Melt-blown filters work on the principle of electrostatic charge for the removal of particulate matter, as in the result of ethanol spraying or dipping the electrostatic charge on the surface of melt-blown filter was lost, so efficiency of melt-blown filter was significantly decreased. On the other hand, the nanofiber filter did not deteriorate in filter performance even after 10 or more uses. However, when the mask was reused after the ethanol disinfection, the filtration efficiency of the melt-blown filter decreased to 64%. The tests also clarified that the inside of the filter can be effectively sterilized by spraying ethanol 3 times or more or immersing it in an ethanol solution for more than 5 minutes. Credit: © 2020 American Chemical Societyįiltration efficiency of both of the filters (melt-blown filter and the nanofiber filter) was 95% or more before use, which indicates that the respiratory organs of the wearer can be effectively protected.

The methods of disinfection test involved directly spraying 75% ethanol on the mask filter and air drying, and soaking the mask filter in 75% ethanol solution for 5 minutes to 24 hours and leaving it to air dry naturally.Įvaluation of breathing comfort by infrared thermal camera. They examined the filtration efficiency, comfort of the wearer, and filter shape change after washing and disinfecting. They looked at commercially available melt-blown nonwoven fabric N95 masks and nonwoven nanofiber masks with N95 filters. students Jaeyun Lee and Yeonsu Jeong, looked into the effectiveness of sterilizing N95 masks. students Sana Ullah and Azeem Ullah and Professor Cha Hyung Joon of POSTECH (specially invited professor of IFES) with Ph.D. Shinshu University has a track record of conducting research on production methods and applications of 'nanofiber non-woven fabric' since before the coronavirus outbreak.Īmidst the current social backdrop, a research team led by Professor Ick Soo Kim of Shinshu University's Institute for Fiber Engineering (IFES) with Ph.D. This is crucial in preventing infections. Particulate filtration and air permeability are key factors in determining performance while cleaning and disinfecting N95 certified masks. N95 masks are currently difficult to obtain, so there is an urgent need for a safe method of prolonging their usability through disinfection and reuse with minimal loss of performance and integrity.

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