The mechanism automatically removes the can from the crusher so that the next can may be loaded. It must be installed in order to function. If you put in six cans, it may become clogged. If you smash cans with the opening facing out, any liquid inside will be squeezed back out. This may cause cans to explode when they hit other objects. Cans are the most common form of beverage container in the United States. They are made from aluminum or steel. Aluminum cans are used for soft drinks and beer while steel cans are used for food products such as soup cans and jars. Aluminum has been called the world's favorite metal because of its light weight and resistance to corrosion when exposed to air but it cannot be recycled using current technology. Instead of recycling aluminum cans, companies throw them away in landfills or incinerators. Incineration produces carbon dioxide, oxygen, water vapor, and nitrogen gases that contribute to global warming. Landfills produce methane, a greenhouse gas, when anaerobic bacteria in the soil convert organic material into carbon dioxide and water. For these reasons, many people think that it is better not to use disposable cans at all. However, there are several advantages to using cans instead of other containers. Cans are inexpensive and easy to make. You can also customize cans by adding artwork or labels. This adds to their appeal for advertisers. Finally, cans are transportable and reusable.