How do washing machines get clothes clean?

Today's washing machines automate just about anything you need to do to your laundry, but how do they actually get clothes clean?
Today's washing machines automate just about anything you need to do to your laundry, but how do they actually get clothes clean?

One of the first things people notice about you is what you're wearing. This doesn't just mean the style and fit of your clothes, but also how clean and new, or dirty and worn those clothes are. Because our clothes are so important to us, we put a lot of energy into keeping them clean.

The most common way we clean our clothes and linens is wet cleaning, or the use of water and some type of soap. In contrast, dry cleaning uses chemicals or ultrasonic devices to loosen and remove dirt and stains without water. While dry cleaning is usually done at professional dry cleaners' shops, wet cleaning is usually done at home or at a self-service laundromat. The washing machine itself has become a major part of setting up a home, and doing laundry is probably part of a regular routine for you and your family.


We've come a long way in automating the chore of doing laundry. The Union Washing Machine was patented in 1860 and consisted of a hand-cranked device that rubbed clothes between two washboards inside a bin of boiling water and soap. The Union Wringer was patented two years later and attached to the washing machine as a means of wringing out clothes when they were finished washing. This design was one of many similar inventions in the 19th century that were dubbed "washing machines" long before they even used electricity [source: Van Name & Co.]

Today's washing machines work with the same principle as these original washing machines: Loosen dirt from clothes and linens with soap and water, rinse and squeeze out as much water as possible. Modern washing machines, though, are almost completely automated. They've had electric motors doing the hard work since the early 20th century, and there's a good chance you've never used a washing machine without a built-in spin cycle.

So what are washing machines actually doing to get the laundry clean? This article answers that question, including the basic mechanics behind modern machines, the various cycles the machine uses to clean clothes, and the important differences between top-loading, front-loading and high-efficiency washers.


Mechanics of Washing Machines

The first thing you see when you open the lid or door to your washing machine is a large drum. The inner part of the drum that you see is often called the basket, and is perforated for water to drain. The outer part of the drum that you can't see is the tub, a solid compartment surrounding the basket that keeps water in or allows it to drain out. The basket can move, but the tub is fixed.

Hoses and pumps move water through the washing machine. When you install the washing machine, you hook hoses up to both hot and cold running water. Another hose takes wastewater that drains from the machine and sends it to a sewer drain pipe. You'll find hot and cold water spigots and a drain pipe ready to use in just about any modern laundry room.


An electric motor in the washing machine moves the basket. If you pick up the repair guide for a washing machine, you'll find detailed terminology and phrases similar to those found in the shop manual for your car. You'll see parts mentioned including belts, hoses, clutch, transmission and even brakes. The motor knows what to do based on the wash program you choose from the buttons and dials on the machine. A combination of digital and mechanical parts carries out that program.

Dispensers let you add detergent, bleach and fabric softener before you start the washing machine so the machine can dispense each of them automatically at the right time. Using dispensers ensures that the detergent mixes thoroughly with the water. Plus, automated dispensers keep clothes from getting spotted from a concentrated splash of bleach or fabric softener.

Washing machines for your home fall into two categories: top-loading and front-loading. They each share the common parts described here, but they have some important differences described on the next page. Washing machines for industrial use, such as in hotels and hospitals, have a lot of the same features on a much larger scale.

Top-loading and Front-loading Washers

A top-loading washing machine showing the agitator in action
A top-loading washing machine showing the agitator in action

While the mechanical features mentioned earlier in this article are common to almost all washing machines, not all washing machines wash your clothes in the same way. There are two main types of washing machine you might have in your home or find in a laundromat. One type is top-loading with a lid on top and an upright basket. The other type is front-loading with a door on the front and a sideways-mounted basket. There are benefits and drawbacks to both types.

Top-loading washing machines use an agitator to move clothes around the basket. The agitator is a vertical device in the center of the basket with ridges that help push the clothes. The agitator alternates directions on that vertical axis. This movement creates the friction the top-loading machine needs to loosen dirt from fabrics. Some washers also have a fabric-softener dispenser mounted on the top of the agitator.


