Introduction: PPE is both necessary and essential when in the fight against COVID-19 and with N95 masks in short supply, surgical masks have become day to day accessories. Surgical masks are far from perfect. The do not provide a tight seal. There have been many good ideas floating around such as using elastic bands (example: https://tinyurl.com/y99mmqkh) or other complicated 3D printed solutions which require users to scan their face and take time and inevitably skill to produce. My Goal with this project is to produce a cheap and easy solution which can be rapidly 3D printed and or CNC cut.
l will be uploading numerous designs as I test and produce iterations but the designs will all follow the same basic principals. They are to be printed flat and then formed around your face so they fit perfectly. An elastic band, attached to the bottom of the devices, going either under your chin or over your lower lip guarantees a tight seal without preventing you from moving your mouth.
Simply follow these steps: Step 1: Print the devices out of PLA, flat on your build plate, or cut them out of PVC. Step 2: In order to get a perfect fit, you now need to form the devices around your face over your mask of choice. To do this you need to heat up the devices so they can be deformed. Here are a few safe ways to do this with a printer or with a kettle. With a printer: Set the heated build plate and to 70-80°C or and allow it to warm up the devices. With a kettle: Set the kettle to boil and hold the device over the steam until it softens. You need not worry too much about burning yourself because PLA does't conduct heat very well and you are molding it over your mask which from personal experience, will insulate you enough from the 70°C plastic. You can make multiple attempts, heating the plastic and molding it over your face until you get a comfortable fit. Step 3: Add elastic bands.
-27/05/2020: Version 4 has been stretched by 10mm horizontally to improve the comfort around the nose by allowing you to leave a gap over the bridge of the nose. However the attachment points are still sub optimal and could be improved upon. Version 5 can be printed or cut out of thin PVC. It has better attachment points and a larger contact area with your face but it rides too high on the wearers nose. It works well with only one elastic band around the back of the head but you can still use a second one to go around the back of your neck. Version 6 is an improvement on v5. Relative to v5, it's slightly shorter, slightly wider, 2mm thick and doesn't sit as high on the bridge of the nose. It's only takes 4g of plastic and 10min to print with a 0.8mm nozzle or 25min to print with a 0.4mm nozzle. Because the 2mm version is slightly flimsy, I've added a 3mm version too.
-26/05/220: 3 Prototypes have been tested, so far: The 3 versions take approx 30min to print. Version 1, made a great seal but was slightly tight around the nose and the attachment points needed improving (too close to eyes). Version 2, the part was made to be wider around the nose. The upper 2 attachment points were lowered away from the eyes and the lower two were tweaked slightly. Version 3, was designed in an attempt to make it easier to get a comfy fit around the nose. Testing it, I concluded that v3 wasn't an improvement on v2 because it was tedious to get the fit right. The final fit was the nicest so far but I think that was simply because I had to spend more time getting it right.