Washing machine
Encyclopedia
A washing machine is a machine designed to wash laundry
, such as clothing
, towel
s and sheet
s. 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.
s 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.
The first English
patent under the category of Washing and Wringing Machines was issued in 1691. A drawing of an early washing machine appeared in the January 1752 issue of "The Gentlemen's Magazine," a British publication. In Germany, Jacob Christian Schäffer
's washing machine design was published in 1767. In 1782 Henry Sidgier was issued a British patent for a rotating drum washer, and in the 1790s Edward Beetham sold numerous "patent washing mills" in England. In 1862, a patented "compound rotary washing machine, with rollers for wringing or mangling" was shown at the 1862 London Exhibition
, done by Richard Lansdale of Pendleton, Manchester.
The first United States Patent titled "Clothes Washing" was granted to Nathaniel Briggs of New Hampshire
in 1797. Because of the Patent Office Fire of 1836, no description of the device exists, and it is not known what kind of washing device Briggs invented. A device that combined a washing machine with a wringer mechanism did not appear until 1843, when John E. Turnbull
of Saint John, New Brunswick
patented a "Clothes Washer With Wringer Rolls."
Electric washing machines were advertised and discussed in newspapers as early as 1904. Alva J. Fisher has been incorrectly credited with the invention of the electric washer. The US patent office shows at least one patent issued before Mr. Fisher's US patent number 966677 (e.g. Woodrow's US patent number 921195). The "inventor" of the electric washing machine remains unknown.
US electric washing machine sales reached 913,000 units in 1928. However, high unemployment rates in the Depression
years hit sales; by 1932 the number of units shipped was down to about 600,000.
The first laundromat opened in Fort Worth, Texas
in 1934. It was run by Andrew Clein. Patrons used coin-in-the-slot facilities to rent washing machines. The term laundromat can be found in newspapers as early as 1884 and they were widespread during the depression. It is almost impossible to determine who had the first laundromat. England established public wash rooms for laundry along with bath houses throughout the 19th century.
Washer design improved during the 1930s. The mechanism was now enclosed within a cabinet, and more attention was paid to electrical safety. Spin dryers were introduced to replace the dangerous power wringers of the day.
Early automatic washing machines were usually connected to the water supply via temporary slip-on connectors to the sink taps. Later, permanent connections to both the hot and cold water supplies became the norm. Most modern front-loading European machines now only have a cold water connection (i.e. cold fill) and rely completely on electric heaters to raise the water temperature.
By 1940, 60% of the 25,000,000 wired homes in the United States had an electric washing machine. Many of these machines featured a power wringer, although built-in spin dryers were not uncommon.
Bendix introduced the first automatic washing machine in 1937, having applied for a patent in the same year. In appearance and mechanical detail, this first machine is not unlike the front loading automatic washers produced today. Although it included many of the today's basic features, the machine lacked any drum suspension and therefore had to be anchored to the floor to prevent "walking".
Many of these early automatic machines had coin-in-the-slot facilities and were installed in the basement laundry rooms of apartment houses. After the attack on Pearl Harbor
, US domestic washer production had to be suspended for the duration of World War II
. However, many US appliance manufacturers were given permission to undertake the research and development of washers during the war years. Many took the opportunity to develop automatic machines, realizing that these represented the future for the industry.
An improved front loading automatic model, the Bendix Deluxe (which retailed at $249.50), was introduced in 1947.
General Electric
also introduced its first top loading automatic model in 1947. This machine had many of the features that are incorporated into modern machines.
A large number of US manufacturers introduced competing automatic machines (mainly of the top loading type) in the late 1940s/early 1950s. Several manufacturers even produced semi-automatic machines, where the user had to intervene at one or two points in the wash cycle. A common semi-automatic type (available from Hoover in the UK until at least the 1970s) included 2 tubs: one with an agitator or impeller for washing and/or rinsing; another, smaller, tub for water extraction or centrifugal rinsing.
One early form of automatic washing machine manufactured by Hoover used cartridges to program different wash cycles. This system, called the Keymatic, used plastic cartridges with key-like slots and ridges around the edges. The cartridge was inserted into a slot on the machine and a mechanical reader operated the machine accordingly. The system did not commercially succeed because it offered no real advantage over the more conventional program dial, and the cartridges were prone to getting lost. In hindsight it can be seen as a marketing gimmick
rather than offering any really useful functionality.
Since their introduction in the late 1930s/mid 1940s, automatic washing machines have relied on mechanical timers to sequence the washing and extraction process. Mechanical timers consist of a series of cams on a common shaft. At the appropriate time in the wash cycle, each cam actuates a switch to engage/disengage a particular part of the machinery (e.g. drain pump motor). The timer shaft is driven by a small electric motor via a reduction gearbox.
On the early mechanical timers the motor ran at a constant speed throughout the wash cycle, although it was possible for the user to truncate parts of the program by manually advancing the control dial. However, by the 1950s demand for greater flexibility in the wash cycle led to the introduction of electronic timers to supplement the mechanical timer. These electronic timers enable greater variation in such functions as the wash time. With this arrangement, the electric timer motor is periodically switched off to permit the clothing to soak, and is only re-energised just prior to a micro-switch being engaged/disengaged.
Despite the high cost of automatic washers, manufacturers had difficulty in meeting the demand. Although there were material shortages during the Korean War
, by 1953 automatic washing machine sales in the US exceeded those of wringer-type electric machines.
In the UK and in most of Europe, electric washing machines did not become popular until the 1950s. This was largely because of the economic impact of World War II on the consumer market which did not properly recover until the late 1950s. The early electric washers were single tub, wringer-type machines, automatic washing machines being extremely expensive. During the 1960s, twin tub machines briefly became very popular, helped by the low price of the Rolls Razor
washers. Automatic washing machines did not become dominant in the UK until well into the 1970s and by then were almost exclusively of the front-loader design.
In early automatic washing machines, any changes in impeller/drum speed were achieved by mechanical means or by a rheostat on the motor power supply. However, since the 1970s electronic control of motor speed has become a common feature on the more expensive models.
Early front loading machines, especially those manufactured in Mediterranean countries (e.g. Italy), had low spin speeds (e.g. 800 rpm or less). Nowadays, a spin speed of 1200 rpm is common and a peak spin speed as high as 1600 rpm is available on many machines. Now models in Europe have speeds of 1800 rpm and a few European washing machines have a spin speed of 2000 rpm. However, because they were not susceptible to gravitational forces, some early top loading machines had spin speeds in excess of 1000 rpm, although some were as low as 360 rpm. Most US top-loading washers have spin speeds less than 1000 rpm.
In the early 1990s, upmarket machines incorporated microcontrollers for the timing process. These proved reliable, so many cheaper machines now incorporate microcontrollers, rather than mechanical timers. Washing machines are a classic application for fuzzy logic
. Miele, from West Germany, was the top of the line front load washer, and was introduced in Kananaskis, Alberta by Glenn Isbister starting a revolution in Laundry in Canada.
In 1994, Staber Industries
released the System 2000 washing machine, which is the only top loading, horizontal-axis washer to be manufactured in the United States. The hexagonal tub spins like a front loading machine, only using about third of the water as conventional top-loaders. This factor has led to an Energy Star
rating for its high efficiency.
In 1998, New Zealand
based company Fisher & Paykel
introduced its SmartDrive washing machine line in the US. This washing machine uses a computer-controlled system to determine certain factors such as load size and automatically adjusts the wash cycle to match. It also used a mixed system of washing, first with the "Eco-Active" wash, using a low level of recirculated water being sprayed on the load followed by a more traditional style wash. Other variations include the Intuitive Eco, which can sense the water level and type of fabric in the wash load, and the agitatorless AquaSmart line.
