Nanostructured media to improve the performance of fibrous filters

Abstract

The main objective of this study was to present one of the possibilities of increasing the initial efficiency of aerosol particle removal from the gas stream, i.e. the application of nanofibers in the filter structure. The modified melt-blown technique of producing such thin fibers is hereby presented. During this work, various filter media with fiber diameters from micro- to nanosized made of selected polymers differing in melt flow index were obtained via this method. Their morphology was precisely analysed using high-resolution equipment. The crucial parameters characterizing those fibrous materials were determined: an initial pressure drop across the filters and an initial filtration efficiency. The behavior of clean filters composed of microfibers were compared with the behavior of those made of nanofibers. An attempt was made to decrease the diameter of fibers to the nano range by using different materials for their formation. Collected data of penetration for melt-blown fibrous media were described via experimentally verified realistic models for better simulation of the air filter's performance. Additionally, the obtained results were compared with predictions of the classic filtration theory predominating in the literature on the subject. © 2013 Hosokawa Powder Technology Foundation.