A garbage disposal uses a small motor to rotate a turntable upon which waste is gathered.

More Info: The centrifugal force thus created forces waste into the serrated wall of the holding chamber and shreds it into small pieces safe for plumbing. Lugs are small mashing pieces within the disposal that help to force all the waste against and eventually through the wall. A constant stream of water from the faucet makes sure all the mechanisms stay clean, helps to maintain smooth operation, and pushes food into the shredding area.

Continuous Feed Models 

Most garbage disposals in the home are of one certain variety: a continuous feed model. This is the one most people are familiar with and allows for garbage to be added while the machine is running without any problems. Because the disposal is spinning so rapidly, people may wonder why the occasional piece of waste doesn't just come flying back out of the drain. A rubber ring fixed to the top of the machine prevents that from happening. The other model of garbage disposal is referred to as a batch feed. In order to use this disposal, waste must be pre-loaded into the chamber and a stopper placed on top before it can be started.

The First Garbage Disposal 

The first garbage disposal was known as the In-Sink-Erator and has been sold by the company of the same name since 1927. Garbage disposals are an American invention, the In-Sink-Erator hails from Racine, Wisconsin, and have since become a common appliance in kitchens throughout the country.