In 2001, Whirlpool Corporation introduced the Calypso, the first vertical-axis high efficiency washing machine to be top-loading. A washplate in the bottom of the tub nutated
to bounce, shake, and toss the laundry around. As this happened, water containing detergent was sprayed on to the laundry. The machine proved to be good at cleaning but gained a bad reputation due to frequent breakdowns and destruction of laundry and the washer was recalled with a lass-action lawsuit]] and pulled off the market.
In 2003, Maytag
introduced their top-loading Neptune washer. Instead of an agitator, the machine had two washplates, perpendicular to each other and at a 45 degree angle from the bottom of the tub. The machine would fill with only a small amount of water and the two washplates would tumble the load within it, mimicking the action of a front-loading washer in a vertical axis design.
In the early first decade of the 21st century, the British inventor James Dyson
launched the ContraRotator, a type of washing machine with two cylinders rotating in opposite directions; which, it is claimed, reduces the wash time and produces cleaner results; however, this machine is no longer in production.
In 2007, Sanyo
introduced the first drum type washing machine with ‘Air Wash’ function. This washing machine uses only 50l of water in the recycle mode.
In 2008, the University of Leeds
created a concept washing machine that uses only a cup (less than 300ml) of water to carry out a full wash. The machine leaves clothes virtually dry, and uses less than 2 per cent of the water and energy otherwise used by a conventional machine, but requires 20 kg of re-usable plastic chips in each load. As such, it could save billions of litres of water each year.
Features available in most modern consumer washing machines:
Additionally some of the modern machines feature:
The top-loading design or vertical-axis clothes washer, most popular in Australia
, New Zealand
, Canada
, the United States and Latin America
, places the clothes in a vertically mounted perforated basket that is contained within a water-retaining tub, with a finned water-pumping agitator
in the center of the bottom of the basket. Clothes are loaded through the top of the machine, which is covered with a hinged door.
During the wash cycle, the outer tub is filled with water sufficient to fully immerse and suspend the clothing freely in the basket. The movement of the agitator pushes water outward between the paddles towards the edge of the tub. The water then moves outward, up the sides of the basket, towards the center, and then down towards the agitator to repeat the process, in a circulation pattern similar to the shape of a torus
. The agitator direction is periodically reversed, because continuous motion in one direction would just lead to the water spinning around the basket with the agitator rather than the water being pumped in the torus-shaped motion. Some washers supplement the water-pumping action of the agitator with a large rotating screw on the shaft above the agitator, to help move water downwards in the center of the basket.
Top-loaders are not well-suited to cleaning large objects such as pillows or sleeping bags due to the tendency for them to just float on the surface of the water without circulating, and the aggressive agitator action can damage delicate fabrics.
In most top-loading washers, if the motor spins in one direction, the gearbox drives the agitator; if the motor spins the other way, the gearbox locks the agitator and spins the basket and agitator together. Similarly if the pump motor rotates one way it recirculates the sudsy water; in the other direction it pumps water from the machine during the spin cycle. Because they usually incorporate a gearbox, clutch
, crank
, etc., top-loading washers are mechanically more complex than front loading machines but are generally lower maintenance since there is no need for a door seal (described below). However, the electromechanical components in conventional top-load washers have largely reached maturity.
The top-loader's spin cycle between washing and rinsing allows an extremely simple fabric softener
dispenser, which operates passively through centrifugal force
and gravity. The same objective must be accomplished by a solenoid-operated valve on a front loader. Another advantage to the top loading design is the reliance on gravity to contain the water, rather than potentially trouble-prone or short-lived front door seals.
As with front-loading washers, clothing should not be packed tightly into a top-loading washer. Although wet cloth usually fits into a smaller space than dry cloth, a dense wad of cloth can restrict water circulation, resulting in poor soap distribution and incomplete rinsing. Extremely overloaded top-loading washers can either jam the motion of the agitator and overload or damage the motor or gearbox, or tear fabrics. Extreme overloading can also push fabrics into the small gap between the underside of the agitator and the bottom of the wash basket, resulting in fabrics wrapped around the agitator shaft, possibly requiring agitator removal to unjam.
and the Middle East
, mounts the inner basket and outer tub horizontally, and loading is through a door at the front of the machine. The door often but not always contains a window. Agitation is supplied by the back-and-forth rotation of the cylinder and by gravity. The clothes are lifted up by paddles on the inside wall of the drum and then dropped. This motion flexes the weave of the fabric and forces water and detergent solution through the clothes load. Because the wash action does not require the clothing be freely suspended in water, only enough water is needed to moisten the fabric. Because less water is required, front-loaders typically use less soap, and the aggressive dropping and folding action of the tumbling can easily produce large amounts of foam.
Front-loaders control water usage through the surface tension
of water, and the capillary wicking action
this creates in the fabric weave. A front-loader washer always fills to the same low water level, but a large pile of dry clothing standing in water will soak up the moisture, causing the water level to drop. The washer then refills to maintain the original water level. Because it takes time for this water absorption to occur with a motionless pile of fabric, nearly all front-loaders begin the washing process by slowly tumbling the clothing under the stream of water entering and filling the drum, to rapidly saturate the clothes with water.
Front-loading washers are mechanically simple compared to top-loaders, with the main motor normally being connected to the drum via a grooved pulley belt and large pulley
wheel, without the need for a gearbox, clutch or crank. But front-load washers suffer from their own technical problems, due to the drum lying sideways. For example, a top loading washer keeps water inside the tub merely through the force of gravity pulling down on the water, while a front-loader must tightly seal the door shut with a gasket
to prevent water dripping onto the floor during the wash cycle. This access door is locked shut during the entire wash cycle, since opening the door with the machine in use could result in water gushing out onto the floor. For front-loaders without viewing windows on the door, it is possible to accidentally pinch fabric between the door and the drum, resulting in tearing and damage to the pinched clothing during tumbling and spinning.
Nearly all front-loader washers for the consumer market must also use a folded flexible bellows
assembly around the door opening, to keep clothing contained inside the basket during the tumbling wash cycle. If this bellows assembly were not used, small articles of clothing such as socks could slip out of the wash basket near the door, and fall down the narrow slot between the outer tub and basket, plugging the drain and possibly jamming rotation of the inner basket. Retrieving lost items from between the outer tub and inner basket can require complete disassembly of the front of the washer and pulling out the entire inner wash basket. Commercial and industrial front-loaders used by businesses (described below) usually do not use the bellows, and instead require all small objects to be placed in a mesh bag to prevent loss near the basket opening.
This bellows assembly around the door is the source of problems for the consumer front-loader. The bellows has a large number of flexible folds to permit the tub to move separately from the door during the high speed extraction cycle. On many machines, these folds can collect lint, dirt, and moisture, resulting in mold
and mildew growth and a foul odor. Some front-loading washer operating instructions say the bellows should be wiped down monthly with a strong bleach solution, while others offer a special freshening cycle where the machine is run empty with a strong dosing of bleach. In the past, suggested remedies have included adding vinegar to the laundry detergent, running an empty cycle with bleach every few weeks, wiping the door gasket with a diluted bleach solution every other week, and leaving the front-loading washer door ajar between loads.
