The BEmask is a 3D-printable reusable mask with replaceable filter inserts. Derived from the Montana Mask, it incorporates improvements to materials, fit, assembly process, seal, structure, sizing, and filter cartridge design.
Design and Features
| Mask | BE Mask V.1.6 |
| Production Process | 3D Print |
| Transparent | No |
| Body Material | TPU |
| Weight | 58 grams |
| Cost | $$ |
| Filter | Merv 15 |
| Strapping | Head |
| Recyclable Materials | No |
| Sizing | Variable |
| Testing Available | Yes |
Pros
- Can be produced at home with consumer 3D printers and common filament
- Ability to customize with model scaling, filament colors and materials, gasket padding for comfort and seal, and strapping
- Uses corrugated filter cassette for improved filtration and breathability
- Mask is reusable and filter is easy to change
Cons
- Body material is not clear and makes a large presence on the face
- Large start up cost for production in time, materials, and funds
User Guide
Assembly
The V.1.6 Mask is a 3D printed mask with a corrugated filter cartridge. The body can either be printed in TPU or PLA filament. The filter is a single sheet of MERV-15 that is folded multiple times within the filter insert in order to increase filter surface area and maximize breathability.
Step 1: Materials Needed
- 3D printed parts (mask body and filter frame)
- Filter material: 1 Sheet of MERV-15
- Gasket material– this is optional for masks printed in TPU. Skip to our video guide for installing the gasket lining on the mask below.
- Strapping material. The instructions below assume ¼” elastic.
Step 2: Description of Filter
What Filters are Recommended?
- We have completed pre-NIOSH testing of the BE mask using a polypropylene filter material with a MERV rating of 15 (filter efficiency above 95% with particles as small as 0.3 microns for air filtration systems)
- We have been purchasing sheets of the filter material we tested from the supplier McMaster-Carr.
- Follow this link to view our filter testing
NOTE: While the material passes ASTM standards for differential pressure, NIOSH testing involving masks using the filter have not been completed. The filter material is not a replacement for an N95 mask, but our testing indicates it works much better than a bandana.
Step 3: Mask Prep
If the mask body is printed in TPU, there may be some hair-like strings and other minor imperfections inside the printed part as a result of travel moves.
- These can be easily cleaned up using a blade and/or a heat gun.
- A rotary tool with a nylon brush attachment is also very useful for smoothing out the inner edges of the mask where it touches the face.
- If the mask is printed in PLA you can achieve a more customized fit by thermoforming the mask to your face.
Follow this link for instructions of thermofitting
Step 4: Filter + Strapping Assembly
- Filter Assembly
- For instructions on how to assemble the filter cartridge please follow this information video.
- Use Filter placement tools
- Strapping Assembly
- Cut a piece of ¼” material about 42 inches long.
- Run the elastic through the strap connectors on the mask body as shown in the photo below:
Use & Fit
A gasket is an optional feature for TPU mask prints, but strongly recommended for PLA or other rigid materials.
Installation of Gasket Material
- Cut a piece of c-channel gasket material (the length varies based on the mask size – a large mask will need about 15 inches of gasket material).
- Line the outer edge of the mask with the gasket material, starting at the center of the bottom edge of the mask. The two ends of the gasket material should meet up at the bottom.
- Secure the gasket material to the mask body using super glue. Do this part in stages. You likely will not need to use glue around the entire mask perimeter. We recommend focusing use of glue where the gasket ends meet and at the sharp contours of the mask.
Care & Sanitization
- Sanitize using methods Care + Sanitation
Production and Distribution
Files and Downloads
Acquire STL or CAD Files
- Here are links to the STL Files:
- STL: link
- When following the STL link you should see the following documents:
- If you wish to see our mask Iterations and changes please follow the link.
