An exploration of thermomechanical softwood pulp for N95 respiratory mask production

Abstract

The COVID-19 pandemic has highlighted supply chain issues for personal protective equipment (PPE) in Canada. In addition, many PPE products are produced from non-renewable feedstocks. Wood pulp is an abundant and renewable natural resource. Currently, wood pulp from one Canadian paper mill in particular is used in combination with synthetic polymers, such as polypropylene, to produce non-woven textiles. Most of the world's population has become familiar with non-woven textiles over the course of 2020 since they are used to produce the 3-ply disposable masks that many people are currently required to wear. Not only are the synthetic polymers produced with the use of solvents that are detrimental to the environment, but these single use masks are piling up in landfills. The goal of this project was to work in partnership with Port Hawkesbury Paper to produce PPE entirely out of Nova Scotian thermomechanical wood pulp (TMP). This pulp is produced in a low effluent mechanical process that uses less harsh chemicals than the production of synthetic polymers. Above all, wood pulp based PPE would be biodegradable, therefore this would have an enormously positive impact on the population's waste output. Overall, this thesis work reviews characteristics of existing PPE and the impact of lignin content on filtration efficiency of pulp fibers. Lastly, chemical modification with deep eutectic solvents is explored to investigate their potential to improve filtration capabilities