Abstract
This paper reports on the measured and theoretical air permeability of needle-punched nonwoven fabrics and the characterization of permeability and tensile properties of the produced nonwoven fabrics for air filtration applications. In the present work, air permeability is characterized in terms of fiber linear density, fabric weight per unit area and fabric thickness. Nonwoven samples were produced using staple polyester fibers having 3, 6 and 12 denier linear density which were selected based on the actual industrial applications. The needle punched structures were further consolidated by calendering at two different temperatures of 180 °C and 210 °C. The measured air permeability values of the samples increased with the increase in fiber linear density. The increase in fabric weight per unit area led to a decrease in air permeability at the same fiber linear density and calendering temperature. Experimental apparent rate of flow values were correlated with the values of calculated theoretical permeability as permeability coefficient, Kfp. Theoretical permeability is a function of fabric porosity and the calendering affects the fabric porosity. Therefore the calendering process had an impact on the accuracy of the proposed prediction model. The statistical evaluation showed that theoretical permeability calculated as a function of mean fiber diameter, porosity and fluid viscosity may be used to predict the actual permeability of the nonwoven filter media. Since the theoretical permeability is a function of fabric porosity, changes in fabric porosity due to calendering have an impact on the difference between the measured and theoretical permeability values.
Original language | English |
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Pages (from-to) | 25-40 |
Number of pages | 16 |
Journal | Tekstil |
Volume | 61 |
Issue number | 1-6 |
Publication status | Published - Jun 2012 |
Keywords
- Air permeability
- Calendering process
- Fabric porosity
- Needle-punched nonwoven fabrics