A front-loading washing machine, empty, with one of the paddles visible
A front-loading washing machine, empty, with one of the paddles visible

Front-loading washing machines use paddles that extend a short ways from the sides of the basket inward toward the center. The paddles help move the clothes and stir the water while the basket turns. Like the agitator in top-loading machines, the paddles loosen dirt from fabrics by creating friction.

High-efficiency front-loading washing machines are growing in popularity because of their low environmental impact. This is because they use less water and detergent to clean the same amount of clothes as the top-loading machine. One disadvantage they have, though, is that they seal and lock at the beginning of the wash program and can't be opened again until the end. The lid on a top-loading machine, though, can be opened any time you need to check the load or add something.

The U.S. Environmental Protection Agency and the U.S. Department of Energy have put pressure on appliance manufacturers to product energy-efficient models. The pressure comes from their Energy Star program, which identifies products that meet a target level of efficiency. Most high-efficiency washing machines are front loaders. Manufacturers recommend only using detergents designed for high-efficiency washing machines because they don't fill the washer with excessive suds.

Washing Machine Cycles

A washing machine has one or more programs from which you can choose. You should be able to find these described in the owner's manual, and they may be referred to as cycles. Each program is a sequence of stages with varied times, speeds and temperatures. Each stage may also be called a cycle. For this article, we'll define cycle to mean the individual stages and use the word program to mean some combination of those stages.

The following are descriptions of the cycles you might use on your washing machine:


  • Wash -- Fill the machine to a certain water level, dispense any chemicals from dispensers, agitate the load for a certain amount of time and drain the water
  • Rinse -- Fill the machine to a certain water level, agitate the load for a certain amount of time and drain the water
  • Spin -- Spin the basket rapidly for a certain amount of time with the drain open so most remaining water is removed by the centrifugal force

These cycles make up parts the following common programs, identified here by what makes them unique:

  • Cotton, linen or normal -- Higher spin speeds and average cycle lengths
  • Permanent press, casual -- Average or slightly slower spin speeds
  • Colors -- Cold wash and rinse temperatures
  • Quick or speed wash -- Hot water and less time in the wash cycle
  • Delicates, hand-wash, wool -- Cold water wash and rinse, plus spin slower or not at all
  • Pre-soak -- Pause for a certain time during the wash cycle between filling the machine with water and starting agitation
  • Bulky or heavy -- Slower spin cycle
  • Sanitize -- Hottest water available during the wash cycle

Depending on your washing machine, you may be able to control certain program details like water level and temperature manually. Many high-end washing machines also use sensors to automatically adjust the water level, cycle length and spin speed based on the size and bulk of the load. Use your owner's manual to find all your program and cycle options.

Take a spin over to the next page for loads more about how washing machines get clothes clean.

Lots More Information

Related Articles

  • Campbell, Edward A. "How to Repair Washing Machines, Clothes Dryers, Refrigerators, Vacuum Cleaners, Fans, Mixers, Toasters and Other Home Appliances." Fawcett Publications. New York, New York. 1957. pp. 59-121.
  • Consumer Energy Center. "Clothes Washers." California Energy Commission. 2010. (Sept. 26, 2010)
  • Energy Star. "How a Product Earns the ENERGY STAR Label." U.S. Environmental Protection Agency and U.S. Department of Energy. (Sept. 26, 2010)
  • "Owner's Manual, Washing Machine, WM2487H*M." LG Electronics. pp. 13-19.
  • Van Name & Co. "Household blessings! … The Celebrated Patent Union Washing Machine. And Clothes Wringer Combined. ..." Advertisement from 1863. American Antiquarian Society and NewsBank, Inc. 2005. (Sept. 26, 2010)
  • Webb, Pauline, and Suggit, Mark. "Gadgets and Necessities: An Encyclopedia of Household Innovations." ABC-CLIO. 2000. pp. 306-310.
  • Whirlpool. "Cabrio, Automatic Washer, Use & Care Guide." Whirlpool Corporation. 2006. pp. 11-18.
  • Whirlpool. "Why is HE High Efficiency detergent the only type of detergent to use in my washer?" Whirlpool Corporation. 2007. (Sept. 26, 2010)
  • Wright, Susan. "Getting Clothes Clean." College of Agriculture, Consumer and Environmental Sciences, New Mexico State University. 2001. (Sept. 26, 2010)