- For extra tools that aid in filter cartridge assembly follow this link
- NOTE: These should be printed in PLA and you will need 2
Printer Setting Details
2.85mm TPU
(Settings based on Ultimaker S5 and S3 using 3D Universe Terrafilum TPU. Similar settings also work well for Ultimaker TPU-95A):
- Extruder Temp: 235C
- Bed Temp: No heat with Magigoo or glue stick applied, or 40-60C without any adhesive
- 2 shells
- 6 top solid layers
- 3 bottom solid layers
- 15% infill (cross 3D infill pattern if using Cura)
- Print speed: 25mm/sec (30mm/sec for infill)
- Flow rate: 106%
- Retraction enabled
- Retraction distance: 10mm
- Retraction speed: 15mm/sec
- Retraction extra prime amount: 0.4mm3
- Fan speed: 50%
1.75mm TPU
(Settings based on Dremel 3D45 using Kodak Flex 98 filament):
- Extruder Temp: 235C
- Bed Temp: No heat
- 2 shells
- 6 top solid layers
- 3 bottom solid layers
- 15% infill (cross 3D infill pattern if using Cura)
- Print speed: 25mm/sec (30mm/sec for infill)
- Retraction enabled
- Retraction distance: 6mm
- Retraction speed: 25mm/sec
- Retraction extra prime amount: 0.2mm3
- Fan speed: 50%
- Coasting enabled
1.75mm PLA
(settings used on a Prusa MK2 printer):
- Use standard PLA settings (depends on the brand of PLA and type of printer)
- 0.20mm first layer height; 0.32mm layer height
- 20% infill
- Consider using a larger nozzle and thicker layers to reduce print time
Testing
Team Testing | November 2020
Initial testing of filtration efficiency of the filter cartridge against micron sized particles. Data obtained using Particle Counter, comparing particle count inside box to outflow on downstream side of filter.
3D Printing FAQ
Q. Can this mask be produced at home?
A. The STL files for the latest version are available below.
Q. Are there recommended 3D printers and settings?
A. While many printers may be suitable to print the BE mask, we offer specific settings for the Ultimaker S5 and S3 and Dremel 3D45 when printing TPU, as well as the Prusa MK2 for printing PLA (see our Printer Setting Details below). When it comes to settings, every printer is different. If you have found better settings for these or other printers, please share your results on the BE Hub space.
For our general TPU printing process, we have used:
- Extruder Temp: 225-235C (depends on TPU brand)
- 0.25-0.32mm layer height
- 15% infill
- 2 shells
- 6 top solid layers
- 3 bottom solid layers
- Print speed: 25mm/sec (30mm/sec for infill)
- Fan speed: 50%
- 106% flow rate
- No supports
Q. How long does it take to print?
A. It can take 2.5 hours to 6 hours to print a mask, depending on nozzle size, layer height, print speed, and other settings. Your printer bed may be large enough to “batch print” multiple masks in a single run, but this may lead to some “stringing” between masks when printing in TPU, which requires additional cleanup after the print. Before attempting a batch print, we suggest you get the settings right for a single mask.
Q. What mask materials do you recommend for production?
A. We designed for a semi-flex TPU mask body, and a PLA filter insert. TPU is flexible, it conforms to the contours of the face for better seal and comfort. PLA is relatively rigid, it’s better for holding the filter firmly in place. For new printers, we recommend the TPU Print Test before creating masks as a quality check. For more information on our materials, please review our Biocompatibility Assessment and Materials within our Testing and Validation.
Q. How many masks can you create with a 1kg spool of material?
A. Each mask uses about 45-55g of TPU material, depending on the mask size being made. This means you can expect to make around 20 masks with each 1kg spool of material.
| The BE mask is offered to the general public for general, non-medical purposes. In accord with FDA Emergency Use Authorization, it has been submitted for review to NIOSH. The safety and efficacy of any mask depends on fitting, sanitization practices, and filter materials. Any mask should be tested and fit to meet local needs and standards. Please see our user liability disclaimer for details. |