The coronavirus pandemic has led to an increased demand for disposable face masks. The huge numbers of discarded masks not only result in an alarming accumulation of plastic in soil and aquatic ecosystems, but they also create a shortage on the polypropylene supply chain. Polypropylene is a petroleum-based polymer that is the main filtering medium used in masks, but it does not filter out bacteria. To tackle this issue, the Popmask project, which received funding by the Marie Skłodowska-Curie Actions programme, aimed to develop filtration media using sustainable and antibacterial poplar fibres that should effectively remove ultra-small particles such as the coronavirus itself. This project had 3 main technical pillars:
(i) Creating wet laid webs from poplar fibers
(ii) Developing a surgical mask
(iii) Developing a filtering facepiece respirators that can effectively filter ultrafine particles.
Poplar trees are very fast-growing trees and are grown on 76 million decares of land in the world. Poplar trees are used as raw materials for industrial products such as paper, cellulose pulp, and plywood. Although poplar trees are widely used in the industrial field, the fibers of these trees have never been used for industrial purposes before.
Poplar fibers have hollow lumen and highly hydrophobic. In this study, wet-laid nonwovens with various weight densities were produced using poplar fibers. These webs were employed as filtration media in surgical mask.