BEFORE DOWNLOADING - Please read the full license. This is a free model, and you can share it. But you must give appropiate credit and may not use it for commercial purposes, NO REMIX is allowed (absolutely no exceptions). If you find this model elsewhere and somehow breaks any of the stated license conditions you can send me a message so I can take appropriate measures. All rights are exclusively of the designer.

BEFORE PRINTING - I recommend to do a fine calibration of your printer before starting printing the mask and its parts. Check your horizontal expansion to ensure your pieces will fit properly (tutorial): https://www.thingiverse.com/thing:1662342

This 3D model has not been approved by any regulatory agency and has not passed any laboratory tests. It is a prototype designed by Giovanni Becchina (bgiovanny), created with the aim of providing emergency protective material to medical professionals who need it, given the current global shortage of supplies. It is not intended to replace any homologated mask, but to provide minimal protection. We cannot guarantee its operation, so use it at your own risk.

Update 18/04/20:
Someone told me that it is difficult to find rubber bands.
I made rubber bands to print in TPE.
I made a buckle for the baffles.

Update 09/04/20:
I made some improvements in the Cover_Filter_Box
I made some improvements in the Filter_Box

Update 03/04/20:
Some people were unable to make the membranes because they were too thin.
I changed the thickness of the membranes and the Cap_Valve.
If you have problems with membranes, print the new membranes and the new Cap_Valve.
I made some improvements in the mask.

Update 02/04/20:
Some people have reported to me that they have difficulty mounting the filter on the mask.
I made a new filter box, with a thickness greater than + 0.2mm where the gasket rests.
Some people do not find the seals for the filter.
I made the seals that can be printed in TPU or TPE "better the TPE".
Some people can't find 3M filters.

I made an adapter to mount a 3M 2138 P3 R or 3M 2135 P3 R filter.
Some people asked me to use a hygrobac filter instead of the 3M filter.
I made an adapter and a gasket to be able to mount the hygrobac filter.

In this terrible moment in history, COVID-19 has combined the ideas of many makers to help the whole world overcome this moment of crisis and limit the death of people as much as possible.

I made a prototype of reusable mask with interchangeable filter. The mask can be washed in water and 5% bleach.
The filter used is a 3M 5935 P3 or 3M 5N1, certified with the filtering percentage equal to 95% FFP3, the highest possible.

The mask is made up of 3 parts and is simple to make with FDM, SLS printers etc...
The mask is composed of: Filter, Mask with valves, Soft part.
The mask must be printed in PLA or PCL with supports on the part where the filter is to be installed. “see pictures”.
The soft part must be printed in TPU or TPE "better the TPE", to make it adhere better to the face.
The filter must be printed in PLA or PCL with supports on the part where the filter is to be inserted and on the part of the fixing. “see pictures”

The valves work with two silicone discs with a thickness of 0.20mm and a size as in the photo. As an alternative to silicone it is possible to print TPU or TPE discs "better the TPE", it is necessary to use a PEI or GLASS "smooth surface" printing surface. The smooth part is the part to be placed on the mask, the part that closes the valve.
The valve must be printed as shown on the photo on a PEI or GLASS "smooth surface" surface.

DO NOT print these parts on a rough surface, the valve will not work!
The exhaust valve must be inserted in the mask, use glue to guarantee the seal.
In the part of the PLA mask where the TPU or TPE part is to be connected, it is recommended to apply some glue. This will ensure the two sides to be airtight.

If the TPU or TPE part does not adhere well to your face, apply some Neoprene Stripping with adhesive, 15 or 20mm wide and 3mm thick.
I made four sizes: extra small, small, medium, large.

Only the soft part changes according to the size that best suits the face.
To keep the mask on your face, use elastic bands 4 or 5mm wide. Excellent elastic tailoring, made of cotton.
At the base of the filter holder, a rubber washer "one for plumbing, for taps" must be applied. Dimensions, internal 35mm external 45mm thickness 2mm.

The supports must be added manually in the slicer, I used Simplyfy 3D, which allows the manual insertion of the supports.
I am working on additional filter holders to be able to use other types of filters, such as the 3M 2138/2135 always P3.

The use of non-certified filters is not recommended, the exclusive use of commercially available certified filters is recommended.
Attached you will find the images relating to the mask and the print positioning.

If you liked my work and it was useful for you, you can contribute by leaving a like, thank you.