Manufacturer Instructions:
For print sizes: Use the following percentages for both sizes: 100% = Large, 95% = Medium, 90% = Small
Mask - Utilized TPU and printed with a 0.4 nozzle at approx 230-240C (pending on type of TPU used; see optimal temps with your TPU manufacturer) with a layer height of .2mm and 20% infil. You can also chose to configure for 4 walls and 10% infil. When printing with TPU, slow down print speed to ensure a good print especially for the first layer (20 or even 15 mm/s). No retraction was used. TPU printing may take some time. PLA can also be used in place of TPU. In this case, adjust printer to match your optimal PLA temps (per manufacturer) and use same settings of .2mm layer height with a .4mm nozzle, 20% infil or increase walls to 4 walls and 10% infil.
Mask Filter Adapter - This is the inner adapter piece that holds the filtration fabric in place. Use regular PLA filament (or harder type) to ensure filter will remain secure inside the mask to ensure a good seal. PLA insert was printed with a 0.4 nozzle at approximately 210-215C with a layer height of 0.2mm.
Filtration Fabric - EnviroCare HEPA cloth vacuum bags (synthetic / polypropylene material) 2000 series (or better can be used) were utilized which provide up to 99.97% filtration of particles up to 0.01 micron. Cut fabric to the shape of the Mask Filter Adapter with at least 15-20mm overlap to enable it to wrap inwards when securing the Mask and Filter Adapter together.
Assembly - When assembling the mask, filter adapter, and fabric, simply lay mask on flat surface with inside of mask facing up. Align filtration fabric inside the mask to match the shape of the opening (where the filter adapter will go). Finally, carefully align the filter adapter (trying to keep the overlapping fabric even) and simply push filter adapter into place to secure fabric with a tight fit.
Strap - Regular bungee-like cord was utilized however any strap can be used. Cord can be fastened with a knot like shown in the pictures.
Silicone Tube - The following silicone tube was utilized to provide additional seal reinforcement:
McMaster-Carr Product #5236K506 High-Temperature Silicone Rubber Tubing for Air&water Soft, Durometer 35A, 1/8" ID, 1/4" OD, Opaque White, 25 ft. Length
Simply cut the silicone tubing to match a length that will cover the surface area that will contact your face. Cut with a little excess to ensure a completed circle when fastened to the mask. With a small amount of superglue, fasten silicone tubing along the inside and very edge of the mask (see photos). go slowly to ensure tubing is straight and adhering to the mask with no gaps. When the silicone tube reaches end to end (completing the circle around the mask), cut the excess to complete the circle leaving a hairline or two extra to ensure the ends are snug to one another (naturally pressing into each other). A little drop of glue on the ends can also seal the deal! If there are any noticeable gaps where air seems to be escaping near the chin area, additional tubing can be cut (slit longways into a half-circle) and fastened on top of first tubing layer.
Comments
Robert123
Wed, 2020-09-02 14:04
Permalink
Some experience
I printed this and things turned out well. I used an Ultimaker S3 with TPU for the mask and CPE for the insert. I used the recommended HEPA filter and silicon tubing material. I found that I had to scale up the insert piece by about 3-4% relative to the size in order to get a tight seal of the HEPA filter material in the mask. The other thing that I found was that not just any SuperGlue seemed to work to bind the silicon tubing to the mask - I found that Loctite 406 worked best. I have been wearing the mask for a couple of months now and it generally works well. I have also printed some for friends neighbors and family. Thanks for the design!