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 L 9 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.

Review of heat and water vapor transfer through multilayer fabrics

“…Therefore, both selection of materials and layer manipulation with or without air spaces should be considered for the design of cold weather clothing. 37 Same fabrics as those in Table 1 3 R et Significant effects of mass per unit area of the middle layer and the pore size of the outer layer on R et Shabaridharan and Das 35 Same fabrics as those in Table 1 3 R et Significant effects of punch density, thickness, linear density, mass per unit area on R et Wakatsuki et al 38 Meta-aramid and para-aramid 3 THL Significant effect of lamination on THL Williamson et al 39 Linen plies of viscose battings with an inner layer and an outer layer of thin nylon fabrics showed that the inner fibrous battings with a higher fiber content, finer fibers, greater fiber emissivity, higher air permeability, a lower disperse coefficient of surface free water, and a lower moisture absorption rate led to less condensation and moisture absorption. In addition, the permeable outer covering fabrics exhibited advantage for reducing water condensation within the battings.…”

“…In addition, the type of coated fabric had a significant effect on the moisture permeability index of multilayer fabric assemblies and the moisture permeability index of the polytetrafluoroethylene (PTFE)coated fabric assembly was higher than those of the polyester polymer-coated fabric assembly and rubbercoated fabric assembly. Shabaridharan and Das 37 measured the thermal and water vapor resistance of nine through air-bonded nonwoven fabrics plus the inner and outer layer and found significant effects of mass per unit area of the middle layer on the thermal and water vapor resistance of through air-bonded nonwoven fabrics. In addition, the significant effects of the pore size of the outer layer on the water vapor resistance of air-bonded nonwoven fabrics were observed.…”

“…[53][54][55][56][57] Similar to single layer fabrics, the thermal resistance of multilayer fabrics was also linearly correlated with the thickness. [33][34][35][36][37] established the relationship between the types of fiber or fabric and the thermal resistance of needle-punched fabrics. The analysis revealed that high linear density of polyester fiber, great mass per unit area, and low level of punch density resulted in high thermal resistance.…”

“…A number of textile scientists have made great endeavors to find the effects of fiber types, fabric parameters, and process variables on the water vapor transfer properties of multilayer fabrics. For example, [33][34][35][36][37] correlated the fiber, fabric, and process parameters of needle-punched fabrics with the water vapor resistance. The reported data showed that high linear density of polyester fiber, great mass per unit area, low level of punch density, and depth of penetration led to high water vapor resistance.…”

Optimization of coating parameters for air permeability of denim fabrics through Taguchi method

“…Also, they analyzed the effect of pore size and porosity on thermal and evaporative resistances of coated fabrics. It was found that the mass per unit area of through air-bonded nonwoven and pore size of coated fabric were found to have significant effect on thermal and evaporative resistances of multilayered fabric ensembles [13].…”