N95 Mask Strap Tensioner by joncruz

Last crawled date: 4 years, 2 months ago

Overview
I saw a request for something to help tighten straps on N95 masks that were loosening from reuse. There were a few quick responses, but I think there are some points they should be addressing.
This tensioner is designed to tighten mask straps that go all the way behind the head, not for those with ear straps. It takes up slack by allowing the strap to be wound up as needed in order to get sufficient pressure to get a good seal.
Design Criteria
The following are a few of the points I tried to keep in mind while designing the print.
Quick to print
Not prone to snapping (some post-based designs can fail here)
Easy to clean/sterilize
Simple
Avoid sharp edges
Avoid threads and screw type mechanisms (more complex, harder to print accurately and hard to clean)
Easy to get on and off
Easy to adjust while wearing gloves
Easy to place and adjust while mask is worn
Printing
The design was made for printing at 0.28 mm resolution, but should print fine with smaller values. Be sure to print with 100% infill to get the corner posts solid and strong. The rest of the tensioner will bee solid due to being so thin.
Post Printing
Slip the strap behind the top flange.
pull the strap tight
slip strap between the posts on one side
Slip other end of strap between the posts on the other side
instead of latching the strap, twist the tensioner to wrap the strap around it.
Feed the strap through the posts to gain a little more tension
A single twist gives a bit more tension
Additional twists give more tension