These days my EDC now includes a face mask.
I am not satisfied with the face masks currently on the market. They are either way too large and leak out the sides, or are simply uncomfortable and bulky.https://www.youtube.com/watch?v=fvCF6S1Vm_8
Via the 3D printing nerd on YouTube: I came across the Bellus 3D App
, which allows you make a surprisingly accurate 3D scan of your face using any iPhone that has Face ID.
Their app also can generate a 3D printable frame that makes existing masks fit better. And their frame solution works great to seal the edges and in general makes the mask a bit more comfortable. However it still pinched the top of my nose, and require extra straps. It also pulled down any mask material such that is smashed the tip of my nose.
As a mechanical product engineer I couldn't leave well enough alone and starting thinking of a better design. There are already a lot of very bulky designs out there, and the NIH is working to share [urlhttps://3dprint.nih.gov/ 3D printable personal protection gear[/url].
Here are my goals:
- Easy to take on/off
- Seals to my face
- Swappable/washable filters
- Easy to clean components
- Doesn't smash my nose
So after many hours of design and various alternate designs that didn't work for one reason or another, I have settled on this design. It uses a gasket, frame, filter holder, and cloth filter.
To design it I used the Bellus3D app to do a full head scan which I could import into my CAD software (Solid Edge). I opened the scan in MeshMixer and then smoothed it out a bit. Solid Edge has some cool reverse engineering tools that let you work from tessellated models and 3D scans. This gives me some surfaces to work from that perfectly fit my face.
I then model in the silicone foam gasket that will seal against my face. The frame is then designed to half-grip the gasket. It specifically has gaps near the bridge of my nose to ensure that the harder plastic doesn't touch, only the gasket. The frame also has hooks for the strap, which I will use either bungee cord, or silicone o-ring stock as the material. (My prototype uses a thinner o-ring stock, and its actually quite stretchy and comfortable).
A series of magnets ring the inside and work to hold the filter onto the frame. A small gap between the two allows the fabric to wrap around and be held in place. The plan is to stitch the cloth layers together into easy to swap/wash patches.
N95 masks are made by actually spraying the fibers directly into molds. You can't buy the raw material on its own (no matter what Alibaba says).
To that end, I need to use a cloth mask. I did some research and can across an article that scientifically compared a bunch of various materials
Their results showed that layers of 600 count cotton and chiffon was nearly as good as N95. So this is what I plan on using.
So far I have 3D printed the prototype design on a FDM printer, and am using a nylon rope in place of the silicone gasket. The prototype only has roughly cut cotton layers right now, but it proves the design is both comfortable and seals very well.
I am still waiting some materials before I order the final 3D printed parts from Shapeways. The final parts will be made from Nylon which is dishwasher safe. It will also be much smoother and more durable than the PLA plastic the prototype is made from.
Even though it is custom fit to my face, it fit my wife quite well. This is many hours of work to design due to the complex curves involved. I ran into constant road blocks with the increasingly complex curves required to both make it fit, and be smooth on my skin.