Experimental design for determining the factors influencing the filtration efficiency of solution-blown spun polylactic acid filters

Abstract

Millions of people are wearing face masks because of the COVID-19 epidemic, and these masks are indiscriminately releasing pollutants into the atmosphere. One of the most appealing and promising bio-based polymers for face masks is polylactic acid (PLA). Solution-blown spinning (SBS) is a rapid and easy way to produce micro and nanofibers that may be quickly deposited on any substrate. This study aims to produce and evaluate solution-blown spun PLA fibers used as filter media. PLA nanowebs were observed for their morphology, weight, thickness, air permeability, water contact angle, and filtration properties. The average diameter of the fibers ranged between ∼163 and ∼282 nm. NaCI aerosol filtration test results showed that the filtration efficiency of these nanowebs was ≥ 94% and the pressure drop was ≤ 240 Pa, meeting requirements was assigned to the class EN 149: FFP2 particle-filtering half-maks. Filtration performance was significantly influenced by the flow rate and polymer concentration. The resulting equations for the design of experiments (DoE) regression model were examined and found to be appropriate for predicting the parameter combinations required for the desired quality factor of PLA filters. The fast and economical features of the SBS process, as well as the biodegradable nature of the PLA polymer, may considerably contribute to the development of environmentally friendly filters.