Abstract: The article reviews some recent significant research trends in warp knit spacer fabrics. Warp knitted spacer fabric made of polyester has been studied for porosity and air permeability by optimizing the structural parameters and using Box and Behnken experimental design. The porosity and air permeability are found to be better at the face layer denier of 100 and middle layer of 20 denier. The statistical analysis makes it evident that the degree of correlation of F values is 12.44 between the filament linear density and air permeability. Knitted spacer fabrics are soft, voluminous and highly porous and hence are expected to be suitable for sound absorbing applications. Attempts have been made to predict the acoustic behaviour of fabrics, a simple geometrical model has been evolved. The frequency dependent sound absorption coefficient of the warp knitted spacer fabric has been predicted using various empirical models. The findings reveal that some of the selected empirical models can predict sound absorption characteristics of warp knitted spacer fabrics in the mid to high frequency ranges. At low frequency ranges, however, none of the empirical models can reasonably predict sound absorption behaviour of the fabrics. Thermo physiological comfort properties are crucial aspects of interlining material comfort for shoe insole which can be examined for permeability and conductivity. In this regard, studies on polyester warp knitted spacer fabrics have revealed that the final comfort properties can be improved by using plasma treatments, and argon plasma treatment is the best method when compared to the oxygen plasma treatment..

Keywords: Warp knit spacer fabrics, Plasma treatment, Acoustic characteristics, Air permeability, Empirical models, Statistical analysis.