Wet Soiling of Cotton

Abstract

The goal of this investigation was to determine the relation between the surface energy of cotton finishes, their tendency to become soiled, and the case with which soil is removed from them. The surface energy of finishing materials was characterized by wetting measurements. The critical surface tension for wetting of finishing agents and of the corresponding finished fabrics was determined. The critical surface tension for wetting by organic liquids of these same materials immersed in water was also determined. Cellulose has a high critical surface tension for wetting in air (high surface energy), but it has an extremely low critical surface tension for wetting in water. Due to this low 'surface energy in water, cellulose has a high resistance to wet soiling by hydro phobic soils. Similarly, hydrophobic soils are relatively easily removed from cotton. Silicone and fluorocarbon finishes have low surface energy in air but form high-energy surfaces in water. This leads to a strong tendency for these finishes to become con taminated in water by hydrophobic soils and, correspondingly, these soils are difficult to remove by laundering.