How Home Dry Cleaning Works

If you have ever done laundry, you've probably run across at least one article of clothing with the label "Dry Clean Only." These clothes are made of fabrics that can't just be tossed into a washing machine with water and detergent.

What's so special about fabrics like rayon, silk, and wool blends? Well, these materials may shrink, change colors or lose their shape if washed in water. Garments made of rayon become rumpled and misshapen because water is attracted to the hydrophilic fibers in this fabric. When submerged in water, the fibers expand because water molecules form hydrogen bonds with individual molecules within each fiber. The water molecules also interfere with weak attractions between adjacent fibers, and the fabric as a whole can lose its strength. In order to avoid ruining your favorite shirt, you'll have to resort to other means of cleaning it -- namely, dry cleaning.

If you've read How Dry Cleaning Works, you know that dry cleaning removes dirt and other stains from clothes without using water. Despite its name, commercial dry cleaning is not actually a "dry" process. Clothes are immersed in a solvent, usually perchlorethylene (perc), instead of in water. These solvents are especially good at removing oil- and grease-based stains, but they have some drawbacks. For instance, the solvents used can make you sick if you're exposed to them constantly. This primarily affects the workers who actually run the dry cleaning machines -- almost all of the perc is removed from your clothing before it is returned to you. However, some people find the remaining traces of the solvent in their clothes to be very irritating to the eyes, nose and throat.

In the past, your only choice was to go to a commercial dry cleaner. Now, you have the option of cleaning dry-clean-only clothes without leaving your home. Several home dry cleaning kits now on the market let you launder these delicate garments using your clothes dryer. In this article, we will explore how home dry cleaning works and whether this method is a good option for you and your delicates.

Home Dry Cleaning Kits

There are three home dry cleaning kits currently available for purchase in most grocery and discount stores:

Custom Cleaner (from Dial)
FreshCare (from Clorox)
Dryel (from Procter & Gamble)

All of these kits promise to clean and/or freshen dry-clean-only or hand-wash-only fabrics without using any of the industrial solvents used by dry cleaners. The basic steps involved in these kits mirror those of commercial dry cleaning, sans immersion in a solvent and specialized machinery:

Pre-treat clothing to remove stains.
Dry clean clothing.
Iron and reshape clothing and make repairs if necessary.

Kit Components

Each of these home dry cleaning kits contains the same components:

Stain remover and/or stain absorbing pads
Dryer activated cloth
Reusable dryer bag

We will explore each of these components and their uses in detail in the next sections.

Pre-treating the Stain

All of the kits advise you to pre-treat or remove stains using the stain remover included. There is nothing particularly special about the stain remover in these kits. It is the same kind that you use to pre-treat stains before regular machine washing, and the pre-treatment process works the same way as well. Most stain removers are simply a cleaning agent in a water-based solution.

The general rule for stain removal is that "like dissolves like." The water in the solution dissolves water-based stains, such as soup. The cleaning agent used is either a detergent or a petroleum-based solvent (depending on which brand you choose). Although the petroleum-based solvents work far better, both detergents and solvents aid in the removal of greasy stains. The informational brochure that accompanies home dry cleaning kits does not specify which of these agents is used in their pre-treatment solutions, and it turns out that the identity of the cleaning agent in the kits is proprietary information. However, given the kits' poor reputation for completely removing greasy stains like butter, it's probably safe to assume that they use detergents rather than oil-based solvents.

The cleaning agent has a number of other important functions, including:

Reducing surface tension to help water penetrate fabrics -- in order to remove a stain, water must be able to reach the molecules of dirt on and in the fibers.
Loosening and dispersing dirt molecules in the water -- if the dirt isn't dissolved in water or another solvent, or somehow separated from the fabric, it will simply redeposit on the surface of your clothes.

The Dryel and FreshCare kits provide the stain removal solution in a bottle, along with absorbent pads that you use to sop up the dirt after you apply the solution. The process works as follows:

You place the tip of the bottle on the stain, with the absorbent pad underneath on the other side of the fabric.
You gently rub the stain while applying solution.
The soil and grease is liberated from the fabric and dissolved in solution with assistance from the cleaning agent.
The dirt is pushed through the fibers by the pressure you're applying.
The absorbent pad captures the dissolved dirt.

