Effect of processing parameters on properties of layered composite needle-punched nonwoven air filters

Abstract

Layered composite needle-punched nonwoven fabrics have been prepared using 6 den and 15 den polyester staple fibres separately and in 50:50 proportion and their air filtration and other associated properties studied. Processing parameter such as punch density has also been altered to investigate its effect on filtration efficiency as well as on associated properties like dimensional stability, air permeability, compression-recovery, tensile strength, abrasion resistance and friction. Filtration efficiency values show an initial rise and then subsequent fall with incremental punch densities in case of layered fabric and those made with fine fibres. In case of coarse fibre, however, the values continue to increase with punch density. The pressure drop required to maintain a certain level of flux of air through the fabrics is also not too high as that of fine fibre fabrics. Dimensional stability of fabric layered with 50:50 proportion of 6 and 15 den fibres is also found to be higher as compared to that of the fabrics of other combinations. Compression / recovery performance of layered fabric is also found to be better. All these positive attributes of the blended 6 and 15 den (50:50) layered fabrics show that the composite needle-punched fabrics will perform better as air filters.