Recent studies of consumer-reviews posted across the internet show a trend for U.S. front-loading washers to have bearing failure problems normally within the first 6 years and repair cost are close to replacement cost, which is the wisest choice. The symptoms are louder noises while spin-rinsing and then soiled clothes shortly before complete failure, if the bearing grease gets into the inner tub. So, the expected life of today's washing machine has decreased by about 10 years compared to 30 years ago. The under-lying cause being the choice of U.S. consumers to get a washing-machine at the lowest-price-point has caused manufacturers to drastically lower their quality standards to the point where today's machines have shorter life-spans and only one year warranties are offered. Compared to washing machines of the 1970's that lasted about 15 years, adjusted for inflation, the same quality machine would cost about $2300 today. Europeans generally spend two to three times more money for better built laundry machines.
As with top-loading washers, clothing should not be packed tightly into a front-loading washer. Although wet cloth usually fits into a smaller space than dry cloth, a dense wad of cloth can restrict water circulation, resulting in poor soap distribution and incomplete rinsing of cloth in the center of the basket. Extreme overloading of front-loading washers pushes fabrics towards the small gap between the loading door and the front of the wash basket, potentially resulting in fabrics lost between the basket and outer tub, and in severe cases, tearing of clothing and jamming the motion of the basket.
use impeller
s instead of agitators. Impellers are similar to agitators except that they do not have the center post extending up in the middle of the wash tub basket. There is also a variant of the horizontal axis design that is loaded from the top, through a small door in the circumference of the drum. These machines usually have a shorter cylinder and are therefore smaller, but offer the efficiency of a front-loader while eliminating the problems of the flexible bellows. This kind of washing machine is sold and popular in Europe
, especially in small households, because it offers the same drum system as front-loaders, just with a smaller footprint.
Many front loading machines have electrical heating elements to heat the wash bath to near boiling. Chemical action is supplied by the detergent and other laundry chemicals. Front loaders use special detergents that are designed to release different chemical ingredients at different temperatures. This is so that different type of stains and soils will be cleaned from the clothes as the wash water is heated up by the electrical heater. Front loaders also need to use low sudsing detergents because the tumbling action of the drum folds air into the clothes load that can cause over-sudsing. Due to the concentration of water and detergent, though, the sudsing issue of front-loaders can also be controlled by simply using less detergent without lessening cleaning action.
Tests comparing front loading and top loading machines have shown that, in general, front-loaders wash clothes more thoroughly, cause less wear, and use less water and energy than top-loaders. As a result of using less water, they require less detergent to be used, or conversely, they can use the same amount of detergent with less water, which increases detergent concentration and increases the amount of chemical action. They also allow a dryer to be more easily mounted directly above the washer.
Top-loading washers do not suffer from continued maintenance problems and need no regular freshening. During the spin cycle, a top-loading tub is free to move about inside the cabinet of the machine, using only a lip around the top of the inner basket and outer tub to keep the spinning water and clothing from spraying out over the edge.
website suggests re-running the rinse cycle again.
Washing machines display an EU Energy Label with grades for energy efficiency, washing performance and spin efficiency. Grades run from A to G (best to worst), providing a simple method for judging running costs and performance. For example a "Triple A" (AAA) rated machine indicates lowest energy consumption, best wash and best water extraction (i.e. spin) performance. This has had the desired effect of driving customers toward more efficient washing machines and away from less efficient ones.
One important factor that is missing from the energy labelling scheme is the washing machine's rinsing performance, which can adversely affect allergy sufferers and people who are sensitive to laundry detergents and chemicals. It is advisable to check an independent consumer report on how well a washing machine can rinse before purchasing, as newer washing machines use a lot less water than older ones.
Many US-market clothes washers are more energy-efficient and water-efficient than required by the mandatory Federal Standard, or even the more stringent Energy Star standard. Manufacturers may be motivated to exceed legally mandated standards by a program of direct-to-manufacturer tax credits. Excessive energy conservation in the laundering process may lead to less-than-satisfactory cleaning, and excessive water conservation may lead to poor rinsing.
A commercial washing machine is intended for more frequent and long-term usage than a consumer washing machine. Because function is more important than style, most commercial washers have a sharp-edged square appearance, often with stainless steel exteriors to minimize rust and corrosion in a constantly moist environment. They are built with large easy-to-open service covers, and the washer mechanisms are internally laid out in a manner that does not require access to the underside of the unit for service. Often commercial washers are installed in long rows with a wide access passageway behind all the machines to allow maintenance without moving the heavy machine.
Many commercial washers are built for use by the general public, and are installed in publicly accessible laundromats or laundrettes, operated by money accepting devices or card readers. The features of a commercial laundromat washer are more limited than a consumer washer, offering just two or three basic wash types plus an option to choose wash cycle temperatures. The common front-loading commercial washing machine also differs from consumer models in its expulsion of wash and rinse water. While the consumer models pump used water out allowing the waste line to be located above the washer, front loading, commercial machines generally use gravity to expel used water. A drain in the rear, at the bottom of the machine opens at the appointed time during the cycle and water flows out. This creates the need for a trough behind machines which leads to a filter and drain. the trough is usually part of a cement platform built for the purpose of raising the machines and can be seen behind washers at most laundromats.
Commercial washers for business (still often referred to as a washer/extractor) can include extra features that are never seen in the consumer market. Many commercial washers offer an option for automatic chemical injection of five or more different chemical types, so that the operator does not have to deal with constantly measuring out soap products and fabric softeners for each load. Instead a precise metering system draws the detergents and wash additives directly from large liquid-chemical storage barrels and injects them as needed into the various wash and rinse cycles.
Some computer-controlled commercial washers offer the operator complete control over the various wash and rinse cycles, allowing the operator to program custom washing cycles.
One special type of continuous-processing washer is known as the tunnel washer
which does not have separate, distinct wash or rinse cycles, but combines them all in sequence inside a single long large-diameter rotating tube.
An industrial clothes washer can be used to batch process up to 800 pounds (140 kg) of textiles at once, and can be used for extremely machine-abusive washing tasks such as stone washing
or fabric bleaching and dyeing
.
An industrial washer can be mounted on heavy shock absorbers and attached to a concrete floor so that it can extract water from even the most severely out-of-balance and heavy wash loads. It may be mounted on hydraulic cylinders, permitting the entire washer to be lifted and tilted so that fabrics can be automatically dumped from the wash drum onto a conveyor belt once the cycle is complete.
In 2009, L'Osservatore Romano
published an article entitled "The Washing Machine and the Liberation of Women" that was controversially meant to demonstrate that the washing machine had done more for the liberation of woman than the contraceptive pill and abortion rights, which are often associated to Women's Day. The article shocked Italian feminists and provoked criticism from Opposition MP Paola Concia
. A study from Université de Montréal
also presented a similar point of view to that of L'Osservatore.
Swedish statistician Hans Rosling
has suggested that the positive effect the washing machine had on liberation of woman, makes it "the greatest invention of the industrial revolution".
Laundry
Laundry is a noun that refers to the act of washing clothing and linens, the place where that washing is done, and/or that which needs to be, is being, or has been laundered...
, such as clothing
Clothing
Clothing refers to any covering for the human body that is worn. The wearing of clothing is exclusively a human characteristic and is a feature of nearly all human societies...
