Physical Parameters Affecting Liquid Penetration and Wetting of Fabrics
Final rept. Apr 1984-Oct 1986
ARMY NATICK RESEARCH AND DEVELOPMENT CENTER MA
Pagination or Media Count:
The purpose of this research is the development and evaluation of a test procedure for determining the water repellency of films and fabrics of military interest. The approach selected has been used by several investigators. The method determines the critical surface tension gamma sub c of the material by measuring the angle of contact between the fabric and a series of liquids of different surface tensions. A camera microscope system is used to obtain the contact angles. Youngs equation and theoretical equations proposed by other researchers are used to analyze test results. Data obtained on several experimental films was analyzed using the approaches of Fowkes and Good. For practical purposes both approaches gave similar results. However, analysis of data reveals a fundamental limitation of the method. When applied to materials of low surface energy, particularly the rough surface of a water repellent woven fabric, a long extrapolation is required to obtain gamma sub c. Keywords Fabrics, Contact angle, Surface tension, Wetting, Liquid penetration, Critical surface tension.
- Chemical, Biological and Radiological Warfare
- Protective Equipment