult and causing discomfort to the user.
A bigger, more commercial variant is self-heating food packing and SHFP. This is an active packaging that has the ability to heat food contents without the requirement of any external sources of powder. Like self-heating cans, self-heating food packing also uses an exothermic chemical reaction to heat food.
Self-Heating Cans Trivia
Hiram Bingham's use of self-heating cans during his 1909-1915 travels is one of the first recorded uses of these cans.