Dry cleaning is the cleansing of a textile utilizing an organic solvent as opposed to water. The development of dry cleaning is predicated on the fact that as a solvent, water is ineffective in the removal of non-water soluble soils. These soils are primarily oilbased stains such as paint, grease, wax, tar, and body oils.
Early attempts at "dry cleaning" were uncovered within the ruins of Pompeii. Evidence suggests that clothing tradesmen used fuller's earth to absorb soils and grease from garments. Until the end of the seventeenth century, absorption by the means of fuller's earth, or (in later centuries) paper and a hot iron, were the only methods available for the removal of oily stains.
The first use of an organic solvent as a spot-removing agent occurred in Western Europe during the 1680s. Oil of turpentine is a by-product derived from the distillation of turpentine (pine pitch). Used in medicines and for the making of varnish, oil of turpentine was discovered to also be an effective solvent for removing grease stains from fabric. Fabric processors known as dyers and scourers began utilizing this new solvent to supplement the washing process.
Early Dry Solvents
By the early nineteenth century, two solvents-camphene (a mixture of oil of turpentine and naphtha) and benzine, a petroleum distillate-had replaced oil of turpentine for use in clothing care. Camphene, primarily sold as illuminating oil, was employed in an immersion bath process for cleansing satin goods, silk dresses, fancy waistcoats, and lace. Another major benefit derived from cleaning natural fibers in dry solvents had been realized.
Dry solvents are liquids that do not wet or swell textile fibers. The cleaning mechanisms of dry solvents are thus different from water, in which wetting and swelling play a significant role. In natural fibers (silk, wool, cotton, and linen), this swelling can lead to shrinkage, distortion, finish loss, or dye bleeding. Cleaning with dry solvents is a gentler process that requires less finishing, thus prolonging the life and feel of the textile.
There were two problems associated with the use of these early solvents. The solvents were extremely flammable, having flashpoints around 70° F. (21° C.), and a strong odor remained in the clothes without proper drying.
Commercial Dry Cleaning
Commercial dry cleaning was first practiced in the Jolly Belin Dye Works in Paris in 1825. William Spindler of Berlin visited the Jolly Works in 1854 and brought the process to Germany. James Pullar, Spindler's son-in-law, introduced commercial cleaning to Scotland.
Innovations in the 20th Century
At the beginning of the twentieth century, mechanized improvements such as rotating cleaning drums, hydro extractors, solvent purification systems, and the first dry solvent soap increased both the safety and effectiveness of the dry-cleaning process. The solvent of choice was gasoline.
Modern dry cleaning was ushered in with the development of two new solvents. In 1926 came Stoddard solvent, a petroleum-based hydrocarbon with a flashpoint of 100° F. (38° C.), and in 1932, nonflammable perchloroethylene, or perc, was introduced. Equipment advances derived from the electric motor and pneumatics allowed for controlled rotation of the cleaning drum and high-speed solvent extraction. The steam boiler enabled controlled drying, utilizing moist heat as well as providing steam for the finishing irons and presses.
Safe Dry Cleaning
In the late 1980s, perchloroethylene was designated a possible carcinogen, and stricter controls monitoring usage were imposed. This led to the development of several alternative solvents: the silicone-based Green Earth process, liquid carbon dioxide, and synthetic hydrocarbons with flashpoints exceeding 145° F. (63° C.). These solvents are considerably less aggressive, meaning they have less degreasing power than perchloroethylene. The benefit is that they can safely clean any material from feathers to a heavily beaded gown. With proper application, the equipment and solvent options available in the early 2000s can effectively clean any fabric or design element used in the realization of haute couture fashions.
See also Laundry.
Cambridge, E. M. "Benzene and Turpentine: The Pre-History of Dry-cleaning." Ambix 38 (2) (July 1991).
International Fabricare Institute. Dry Cleaning Fundamentals. Silver Spring, Md.: IFI, 2003.
Textile Conservation Center. "Dry-cleaning I: Solvents." Technical Bibliographies. North Andover, Mass.: Museum of American Textile History.