Perhaps it seems odd that a water-based stain remover can be used on dry-clean-only clothes without damaging them. But because you only apply a small amount of solution to a discrete area, you don't add enough water to disrupt the structure of the fibers globally or weaken the fabric, and then you remove most of the water when you blot the fabric with the absorbent pad.

Some product reviews note that the Custom Cleaner kit doesn't remove stains as well as the others, even though it uses a similar cleaning agent. This may be due to the fact that the detergent is not provided in a water-based solution. With Custom Cleaner, the dryer-activated cloth itself is laced with the stain remover, and you provide your own absorbent pad in the form of a clean paper towel. These dryer-activated cloths contain only a trace amount of water. While too much water can damage a dry-clean-only fabric, too little makes it difficult to thoroughly remove all of a water-based stain.

All of the home dry cleaning kits are incapable of removing large stains. Whether water-based or oil-based, large stains must be thoroughly saturated with the proper solvent to attract and remove all the molecules of grime, especially the ones embedded deep within a fabric. Even machine-washable clothes sometimes require special efforts beyond what you can reasonably do at home. For example, grease stains on synthetic fibers, such as acrylic, nylon, olefin, polyester and blends of these fibers are particularly hard to remove. Many of these fibers are specially made to resist penetration by water. Because they repel water, they attract other molecules, such as fats, that also repel water. This makes greasy stains on these fabrics nearly impossible to remove with water and/or water-based detergents alone.

The precautions for pre-treating clothes before machine washing also apply when using these kits:

Don't rub the fabric harshly while applying the stain remover. Most dry-clean-only fabrics are not tough and durable, so rough treatment can damage them.
Don't treat suede, velvet, fur or leather -- and don't try to home dry clean them, for that matter. These fabrics must go to a professional dry cleaner!
Test the stain remover on a small, hidden area of the clothing before applying it to a stain. You don't want to create another problem by destroying the color or finish of the fabric.

Inside Your Dryer

What actually happens inside your dryer is the "black box" of this process for most people. All three kits instruct you to place one to four articles of clothing inside their respective "special" dry cleaning bag. Then, you add the dryer-activated cloths, seal the bag and put it in the dryer for 15 to 30 minutes (depending on which kit you're using). At the end, you remove your newly home-dry-cleaned clothes.

So what's really going on inside that bag? It's actually an incredibly simple system, involving only steam, perfume and an emulsifier.

Here's how it works:

The dryer-activated cloth holds a small amount of water, as well as perfume and an emulsifying agent. This emulsifying agent keeps the water and perfume dispersed within the cloth. When you turn on the dryer, the heat generated raises the temperature of the liquids inside the cloth. This increase in thermal energy allows the molecules to bounce around more rapidly than usual. When the molecules reach a high enough temperature, they overcome their attraction to one another and leave the surface of the liquid. The molecules form a dense, high-pressure gas (steam/vapors).
The vapors are contained within the nylon or plastic bag. When the vapors penetrate the fibers of the clothing, some of the water and perfume condenses within the fabric. This is the secret behind how these kits "freshen" your clothing; they simply infuse it with a fragrance! If you are allergic to perfumes or the kinds of fragrances that manufacturers typically put in cleaning products, you may want to avoid these kits. Clothes cleaned with them smell strongly of the scents used, even weeks after cleaning.
The same steam vapors are used to remove wrinkles from the clothes. The kits operate under the same principle as steam irons. When you press clothes on an ironing board, the steam carries its heat through the fabric. The combination of the water molecules and the heat temporarily breaks weak attractions between the fibers. This unlocks the fibers from the wrinkled state they have been in, and you can then press the fabric flat with the iron. The kits are slightly different, because you don't have the weight and additional heat of the iron to press wrinkles out. The home dry cleaning kits rely on gravity to help wrinkles "fall out" from your clothes once you've removed them from the dryer and hung them up. This is why the kits emphasize getting your garments out of the dryer as soon as it clicks off. Outside the dryer, the clothes quickly cool down, and the fibers become less pliant. So, given the limited window of opportunity for gravity to do its job while clothes are still hot, clothing that is heavily wrinkled will most likely still be wrinkled after home dry cleaning. The FreshCare kit even advises you to launder dress shirts professionally, given their propensity to wrinkle.

