Filtration mechanisms and manufacturing methods of face masks: An overview

Abstract

Face masks are loose-fitting masks that cover the nose and mouth and have ear ties at the back of the head whereas respirators are tight-fitting face covering devices which filter the air during inhalation and exhalation. Guidelines issued by the US Centers for Disease Control and Prevention (CDC) regarding proper design, filtration process and wearing should be followed. The mask equipment provides protection against the infections caused by particulate matters (PM), especially PM2.5, and biological pathogens such as bacteria and viruses. Although face masks offer benefits to a greater extent, it is not recommended to wear them for a long period of time. As N95 masks closely fit with the face, it may result in negative impact on respiratory and dermal mechanisms of human thermoregulation. In this article, currently available face masks including cloth masks, their filtration mechanisms, manufacturing methods and decontamination methods are reviewed for the purpose of helping with the coronavirus pandemic (COVID-19).

COVID-19: Acoustic Measures of Voice in Individuals Wearing Different Facemasks

“…Data revealed how fabric porosity, viscosity-resistance, and resonant features of facial coverings may influence the amplitude of a signal or transmission loss of a material 12 , 13 , 14 , 15 , 16 . Higher frequencies of speech may be more impacted by viscosity-resistance (friction between air molecules and fabric pores), and lower frequencies by resonance 12 , 13 , with resonant characteristics of fabric type augmenting amplitude at certain frequencies 14 , 15 .…”

Vrste, primjenjivost i označivanje maski za lice u Republici Hrvatskoj tijekom pandemije COVID-19

“…Veličine čestičnih onečišćenja prisutnih u zraku znatno se razlikuju i iznose primjerice za pelud od ~15 μm do 200 μm, za čestice prašine od ~1 μm do 100 μm, dok su bakterije okvirne veličine od ~0,2 μm do 2 μm, a virusi od ~20 nm do 400 nm (slika 1). 6,7 Kako se utvrđena veličina SARS-CoV-2 virusa, kuglasta do blago pleomorfna oblika, kreće između 60 nm do 140 nm (0,06 μm -0,14 μm), 8,9 pri odabiru maske za lice posebice treba voditi računa o poroznosti materijala i mogućnostima filtriranja virusa te respiratornih kapljica koje sadrže virus. Respiratorne kapljice mogu biti različitih veličina, ali prema dosadašnjim saznanjima aerosol koji sadrži kapljice veličine manje od 5 μm nalazi se primarnim izvorom transmisije respiratorne infekcije i zaostaje u zraku u vremenu oko 3 h. 10,11 Sveučilište u Zagrebu, Tekstilno-tehnološki fakultet, Prilaz baruna Filipovića 28a, 10 000 Zagreb Sažetak U današnje vrijeme, pojavom novog koronavirusa SARS-CoV-2 i njime uzrokovane bolesti nazvane COVID-19 suočeni smo na europskoj, ali i svjetskoj razini s pandemijom širokih razmjera i tzv.…”

“…Valja istaknuti da je nanočestice veličine oko 100 nm i manje, uglavnom moguće uspješno filtrirati mehanizmom elektrostatskog privlačenja i njihovim zadržavanjem na elektrostatski suprotno nabijenoj površini vlakana. 6,12,13 Kako su sintetska vlakna sklona elektrostatskom nabijanju, to je jedan od razloga njihove masovne primjene u izradi netkanih čestičnih filtara.…”

Assessing face mask littering in urban environments and policy implications: The case of Bangkok

“…Since the outbreak of the contagious COVID-19 (Coronavirus of 2019) pandemic, the usage of face masks has been an essential safety measure to protect the public and health workers from viral infection. Face mask absorbs droplets released from the wearer and at the same time protects the wearer from inhaling pathogens in the air ( Adanur and Jayswal, 2020 ; Chellamani et al, 2013 ; Colomer et al, 2021 ; Li et al, 2006 ; Metwaly et al, 2013 ). Due to the COVID-19 pandemic, many countries have enforced laws that mandate citizens to wear face masks in public places.…”