Air permeability of needle-punched filter media—virgin and recycled polyester

Abstract

Air permeability is an important property of any filter media and mostly depends on its constructional parameters. In this article, virgin and recycled polyester fibers were used to prepare needle-punched nonwoven filter medium varying fabric weight (GSM (grams/m2)), needling density (punches/cm2) and depth of needle penetration (mm). The effects of these variables on air permeability of virgin and recycled polyester needle-punched filters have been studied using response surface method. Air permeability of needle-punched nonwoven filter fabric made from virgin polyester fiber is lower compared with recycled polyester fiber due to the formation of consolidated structure. It also revealed that increase in fabric weight resulted decrease in air permeability. Also, the increase in needling density and depth of needle penetration resulted initially in a decrease in air permeability; beyond certain increase in needle parameters, the extent of air permeability increased. These similar trends were observed in case of both virgin and recycled polyester fiber fabrics. Considering the recyclability aspects, the recycled polyester needle-punched nonwoven fabric perform similar or better in case of filtration application because of higher air permeability.