, towel
Towel
A towel is a piece of absorbent fabric or paper used for drying or wiping. It draws moisture through direct contact, often using a blotting or a rubbing motion. Common household textile towels are made from cotton, rayon, bamboo, nonwoven fibers or a few other materials.-Types of towels:* A bath...
s and sheet
Bed sheet
A bed sheet is a piece of cloth used to cover a mattress. It is this sheet that one typically lies on.In many areas of the world, a second flat bed sheet is laid on top of the sheet covering the mattress. This is known as a "top sheet" and when a top sheet is used, the sheet covering the mattress...
s. The term is mostly applied only to machines that use water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
as the primary cleaning solution, as opposed to dry cleaning
Dry cleaning
Dry cleaning is any cleaning process for clothing and textiles using a chemical solvent other than water. The solvent used is typically tetrachloroethylene , abbreviated "perc" in the industry and "dry-cleaning fluid" by the public...
(which uses alternative cleaning fluids, and is performed by specialist businesses) or even ultrasonic cleaners.
History
Laundering by hand involves beating and scrubbing dirty cloth. It is hard work even with manufactured aids like washboardWashboard
A washboard is a tool designed for hand washing clothing. With mechanized cleaning of clothing becoming more common by the end of the 20th century, the washboard has become better known for its originally subsidiary use as a musical instrument....
s and soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
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
Hit and miss engine
A hit-and-miss engine is a type of four-stroke internal combustion engine that was conceived in the late 19th century and was produced by various companies from the 1890s through approximately the 1930s. The name comes from the method of speed control that is implemented on these engines...
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
Mangle (machine)
A mangle or wringer is a mechanical laundry aid consisting of two rollers in a sturdy frame, connected by cogs and, in its home version, powered by a hand crank or electrically...
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
Clothes dryer
A clothes dryer or tumble dryer is a household appliance that is used to remove moisture from a load of clothing and other textiles, generally shortly after they are cleaned in a washing machine....
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.
Milestones
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
patent under the category of Washing and Wringing Machines was issued in 1691. A drawing of an early washing machine appeared in the January 1752 issue of "The Gentlemen's Magazine," a British publication. In Germany, Jacob Christian Schäffer
Jacob Christian Schäffer
Jakob or Jacob Christian Gottlieb Schäffer or Schäffern was a German dean, professor, botanist, mycologist, entomologist, ornithologist and inventor.-Biography:...
's washing machine design was published in 1767. In 1782 Henry Sidgier was issued a British patent for a rotating drum washer, and in the 1790s Edward Beetham sold numerous "patent washing mills" in England. In 1862, a patented "compound rotary washing machine, with rollers for wringing or mangling" was shown at the 1862 London Exhibition
1862 International Exhibition
The International of 1862, or Great London Exposition, was a world's fair. It was held from 1 May to 1 November 1862, beside the gardens of the Royal Horticultural Society, South Kensington, London, England, on a site that now houses museums including the Natural History Museum and the Science...
, done by Richard Lansdale of Pendleton, Manchester.
The first United States Patent titled "Clothes Washing" was granted to Nathaniel Briggs of New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
in 1797. Because of the Patent Office Fire of 1836, no description of the device exists, and it is not known what kind of washing device Briggs invented. A device that combined a washing machine with a wringer mechanism did not appear until 1843, when John E. Turnbull
John E. Turnbull
John E. Turnbull lived in Saint John, New Brunswick, Canada in the 19th century. He is notable for inventing the first rolling wringer clothes washer in 1843.-References:...
of Saint John, New Brunswick
Saint John, New Brunswick
City of Saint John , or commonly Saint John, is the largest city in the province of New Brunswick, and the first incorporated city in Canada. The city is situated along the north shore of the Bay of Fundy at the mouth of the Saint John River. In 2006 the city proper had a population of 74,043...
patented a "Clothes Washer With Wringer Rolls."
Electric washing machines were advertised and discussed in newspapers as early as 1904. Alva J. Fisher has been incorrectly credited with the invention of the electric washer. The US patent office shows at least one patent issued before Mr. Fisher's US patent number 966677 (e.g. Woodrow's US patent number 921195). The "inventor" of the electric washing machine remains unknown.
US electric washing machine sales reached 913,000 units in 1928. However, high unemployment rates in the Depression
Great Depression
The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
years hit sales; by 1932 the number of units shipped was down to about 600,000.
The first laundromat opened in Fort Worth, Texas
Fort Worth, Texas
Fort Worth is the 16th-largest city in the United States of America and the fifth-largest city in the state of Texas. Located in North Central Texas, just southeast of the Texas Panhandle, the city is a cultural gateway into the American West and covers nearly in Tarrant, Parker, Denton, and...
in 1934. It was run by Andrew Clein. Patrons used coin-in-the-slot facilities to rent washing machines. The term laundromat can be found in newspapers as early as 1884 and they were widespread during the depression. It is almost impossible to determine who had the first laundromat. England established public wash rooms for laundry along with bath houses throughout the 19th century.
Washer design improved during the 1930s. The mechanism was now enclosed within a cabinet, and more attention was paid to electrical safety. Spin dryers were introduced to replace the dangerous power wringers of the day.
Early automatic washing machines were usually connected to the water supply via temporary slip-on connectors to the sink taps. Later, permanent connections to both the hot and cold water supplies became the norm. Most modern front-loading European machines now only have a cold water connection (i.e. cold fill) and rely completely on electric heaters to raise the water temperature.
By 1940, 60% of the 25,000,000 wired homes in the United States had an electric washing machine. Many of these machines featured a power wringer, although built-in spin dryers were not uncommon.
Bendix introduced the first automatic washing machine in 1937, having applied for a patent in the same year. In appearance and mechanical detail, this first machine is not unlike the front loading automatic washers produced today. Although it included many of the today's basic features, the machine lacked any drum suspension and therefore had to be anchored to the floor to prevent "walking".
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...
, US domestic washer production had to be suspended for the duration of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. However, many US appliance manufacturers were given permission to undertake the research and development of washers during the war years. Many took the opportunity to develop automatic machines, realizing that these represented the future for the industry.
An improved front loading automatic model, the Bendix Deluxe (which retailed at $249.50), was introduced in 1947.
General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
also introduced its first top loading automatic model in 1947. This machine had many of the features that are incorporated into modern machines.
A large number of US manufacturers introduced competing automatic machines (mainly of the top loading type) in the late 1940s/early 1950s. Several manufacturers even produced semi-automatic machines, where the user had to intervene at one or two points in the wash cycle. A common semi-automatic type (available from Hoover in the UK until at least the 1970s) included 2 tubs: one with an agitator or impeller for washing and/or rinsing; another, smaller, tub for water extraction or centrifugal rinsing.
One early form of automatic washing machine manufactured by Hoover used cartridges to program different wash cycles. This system, called the Keymatic, used plastic cartridges with key-like slots and ridges around the edges. The cartridge was inserted into a slot on the machine and a mechanical reader operated the machine accordingly. The system did not commercially succeed because it offered no real advantage over the more conventional program dial, and the cartridges were prone to getting lost. In hindsight it can be seen as a marketing gimmick
Gimmick
In marketing language, a gimmick is a unique or quirky special feature that makes something "stand out" from its contemporaries. However, the special feature is typically thought to be of little relevance or use. Thus, a gimmick is a special feature for the sake of having a special feature...
rather than offering any really useful functionality.
Since their introduction in the late 1930s/mid 1940s, automatic washing machines have relied on mechanical timers to sequence the washing and extraction process. Mechanical timers consist of a series of cams on a common shaft. At the appropriate time in the wash cycle, each cam actuates a switch to engage/disengage a particular part of the machinery (e.g. drain pump motor). The timer shaft is driven by a small electric motor via a reduction gearbox.
