Abstract
In this paper, the water-penetrating pressure in the composite fabrics of hydrophilic and hydrophobic yarns is discussed in relation to the wettability of the materials and the structure of fabrics.
The following results were obtained;
(1) The penetrating pressure P is given by the following equation as a function of the advancing contact angles of both component materials, θ1 θ2, radius of yarns, γ, the gap between the yarns, D, and the surface tension of liquid, γ,
P=γ(I/Rw+I/Rf)
Rw and Rf are calculated for the warps and the wefts, respectively.
(2) The observed pressure agrees approximately with the calculated value, except in the case where one of dvancing contact angles of the components is smaller than the critical angle. In such a case, the observed pressure is much lower than the calculated. However, the deviation becomes smaller when the hydrophilic yarns are neglected.
(3) Generally, the pressure reduces steeply with the decrease of the advancing contact angle of one component or with the increase of mixed ratio of the hydrophilic component.
(4) The water-penetrating pressure in composite fabrics of hydrophilic and hydrophobic yarns is dependent not only on the mixed ratio of yarns but also on the structure. Thus the proper design improves the comfortability of the apparel with little deterioration of water-repellency.
