Dry cleaning and water washing have a lot in common. They both involve putting clothes in a drum of liquid and swishing it around for a while, then draining them and putting them into another drum and tumbling them in hot air.
Why do some clothes require the liquid to be something other than soapy water?
Bonus round: Clothes that I get dry cleaned come back with a much better press than the clothes I wash and iron at home. Is that related to the cleaning process, or do they just have more sophisticated presses than my iron?
I can only answer the bonus question, but yes, they do have much more sophisticated presses at a dry cleaners (including one that appears kind of like an inflatable manikin). Also, they press hundreds of items each day, every day. With that volume, you’re going to learn a few techniques and develop a few tools the normal person wouldn’t have.
We had a recent GQ thread on how creasing/wrinkling of fabric works, and that’s related to your question.
Some clothes can’t be washed in water because the bonds between fibers that break when exposed to water get permanently messed up, and the garment shrinks or loses its “hand”.
However, some garments that say “dry clean only” are actually made of fibers that CAN be washed, if you wash them properly.
“Dry clean only” is sometimes a necessary restriction and sometimes just code for “our customers are clueless about proper fabric care and this garment can be damaged if they screw it up, so we’ll tell them to let the professionals deal with it”.
As for the ironing, yes, dry cleaners press garments before returning them. They have fancier equipment than you do and they’re also more skilled and experienced.
I’m not a dry cleaner but my understanding is that many common stains are oil-based so they don’t dissolve all that well in water. But the liquids used in dry cleaning are also oil-based so they dissolve these stains easily.
The ability to dissolve oils is the whole purpose of soap!
Anyway, AFAIK dry cleaning fluids – typically tetrachloroethene (I think the same stuff that’s also called perchlorethylene) are chlorocarbons and not hydrocarbons. They’re volatile liquids somewhat like alcohol that can clean and then evaporate at low temperatures.
I agree about the pressing! Sometimes the only reason I take stuff to dry cleaners is to get shirts and pants neatly pressed!
You might want to ask if you can bring clean shirts and pants in, anad just pay to get them pressed. My sister-in-law hates ironing, so she washes shirts at home and gets them pressed at a cleaners. The cost is less than having them washed, and she doesn’t have to iron. Win-win.
Some things are water soluble. Some things are oil-soluble. A lot of stains are more of the latter than the former.
The whole thing was discovered when some french dude accidentally knocked over a lamp and watched the kerosene remove the wine stain on the tablecloth. It’s gone from there ever since then. You can even do it yourself if you don’t have dry cleaning services around you; I remember a story a while ago about a runner in some poor(er) Caribbean country who got burned when washing her clothes in kerosene. She heated up the kerosene in a bucket over a fire, which was her mistake. It helps if the sovent is warm, of course, but her choice of heating set up was kinda dumb, since kerosene is flammable.
Dry cleaning is also way gentler on natural fabrics. Obviously, natural things react to water, and all the fibers and molecules absorb water and stretch out, and then like shrink too much when heat dried, something like that. So water washing with subsequent dryer drying can mess with delicate fabrics. Dry cleaning is a good substitute. Of course the companies put “dry clean only” on the tags to be on the safe side. Normally I’d say it’s a liability thing, but I don’t think “You made me ruin my clothes!” is a tort, but I mean let’s face it in general in America business always leans to the safe side/the the-customer-is-dumb side.