On the early mechanical timers the motor ran at a constant speed throughout the wash cycle, although it was possible for the user to truncate parts of the program by manually advancing the control dial. However, by the 1950s demand for greater flexibility in the wash cycle led to the introduction of electronic timers to supplement the mechanical timer. These electronic timers enable greater variation in such functions as the wash time. With this arrangement, the electric timer motor is periodically switched off to permit the clothing to soak, and is only re-energised just prior to a micro-switch being engaged/disengaged.
Despite the high cost of automatic washers, manufacturers had difficulty in meeting the demand. Although there were material shortages during the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
, by 1953 automatic washing machine sales in the US exceeded those of wringer-type electric machines.
In the UK and in most of Europe, electric washing machines did not become popular until the 1950s. This was largely because of the economic impact of World War II on the consumer market which did not properly recover until the late 1950s. The early electric washers were single tub, wringer-type machines, automatic washing machines being extremely expensive. During the 1960s, twin tub machines briefly became very popular, helped by the low price of the Rolls Razor
Rolls Razor
Rolls Razor Limited was a British company known for its manufacture of a sophisticated safety-razor and an "affordable" twin-tub washing machine.-Origins: razor:...
washers. Automatic washing machines did not become dominant in the UK until well into the 1970s and by then were almost exclusively of the front-loader design.
Early front loading machines, especially those manufactured in Mediterranean countries (e.g. Italy), had low spin speeds (e.g. 800 rpm or less). Nowadays, a spin speed of 1200 rpm is common and a peak spin speed as high as 1600 rpm is available on many machines. Now models in Europe have speeds of 1800 rpm and a few European washing machines have a spin speed of 2000 rpm. However, because they were not susceptible to gravitational forces, some early top loading machines had spin speeds in excess of 1000 rpm, although some were as low as 360 rpm. Most US top-loading washers have spin speeds less than 1000 rpm.
In the early 1990s, upmarket machines incorporated microcontrollers for the timing process. These proved reliable, so many cheaper machines now incorporate microcontrollers, rather than mechanical timers. Washing machines are a classic application for fuzzy logic
Fuzzy logic
Fuzzy logic is a form of many-valued logic; it deals with reasoning that is approximate rather than fixed and exact. In contrast with traditional logic theory, where binary sets have two-valued logic: true or false, fuzzy logic variables may have a truth value that ranges in degree between 0 and 1...
. Miele, from West Germany, was the top of the line front load washer, and was introduced in Kananaskis, Alberta by Glenn Isbister starting a revolution in Laundry in Canada.
In 1994, Staber Industries
Staber Industries
Staber Industries, Inc. is a manufacturer of residential laundry home appliances, with a headquarteres in Groveport, Ohio. The products they currently manufacture include a washing machine, a clothes dryer, and a clothes drying cabinet.-History:...
released the System 2000 washing machine, which is the only top loading, horizontal-axis washer to be manufactured in the United States. The hexagonal tub spins like a front loading machine, only using about third of the water as conventional top-loaders. This factor has led to an Energy Star
Energy Star
Energy Star is an international standard for energy efficient consumer products originated in the United States of America. It was first created as a United States government program during the early 1990s, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted...
rating for its high efficiency.
In 1998, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
based company Fisher & Paykel
Fisher & Paykel
Fisher & Paykel is a major appliance manufacturing company based in East Tamaki, New Zealand.Originally an importer of domestic refrigerators, Fisher & Paykel now holds over 420 patents and bases its identity on innovative design, particularly in the areas of usability and environmental...
introduced its SmartDrive washing machine line in the US. This washing machine uses a computer-controlled system to determine certain factors such as load size and automatically adjusts the wash cycle to match. It also used a mixed system of washing, first with the "Eco-Active" wash, using a low level of recirculated water being sprayed on the load followed by a more traditional style wash. Other variations include the Intuitive Eco, which can sense the water level and type of fabric in the wash load, and the agitatorless AquaSmart line.
In 2001, Whirlpool Corporation introduced the Calypso, the first vertical-axis high efficiency washing machine to be top-loading. A washplate in the bottom of the tub nutated
Nutation
Nutation is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behavior of a mechanism...
to bounce, shake, and toss the laundry around. As this happened, water containing detergent was sprayed on to the laundry. The machine proved to be good at cleaning but gained a bad reputation due to frequent breakdowns and destruction of laundry and the washer was recalled with a lass-action lawsuit]] and pulled off the market.
In 2003, Maytag
Maytag
Maytag Corporation is an American home and commercial appliance company, headquartered in Newton, Iowa, that is a division of the Whirlpool Corporation.-Company history:...
introduced their top-loading Neptune washer. Instead of an agitator, the machine had two washplates, perpendicular to each other and at a 45 degree angle from the bottom of the tub. The machine would fill with only a small amount of water and the two washplates would tumble the load within it, mimicking the action of a front-loading washer in a vertical axis design.
In the early first decade of the 21st century, the British inventor James Dyson
James Dyson
Sir James Dyson is a British industrial designer and founder of the Dyson company.He is best known as the inventor of the Dual Cyclone bagless vacuum cleaner, which works on the principle of cyclonic separation. His net worth in 2011 was said to be £1.45 billion.-Early life:Dyson was born in...
launched the ContraRotator, a type of washing machine with two cylinders rotating in opposite directions; which, it is claimed, reduces the wash time and produces cleaner results; however, this machine is no longer in production.
In 2007, Sanyo
Sanyo
is a major electronics company and member of the Fortune 500 whose headquarters is located in Moriguchi, Osaka prefecture, Japan. Sanyo targets the middle of the market and has over 230 Subsidiaries and Affiliates....
introduced the first drum type washing machine with ‘Air Wash’ function. This washing machine uses only 50l of water in the recycle mode.
In 2008, the University of Leeds
University of Leeds
The University of Leeds is a British Redbrick university located in the city of Leeds, West Yorkshire, England...
created a concept washing machine that uses only a cup (less than 300ml) of water to carry out a full wash. The machine leaves clothes virtually dry, and uses less than 2 per cent of the water and energy otherwise used by a conventional machine, but requires 20 kg of re-usable plastic chips in each load. As such, it could save billions of litres of water each year.
Features available in most modern consumer washing machines:
- Predefined programs for different laundry types
- Variable temperatures including cold wash
- Rotation speed settings
- Delayed execution: a timer to delay the start of the laundry cycle
Additionally some of the modern machines feature:
- Child lock
- Time remaining indication
- Steam
Top versus front loading
Modern washing machines are available in two configurations: top loading and front loading.Market share
| Market | Top Loading Washer | Front Loading Washer |
|---|---|---|
| European Market Share | 10%** | 90% |
| US Market Share | 65% | 35% |
| Indian Market Share | 50% | 50% |
Top-loading
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, the United States and Latin America
Latin America
Latin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
, places the clothes in a vertically mounted perforated basket that is contained within a water-retaining tub, with a finned water-pumping agitator
Agitator (device)
An agitator is a device or mechanism to put something into motion by shaking or stirring.-Manual agitator:* Manual dishwashers* A rock can be a device used to agitate dirt and other solids from fabric in washing* A stirring rod...
in the center of the bottom of the basket. Clothes are loaded through the top of the machine, which is covered with a hinged door.
During the wash cycle, the outer tub is filled with water sufficient to fully immerse and suspend the clothing freely in the basket. The movement of the agitator pushes water outward between the paddles towards the edge of the tub. The water then moves outward, up the sides of the basket, towards the center, and then down towards the agitator to repeat the process, in a circulation pattern similar to the shape of a torus
Torus
In geometry, a torus is a surface of revolution generated by revolving a circle in three dimensional space about an axis coplanar with the circle...
