DIY Particle Filter Mask Assembly System

thingiverse

*4/5/2020: Instructable will soon be updated with Version 7.0 instructions* Summary: The COVID-19 crisis has led to a shortage of personal protective equipment (PPE) for healthcare workers. The DIY community has responded by creating various solutions, including hand-sewn cloth surgical masks and 3D-printable face shields. I have developed a simple system for making disposable particle filter masks using 2+ layers of material from commonly available HVAC filters. The specific material I chose comes from 3M MPR 2200 (MERV 13) pleated electrostatic filters, which yield several feet of material for the masks. Each mask contains a thin metal wire embedded in the base that can be bent to conform to different face shapes. The Mask Assembly System involves two 3D printed tools: an assembly jig and a flat pattern cutting template. These tools can be made on most hobby-grade 3D printers with sufficient build volume, such as my Prusa i3 MK3S. The STL files for the Jig and Flat Pattern will be available for anyone interested in making masks using this system. To assemble the mask, use the Flat Pattern to cut pieces of suitable filter material. Wrap one layer around the Jig and seal all seams with LOW TEMP hot glue. Apply two loops of .025" or similar size steel wire around the first layer using the integrated groove and tension it using the wire posts. Glue all around the wire with hot glue and trim off excess. Apply another layer of filter material for a minimum of 2 layers, then trim the excess below the wire loops. Finally, glue on straps using the guide slots at preferred locations. Disclaimer: I make no claims about the filtration performance or efficacy of these masks against infection from SAR-CoV2 or any disease. 3M and other manufacturers do not endorse this use of their HVAC filter products. This project is intended to create emergency PPE like cloth masks or PET bottle face shields made by others in the community – it is not certified or regulated in any way. Use at your own risk.