Filtration Efficiency of the Composite Nanofiber Media

HEPA filters are characterized by high filtration efficiency, which are obtained by producing nonwoven filters via fibrous electrets and composite filter media. The objective of the study is to enhance the filtration properties of a nonwoven composite media by increasing porosity and surface area by incorporating nanofibers. In this study, electrospun fibers were collected over a cotton fabrics and meltblown web, which form different nonwoven composite media. The structural design of the composite media plays a significant role in precise arrangement of electrospun fibers for enhancing functionality of the filter. Overall, the efficacy of filter media is based on filtration efficiency and pressure drop that in turn determines the quality factor of the filter. The morphological structure of electrospun nanofibers showed micro-scale highly porous structure, which showed significant influence over the filtration efficiency and pressure drop. Testing of the meltblown-nanofiber composite filter in this study for fractional filtration efficiency showed high particle removal efficiency with less air flow resistance. Results are compared with cotton fabric-nanofiber webs.