Editing Washing machine (section)

==Wash cycles==
[[File:Waescheschleuder.jpg|thumb|upright|German laundry [[centrifuge]] to extract water from laundry; the advent of automatic washing machines with spin cycles made such specialized appliances largely obsolete by the 1970s.]]
The earliest washing machines simply carried out a washing action when loaded with clothes and soap, filled with hot water, and started. Over time machines became more and more automated, first with complex electromechanical controllers, then fully electronic controllers; users put clothes into the machine, select a suitable program via a switch, start the machine, and come back to remove clean and slightly damp clothes at the end of the cycle. The controller starts and stops many different processes including pumps and valves to fill and empty the drum with water, heating, and rotating at different speeds, with different combinations of settings for different fabrics.

Longer wash cycles can allow greater water and energy efficiency (with less water to heat up). For a {{Convert|3.5|kg|abbr=on}} load, from 2011 to 2021, the average Australian<!--why not others--> washing machine cycle (including rinsing and spinning) has lengthened from 99 to 144 minutes for front-loaders, and 55 to 59 minutes for top-loaders.<ref>{{Cite web |date=2021-06-23 |title=How long are washing machine cycle times? |url=https://www.choice.com.au/home-and-living/laundry-and-cleaning/washing-machines/articles/cycle-times |access-date=2022-08-13 |website=CHOICE |language=en-au}}</ref>

===Washing===
Many front-loading machines have internal electrical heating elements to heat the wash water, to near boiling if desired. The rate of the chemical cleaning action of the detergent and other laundry chemicals increases greatly with temperature, by the [[Arrhenius equation]]. Washing machines with internal heaters can use special detergents formulated to release different chemical ingredients at different temperatures, allowing different types of stains and soils to be cleaned from the clothes as the wash water is heated by the electrical heater.

However, higher-temperature washing uses more energy, and many fabrics and elastics are damaged at higher temperatures. Temperatures exceeding {{convert|40|°C}} have the undesirable effect of deactivating the [[enzyme]]s when using [[biological detergent]].

Many machines are cold-fill, connected to cold water only, which they internally heat to [[operating temperature]]. Where water can be heated more cheaply or with less [[Greenhouse gas emissions|carbon dioxide emission]] than by electricity, a cold-fill operation is inefficient.

Front-loaders need to use low-sudsing detergents because the tumbling action of the drum entrains air into the clothes load, which can cause excessive foamy suds and overflows. However, due to the efficient use of water and detergent, the suds issue with front-loaders can be controlled by simply using less detergent, without lessening the cleaning action.

===Rinsing===
Washing machines perform several rinses after the main wash to remove most of the [[detergent]]. Modern washing machines use less [[hot water]] due to [[environmental concern]]s; however, this has led to the problem of poor rinsing on many washing machines on the [[Market (economics)|market]],<ref name="whitegoodshelp1">{{cite web|url=http://www.whitegoodshelp.co.uk/wordpress/why-cant-modern-washing-machines-rinse-properly/ |title=Why can't modern washing machines rinse properly? |date=31 August 2007 |publisher=Whitegoodshelp.co.uk |access-date=2010-02-16}}</ref> which can be a problem to people who are [[Allergy|sensitive]] to detergents. The [[Allergy UK]] website suggests re-running the rinse cycle, or rerunning the entire wash cycle without [[detergent]].<ref>{{cite web |url=http://www.allergyuk.org/fs_handyhints.aspx |title=Allergy Tips and Advice for Household Cleaning |publisher=Allergyuk.org |access-date=2010-02-16 |archive-url=https://web.archive.org/web/20100613062143/http://allergyuk.org/fs_handyhints.aspx |archive-date=2010-06-13 |url-status=dead }}</ref>

In response to complaints, many washing machines allow the user to select additional rinse cycles, at the expense of higher [[water usage]] and longer cycle time. Bosch, for example, in its allergy wash program, incorporates an additional three-minute rinse cycle with water of at least {{convert|60|C}} to rinse off detergent residues and any allergens.<ref>{{cite web |last1=Sudeep |first1=Anamika |title=Get To Know Your Washer Dryer Settings |url=https://www.bosch-home.in/experience-bosch/living-with-bosch/fresh-reads/getting-to-know-your-washer-dryer-settings |website=Bosch |publisher=Anamika Sudeep |access-date=24 July 2020}}</ref>

===Spin===
Front-loading machines spin in multiple stages of their cycle: after main wash, after individual rinses, and the final high-speed spin. Some of those spins may be absent depending on the particular cycle.

