A washing machine (laundry machine, clothes washer, or washer) is a machine designed to wash laundry, such as clothing, towels and sheets. The term is mostly applied only to machines that use water as the primary cleaning solution, as opposed to dry cleaning (which uses alternative cleaning fluids, and is performed by specialist businesses) or even ultrasonic cleaners.
Laundering by hand involves beating and scrubbing dirty cloth. It is hard work even with manufactured aids like washboards and soap to help.
Clothes washer technology developed as a way to reduce the drudgery of this scrubbing and rubbing process by providing an open basin or sealed container with paddles or fingers to automatically agitate the clothing. The earliest machines were hand-operated. As electricity was not commonly available until at least 1930, some early machines were operated by a low-speed single-cylinder hit and miss gasoline engine. By the mid-1850s steam-driven commercial laundry machinery was on sale in the USA and Great Britain. Technological advances in machinery for commercial and institutional laundries proceeded faster than domestic washer design for several decades, especially in the UK. In the US there was more emphasis on developing machines for washing at home, as well as machines for the commercial laundry services which were widely used in the late 19th and early 20th centuries.
Because water often had to be carried, heated on a fire for washing, then poured into the tub, the warm soapy water was precious and would be reused over and over, first to wash the least soiled clothing, then to wash progressively dirtier laundry. While the earliest machines were constructed from wood, later machines made of metal permitted a fire to burn below the washtub, to keep the water warm throughout the day’s washing.
Removal of soap and water from the clothing after washing was originally a separate process. After rinsing, the soaking wet clothing would be formed into a roll and twisted by hand to extract water. To help reduce this labour, the wringer/mangle was developed, which uses two rollers under spring tension to squeeze water out of clothing and household linen. Each item would be fed through the wringer separately. The first wringers were hand-operated, but were eventually included as a powered attachment above the washer tub. The wringer would be swung over the wash tub so that extracted wash water would fall back into the tub to be reused for the next wash load.
The modern process of water removal by spinning did not come into use until electric motors were developed. Spinning requires a constant high-speed power source, and was originally done in a separate device known as an extractor. A load of washed clothing would be transferred from the wash tub to the extractor basket, and the water spun out. These early extractors were often dangerous to use since unevenly distributed loads would cause the machine to shake violently. Many efforts have been made to counteract the shaking of unstable loads, first by mounting the spinning basket on a free-floating shock-absorbing frame to absorb minor imbalances, and a bump switch to detect severe movement and stop the machine so that the load can be manually redistributed. Many modern machines are equipped with a sealed ring of liquid that works to counteract any imbalances.
What is now referred to as an automatic washer was at one time referred to as a washer/extractor, which combines the features of these two devices into a single machine, plus the ability to fill and drain water by itself. It is possible to take this a step further, to also merge the automatic washing machine and clothes dryer into a single device, but this is generally uncommon because the drying process tends to use much more energy than using two separate devices; a combined washer/dryer not only must dry the clothing, but also need to dry out the wash chamber itself.