Chemistry in Everyday Life (Dry cleaning)

Dry cleaning is any cleaning process for clothing and textiles using an organic solvent rather than water. The solvent used is typically tetrachloroethylene (perchloroethylene), abbreviated "perc" in the industry and "dry-cleaning fluid" by the public. Dry cleaning is necessary for cleaning items which would otherwise be damaged by water and soap or detergent. It may be used ifhand washingneeded for some delicate fabrics - is excessively laborious.
Solvents used:
Modern
- Glycol ethers (dipropylene glycol tertiary-butyl ether) (Rynex) - In many cases more effective than perchloroethylene (perc) and in all cases more environmentally friendly.
- Hydrocarbon - This is most like standard dry cleaning, but the processes use hydrocarbon solvents such as Exxon-Mobil's DF-2000 or Chevron Phillips' EcoSolv. These petroleum-based solvents are less aggressive than perc and require a longer cleaning cycle.
- Liquid silicone (decamethylcyclopentasiloxane or D5) - gentler on garments than Perc and does not cause color loss.
- Modified hydrocarbon blends (Pure Dry)
- Perchloroethylene - In use since the 1940s, perc is the most common solvent, the "standard" for cleaning performance, and most aggressive cleaner. It can cause color bleeding/loss, especially at higher temperatures, and may destroy special trims, buttons, and beads on some garments. Better for oil-based stains (which account for about 10% of stains) than more common water-soluble stains-(coffee, wine, blood, etc). Known for leaving a characteristic chemical smell on garments. Nonflammable.
- Liquid CO2 - superior to conventional methods, but the Drycleaning and Laundry Institute commented on its "fairly low cleaning ability" in a 2007 report .
- Wet cleaning - Not a solvent, but a system that uses water and biodegradable soap. Computer-controlled dryers and stretching machines ensure that the fabric retains its natural size and shape. Wet cleaning is claimed to clean a majority of "dry clean only" garments safely, including leather, suede, most tailored woolens, silk and rayon. (Neckties seem to be the one exception.)
Historical
- Carbon tetrachloride - Toxic and corrosive.
- Trichloroethane - Overly aggressive and harsh.
- Stoddard solvent - Very flammable and explosive .
- CFC-I13 - Freon - Ozone destroying CFC.