Finishing Touches

Your dryer cycle has finished, and you've hung your still-warm clothes up to make the wrinkles fall out. What happens next?

Just like a professional dry cleaner, you now have to inspect your clothes to see how well they turned out. There are several things to look for and try to correct. They include:

Wrinkles - A professional cleaner will steam press your clothes if they are misshapen following their solvent bath. If you find wrinkles after home dry cleaning, you'll need to iron them yourself.
Loose buttons and ripped seams - You may need to fix any buttons that are in danger of falling off, or fix any seams where the thread has unraveled.
Remaining stains - Professional cleaners will do post spotting to try to get rid of any stains that remain after cleaning. Your options are to either clean them again with the kit or take them to a professional dry cleaner.

Common Questions About The Home Dry Cleaning Process

Why don't delicate fabrics just shrink in the dryer? First, the nylon or plastic bag protects the clothes from the harsh, dry heat generated by the dryer. Because of this, any bag with a hole in it can't be used anymore. Also, a ripped bag will allow the steam vapors to escape, ruining the entire cleaning process. The steam itself is not damaging because, as in steam ironing, its temperature is just below that needed to melt or shrink most synthetic fibers. However, you aren't supposed to use the kits to clean leather, velvet, suede or fur, because these fabrics can be damaged by steam.
Why doesn't the bag blow up from the gas pressure? The bag is sealed using Velcro strips that line its opening. This is not a tight seal; it leaves tiny spaces through which steam can be vented. The majority of the vapors are retained within the bag; but enough is let out to keep gas pressure from building up too high.
What about the dirt and grime you can't see? This is one of the major drawbacks to the home dry cleaning kits. The commercial dry cleaning process bathes your clothes in a large quantity of solvent that strips stains, especially greasy ones, from the fabric. With home dry cleaning, dirt removal is mainly limited to the pre-treatment stage, when you treat visible stains. Home dry cleaning kits don't address things like sweat or other body oils picked up into the clothing with everyday wear. Also, they do not remove lint or things like pet hair that can build up on the surface of your clothing. These kits can't really replace commercial dry cleaning; the Dryel kit notes that it is designed as a complement to professional dry cleaning.

Advantages and Disadvantages

The final wrinkle-removing step, in addition to the time you spend pre-treating clothes and waiting for the dryer cycle to end, make home dry cleaning a pretty time-consuming endeavor! This is one benefit of professional dry cleaning -- all the hard work is done for you.

However, if money is a concern, you might help your budget by using the kits. With home dry cleaning, you can clean 16 garments for about what you'd pay for one garment to be professionally dry cleaned. As long as you're not trying to remove large, set-in or greasy stains, these kits can be used to freshen garments and stretch the time between visits to the cleaner. You have to weigh the money you could save using the kits against the time you'll lose actually doing your dry cleaning at home.

One big plus of home kits is that they do prevent you from being exposed to the solvent, perchlorethylene, used by commercial cleaners. This does make them a good alternative for people with chemical sensitivities (not including perfume) or those who are looking for a process that's less harmful to the environment. Perchlorethylene can damage your liver, kidneys and brain, and is a contaminant in up to 25 percent of the U.S. water supply. The chemicals used in home dry cleaning don't accumulate in the environment, and, compared to perchlorethylene, they are fairly safe.

In the end, home dry cleaning kits don't represent a major step forward in cleaning technology. The kits simply take advantage of some pretty basic chemistry (the generation of steam from water, for example). Whether you choose to use them or not depends on the relative importance of their advantages and disadvantages to you.