Mask brace for surgical masks

Spunbond polypropylene - cos I have lots of it, it doesn't fray and is a little stretchy. Inspired by Iris Luckhaus' HYBRID MASK FRAME FOR SEWING OR STAPLING

Note: see v2 of this

Template.  

On a cheap polystyrene head that seems to be 8/10 size of my head that doesn't have ears:

The top straight edge of the template is a fold line. Inside that, centered before sewing is a double thickness alumunm nosewire (two pieces stuck back to back). 

After that initial straight-ish line sewing, all other edges were cut (cutting thru two layers), then the left right edges where zig-zag sewn once more, and the two bits at the bottom were joined to make the 3D shape.  For the ambitious, the cutting after sewing could be through four layers if you'd done a temp fold left to right.

Straps and bow-behind-head is the same as for my Rag Mask Max 

The polystyrene head doesn't have ears so the surgical mask is stretched past wear the ears would be and joined at the back with wire - which is NOT what you'd do in real life.  It looks a better fit on my head that this polystyrene head, but I'm not photogenic. 

I've not PortaCount tested this yet. The Zhende mask in the pic has been pressure cooked five times with the PFE results for the last three being 85% or so without a brace like this, and 94% or so with the mask artificially pressed on to my face.  The two blue rows here:

I'd want to see 98% or more to think this was worth it versus chucking out the Zhende and an using fitted N95/FFP2 instead.  Those non-brace results are higher than the worst case for surgical (50%), because the Zhende is a premium brand and I'm now really good at sitting still during PortaCount tests and pressing the mask down in the 30 second setup phase before that.

For the next version I'm going to attempt to make the anchor point slight higher on he head - more curves to the left and right.