Analysis of thermal properties of multilayered fabrics by full factorial and Taguchi method

Abstract

The present paper reports the thermal and evaporative resistances of multilayered fabric ensembles meant for cold weather conditions. A three-layered structure was used to simulate the multilayered fabric ensemble. Knitted, through air-bonded nonwoven and coated fabrics were used as inner, middle and outer layer fabrics, respectively. Inner and middle layer fabrics were varied in mass per unit area in three different levels. Three different coated fabrics, namely, polyester polymer-coated fabric and two different polytetrafluoroethylene-coated fabrics which vary in pore size and porosity were used in outer layer. Taguchi’s L9 orthogonal array, meant for three variables and three levels were used to form nine different multilayered fabric ensembles. Signal to noise ratio was studied to predict and optimize the thermal properties of multilayered fabric ensembles. Full factorial design was used to study the effectiveness of predicting thermal properties of multilayered fabrics using Taguchi’s approach. Regression equations were developed and contour plots were drawn to analyse the effect of chosen parameters on thermal properties of fabrics. In both the methods, the percentage contributions of each factor for thermal and evaporative resistances of multilayered fabrics were studied using sum of squares method. It was found that the Taguchi’s method reduces the number of experiments significantly and predicts the thermal properties of multilayered fabrics with good prediction performance. Mass per unit area of inner layer was found to have no significant effect on thermal and evaporative resistances of multilayered fabric ensembles. Mass per unit area of through air-bonded nonwoven fabric was found to be the most significant parameter in determining the thermal resistance of multilayered fabrics. Mass per unit area of middle layer and pore size of coated fabrics were found to contribute almost equal level in deciding the evaporative resistance of multilayered fabrics.