Multi-Layered, Corona Charged Melt Blown Nonwovens as High Performance PM0.3 Air Filters

Abstract

Particulate matter (PM) and airborne viruses bring adverse influence on human health. As the most feasible way to prevent inhalation of these pollutants, face masks with excellent filtration efficiency and low press drop are in urgent demand. In this study, we report a novel methodology for producing high performance air filter by combining melt blown technique with corona charging treatment. Changing the crystal structure of polypropylene by adding magnesium stearate can avoid charge escape and ensure the stability of filtration performances. Particularly, the influence of fiber diameter, pore size, porosity, and charge storage on the filtration performances of the filter are thoroughly investigated. The filtration performances of the materials, including the loading test performance are also studied. The melt blown materials formed by four layers presented a significant filtration efficiency of 97.96%, a low pressure drop of 84.28 Pa, and a high quality factor (QF) of 0.046 Pa−1 for paraffin oil aerosol particles. Meanwhile, a robust filtration efficiency of 99.03%, a low pressure drop of 82.32 Pa, and an excellent QF of 0.056 Pa−1 for NaCl aerosol particles could be easily achieved. The multi-layered melt blown filtration material developed here would be potentially applied in the field of protective masks.

Masks for COVID‐19

“…Therefore, to address this issue of improving filtration performance without sacrificing good air permeability, the filter layer is charged through some charging technologies such as corona discharge, induction charging, and triboelectric techniques during fabrication into quasi‐permanent dipoles called electrets, in which corona discharge technique is the most commonly used one. [ 52 , 54 , 55 , 56 , 57 , 58 , 59 ] These electrets can absorb fine aerosols, which can significantly increase the filtration efficiency through the mechanism of electrostatic interaction, [ 60 , 61 , 62 , 63 , 64 ] as shown in Figure 4d .…”

Enhanced air filtration performances by coating aramid nanofibres on a melt-blown nonwoven

“…When used for filtration purposes, melt-blown nonwovens usually go through an electret treatment. [46][47][48][49] This process enables the nonwovens to carry positive charges that can capture more particulate matters (PMs). Considering that PPTA and the resulting ANFs possess negative charges, we hypothesize that ANFs may be directly coated on melt-blown nonwovens to further enhance their filtration performances.…”

Eco-Friendly Poly(Vinyl Alcohol) Nanofiber-Based Air Filter for Effectively Capturing Particulate Matter

“…and respiratory viral infections (coronavirus, Spanish flu, etc.) [1][2][3][4]. PP is an extremely useful plastic because of its physical and thermal properties, such as light weight and heat resistance.…”