Effect of Laundering and Starching on Insulation and Vapor Permeability of Standard Fatigues

Abstract

An electrically heated copper manikin with a wettable "skin" has been used to assess the effect of laundering and starching on the insulating value and evaporative heat transfer characteristics of a new, unused U. S. Army fatigue uniform. Except for small changes attributable to shrinkage of the clothing items, machine washing with detergents or commercial laundering with soap, followed by medium heavy starching and pressing, had no effect on the insulation value or moisture permeability index of the uniform. The effect of starching and pressing was also studied on volunteer subjects performing a rest-walk-rest routine in a hot humid environment. Based on body heat storage during the period, heat stress was unaffected by starching the uniform. This study, which included three other types of uniforms, also provided evidence that the level of heat stress in a given uniform is directly related with the ratio of the permeability index to the insulating value for the uniform as measured on the "sweating" copper manikin.