Introduction: Face Shield for Medical Personnel
This face shield design is intended as a stopgap measure during the COVID-19 emergency. It is not approved by any official entity. It is currently being used by some local nurses who have given feedback towards the design, to the point where I know it is useful for us here. Anyone who has the ability to make face shields or other supplies, please first find a local group who is in touch with the need in your area. A good place to start is https://www.facebook.com/groups/opensourcecovid19medicalsupplies/announcements/
This document describes a 4 part shield consisting of visor, window, forehead foam, and elastic. Foam and elastic can be found in many varieties. Window can be any clear plastic with the appropriate hole pattern for attachment to the visor. Visor is a CNC cut assemblage from 1/2" expanded PVC. The whole thing is based off the budmen.com 3d printed design, and uses the same window. (I have tweaked the holes for a shield that sticks out slightly less but the windows are interchangeable).
1/2" Sintra or other expanded PVC. May work with other plastics but I have not tested anything else as yet.
clear plastic, 20-50mil or thereabouts. PETG, polycarbonate, mylar all known to work (acetate less strong)
Elastic to keep the visor on the head. Can be 1/2" sewing elastic from any fabric store as in my photos, thinner or wider elastic, a drugstore headband, a few ponytail bands looped together, or anything with the appropriate stretch that won't pull hair
Step 1: Cut Files
The visor and window 2d CAD files are attached (visor temporarily unavailable, please check back in a couple hours). The visor as we are making it is in two parts because it made the most sense with our resources, but in theory it could be cut from 1" thick material in one piece. We have cut it from 1/2" Sintra, both parts; and also the visor part from 1/4" Sintra and the brow extension from 3/4" Sintra.
The window we have cut from (so far):
- 10mil PETG
- 15mil polycarbonate
- 5mil mylar, but this is really thin
- Office Depot notebook dividers
- 40mil PETG but this is thick and stiff and doesn't work super well
Some of these window materials can be lasercut. All can be cut with scissors and hole punch, if necessary.
Step 2: Visor Assembly
The visor could be cut in a single piece from 1" but that thickness is much harder to find and handle than 1/2" (and wastes more material). So I cut them in 2 sections and the 2 parts must be glued. Any PVC cement will do, it is sold in hardware stores for pipe fitting. Most kinds come in a metal can as shown, with an applicator attached to the cap. Follow the directions on the product you are using. Generally, you apply a moderately thick layer of glue to the whole area to be glued, press the two parts together firmly for about 30 seconds, then let it sit for 15 min or so. It will gradually harden over the next 12-24 hours but it can accept the foam pretty much right away (I actually tested a number without glue, being held together with just the foam, and that worked completely fine but for changing the foam, the visor needs to be a single piece)
Step 3: Foam and Elastic
Cut a piece of elastic 19" long. Tie it into a loop with an overhand knot.
Cut a piece of foam 9" long. Peel the backing and press it into the inside curve of the visor.
Slip the elastic onto the hooks of the visor.
Step 4: Window Assembly
The window has four 1/4" holes which fit over the knobs on the visor. The fit is tight so that they won't come off easily. The plastic will stretch slightly to fit over the knobs, and set securely into the notches behind the knobs. Be sure to push it all the way back.