Thermal resistance and water vapor permeability of compound woven fabrics containing silver multifilament

Abstract

Two sets of compound woven fabrics containing three layers of simple woven fabrics were manufactured (five samples made of cotton yarns and five samples with one-third hybrid cotton/silver yarns). The thermal resistance and water vapor permeability of all the fabrics were measured and compared. It should be noted that the small dissimilarity in the thickness of the manufactured fabrics was due to the movement of the yarns through the thickness in the relaxing state of the fabrics. However, they were designed in a way to have the same thickness on the weaving loom. The results stated that the thermal resistance of asymmetric fabrics for both sets of fabrics (with and without silver) was different regarding which exterior face (face or back) was in contact with the hot plate (20°C). It should be noted that the fabric is not symmetric through its thickness due to the dissimilarity of weave pattern of the layers or the orientation of silver yarns. It affirms that the internal voids of each ply (which is correlated to the wave pattern) play a significant role in thermal resistance of the manufactured compound woven fabrics. As a result, the asymmetry of a compound woven fabric throughout the thickness makes it a potential fabric to be applied as double-face fabric for different climate conditions as the order of the layers changed the thermal resistance of the compound fabric due to the porosity of each ply. Furthermore, a reduction was observed in thermal resistance for the fabrics with silver presence (~40%) while the other parameters remained unchanged (e.g. yarn density, fabric structure, and fabric porosity). The reason is correlated to the high conductivity of silver as conductive materials improve the heat transfer of the fabrics. Moreover, the influence of silver presence on water vapor permeability was not significant although the water vapor permeability was slightly increased for the fabrics having silver in their structures.