How do washing machines 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 you'll usually go to a professional dry cleaner shop for dry cleaning, you can do wet cleaning yourself 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. Patented in 1860, the Union Washing Machine consisted of a hand-cranked device that rubbed clothes between two washboards inside a bin of boiling water and soap. Two years later came the Union Wringer patent. The wringer attached to the washing machine as a means of wringing out clothes after the machine finished washing. This design was one of many similar inventions in the 19th century that people dubbed "washing machines" long before the use of electricity [source: Van Name & Co.].

Today's washing machines work with the same principle as the originals: They loosen dirt from clothes and linens with soap and water, and then rinse and squeeze out as much water as possible. Modern washing machines, though, are almost completely automated. Electric motors have completed 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. The perforations along the drum drain water. 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 fixed tub cannot.

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 by 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 distinguishing attributes. Washing machines for industrial use, such as in hotels and hospitals, have a lot of the same features on a much larger scale.

Don't Skip Regular Washing Machine Maintenance

Though modern washing machines can last a couple of decades, some of their parts need regular maintenance. Belts and hoses often go ignored until they break, and filters — used to trap hard water minerals — go unnoticed until there's a clog. If you don't want to check these things yourself, get a trained small appliance mechanic to check them once every year or so. Also note that if the washing machine is in a garage or other unheated area, you can prevent damage from water freezing in the hoses by disconnecting and draining them when temperatures drop below freezing.

Top-loading and Front-loading Washers

While mechanical features 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 machines you might have in your home or find in a laundromat: top-loading and front-loading washers. A top-loading machine has a lid on top and an upright basket. The other type is front-loading, which has 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
iStockphoto/Thinkstock

Front-loading washing machines use paddles that extend a short way 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 you cannot open many of them again until the end. You can open the lid on a top-loading machine, though, at 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 produce energy-efficient models. Through their Energy Star program, they identify 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. Sometimes referred to as cycles, you should be able to find these described in the owner's manual. 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 that centrifugal force removes most remaining water.

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
Presoak: 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.

Fighting Germs in Your Laundry

Even if you're washing something that's safe for a washing machine, the fabric may not come clean. It may have some dirt or stain remaining that a cycle could not remove, or it may not have rinsed well, leaving detergent trapped in the fabric fibers. One big concern in laundry is killing germs. A high-temperature wash and rinse may not be enough to kill all the germs in your clothes and linens. You can kill most germs if you use one of the following: a liquid chlorine bleach with at least 5.4 percent sodium hypochlorite (Clorox, Purex), a quaternary disinfectant (Roccal, CO-OP Sanitizer), a phenolic disinfectant (Lysol, Pine-Sol) or a concentrated pine oil disinfectant that's at least 80 percent pine oil. [source: Wright]

How do washing machines get clothes clean?

Mechanics of Washing Machines

Top-loading and Front-loading Washers

Washing Machine Cycles

Lots More Information

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