TYPES OF SOIL

There are three basic types of soil:

• WATER-SOLUBLE SOILS often consist of body fluids, salts, or sugars and are best removed by water.
  

• SOLVENT-SOLUBLE SOILS are oils and greases, including natural oils secreted by the body, that dissolve readily in solvents and are best removed by dry-cleaning.
  

• INSOLUBLE SOILS do not readily dissolve in either water or solvent and are normally removed by mechanical action and flushed away from the fabric.

Laundering and wet cleaning processes can be modified to remove some solvent-soluble soils with the addition of detergents or soaps.  Detergents used for laundering are normally formulated with mild caustic materials.  Because only milder detergents can be used in wet-cleaning, the process is somewhat limited in its ability to remove oils.  Similarly, dry-cleaning solvents can be enhanced with the addition of detergents to remove water-soluble soils.  The degree of removal is dependent on the detergent used and the careful control of moisture during the cleaning process.