Design and development of an affordable and washable multilayered mask with a recycled hydrophobic layer for preventive health care (preprint)

ABSTRACT

The sudden onset of Covid-19 pandemic has led to the implementation of various health-care measures, among which the facemask has become the primary line of defense. Several masks available in the market are single-use that would choke the environment through plastic pollution, or too expensive for the commoner to afford. As the pandemic affected population of all races, religions and communities across the globe, there was a need to design a low-cost mask that could be washed and reused multiple times without loss in barrier properties. The present work relates to the design of a facemask that incorporates a waste derived warp knit polyethylene terephthalate (PET) permeate spacer extricated from used reverse osmosis (RO) and other membrane modules. A non-woven polypropylene (PP) layer was incorporated immediately after the PET layer to provide high hydrophobicity and increase the threshold pressure for the respiratory droplets to penetrate. These two active layers were sandwiched between two tightly woven cotton layers as the first and fourth layers. The cotton fabric of the developed mask provides comfort, good appearance, biodegradable nature and tightly woven that reject larger particulate matter including dust. The unique PET layer has high mechanical strength and 3D shape holding capability that extended from the nose bridge to the chin, leaving an air gap between the mouth and the inner layer of the facemask, enabling smooth facial movement, hindrance-free speaking and prevents spectacle fogging. The PP layer is also known to exhibit electrostatic repulsion towards pathogens present in the air and prevents the chances of infections. Compared to commercial N95 mask, the developed mask exhibits high breathability, reusable up to 30 washes and is produced at an affordable cost of Rs.17 (0.22 USD) including labor charges and sold at 100% profit margin @ Rs.35 (0.45 USD) per unit. The developed mask has high bacterial filtration efficiency and prevents respiratory droplets containing infection causing organisms, dust allergies, and those arising from environmental pollution. Moreover, the mask was certified by neutral testing agencies and sold to a population of more than 6 lakhs thus playing a major role in mitigation of Covid-19.