The Laundry Industry is made up of laundry detergents and soap. The need for laundry detergents is increasing and the need to produce laundry detergents in a responsible manner to the environment is of paramount importance.
Soap cleans because each soap molecule consists of a hydrocarbon chain and a carboxylic group (fatty acids) that perform two important functions. The carboxylate end of the soap molecule is hydrophilic, meaning that it is attracted to water, while the hydrocarbon end of the molecule is hydrophobic (repelled by water) and attracted to the oil and grease in dirt. While the hydrophobic end of a soap molecule attaches itself to dirt, the hydrophilic end attaches itself to water. The dirt attached to the carboxylate end of the molecule is chemically dragged away from the clothes being cleaned and into the wash water. Properly agitating and rinsing the clothes improve the cleaning process When these chemicals react with soap, they form an insoluble curd called a precipitate. Difficult to rinse out, the precipitate leaves visible deposits on clothing and makes fabric feel stiff. Even water that is not especially hard will eventually produce precipitates over a period of time.
Laundry detergent is a synthetic combination that functions much like a traditional soap, but with significant improvements. Unlike soap, a detergent when formulated correctly can be effective in hard water. The hydrocarbons used in soap generally come from plants or animals, but those used in detergent can be derived from crude oil. Adding sulfuric acid to the processed hydrocarbon produces a molecule similar to the fatty acids in soap. The addition of an alkali to the mixture creates a surfactant molecule that will not bond with the minerals in hard water, thus avoiding the accumulation of precipitates.