Face Mask

thingiverse

This is my innovative design for a reusable face mask frame that leverages multiple filter media options. This is not a respirator, but its features were inspired by those used in respirators. I invite all feedback in the comments section to further refine and optimize. It consists of the following components: - A flexible liner made from TPU/TPE designed to roll inward and conform to the face. This creates a tighter seal than rigid shells or folded TPU sheet designs, but may not match the softness of medical-grade silicone. Print with four top layers, 0% infill, and zero bottom layers for optimal results. The shape was crafted using OpenSCAD, so please don't judge. - A rigid shell onto which everything mounts. The lip is intentionally oversized to create a seal between the liner and the shell. Grills require a printer capable of bridging 8mm. - A gasket/flap piece combining two functions to reduce complexity and parts count. - Filter media, which can be locally sourced. I've tested this design with vacuum cleaner bags, cloth, and one third of a surgical mask. - The cover piece applies pressure to the gasket and forces the valve flaps against the exhaust openings. It also ducts exhaust to the rear. This component should be printed in 100% TPU. - Strap mounts designed to be modified for different configurations. They snap into place once the cover is added. The usual caveats about printing this type of device apply, as testing has been limited. However, all plastics used during prototyping survived my local hospital's H2O2 atomizing autoclave device, so it can be sterilized. My medical provider and the local medical engineering team will continue to conduct further testing on plastics used, including more field-expedient methods of sanitizing, porosity/liquid absorption, and oxygen flow/CO2 build-up with different filter media (although the one-way valves should help with the last). I also want to coordinate for a vapor spectrometer test to see if the printing process releases VOCs in printed samples. I believe this design is as complex as one can make it for a face mask producible on a consumer-grade printer using commonly available filaments. It requires about 6 hours total to print all parts, so production is not scalable as I would prefer though it might present an interesting exercise in distributed manufacturing. Regarding safety considerations: - Use this design at your own risk...something something neither liable nor responsible...something something... - 3D printed items can be porous and permeable - Recommend checking the SDS of whatever you print for particulates and hazardous volatile compounds - This will be an inferior/less desirable solution than similar parts from approved sources - Pretend that you have COVID-19 when moving the part from the print bed to a sealed container for delivery - I fly helicopters and ride motorcycles, so my perception of acceptable risk likely doesn't match yours or the FDA's. - Also, properly washing your hands for 20 seconds and practicing disciplined social isolation will almost assuredly do more to improve your health outcomes than any mask you can buy or print. Don't risk compensate. Special thanks to Dr. Connor, Mr. Saesz of O2 Canada, and the S&T Team for input and ongoing evaluation of this design.