. The agitator direction is periodically reversed, because continuous motion in one direction would just lead to the water spinning around the basket with the agitator rather than the water being pumped in the torus-shaped motion. Some washers supplement the water-pumping action of the agitator with a large rotating screw on the shaft above the agitator, to help move water downwards in the center of the basket.
Top-loaders are not well-suited to cleaning large objects such as pillows or sleeping bags due to the tendency for them to just float on the surface of the water without circulating, and the aggressive agitator action can damage delicate fabrics.
In most top-loading washers, if the motor spins in one direction, the gearbox drives the agitator; if the motor spins the other way, the gearbox locks the agitator and spins the basket and agitator together. Similarly if the pump motor rotates one way it recirculates the sudsy water; in the other direction it pumps water from the machine during the spin cycle. Because they usually incorporate a gearbox, clutch
Clutch
A clutch is a mechanical device which provides for the transmission of power from one component to another...
, crank
Crank (mechanism)
A crank is an arm attached at right angles to a rotating shaft by which reciprocating motion is imparted to or received from the shaft. It is used to change circular into reciprocating motion, or reciprocating into circular motion. The arm may be a bent portion of the shaft, or a separate arm...
, etc., top-loading washers are mechanically more complex than front loading machines but are generally lower maintenance since there is no need for a door seal (described below). However, the electromechanical components in conventional top-load washers have largely reached maturity.
The top-loader's spin cycle between washing and rinsing allows an extremely simple fabric softener
Fabric softener
Fabric softener is used to prevent static cling and make fabric softer. It is available as a liquid, crystals and dryer sheets.- Varieties :...
dispenser, which operates passively through centrifugal force
Centrifugal force
Centrifugal force can generally be any force directed outward relative to some origin. More particularly, in classical mechanics, the centrifugal force is an outward force which arises when describing the motion of objects in a rotating reference frame...
and gravity. The same objective must be accomplished by a solenoid-operated valve on a front loader. Another advantage to the top loading design is the reliance on gravity to contain the water, rather than potentially trouble-prone or short-lived front door seals.
As with front-loading washers, clothing should not be packed tightly into a top-loading washer. Although wet cloth usually fits into a smaller space than dry cloth, a dense wad of cloth can restrict water circulation, resulting in poor soap distribution and incomplete rinsing. Extremely overloaded top-loading washers can either jam the motion of the agitator and overload or damage the motor or gearbox, or tear fabrics. Extreme overloading can also push fabrics into the small gap between the underside of the agitator and the bottom of the wash basket, resulting in fabrics wrapped around the agitator shaft, possibly requiring agitator removal to unjam.
Front-loading
The front-loading design or horizontal-axis clothes washer, most popular in EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, mounts the inner basket and outer tub horizontally, and loading is through a door at the front of the machine. The door often but not always contains a window. Agitation is supplied by the back-and-forth rotation of the cylinder and by gravity. The clothes are lifted up by paddles on the inside wall of the drum and then dropped. This motion flexes the weave of the fabric and forces water and detergent solution through the clothes load. Because the wash action does not require the clothing be freely suspended in water, only enough water is needed to moisten the fabric. Because less water is required, front-loaders typically use less soap, and the aggressive dropping and folding action of the tumbling can easily produce large amounts of foam.
Front-loaders control water usage through the surface tension
Surface tension
Surface tension is a property of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects to run on the water surface...
of water, and the capillary wicking action
Capillary action
Capillary action, or capilarity, is the ability of a liquid to flow against gravity where liquid spontanously rise in a narrow space such as between the hair of a paint-brush, in a thin tube, or in porous material such as paper or in some non-porous material such as liquified carbon fiber, or in a...
this creates in the fabric weave. A front-loader washer always fills to the same low water level, but a large pile of dry clothing standing in water will soak up the moisture, causing the water level to drop. The washer then refills to maintain the original water level. Because it takes time for this water absorption to occur with a motionless pile of fabric, nearly all front-loaders begin the washing process by slowly tumbling the clothing under the stream of water entering and filling the drum, to rapidly saturate the clothes with water.
Front-loading washers are mechanically simple compared to top-loaders, with the main motor normally being connected to the drum via a grooved pulley belt and large pulley
Pulley
A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present...
wheel, without the need for a gearbox, clutch or crank. But front-load washers suffer from their own technical problems, due to the drum lying sideways. For example, a top loading washer keeps water inside the tub merely through the force of gravity pulling down on the water, while a front-loader must tightly seal the door shut with a gasket
Gasket
thumb|sright|250px|Some seals and gaskets1. [[o-ring]]2. fiber [[Washer |washer]]3. paper gaskets4. [[cylinder head]] [[head gasket|gasket]]...
to prevent water dripping onto the floor during the wash cycle. This access door is locked shut during the entire wash cycle, since opening the door with the machine in use could result in water gushing out onto the floor. For front-loaders without viewing windows on the door, it is possible to accidentally pinch fabric between the door and the drum, resulting in tearing and damage to the pinched clothing during tumbling and spinning.
Nearly all front-loader washers for the consumer market must also use a folded flexible bellows
Bellows
A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location.Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet...
assembly around the door opening, to keep clothing contained inside the basket during the tumbling wash cycle. If this bellows assembly were not used, small articles of clothing such as socks could slip out of the wash basket near the door, and fall down the narrow slot between the outer tub and basket, plugging the drain and possibly jamming rotation of the inner basket. Retrieving lost items from between the outer tub and inner basket can require complete disassembly of the front of the washer and pulling out the entire inner wash basket. Commercial and industrial front-loaders used by businesses (described below) usually do not use the bellows, and instead require all small objects to be placed in a mesh bag to prevent loss near the basket opening.
This bellows assembly around the door is the source of problems for the consumer front-loader. The bellows has a large number of flexible folds to permit the tub to move separately from the door during the high speed extraction cycle. On many machines, these folds can collect lint, dirt, and moisture, resulting in mold
Mold
Molds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...
and mildew growth and a foul odor. Some front-loading washer operating instructions say the bellows should be wiped down monthly with a strong bleach solution, while others offer a special freshening cycle where the machine is run empty with a strong dosing of bleach. In the past, suggested remedies have included adding vinegar to the laundry detergent, running an empty cycle with bleach every few weeks, wiping the door gasket with a diluted bleach solution every other week, and leaving the front-loading washer door ajar between loads.
Recent studies of consumer-reviews posted across the internet show a trend for U.S. front-loading washers to have bearing failure problems normally within the first 6 years and repair cost are close to replacement cost, which is the wisest choice. The symptoms are louder noises while spin-rinsing and then soiled clothes shortly before complete failure, if the bearing grease gets into the inner tub. So, the expected life of today's washing machine has decreased by about 10 years compared to 30 years ago. The under-lying cause being the choice of U.S. consumers to get a washing-machine at the lowest-price-point has caused manufacturers to drastically lower their quality standards to the point where today's machines have shorter life-spans and only one year warranties are offered. Compared to washing machines of the 1970's that lasted about 15 years, adjusted for inflation, the same quality machine would cost about $2300 today. Europeans generally spend two to three times more money for better built laundry machines.
As with top-loading washers, clothing should not be packed tightly into a front-loading washer. Although wet cloth usually fits into a smaller space than dry cloth, a dense wad of cloth can restrict water circulation, resulting in poor soap distribution and incomplete rinsing of cloth in the center of the basket. Extreme overloading of front-loading washers pushes fabrics towards the small gap between the loading door and the front of the wash basket, potentially resulting in fabrics lost between the basket and outer tub, and in severe cases, tearing of clothing and jamming the motion of the basket.
