Study On The Sunshade Property Of Fabric Based On The Dope-dyeing Filament

Fabric sunshade property is an ability to block light when light projected onto the fabricsurface and the study of this property involves textile materials, optics and chromatology. Atpresent, based on the research of the shading property is not much and its measure index alsoonly in visual or simple optical testing phase. Vast space of the shading property for theresearch were provided because of the emergence of dyeing filament, and it also made greatcontribution for saving energy and reducing emissions. For this reason, to carry out research inthese areas will play an important role in academic and applied value.The decorative fabrics based on dope-dyeing filament as the main research object werestudied and analyzed from the angle of optical properties, color theory (including color system,color space) and fabric structure design. The detecting methods and testing principle betweendifferent test apparatus were discussed in order to find out the reasonable test method. Therelationship was also analyzed between shading property and influencing factors. The resultsshowed that:The basic characteristics and error was expressed quantitatively between the luxmeter andspectrophotometer. The spectrophotometer can be used as the reliable instrument finally whichcan measure the fabric shading efficiency after evaluating by the method of correlationcoefficient or coefficient of rank correlation.For different fabric structure in the same process parameters, the correlation betweenfabric porosity and shading efficiency is negative, the higher the porosity is, the lower shadingefficiency it shows. Fabric porosity can be represented by the rate of coverage, and the rate canbe effectively analyzed with the processing by MATLAB software on the fabric images. Amongthe numerous factors that have influence on the fabric shading property, the weight of porosityis heavier than that of thickness and glossiness when different fabric structures have the samewarp and weft density.In visible and ultraviolet light, there is positive correlation between transmittance and values of tricolor XYZ. The higher the values of XYZ are, the more transmittance the fabricshows. In the near-infrared light, RGB values and near infrared transmittance values did notshow the regular trend relatively and the values which concentrate in the range of35%-55%arelittle affected by color. In general, the higher the fabric brightness value is, the lower shadingefficiency it shows, wherein, the fabric color brightness has maximum correlation with visiblelight transmittance in all wavelengths.The three layers fabric has high shielding effect to ultraviolet light and the shadingefficiency can reach80%--90%according to the interlayer of different colors. In the visiblelight, most fabric’s transmittance were maintained at20%-35%.In the near infrared lightregion, coefficient variation curves of fabric transmittance show regular changes in this state. Apositive correlation was showed between the number of black yarns and shading efficiency. Theshading percentage can reach more than99%, nearly100%when the yarn specifications around17tex, density of black yarns in about300. In addition, the shading efficiency and the thicknessof high-shading effect fabric also showed a positive correlation. By using the principalcomponent analysis method, three principle components were extracted—thickness and weightcomponent, color component and tightness component. These three principal components couldexplain the sunshade property of fabrics reasonably. The level of the sunshade property can bereflected by Y—value of the comprehensive score of the fabrics.