Continuous production and properties of mutil-level nanofiber air filters by blow spinning

Nanofibers are gradually being widely used in air filtration due to their unique characteristics. However, the mass production of nanofiber filter material faces several problems. Blow spinning is an emerging technology, which have great potential for mass production of nanofibers. In this work, we have successfully realized the continuous production of 500 mm wide nanofiber membranes by blow spinning, which enables continuous preparation of multi-level nanofiber filter materials: PAN60 (filtration efficiency is 63.2%, pressure drop is 18 Pa), PAN80 (filtration efficiency is 80.7%, pressure drop is 38 Pa), PAN90 (filtration efficiency is 92.9%, pressure drop is 58 Pa) and PAN99 (filtration efficiency is 99.5%, pressure drop is 123 Pa). In order to improve the stability performance of melt-blown filters, we provide a strategy that combines nanofibers with a melt-blown filter. PAN nanofibers were sprayed directly on the melt-blown filter by blow spinning. The composite filters have more stable filtration performance and higher efficiency when intercepting particles with a diameter below 100 nm than melt-blown filters.