Spreading of Liquids in Textile Assemblies

In a series of studies on the effects of finishes on textile wetting, the capillary spreading of a liquid drop in fabric was investigated by a photographic technique as a function of time, drop volume, and surface tension/viscosity ratio. The area covered by the spreading liquid was found to be expressed by an exponential equation. During phase I, when some of the liquid is on the fabric surface, the area of the spreading liquid is proportional to the square root of time, in accord with the Washburn equation. Phase II is when the liquid is contained within the fabric. For impermeable fibers, the ex ponents are in agreement with previously reported values. When the liquid diffuses into the fibers, the exponents decrease, increase, or remain essentially constant. The exponent of the spreading of n-decane increases with increasing hydrophobicity of the fibers. The exponents of rayon fabric exhibit anomalies caused by the geometry of rayon fibers.