Half face respirator mask (COVID-19)

thingiverse

We have conducted extensive testing on various filtering materials at our physics university, including cotton pads and HEPA bags from vacuum cleaners. The results are as follows: Cotton Pads: We tested generic brand cotton pads from Carefour, which achieved 70% filtration of 0.3um particles and 88% filtration of 10um particles (dust, mold, pollen, etc). However, we do not recommend using these materials due to their inadequate performance. HEPA Bags: Vacuum cleaner HEPA bags showed a higher filtration efficiency, ranging from 85% to 91% for 0.3um particles. This makes them a more promising candidate for use in masks. Important Note: Always conduct thorough research and consult the manufacturer regarding potential hazardous materials (e.g., fiberglass or antibacterial polymers). When using HEPA bags, ensure that you utilize the inner surface of the bag as the outer side when attached to a facemask. Microfiber Cloth: Praktiker brand microfiber cloth used for cleaning windows obtained 95% filtration efficiency for 0.3um particles; however, airflow is significantly restricted. Disclaimer: This design has not been approved by any regulatory agency and should be used at your own risk as a last resort if no certified protection is available. Since sourcing P2 or P3 filtering materials is challenging, you can use two cotton pads instead. However, keep in mind that this will not provide the same level of performance as certified filters. It is crucial to achieve an airtight fit around the face and avoid any air gaps. Men are advised to shave their beards for optimal sealing. To further enhance protection, consider wearing goggles and disposable surgical gloves when using this mask. Avoid exposing yourself to crowds or potentially infected individuals, as this mask should not provide a sense of complete safety. I created a revised design by combining elements from various sources, which offers a more robust and air-tight screw-type filter mount. The mask can be printed using different materials (PLA / PET-G / ABS / ASA / TPU, etc.). For information on the effect of 70% IPA and UV sterilization on various material types, refer to this study: https://www.youtube.com/watch?v=txrXX0CQHhU&t=1s. Dual elastic straps are recommended for a better fit (rear mounts), but you can also use only one strap if desired (using the front mounts). When it comes to filters, it is advisable to use certified P2 or P3 filter materials cut to size. Since I was unable to source these materials, I used two cotton pads cut to size instead. Remember to replace filters regularly, especially when they become moist due to breathing. Sterilize all parts with 70% IPA or other biocide substances.