Effect of Fabric Layers on the Relationship between Fabric Constructional Parameters and Percentage Reflectance Values of Polyester Fabrics

This paper focused on the assessment of the relation between constructional properties and percentage reflectance values of fabrics woven from polyester yarns through fabric layer numbers. Reflectance measurements were conducted on pretreated but undyed fabric samples at five different fabric layers. Twelve polyester fabrics having different constructional parameters were used and fabrics differed from each other by their weft yarn densities, weave patterns, and weft yarn filament fineness. Warp yarn properties (type, count, and density) were the same at all the fabrics. Percentage reflectance values of the fabrics changed according to yarn density, weave pattern, and filament fineness in accordance with fabric layer numbers during reflectance measurement. Percentage reflectance values gradually increased as fabric layer numbers increased. The highest reflectance values were obtained at 16 layers of fabric. The effects of single constructional parameters on reflectance values disappeared as fabric layer numbers increased. Percentage reflectance values were analyzed according to ANOVA (Analysis of Variance) and statistical results revealed the cross relations obtained. Light-trap phenomenon was discussed according to reflectance characteristics of woven fabrics. 1. Introduction Color measurements on opaque surfaces (textile fabrics) are made by measuring the percentage reflectance of surfaces and the measured reflectance values are transferred to color computing software for the determination of color coordinates and other color related properties, that is, whiteness. Whiteness of textiles is an important aspect which is considered in daily life. White textiles are usually preferred by customers especially in summer because of comfort reasons. Also white, being an achromatic color, has a physiological effect on human sensation. Fibers which are used in textile fabric production for domestic purposes have intrinsic colors of their own mainly given at the production stage. Polyester fibers, being synthetic ones, are usually produced in white color from matt to bright by the usage of delustering agents such as titanium dioxide. The white color of fabrics produced from polyester yarns could be changed to a whiter shade by wet treatments using textile auxiliary agents or by applying fluorescent whitening agents (FWAs) to fabrics. Depending on the domestic usage, polyester fabrics could be used without any application of FWAs. When the constructional properties of fabrics are considered in relation with their color, it is recognized that the visual color could