Layered nonwoven filter embodied with packing density gradient measured by X-ray computed tomography for enhanced filtration performance

Abstract

This research explores the possibility of tuning the structure of needle-punched nonwoven fabrics by incorporating layers of differently oriented fibres. The fibre orientation in carded batts is regulated with the help of carding parameters viz. feeder, cylinder, and doffer speeds. The carding parameters were optimized by using response surface methodology to obtain carded batts of differently oriented fibers, which were then placed distinctly to form composite layered nonwoven fabrics. The physical, mechanical, and functional properties of layered fabrics were evaluated. X-ray computed tomography technique was used for comprehensive evaluation of the packing densities at incremental thickness of layered fabrics. The obtained trends of packing density were found to be in good agreement with the measured properties of nonwoven fabrics. The creation of an inverse gradient of packing density in a layered nonwoven fabrics displayed close to highest filtration efficiency and close to lowest pressure drop.

Keywords:

• Nonwoven filter media
• fibre orientation
• gradient structure
• computed tomography
• filtration efficiency
• pressure drop

Disclosure statement

No potential conflict of interest was reported by the authors.