Introduction: Protective Face Shields for Covid-19 Frontliners
Due to the shortage of Personal Protective Equipment (PPE) for those working in the front-line amidst the Covid-19 outbreak, we thought it would be best to share a collaborative design for a fast and efficient protective face shield that could be easily replicated and mass-produced. In our search over the past few days we have found that 3D printed parts, although highly effective, cannot be produced fast enough to meet with the current demands globally.
It is our hope that products such as this can be reproduced around the world through rapid prototyping for those who are in dire need of it. This initiative is the result of a request by our friends in the medical sector who have expressed a need of about 30 thousand units per month of this face shield due to the outbreak.
Please follow the steps below and make sure to share with others that may have the capacity to build the protective face shields too!
1) Acrylic sheets (preferably 4mm or 5mm thickness)
2) A4 sized transparent PVC rigid sheet (0.2mm)
3) Sponge or EVA / PU Foam equivalent
4) Scissors and cutters
5) Hot glue gun + Glue sticks
6) Elastic bands (the kinds used for tailoring) or equivalents such as Household rubber bands
7) Laser Engraving Machine (in our case we use the Epilog Helix 75W)
Step 1: Laser Cutting the Face Shield Holder
The design file for the Face Shield Holder is attached below in several formats. The dimensions for each Holder is 200mm x 155mm. Please upload it to Coral DRAW or any other software that you use for laser engraving.
The Laser Engraving Machine that we are using is the Epilog Helix 75 with a bed size of 24" x 18". We are cutting a 5mm acrylic sheet at a setting of 100% Power and 7% speed. Our team is currently working on optimizing the design process to improve manufacturing capability and any updates will be posted here. Please follow these guidelines to ensure the Face Shield Holder is cut properly.
The holder serves as the base point with which the transparent PVC sheet can be slot into and also hooks for the band that allows for the mask to be placed on your head.
Step 2: Separate the Laser Cut Pieces
Once the acrylic sheet has been cut, separate the holders and ensure all edges are polished smooth for your medical officer. If you get this step wrong, the pieces are not going to come off right so please do a few test cuts on single pieces until you get your laser settings right. Only then should you get your production template under way.
In our case, we tested cutting a few of the holders with 5mm plywood first before moving on to the acrylic sheets for mass production.
Step 3: Attach a Sponge or Foam to the Face Shield Holder
Cut a piece of EVA foam into a 250mm x 20mm strip to fit the inside of the Face Shield Holder. Using a hot glue gun, stick the strip of foam on the inner side of the shield for added comfort and fit.
Step 4: Alternative Method for Foam Attachment
This is an alternative method of attaching the foam onto the back of the Holder using a foam with a thickness of 20mm-25mm.
First, cut your PU foam into 250mm x 20mm strips and make a small incision along the middle line of the strip with a cutter. Being very careful, ensure that the incision only cuts halfway through the foam and not all the way through.
You can now slot the foam onto the back of the Holder where it should sit nicely without the need for a glue gun.
Step 5: Attach the Transparent Sheet to the Holder
Carefully slot the A4 transparent PVC rigid sheet (0.2mm) horizontally into the slit that was cut into the Face Shield Holder.
For longer coverage, an A3 transparent sheet attached vertically would also work.
Secure this connection by stapling along the top edge of the transparent sheet with a margin of about 5mm from the top so that it doesn't slip out.
Alternatively, you can also attach a thick foam tape 5mm - 10mm from the top of the sheet in place of the staples.
Step 6: Curving the Edges on the Transparent Sheet
Round off the edges on the bottom of the transparent sheet with a pair of scissors to make it safer for use by the medical officers.
Step 7: Attaching a Band to the Face Shield
Using a piece of Elastic band (or multiple rubber bands) connect both ends of the Face Shield Holder to create tension within the band and to allow for the Face Shield to be fastened on the head.
We have found out that the front liners are using a similar piece of equipment in a ward to screen 20-30 patients per face shield, and then later disposing of it for hygiene purposes. Hence we've designed it to be modular so that it's not merely a single use product.
The transparent sheets and elastic / rubber bands are interchangeable which makes the Holder reusable provided it gets sterilized after each use.
Step 8: Finishing
The Face Shield is now complete and ready to be packed!
This process is quick and efficient, allowing for over 10 pieces to be made in an hour using a small 2' x 1.5' laser cutter (depending on manpower and resources) and should increase by several factors if made using an industrial 4' x 8' CO2 laser.
Make sure to share this with all relevant personnel to help provide this basic necessity for those fighting in the front line to combat the virus.