Introduction: Anti Virus Mask for Doctors
As the COVID-19 spreads across the globe, the demand for protective masks for medical workers will increase.
This mask protects your face from respiratory droplets and is comfortable enough to be worn during the whole day, minimizing the risk of exposure.
This is a forced ventilation mask. Air is filtered through a medical face mask or another filter and escapes through valves at the bottom.
The mask is comfortable, as the face plate doesn't fog. Also, you can't accidentally touch your face. It's lightweight and beard-friendly.
A typical 10000 mAh powerbank gives you about 12 hours of operation.
Grinding face shield
Thick polyethylene sheet
Powerbank of other power source
12V 80mm computer fan with CFM > 32
Thin rubber tape (e.g. Esmarch Bandage)
1-2 litre PET bottle
Air filter (regular face mask will do)
Tools you need:
- Soldering iron
- Permament marker
- Iron or high-power soldering iron for PE sheet melting
If you're using a medical mask as a filter, you'll need a fan with at least 32 CFM (cubic feet per minute), which means over 0.15 Amps. Try to get a low-noise fan (under 20 Db).
If you want to power the fan with a powerbank, you'll need a DC/DC converter. We used MT3608 board.
Set voltage by slowly turning the potentiometer while measuring across the output terminals with a multimeter.
Cut the PET bottle according to the picture.
Wrap plastic around the fan and fix through holes with a cable tie.
Choose fan placement.
Drill holes for cable ties.
Loosely tighten to make room for adjustment. Link several zip ties if required.
Make holes for outlet valves in the bottom of the mask.
The total area of holes should be equal to the size of the fan.
For a 80 mm fan 12 holes of 20 mm is enough.
Mark the locations of the holes at least 40 mm from the edges.
Use a step drill bit to prevent cracking. Mark the required diameter on the drill bit.
Alternatively, make series of small holes.
Cut thin strips of rubber so that they overlap the holes for at least 5 mm.
Glue only the vertical edges (marked in red on the photo).
Fold polyethylene sheet in half and cut according to the picture.
Adjust the dimensions according to your head size.
Red line indicates a seam. It's better to weld the seam with an iron or a soldering iron, through a sheet of paper.
Make some test seams - it's easy to burn through polyethylene. Use paper spring clips to position plastic on the mask. Attach polyethylene to the mask with sticky tape. The edges of rubber shoud remain free of sticky tape.
Wrap PE around the bottle. The seam should be airtight.
Finally, attach the medical mask or another filter of choice.
Don't get sick!