An Efficient Ethanol-Vacuum Method for the Decontamination and Restoration of Polypropylene Microfiber Medical Masks & Respirators

Albert I. Nazeeri; Isaac A. Hilburn; Daw-An Wu; Kabir A. Mohammed; D. Yovan Badal; Moses H.W. Chan; Joseph L. Kirschvink

Although our design is less expensive, it is quite accurate within its domain, and has several advantages over established testing methods. In particular, conventional testing rigs do not test the impact of mask fit on performance. The standard procedure is to seal the mask onto the flat surface of the device with beeswax or other adhesive, even deforming the mask if necessary. This is unfortunate because studies have shown that the leakage around the mask, not through the medium, is the main determinant of total mask efficiency 18 . Poor fit can reduce an N95 mask from 95% to below 60% efficiency, which is below that of some masks made from commercial fabric 19, 20 . In contrast, our testing setup uses a head model, upon which the mask is "worn", and is remarkably quick and easy to seal completely against the plastic film wrapped around the head model. We are seeking to improve upon this with 3D-printed head models and synthetic skin coverings (e.g. 21 ). Such an improved version could then be used to validate inexpensive head forms for testing rigs.