Further comparisons
There are many variations of these two general themes. Top-loading machines in AsiaAsia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
use impeller
Impeller
An impeller is a rotor inside a tube or conduit used to increase the pressure and flow of a fluid.- Impellers in pumps :...
s instead of agitators. Impellers are similar to agitators except that they do not have the center post extending up in the middle of the wash tub basket. There is also a variant of the horizontal axis design that is loaded from the top, through a small door in the circumference of the drum. These machines usually have a shorter cylinder and are therefore smaller, but offer the efficiency of a front-loader while eliminating the problems of the flexible bellows. This kind of washing machine is sold and popular in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, especially in small households, because it offers the same drum system as front-loaders, just with a smaller footprint.
Many front loading machines have electrical heating elements to heat the wash bath to near boiling. Chemical action is supplied by the detergent and other laundry chemicals. Front loaders use special detergents that are designed to release different chemical ingredients at different temperatures. This is so that different type of stains and soils will be cleaned from the clothes as the wash water is heated up by the electrical heater. Front loaders also need to use low sudsing detergents because the tumbling action of the drum folds air into the clothes load that can cause over-sudsing. Due to the concentration of water and detergent, though, the sudsing issue of front-loaders can also be controlled by simply using less detergent without lessening cleaning action.
Tests comparing front loading and top loading machines have shown that, in general, front-loaders wash clothes more thoroughly, cause less wear, and use less water and energy than top-loaders. As a result of using less water, they require less detergent to be used, or conversely, they can use the same amount of detergent with less water, which increases detergent concentration and increases the amount of chemical action. They also allow a dryer to be more easily mounted directly above the washer.
Top-loading washers do not suffer from continued maintenance problems and need no regular freshening. During the spin cycle, a top-loading tub is free to move about inside the cabinet of the machine, using only a lip around the top of the inner basket and outer tub to keep the spinning water and clothing from spraying out over the edge.
- Water leakage: Top loading machines are less prone to leakage. Front loading machines require a seal on the front door, and similarly the front door must be latched during operation to prevent opening, lest large amounts of water spill out. This seal may leak or require replacement. Many current front-loaders, though, can be stopped and added to or removed from, by way of keeping the water level in the horizontal tub below the door level.
- Energy usage: Front loaders use less energy, water and detergent and clean more effectively than the best top loaders. "High Efficiency" washers use 20% to 60% of the detergent, water & energy of "standard" washers. They usually take somewhat longer (20-110 min.) to wash a load, but are computer controlled with additional sensors, to adapt the wash cycle to the needs of each load. As this technology improves, the human interface will also improve.
- Water usage: Front loaders generally use less water than top-loading residential clothes washers. Estimates are front loaders use anywhere from about one third to one half as much as top loaders.
- Compactness: Front loading machines may be installed underneath counters. A front loading washing machine, in a fully fitted kitchen, may even be disguised as an ordinary base cabinet/unit. They may also be convenient in homes with limited floor area, since the dryer may be installed directly above the washer.
- Spin-dry effectiveness: Front loaders also offer much higher spin drying speeds of up to 2000 RPM, although those marketed to consumers tend to be in the 1100 or 1200 RPM range, but still considerably higher than the 650 RPMs that are typically found in top loaders. This makes it possible to dry clothes very quickly by hanging them on washing lines or airing racks or can substantially reduce the length of time required in a tumble dryer.
- Noise: Front loaders tend to operate more quietly than top loaders, because the door seal helps contain noise and because there is less of a tendency to imbalance.
- Accessibility and Ergonomics: Front loaders are more convenient for little peopleDwarfismDwarfism is short stature resulting from a medical condition. It is sometimes defined as an adult height of less than 4 feet 10 inches , although this definition is problematic because short stature in itself is not a disorder....
and those with paraplegiaParaplegiaParaplegia is an impairment in motor or sensory function of the lower extremities. The word comes from Ionic Greek: παραπληγίη "half-striking". It is usually the result of spinal cord injury or a congenital condition such as spina bifida that affects the neural elements of the spinal canal...
, as the controls are front-mounted and the horizontal drum eliminates the need for standing and/or climbing. For people who are sufficiently tall and can stand, top-loaders may be easier to load and unload, since reaching into the tub does not require stooping. However, this issue can be mitigated due to the offering of risers (usually with storage drawers underneath) to raise the front loader door opening closer to the user's level.
Rinsing
Washing machines perform several rinses after the main wash to remove most of the detergent. Modern washing machines use less water due to environmental concerns; however, this has led to the problem of poor rinsing on many washing machines on the market, which can be a problem to people who are sensitive to detergents. The Allergy UKAllergy UK
Allergy UK is a British medical charity dedicated to helping humans with their allergies, food intolerance and chemical sensitivity. It was founded in 1991 as the British Allergy Foundation, and in 2002 the operational name of the charity became Allergy UK...
website suggests re-running the rinse cycle again.
Spinning
At the end of the cycle, washing machines spin the load at a high speed to remove most of the water and quicken and ease the drying process. Early machines would spin at only 300 RPM and, because of lack of any suspension, would often shake and vibrate. Today, machines can spin as fast as 2,000 RPM and include built-in suspension and shock systems to reduce noises well as sensors and software to detect and correct a load that is spinning out of balance. Front-loading washers can be significantly quieter during spin than top loaders because of the lack of a noisy gearbox to drive the machine's moving parts.Maintenance wash
Most, if not all consumer washing machines, now use a plastic outer shell instead of stainless steel to contain the water. Washing machine manufacturers are now advising users, due to the plastic's adhesion properties with laundry detergent and mold, to perform a regular maintenance wash which cleans the inside of the washing machine. A maintenance wash is performed without any laundry on the hottest wash programme, using either one of the following: white vinegar, a detergent with bleaching properties (it is not advisable to put actual bleach inside the washing machine !) or a proprietary washing machine cleaner. The purpose of a maintenance wash is to remove any mold, bacteria, old detergent residue and grunge. If using white vinegar, it is important to allow the washing machine to fill for about 30 seconds before adding the vinegar, as the first bit of water goes into the sump.Europe
Capacity and cost are the main considerations when purchasing a washing machine. If intended for use by a small family, a capacity of under 5 kg should be sufficient (thus saving energy and running costs).Washing machines display an EU Energy Label with grades for energy efficiency, washing performance and spin efficiency. Grades run from A to G (best to worst), providing a simple method for judging running costs and performance. For example a "Triple A" (AAA) rated machine indicates lowest energy consumption, best wash and best water extraction (i.e. spin) performance. This has had the desired effect of driving customers toward more efficient washing machines and away from less efficient ones.
One important factor that is missing from the energy labelling scheme is the washing machine's rinsing performance, which can adversely affect allergy sufferers and people who are sensitive to laundry detergents and chemicals. It is advisable to check an independent consumer report on how well a washing machine can rinse before purchasing, as newer washing machines use a lot less water than older ones.
United States
Top-loading and front-loading clothes washers are covered by a single Federal Standard regulating energy consumption. The Federal Standard effective up until January 1, 2011 includes no restriction on water consumption. Therefore, washer manufacturers face no legal restriction on how much unheated rinse water may be used, in washers manufactured before that date.Many US-market clothes washers are more energy-efficient and water-efficient than required by the mandatory Federal Standard, or even the more stringent Energy Star standard. Manufacturers may be motivated to exceed legally mandated standards by a program of direct-to-manufacturer tax credits. Excessive energy conservation in the laundering process may lead to less-than-satisfactory cleaning, and excessive water conservation may lead to poor rinsing.
