Reusable Facemask (AG3D Montana Mask MOD)

thingiverse

This is a modified facemask designed for extended wear periods, such as an 8-hour shift. We've elongated the original mask to provide additional space inside. The flanged insert used to install this feature remains unchanged from the original file. A layer height of 0.35mm and nozzle diameter of 0.40mm were employed. The final print time was approximately three hours and fifty minutes. To avoid filament jamming, we reduced TPU printing speed to 30-40% immediately after changing filaments. If you're interested in printing a filter cut guide like the one shown above, the file is available here: https://www.thingiverse.com/thing:4440660 Initially, we printed these masks solidly using PETG material. However, users found cloth masks more comfortable to wear over long periods. We decided to develop a multi-material option combining comfort with leak test performance. By printing with both PETG for the filter area and TPU for the rest, we achieved a semi-flexible material that provided a better fit and performed significantly better than the rigid mask in leak testing. We printed this design on the Prusa i3 MK3 using its direct drive extruder. A Bowden system would make it more challenging to print (i.e., difficult). Since PETG and TPU have similar extrusion temperatures (240*C), adding a material change Gcode at layer 100 was straightforward. The key challenge lies in getting the TPU to extrude enough remaining PETG during filament changes, as otherwise you may experience jamming. We found that using a higher speed when loading the new filament worked better than slowly loading it, as the filament would start bending and wrapping around the knurled gear. This is an experiment worth trying, as it yields excellent results if done correctly.