Not every face shield is created equal. This is especially true in 3D printed face shield frames. An ICUshieldsMN face shield takes 5 hours to make each. This article Goes through the basic steps involved in making our shields.
One face shield frame takes 3 hours to 3D print (more on that below). The final 2 hours are hand processing the shield frames by cleaning them up and putting straps and shield sheets on them etc. Our focus is on quality over quantity. While other shield frames can print and assemble faster and cheaper they are are also thin, fragile, hold small shields, and only have one strap.
Quality doesn't mean our shields are thick and cumbersome. A shield frame still weighs in at just 2 ounces and a completed shield is under 5 ounces.
In April of 2020 I came up with the idea to improve the face shield. Working in the ICU and wearing the employer offered flimsy shield was not adequate. So I came up with the first initial design on a armature CAD program that is free online called TinkerCad:
With the design made I took it to my 3D printer that I have owned for a few years. I used it to make plastic molds that I could inlay carbon fiber with epoxy resin. The part would cure in the 3D printed mold and the carbon fiber part would pop out. Mostly I made parts for motorcycles that are unique and light weight.
This first design (and all our subsequent improved designs by Luke Swanson) have two straps that are actually phlebotomy tourniquets. I picked this for the strap material because it was affordable and most important cleanable and easy replaced on site. Most areas we donate shields to have tourniquets supplied on site. Unlike other shields that have only one strap that is made of cloth elastic and has foam that can absorb bacteria, viruses, and sweat.
For the face shield clear sheet I choose a specific blend of PTEG plastic that it .02 inches thick. The plastic is flexible enough to resist cracking, yet sturdy and fog free. The thickness is up to three times more than what the other shields use. Many shields use flimsy clear page insert sheets that are too small for face shields. So our shields use 12 inch wide and 9.5 inch sheets we cut out and hole punch.
Back to 3D printing the frame.... The 3D printer is a machine that takes plastic filament that is in a wire shape on a roll and melts it while extruding it onto a print bed. By moving back and forth and side to side it builds a layer at a time for hundreds of layers to eventually make a plastic part. Home 3D printers have become popular in the last 10 years or so as they have come down in price to about $250 for a 3D printer that you build yourself from the box of hundreds of parts they mail you. That's what my printer is. Other models are about $300 and up and come to you mostly assembled.
Here's a video of my 3D printer printing a frame.
With my one 3D printer I was making a couple dozen face shields a week. I could print one and then take it off the printer and restart the printer to do new a print every 3 hours. This process was tedious because I had to be around to print and then start another print 3 hours later.
Then in May 2020 a family friend Jenifer Swanson told me about her son Luke Swanson who does professional level CAD designs and 3D prints. I met them on a video chat meeting along with my friend Chad Schwartz who is an expert in 3D printing and technology and owns many 3D printers. I asked the three if they could co-lead ICUshieldsMN with me and here we are.
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| Luke Swanson, Lead Design Engineer |
Back to Luke Swanson, I asked him if there was a way to improve my first shield design (the red frame picture above). He took to his CAD program and made wonderful improvements I couldn't even have imagined was possible. He improved the four strap holes so that the tall wings were no longer needed and made a model that could stack one print on top of another. The 3D printers could print a tower of 8 or more shield frames over 24 hours independently. No longer would we have to sit by our printers to reset them every three hours.
So with 3D printers of Chad, myself, and local 3D printing groups like Chris Taylor's "Minnesota Maker Collective" we've been printing stacks of face shield frames.
After a volunteer has several stacks of frames printed with donor funded plastic filament I take the shield prints and cut the stacks apart :
After they are cut apart I sand the remaining sharp "teeth" or the support poles between each print. I smooth them down with a belt sander on both sides.
After a frame is cut and sanded it looks like this:
The volunteers are added to a messenger thread we have and get updates on work that needs to be done. They can pick up in a contact-less manner from outside a Woodbury location anytime knowing ahead of time what is available from the messages in the group chat. They are usually a paper bag of 30 shield frames to clean up at their convenience with zero pressure to get it done as soon as possible. When finished they drop them off with no need to to contact me. At this time they can pick up more to work on. More information on volunteering here or message our facebook page.
Welcome to Volunteering for ICUshieldsMN in Woodbury
After the prints are cleaned up they need to have the adjustable straps put on in a specific way to ensure easy adjust-ability.
How to: Straps for ICUshieldsMN frames
Once the straps are on it's time for the sheets of plastic. They need to be traced and cut out by hand. The volunteers help me do this to. (the sheets have a protective sheet on both sides the owner can remove)
How to: Cut out the shield clear sheets
Once the sheets come back I punch the holes for them to mount on the frame with the hole puncher I made. I also trim the top corners and insert an instructions slip of paper for each shield:
Thank you for your support. All donations are for shield materials only. No side costs.