Higher spin speeds, along with larger tub diameters, remove more water, leading to faster drying. On the other hand, the need for [[ironing]] can be reduced by not using the spin cycle in the washing machine.

If a heated [[clothes dryer]] is used after the wash and spin, energy use is reduced if more water has been removed from clothes. However, faster spinning can crease clothes more. Also, mechanical wear on bearings increases rapidly with rotational speed, reducing life. Early machines would spin at 300 RPM and, because of lack of any mechanical suspension, would often shake and vibrate.

In 1976, most front-loading washing machines spun at around 700&nbsp;RPM, or less.{{citation needed|date=October 2015}} Today, most machines spin at 1000–1600&nbsp;RPM. Most machines have variable speeds, ranging 300–2000&nbsp;RPM depending on the machine.

Separate spin dryers, without washing functionality, are available for specialized applications. For example, a small high-speed [[centrifuge]] machine may be provided in [[locker room]]s of communal [[swimming pool]]s to allow wet [[swimsuit]]s to be substantially dried to a slightly damp condition after daily use.

Washing machines often incorporate balance rings filled with a liquid such as a [[calcium chloride]] salt water solution,<ref>{{cite web | url=https://patents.google.com/patent/US9518352B2/en | title=Unitary balance ring for a washing machine appliance }}</ref> that are designed to balance the inner drum of the washer during spin cycles.<ref>{{Cite web|url=https://asmedigitalcollection.asme.org/ESDA/proceedings-abstract/ESDA2010/49194/321/346118|title=Experimental and Analytical Investigation on a Liquid Balance Ring for Automatic Washing Machines &#124; ESDA &#124; ASME Digital Collection|date=28 December 2010 |pages=321–330 |doi=10.1115/ESDA2010-24902 }}</ref><ref>{{Cite web|url=https://patents.google.com/patent/US9695538B2/en|title=Balance ring and fastener guide for a washing machine}}</ref> The balance ring may be filled with oil and contain balls on races, somewhat similarly to a ball bearing, to achieve the same effect.<ref>{{Cite web|url=https://patents.google.com/patent/US8156592B2/en?q=(Washing+machine+ball+balancers)&oq=Washing+machine+having+ball+balancers|title=Washing machine and method of controlling the same}}</ref><ref>{{Cite web|url=https://www.freepatentsonline.com/y2008/0110212.html|title=Washing machine having ball balancers}}</ref> The Bendix Economat used a flexible rubber inner tub that would squeeze the clothes towards the agitator located in the center of the inner tub in order to remove water from the clothes, instead of spinning the inner tub. This was performed by exerting a vacuum on the inner tub.<ref>{{Cite web|url=https://books.google.com/books?id=AFMEAAAAMBAJ&dq=Bendix+Economat&pg=PA5|title=LIFE|date=March 20, 1950|publisher=Time Inc|via=Google Books}}</ref><ref>{{Cite web|url=https://cdnc.ucr.edu/?a=d&d=OT19490725.1.12&e=-------en--20--1--txt-txIN--------|title=Oakland Tribune 25 July 1949 — California Digital Newspaper Collection|website=cdnc.ucr.edu}}</ref>

===Maintenance wash===
Many home washing machines use a plastic, rather than metal, outer shell to contain the wash water; residue can build up on the plastic tub over time. Some manufacturers advise users to perform a regular maintenance or "freshening" wash to clean the inside of the washing machine of any [[Mold (fungus)|mold]], [[bacteria]], encrusted detergent, and unspecified dirt more effectively than with a normal wash.{{citation needed|date=December 2019}}

A maintenance wash is performed without any laundry, on the hottest wash program,<ref>{{cite web |url=http://www.washerhelp.co.uk/usage_2.html |title=Washing machine usage (part 2) |publisher=Washerhelp.co.uk |access-date=2010-02-16}}</ref> adding substances such as [[white vinegar]], 100 grams of [[citric acid]], a detergent with bleaching properties, or a proprietary washing machine cleaner. The first injection of water goes into the sump<ref>{{cite web|url=http://www.washerhelp.co.uk/diy-repair-help_4.html |title=DIY washing machine repairs (Part 4) |publisher=Washerhelp.co.uk |access-date=2010-02-16}}</ref> so the machine can be allowed to fill for about 30 seconds before adding cleaning substances.