Commercial use
Many commercial washers are built for use by the general public, and are installed in publicly accessible laundromats or laundrettes, operated by money accepting devices or card readers. The features of a commercial laundromat washer are more limited than a consumer washer, offering just two or three basic wash types plus an option to choose wash cycle temperatures. The common front-loading commercial washing machine also differs from consumer models in its expulsion of wash and rinse water. While the consumer models pump used water out allowing the waste line to be located above the washer, front loading, commercial machines generally use gravity to expel used water. A drain in the rear, at the bottom of the machine opens at the appointed time during the cycle and water flows out. This creates the need for a trough behind machines which leads to a filter and drain. the trough is usually part of a cement platform built for the purpose of raising the machines and can be seen behind washers at most laundromats.
Commercial washers for business (still often referred to as a washer/extractor) can include extra features that are never seen in the consumer market. Many commercial washers offer an option for automatic chemical injection of five or more different chemical types, so that the operator does not have to deal with constantly measuring out soap products and fabric softeners for each load. Instead a precise metering system draws the detergents and wash additives directly from large liquid-chemical storage barrels and injects them as needed into the various wash and rinse cycles.
Some computer-controlled commercial washers offer the operator complete control over the various wash and rinse cycles, allowing the operator to program custom washing cycles.
One special type of continuous-processing washer is known as the tunnel washer
Tunnel washer
A tunnel washer, also called a continuous batch washer, is an industrial laundry machine designed specifically to handle heavy loads.As the name implies, the device consists of a long metal cylinder called a tunnel...
which does not have separate, distinct wash or rinse cycles, but combines them all in sequence inside a single long large-diameter rotating tube.
An industrial clothes washer can be used to batch process up to 800 pounds (140 kg) of textiles at once, and can be used for extremely machine-abusive washing tasks such as stone washing
Stone washing
Stone washing is a textile manufacturing process used to give a newly manufactured cloth garment a worn-out appearance. Stone-washing also helps to increase the softness and flexibility of otherwise stiff and rigid fabrics such as canvas and denim....
or fabric bleaching and dyeing
Dyeing
Dyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is normally done in a special solution containing dyes and particular chemical material. After dyeing, dye molecules have uncut Chemical bond with fiber molecules. The temperature and time controlling...
.
An industrial washer can be mounted on heavy shock absorbers and attached to a concrete floor so that it can extract water from even the most severely out-of-balance and heavy wash loads. It may be mounted on hydraulic cylinders, permitting the entire washer to be lifted and tilted so that fabrics can be automatically dumped from the wash drum onto a conveyor belt once the cycle is complete.
Social impact
The historically laborious process of washing clothes has at times been labelled "woman's work" and women from all classes tried to find ways to get relief from doing laundry.In 2009, L'Osservatore Romano
L'Osservatore Romano
L'Osservatore Romano is the "semi-official" newspaper of the Holy See. It covers all the Pope's public activities, publishes editorials by important churchmen, and runs official documents after being released...
published an article entitled "The Washing Machine and the Liberation of Women" that was controversially meant to demonstrate that the washing machine had done more for the liberation of woman than the contraceptive pill and abortion rights, which are often associated to Women's Day. The article shocked Italian feminists and provoked criticism from Opposition MP Paola Concia
Paola Concia
Anna Paola Concia is an Italian politician and gay rights activist. She was the first openly lesbian member of the Italian Chamber of Deputies.-Biography:...
. A study from Université de Montréal
Université de Montréal
The Université de Montréal is a public francophone research university in Montreal, Quebec, Canada. It comprises thirteen faculties, more than sixty departments and two affiliated schools: the École Polytechnique and HEC Montréal...
also presented a similar point of view to that of L'Osservatore.
Swedish statistician Hans Rosling
Hans Rosling
Hans Rosling is a Swedish medical doctor, academic, statistician and public speaker. He is Professor of International Health at Karolinska Institute and co-founder and chairman of the Gapminder Foundation, which developed the Trendalyzer software system.-Study and career:From 1967 to 1974 Rosling...
has suggested that the positive effect the washing machine had on liberation of woman, makes it "the greatest invention of the industrial revolution".
Environmental Impact
Due to the decreasing gap between the cost of repairs and the cost of purchasing a washing machine, there has been a major decline in the number of washing machines being repaired (to the detriment of the environment). The cost of having a washing machine repaired once they develop faults is often so high relative to the cost of purchasing a new one that most washing machines are scrapped because they are considered beyond economical repair. http://www.washerhelp.co.uk/buying-advice-2.htmlManufacturers and brands
- LG
- Samsung
- Indesit
- Siemens
- AEG
- Washex
- Whirlpool: including the brand names Admiral, Amana, Bauknecht, Estate, Inglis, Kenmore, Laden, Maytag, Magic Chef, Kirkland, Roper & Philips
- Zanussi
See also
- CentrifugationCentrifugationCentrifugation is a process that involves the use of the centrifugal force for the sedimentation of mixtures with a centrifuge, used in industry and in laboratory settings. More-dense components of the mixture migrate away from the axis of the centrifuge, while less-dense components of the mixture...
- Clothes dryerClothes dryerA clothes dryer or tumble dryer is a household appliance that is used to remove moisture from a load of clothing and other textiles, generally shortly after they are cleaned in a washing machine....
- Combo washer dryerCombo washer dryerA combo washer dryer is a combination of a washing machine and a clothes dryer.Combination washer dryers are popular amongst those living in smaller urban properties as they only need half the amount of space usually required for a separate washing machine and clothes dryer and do not require an...
- DetergentDetergentA detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...
- Drying cabinetDrying cabinetA drying cabinet is an electronic machine designed to expedite the drying of items - usually clothing - that are unsuitable for a traditional clothes dryer...
- Energetic efficiency
- Home applianceHome applianceHome appliances are electrical/mechanical machines which accomplish some household functions, such as cooking or cleaning. Home appliances can be classified into:*Major appliances, or White goods*Small appliances, or Brown goods...
- IroningIroningIroning is the use of a heated tool to remove wrinkles from fabric. The heating is commonly done to a temperature of 180-220 °Celsius, depending on the fabric. Ironing works by loosening the bonds between the long-chain polymer molecules in the fibers of the material...
- Laundry detergentLaundry detergentLaundry detergent, or washing powder, is a substance that is a type of detergent that is added for cleaning laundry. In common usage, "detergent" refers to mixtures of chemical compounds including alkylbenzenesulfonates, which are similar to soap but are less affected by "hard water." In most...
- Laundry symbolsLaundry symbolsA laundry symbol, also called a care symbol, is a pictogram which represents a method of washing, for example drying, dry-cleaning and ironing clothing. Such symbols are written on labels, known as care labels, attached to clothing to indicate how a particular item should best be cleaned. There are...
- Major applianceMajor applianceA major appliance, or domestic appliance, is usually defined as a large machine which accomplishes some routine housekeeping task, which includes purposes such as cooking, or food preservation, whether in a household, institutional, commercial or industrial setting...
- Silver NanoSilver NanoSilver Nano is a trademark name of an antibacterial technology which uses silver nanoparticles in washing machines, refrigerators, air conditioners, air purifiers and vacuum cleaners introduced by Samsung in April 2003....
- Tunnel washerTunnel washerA tunnel washer, also called a continuous batch washer, is an industrial laundry machine designed specifically to handle heavy loads.As the name implies, the device consists of a long metal cylinder called a tunnel...